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Science / Space Race

[August 8, 1969] Two by Four (Mariners 6 and 7 go to Mars)

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photo of a man with glasses and curly, long, brown hair, and a beard and mustache
by Gideon Marcus

Into the Wild Black Yonder

Ten years ago, when we started our planetary series of articles, none of other worlds in our solar system had been explored.  Since then, five intrepid spacecraft have toured two planets.  Mariner 2 and Mariner 5 probed Venus, returning the revelation that the shrouded world is a seething cauldron.  Mariner 4 returned the first pictures of the Red Planet, shocking humanity with images of Moonlike craters and reports of a vanishingly thin atmosphere, dashing forever the vivid, science fictional conception of Mars as an inhabitable world.

Now, twin Mariners 6 and 7 have flown by Mars, dramatically increasing what we know about the fourth planet.  While we'll never get back that fantasy so elegantly woven by Edgar Rice Burroughs and Leigh Brackett, the new Mars is also not a blasted husk either.


Distant views of Mars, as seen by Mariner 7 as it approached the planet

The Next Generation

Despite the blow to morale given by Mariner 4, Mars still seemed like the most hospitable place for life to have arisen apart from Earth.  After all, are there not microorganisms living in the harsh environments of Antarctica and at the bottom of the sea?  Even though the Martian atmosphere is just 1% as thick as that of Earth, this is still plenty dense compared to, say, the Moon.  Moreover, Earth's atmosphere is just 1% that of Venus.  Who's to say when an atmosphere is "thick enough"?

So, just a few months after Mariner 4 flew past Mars, Mariners 6 and 7 were authorized.  At first glance, they look a lot like their predecessor, but the differences are profound—both internally and externally.


From top to bottom: Mariners 2, 4, 5, and 6/7 (note the family resemblance of the last three—Mariner 5 was actually a modified Mariner 3/4 backup!)

First, the insides: the new Mariners are the first spacecraft made only to examine their target planet.  All of the prior Mariners had experiments for monitoring the interplanetary environment—solar wind, magnetic fields, that sort of thing.  Mariners 6 and 7 carry two TV cameras (one narrow, one wide-angle), an infrared radiometer (to measure the temperature of Mars), and ultraviolet and infrared spectrometers (to determine the chemical makeup of the Martian atmosphere and surface).  That's it.

As for the outsides, since 1965, when Mariner 4 passed by the Red Planet, there has been a revolution in communications technology.  Not only do the new Mariners carry more powerful transmitters and antennas, but with the construction of the new 210 foot antenna at Goldstone, supplementing the old 85 footers, data can be transferred between the spacecraft and Earth at a rate more than 2000 times the 8.33 bits per second speed of Mariner 4.  It also helps that Mars is closer to Earth this time around, and that the rocket carrying Mariners 6 and 7 is the beefy new Atlas Centaur, which can loft more weight than the old Atlas Agena so the onboard electronics can be heftier and thus more capable.


The 210' "Mars Dish" at Goldstone, California

What this means for us on the ground is that instead of sending back just 22 images of Mars, the new Mariners could transmit hundreds of pictures, all while returning real-time spectrographic and radiometer data.  All of this aided by the installation of the first computer equipped on an interstellar probe, capable of remembering 128 "words" some 22 characters in length.  And that computer can be reprogrammed on the fly from Earth!

On their Way

Jet Propulsion Laboratory, the same folks who built the other Mariners, assembled four spacecraft for the mission.  The first was a stay-at-home test model, the second a source of spare parts.  The other two were redundant probes—an understandable precaution given the loss of Mariners 1 and 3.  However, the twin ships weren't entirely redundant; Mariner 6 was targeted to fly over the Martian North Pole while #7 was aimed over the South Pole.

Problems with the spacecraft began before liftoff.  Mariner 6's Atlas rocket, which maintains its structure through internal fuel pressure, sprung a leak and began to deflate like a balloon.  It had to be replaced with Mariner 7's rocket, and a new one ordered from Convair.  This did not delay the launch, however (which had to go at a set time to reach Mars with a minimum of fuel use), and Mariner 6 blasted off on February 24th.  Mariner 7 took off on March 27, but because of its course, was set to reach Mars just five days after its sister.


The launch of Mariner 7

Both rockets performed beautifully, requiring only minor mid-course corrections early in the flight to ensure they zoomed close by the fourth planet.  There were some minor technical problems: The radio on Mariner 6, used to determine range from Earth, kept locking on its own signal rather than Earth's, making it useless.  It fixed itself later in the flight, however.

Similarly, the star tracker designed to keep Mariner positioned properly lost sight of Canopus.  After weeks of engineers scrambling to find an alternative guiding star (they even tried the Large Magellanic Cloud, but the galaxy was too diffuse to be useful), that system fixed itself, too.  Finally, the onboard solar sensors that told how much sunlight was hitting Mariner 6's power panels, began reading too low.  Was the Sun going out?  No.  The sensors had just drifted out of calibration.

Mariner 7's only issue was a radio receiver that dropped to about 20% of its sensitivity, apparently due to cold.  Ground controllers switched it to high power, which warmed the thing up and fixed it.

Thus, its vexing teething pains dealt with, NASA now had, for the first time, two fully operating probes with which to explore Mars.

The Great Galactic Ghoul

On July 29, even as Mariner 6 was finishing the transmission of 33 low-resolution approach images, Mariner 7 suddenly began spinning wildly, all of its scientific data telemetry channels scrambled.  Had an asteroid hit the spacecraft?  Had there been an instrument explosion or some kind of short circuit?  Was there some kind of Great Galactic Ghoul guarding the Red Planet?  No answer was quickly forthcoming.


Collage of Mariner 6 images as it approached Mars

Nevertheless, engineers raced to salvage the mission—with Mariner 7 arriving shortly after its sister, and from a more favorable angle, the JPL science team wanted the spacecraft's experiments all in working order. 

Cautiously, computer engineers went over every bit of code and methodically tested all of Mariner 7's instruments.  They were in working order, but because of the accident, uncalibrated and useless.  How to get real data points to use to base the radiometer and spectrometer data against?


Engineers at the Mariner control center at JPL

As it turned out, the two TV cameras on board were in good order and unaffected.  By pointing them at Martian targets and using the data they returned, it was possible to calibrate the other experiments.  And so, just in the nick of time, Mariner 7 was ready, come close encounter time, to do some real science.

Exploring Barsoom

So what did the two probes find as they whizzed past Mars, almost grazing it from a scant few thousand miles away?

Well, at first they seemed to confirm Mariner 4's findings.  There were all the craters in stark detail.  There was no evidence that there had ever been widespread water—absent was the erosion one would expect from oceans or even rivers.


A lunar landscape, courtesy of Mariner 7

On the other hand, if Mars wasn't Earth's twin, neither was it sister to the Moon.  As each Mariner went behind the planet, beaming radio signals through the Martian atmosphere, it was confirmed that surface pressure was around 7 millibar—a refinement rather than a revelation.  But they did determine that carbon dioxide makes up a greater percentage of the air than even on Venus.  Nitrogen was completely absent, which was a surprise.  So was ozone, which means that the surface is fairly baked by ultraviolet—again, a strike against life on the planet.

The Red Planet is not quite geologically moribund, however.  The vast Hellas region, smooth of craters, and a region of convoluted terrain akin to the American Badlands, suggests some kind of volcanic activity in comparatively recent times.

Unlike the Moon, clouds scud across the Martian sky, mostly composed of dry ice.  While it may not rain on the planet, it does frost, and maybe even snow ice and carbon dioxide.  The climate changes with the seasons, with polar (dry?) ice caps spreading and receding.  The tropical highs soar to a balmy 60 degrees, but the polar lows plunge to 240 degrees below zero.


A view of the Martian North Pole, snapped by Mariner 6—note the ice cap

Thus, Mars is an inhospitable place…but it if it lacks biological life, it is nevertheless an interesting living, breathing planet in its own right.

What's next?

Mariners 6 and 7 are still functioning, and their onboard systems should work until at least 1971.  Not only might they return pictures of any asteroids or comets that drift by, they will also constitute an experiment in and of themselves.  As they drift through the solar system, terrestrial scientists will measure variations in the timing of their telemetry signals and use them to prove General Relativity—something that requires great distances to detect subtle theoretical variations.

As for successors, a Martian orbiter is already in the works for the 1971 alignment, and in 1973, a probe will use the gravity of Venus to enable a probe to fly by and then visit, for the first time, Mercury, the closest planet to the Sun.

And also in 1973, the Viking orbiter/lander combo, successor to the overlarge Voyager project, will give Mars a real look.


The 1971 Mars Orbiter

If the 1960s were the dawn of interplanetary science, the 1970s will see its maturity.  I find this as momentous an achievement as footprints on the Moon.

I can't wait to rewrite all of the articles in our solar system series!




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Science / Space Race

[October 28, 1967] Unveiling Venus – at Least a Little (Venera-4 and Mariner-5)

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by Kaye Dee

Despite the hiatus in manned spaceflight missions while the Apollo-1 and Soyuz-1 accident investigations continue, October has been a very busy month for space activities – so much so that I’ve had to defer writing about some of this month’s events to an article next month!

Spaceflight Slowdown?

4 October saw the tenth anniversary of the launch of Sputnik-1, the Soviet satellite that surprised the world and ushered in the Space Age and the Space Race. Since that first launch, the pace of space exploration has been breathtaking, far surpassing what even its most ardent proponents in the 1950s anticipated.

In the famous Colliers’ “Man Will Conquer Space Soon” article series, reproduced even here in Australia, Dr Wernher von Braun predicted that the first manned mission to the Moon would not occur until the late 1970s

As part of the USSR’s Sputnik 10th anniversary celebrations, many space-focussed newspaper articles were published.  One of these, written by Voskhod-1 cosmonaut and engineer Dr. Konstantin Feoktistov, strongly hinted that Russia's next major space feat would be the launch of an orbiting space platform. This would certainly be an important development in establishing a permanent human presence in space and put the Soviet Union once again ahead in the Space Race, especially if the US and USSR lunar programmes are faltering.

Earlier this month, the head of the NASA, Mr James Webb, said it was increasingly doubtful that either the United States or the Soviet Union would land people on the Moon in this decade. He delivered a gloomy prognostication for the second decade of the Space Age, saying the entire US programme was “slowing down”. Mr. Webb criticised recent Congressional cuts of 10 per cent to the space-agency budget projected for the year ending next 30 June, saying that NASA was laying off over 100,000 people.

Administrator Webb also cast doubt on some proposed NASA planetary exploration missions. “The serious question is whether or not this country wants to start a Voyager mission to Mars in 1968”, he is reported to have said. The Voyager programme is a 10-year project that envisages sending two spacecraft to Mars (one to orbit around it, the other to land on its surface), with the additional possibility of landing a spacecraft on Venus and exploring Jupiter. These would undoubtedly be exciting missions that would reveal new knowledge about these planets, but Mr Webb said he had virtually no money for the Voyager programme as a result of the budget cut.

Parallel Planetary Probes: Venera-4 and Mariner-5

But possible future downturns in space activity can’t detract from this month’s big news: the safe arrival of two spacecraft at Venus!

Back in June, a suitable launch window meant that both the USSR and NASA sent spacecraft on their way to our closest planetary neighbour. First off the blocks was the Soviet Union, which launched its Venera-4 mission (generally known in the West as Venus-4) on 12 June from the Baikonur Cosmodrome in Kazakhstan. NASA’s Mariner-5 followed two days later, on 14 June, launched from Cape Kennedy.

Pre-launch photo of Venera-4

Venera-4 is the most recent Soviet attempt to reach the planet after Venera-2 and 3 failed to send back any data in March last year. There is some speculation that, since its previous Venus mission employed twin spacecraft, Russia may have also intended this Venus shot to be a two-spacecraft mission. It’s possible that the short-lived Cosmos 167 spacecraft, launched on 17 June, was Venera-4’s twin that failed to leave orbit, although with the secrecy that surrounds so much of the Soviet space program, who knows if we’ll ever get the truth of it? Venera-4 was itself first put into a parking orbit around the Earth before being launched in the direction of Venus. A course correction was performed on 29 July, to ensure that the probe would not miss its target.


Mariner-5 being prepared for launch

Mariner-5 is NASA’s first Venus probe since Mariner-2 in 1962. Originally constructed as a backup for the Mariner-4 Mars mission, that probe’s success meant that the spacecraft could be repurposed to take advantage of the 1967 Venus launch window. Interestingly, I understand from my friends at the Sydney Observatory that there were initial suggestions to send the Mariner back-up spacecraft to either comet 7P/Pons–Winnecke or comet 10P/Tempel, before the Venus mission was decided upon. While it’s useful to have additional data from Venus, it would have been fascinating to send an exploratory mission to a comet, since we know so little about these transient visitors to our skies. 

At its closest, Venus is just 36 million miles from Earth, but Mariner-5 followed a looping flightpath of 212 million miles, to enable it to fly past Venus at a distance of around 2,500 miles (about 10 times closer than Mariner-2’s flyby). Australia’s Deep Space Network (DSN) stations at Tidbinbilla, near Canberra, and Island Lagoon, near the Woomera Rocket Range, were respectively the prime and back-up monitoring and control stations for Mariner-5’s mid-course correction burn that placed it on its close flyby trajectory. 

Keys to Unlock a Mystery

Venus has always been a planet shrouded in mystery since its thick, cloudy atmosphere prevents any telescopic observation of its surface. For this year’s launch window, one could almost believe that Cold War tensions had been overcome and the USSR and USA had agreed to work together on a Venus exploration program, given that their two spacecraft effectively complement each other.

Venera-4’s mission was announced as “direct atmospheric studies”, with Western scientists speculating that this meant that it would follow Venera-3 in attempting to land on the planet’s surface. The spacecraft’s arrival at Venus has proved this speculation to be correct, and the few images of Venera-4 now available show the 2,436 lb spacecraft to be near-identical to Venera-3. 11 ft high, with its solar panels spanning 13 ft, Venera-4 carried a 1 metre (3 ft 3 in) spherical landing capsule that was released to descend through the atmosphere while the main spacecraft flew past Venus and provided a relay station for its signals.
Soviet models of the Venera-4 spacecraft and its descent capsule

The 844 lb descent capsule was equipped with a heat shield, capable of withstanding temperatures up to 11,000°C (19,800 °F) and had a rechargeable battery providing 100 minutes of power for the instruments and transmitter. During the flight to Venus the battery was kept charged by the solar panels of the carrier spacecraft. Supposedly, the entire Venera-4 probe was sterilised to prevent any biological contamination of Venus, but some Western scientists have cast doubt on this claim. The capsule was pressurized up to 25 atmospheres since the surface pressure on Venus was unknown until Venera-4’s arrival.
Picture of the Venera-4 descent capsule released by the USSR. Western scientists are wondering what that heat shield is made of

Information recently released by the Soviet Academy of Sciences has said that the descent vehicle carried two thermometers, a barometer, a radio altimeter, an atmospheric density gauge, 11 gas analysers, and two radio transmitters. Scientific instruments on the main body of the spacecraft included a magnetometer and charged particle traps, both for measuring Venus' magnetic field and the stellar wind on the way to Venus, an ultraviolet spectrometer to detect hydrogen and oxygen gases in Venus' atmosphere, and cosmic ray detectors.


Much smaller than Venera-4, the 5401b Mariner-5 was designed to flyby Venus taking scientific measurements: it was not equipped with a camera, as NASA considered this un-necessary in view of the planet’s cloud cover. NASA controllers initially planned a distant flyby of Venus, to avoid the possibility of an unsterilised spacecraft crashing into the planet, but the final close flyby was eventually chosen to improve the chances of detecting a magnetic field and any interaction with the solar wind.

As Mariner-4’s backup, Mariner-5 has the same basic body – an octagonal magnesium frame 50 in diagonally across and 18 in high. However, since it was heading to Venus instead of Mars, Mariner-5 had to be modified to cope with the conditions much closer to the Sun. Due to its trajectory, Mariner-5 needed to face away from the Sun to keep its high-gain antenna pointed at Earth. Its solar panels were therefore reversed to face aft, so they could remain pointed at the Sun. They were also reduced in size, since closer proximity to the Sun meant less solar cells were needed to generate the same level of power. Mariner-5's trajectory also required the high-gain antenna to be placed at a different angle and made moveable as part of the radio occultation experiment. A deployable sunshade on the aft of the spacecraft was used for thermal control, and Mariner-5 was fully attitude stabilized, using the sun and Canopus as references.
View from below showing the main components of Mariner-5

Mariner-5’s prime task was to determine the thickness of Venus’ atmosphere, investigate any potential magnetic field and refine the understanding of Venus’ gravity. Its suite of instruments included: an ultraviolet photometer, a two-frequency beacon receiver, a S-Band radio occultation experiment, a helium magnetometer, an interplanetary ion plasma probe and a trapped radiation detector. The spacecraft instruments measured both interplanetary and Venusian magnetic fields, charged particles, and plasmas, as well as the radio refractivity and UV emissions of the Venusian atmosphere.

During its 127-day cruise to Venus, Mariner-5 gathered data on the interplanetary environment. In September and October, observations were co-ordinated with measurements made by Mariner-4, which is on its own extended mission, following its 1965 encounter with Mars. Similar observations were made by Venera-4 during its flight to Venus, which found that the concentration of positive ions in interplanetary space is much lower than expected. 

Missions Accomplished

A few days before it arrived at Venus, the Soviet Academy of Sciences requested assistance from the massive 250 feet radio telescope at the Jodrell Bank Observatory in the UK, asking the facility to track Venera-4 for the final part of its voyage. This has provided Western scientists with some independent verification of Soviet claims about the mission. Jodrell Bank even announced the landing of the Venera-4 descent capsule more than seven hours before it was reported by the Soviet news agency Tass!

On 18 October, Venera-4’s descent vehicle entered the Venusian atmosphere, deploying a parachute to slow its fall onto the night side of the planet. According to a story that one of the Sydney Observatory astronomers picked up from a Soviet colleague at a recent international scientific conference, because there was still the possibility that, beneath its clouds Venus might be largely covered by water (one of the main theories about its surface), the capsule was designed to float if it did land in water. Uniquely, the spacecraft’s designers made the lock of the capsule using sugar, which would dissolve in liquid water and release the transmitter antennae in the event of a water landing.

Although the Venera-4 capsule had 100 minutes of battery power available and sent back valuable data as it fell through the atmosphere, Jodrell Bank observations, and the official announcement from Tass, indicated that the signal cut off around 96 minutes. While it was initially thought that this meant that the capsule had touched down on the surface, and there were even early reports claiming it had detected a rocky terrain, questions are now being raised as to whether it actually reached the surface, or if the spacecraft failed while still descending. Tass has said that the capsule stopped transmitting data because it apparently landed in a way that obstructed its directional antenna. A recording of the last 20 seconds of signal received at Jodrell Bank was delivered to Vostok-5 cosmonaut Valery Bykovsky during a visit to the radio telescope on 26 October. Perhaps once it is fully analysed, the question of the capsule’s fate will be clarified. Of course, if the landing is confirmed, Venera-4 will have made history with the first successful landing and in-situ data gathering on another planet.

Diagram illustrating the major milestones during the Mariner-5 encounter with Venus on 19 October
Mariner-5 swept past Venus on 19 October, making a close approach of 2,480 miles. At 02:49 GMT the Island Lagoon DSN station commanded Mariner 5 to prepare for the encounter sequence and 12 hours later its tape recorder began to store science data. Tracked by the new 200 in antenna at NASA’s Goldstone tracking station, Mariner reached its closest encounter distance at 17:35 GMT, and minutes later entered the “occultation zone” before passed behind Venus as seen from the Earth. 17 minutes later, Mariner-5 emerged from behind Venus and completed its encounter at 18:34 GMT.

The following day, Mariner-5 began to transmit its recorded data back to Earth. Over 72½ hours there were three playbacks of the data to correct for missed bits. Mariner-5's flight path following its Venus encounter is bringing it closer to the Sun than any previous probe and the intention is for to be tracked until its instruments fail.

A Peep Behind the Veil

So what have we learned about Venus from these two successful probes? There has long been controversy among astronomers as to whether Venus is a desert planet, too hot for life, or an ocean world, covered in water. The data from both Venera and Mariner has come down firmly on the side of the desert world hypothesis.
Astronomical artist Mr. Chesley Bonestell's 1947 vision of a desert Venus

The effects of Venus’ atmosphere on radio signals during Mariner-5’s occultation experiment have enabled scientists to calculate temperature and pressure at the planet's surface as 980°F and 75 to 100 Earth atmospheres. These figures disagree with readings from Venera 4 mission, which indicate surface temperatures from 104 to 536°F and 15 Earth atmospheres’ pressure, but both sets of data indicate a hellish world, with little evidence of water and an extremely dense atmosphere.

Venera has established that Venus’ atmosphere consists almost exclusively of carbon dioxide with traces of hydrogen vapour, very little oxygen, and no nitrogen. Mariner-5's data indicates that the atmosphere of Venus ranges from 52 to 87 per cent carbon dioxide, with both hydrogen and oxygen in the upper atmosphere: it found no trace of nitrogen. It detected about as much hydrogen proportionately as there is in the Earth's atmosphere. Mariner scientists, however, have pointed out that further analysis and refinements of both Russian and American data could clear up the apparent discrepancies.

Although Mariner’s instruments could not penetrate deeply enough into Venus’ atmosphere to obtain surface readings, they determined that the outer fringe of the atmosphere, where atoms were excited by direct sunlight, had a temperature of 700°F, below which was a layer close to Zero degrees, lying about 100 miles above the surface. Chemicals in the atmosphere, or electrical storms far more intense than those of Earth, give the night side of the planet an ashen glow.
A view of the Mariner-5 control room at JPL during the Venus encounter

A fascinating finding is that the dense atmosphere acts like a giant lens, bending light waves so they travel around the planet. Both American and Russian researchers agree that astronauts standing on the surface would feel like they were “standing at the bottom of a giant bowl”, with the back of their own heads a shimmering mirage on the horizon. Vision would be so distorted that the sun would appear at sunset to be a long bright line on the horizon: its light could penetrate the atmosphere, but not escape because of scattering, so that it would appear as a bright ball again for a time at sunrise until the atmosphere distorted its rays.

Neither spacecraft found any evidence of radiation belts comparable to the Van Allen belts around the Earth, and both established that Venus has only a very slight magnetic field, less than 1% that of the Earth. Observing how much Venus' gravity changed Mariner 5's trajectory established that Venus’ mass is 81.5 % that of Earth. Tracking of radio signals from Mariner-5 as it swept behind Venus, has shown that the planet is virtually spherical, compared with Earth's slightly pear-shape. (Other celestial mechanics experiments conducted with Mariner-5 obtained improved determinations of the mass of the Moon, of the astronomical unit, and improved ephemerides of Earth and Venus).

Life on Venus?

Although neither spacecraft was equipped to look for life on Venus, their findings will undoubtedly contribute to the growing scientific controversy over whether life does, or can, exist there. Based on its Venera results, the Soviet Union has said that Venus is “too hot for human life”, although Sir Bernard Lovell, the Director of Jodrell Bank Station, has suggested that future probes might find remnants of some early organic development, even if conditions today make life highly unlikely. However, German/American rocket pioneer and space writer Dr Willy Ley, has suggested there might be the possibility of “a very specialised kind of life on Venus”, possibly at the poles, which he believes would be cooler that the currently measured temperatures. The USSR’s Dr Krasilnikov has said that Earth bacteria could withstand the atmospheric pressure on Venus and might even be able to survive the intense heat. 


But just as Mariner-4 demolished fantasies of canals made by intelligent Martians, so the results from Venera-4 and Mariner-5, in allowing us a glimpse behind its cloudy veil, have swept aside any number of science fiction visions of Venus. Edgar Rice Burroughs’ verdant Amtor, with its continents and oceans, and Heinlein’s swampy Venus are no more. They have been replaced by a new vision of a hellish Venus, almost certainly inimical to life, with fiery storms raging in a dense, metal melting atmosphere which traps and bends light waves in a weird manner. I wonder where the SF writers of the future will take it?



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Science / Space Race

[June 14, 1967] What's Easy for Two (Venus 4 and Mariner 5)

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by Gideon Marcus

Red Venus?

Every 19 months, Venus and Earth reach positions in their trips around the Sun such that travel to the former from the latter uses a minimum of energy. Essentially, a rocket blasts off and thrusts itself toward the Sun just long enough to drift inward and meet Venus after about half an orbit (a direct path would be very costly in terms of fuel use). The less energy used, the bigger the spacecraft can be sent. That means more payload for experiments.

The Soviets have been trying to reach the Planet of Love, Earth's closest neighbor (besides the Moon) for more than six years now. In February 1961, they launched Venera 1 (Venus 1), the first interplanetary probe to fly by another world–but it had gone silent by the time it got there.  Veneras 2 and 3 went up three opportunities later, in November 1965, but fell silent the next spring, just before reaching their target.  Indeed, Venera 3, a soft-lander, is believed to have rammed the cloud-shrouded world, becoming the first artificial object to reach another world.  Either way, no useful data was received.

Why didn't they launch any Veneras in 1962 or 1964?  In fact, it looks like they did.  The Soviets don't herald their failures.  Nevertheless, according to NASA officials, we have a pretty good catalog of them, thanks to careful parsing of Russian news reports as well as radar and telemetry data we've managed to gather.  Three Russkie Venus probes were launched in September 1962 and three more in February 1964.  Getting out of Earth orbit can be tough, requiring a second firing of onboard engines once a spacecraft is circling our planet.  Apparently, these six probes never got away.

But Venera 4, launched on June 12, 1967, has apparently passed that first hurdle.  Moreover, at one and a quarter tons, it is several hundred pounds heavier than any of its predecessors.  We don't know much about what's on the latest Communist probe, but scientists speculate some of the extra weight has been devoted to heat shielding.  Venus is very hot, perhaps 900° Fahrenheit, and it is believed that heat is what caused Venera 3 to fail.  Given that TASS, the Soviet news service, reported that Venera 4 is going to Venus, rather than by, it is assumed the spacecraft will make another landing attempt.

Provided it doesn't go slient like its predecessors.  Communicating across planetary distances is a hurdle the Soviets only recently surmounted with their Zond 3 probe, which tested radio reception at about 150 million kilometers' distance–far enough for a Martian mission.  Essentially, Zond 3 was the Soviet version of Pioneer 5–but five years later.  This is suggestive as to the Soviet level of communications technology, at least.  America would seem to have the clear lead there.

Well, I wish the Soviets luck.  Politics or no, I want to know more about that mysterious, seared world that is Venus!

Yankee Two-dle

If Venera 4 fails, it has a back-up of sorts.  Mariner 5, itself a back-up for the Mars-bound Mariner 4, was launched today early this morning, destination: Venus.

Already several hundred thousand kilometers from Earth, zooming at more than 10,000 kilometers per hour, it should reach Venus in October.  The spacecraft, launched via Atlas-Agena, the same rocket that launched our first Venus probe, Mariner 2, is barely a quarter the mass of Venera 4.  Moreover, Mariner 4's TV camera has been deleted, a decision that likely irks Venus scientist Dr. Carl Sagan, who insists doing so is short-sighted, clouds or no. 

But that removal, along with the reduction in the size of the solar panels (less is needed so close to the sun) means that when Mariner 5's planned flight path brings it within 3000 kilometers of Venus, it will be able to investigate the planet with a wide suite of instruments.  An ultraviolet photometer should not only refine temperature estimates of the Venusian upper atmosphere, it will tell us a bit about what gasses constitute it.  For instance, if there be any water there, perhaps life exists in the cloud tops, above the intense heat at the surface.

The rest of the instruments are likely ho-hum for the general audience, but should return a bonanza for scientists.  They include a magnetometer and various radiation sensing equipment that not only will measure the Venusian version of the Van Allen Belts (if they exist–Mariner 2 couldn't find any), but also tell us a lot about the solar wind on the way to Venus.

I will say, I'm glad we're sending a craft to Venus, and it does seem we did it on the cheap ($35 million), but I think I'm with Sagan on this one: for all the effort, it seems we're not going to find out very much about Venus with Mariner 5.  Another reason to root for Venera 4.

And a good reason to write your Congressman about the importance of planning a bigger Venus shot, perhaps on the more powerful Atlas Centaur rocket, when the next opportunity rolls around in January 1969!

Want to find out what we currently know about Venus?  Come read our previous articles on the planet of love!



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Science / Space Race

[July 20, 1965] No War of the Worlds After All? (Mariner IV reaches Mars)

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by Kaye Dee

Just a few days ago, on July 15, NASA’s Mariner IV space probe made history by being the first spacecraft to successfully reach the planet Mars, capturing images of its surface. These are the first close-up views of another planet in our solar system and the initial pictures suggest that, despite what science fiction would have us believe, Earth won’t have to fear an invasion from Mars any time soon!

The first close-up image ever taken of Mars, showing the limb of the planet and a haze-like feature that might be clouds. The smallest features in this image are roughly 3 miles across, but there's no sign of Martian canals!

The Canals of Mars

Mars has been an object of intense scientific and popular fascination since the last century, when telescope observations first suggested that the planet was potentially Earthlike, since it showed polar caps and surface changes that appeared to represent seasonal variations due to the growth and die-back of vegetation. Then, in 1877, the Italian astronomer Schiaparelli observed what he called “canali” on Mars. He apparently meant grooves or channels on the Martian surface, but his work was translated into English as “canals” and some astronomers took this literally to mean that he had observed structures that were the work of intelligent beings.

A section of one of Percival Lowell’s maps of Mars, published in his 1895 book Mars. The complete map depicted 184 named canals marked on it using numbers.

By the end of the 19th Century, the idea that there is intelligent life on Mars had taken hold, thanks particularly to the writings of American astronomer Percival Lowell (the same Percival Lowell who is also associated with the discovery of the Planet Pluto!) He believed in a Martian civilisation that had constructed vast networks of canals to bring water from the planet’s poles and wrote several books and innumerable newspaper articles detailing his observations of canal systems on the Red Planet. Science fiction stories like H.G. Well’s War of the Worlds, first published in 1897, and Edgar Rice Burroughs' "Barsoom" series further encouraged popular belief that there was intelligent life on Mars and generated something of a ‘Mars mania’ that has grown across the 20th Century.

Cover of the August 1927 issue of Amazing depicting the iconic Martian machines from Wells' War of the Worlds. This powerful story has been re-interpreted on radio and film and has had a tremendous influence in shaping popular perceptions of life on Mars.

The Mars Race

Most scientists have accepted for a decade or more now that modern telescope observations indicate that it is unlikely that higher forms of life will be found on Mars after all. Yet the fascination with Mars has been so strong that it’s not surprising the planet became an early target for space exploration, after the Moon. The Soviet Union started the race to Mars in October 1960, with “Marsnik” 1 and 2. We don’t know much about these probes, but it seems they both failed even to reach orbit. The USSR’s Mars 1 flew past Mars in June 1963, but it had stopped sending back data in March. Sputnik 22 and Sputnik 24, both launched around the same time as Mars 1, are also believed to be elements of a failed Mars mission. Zond 2, launched just 2 days after Mariner IV, is also assumed to be an attempted Mars mission, though it, too, ceased transmitting en route. Clearly, getting to Mars is hard. Mariner IV was meant to be a twin mission with Mariner III, but that mission also failed at launch.

Even though Mars 1 ceased transmitting long before it reached Mars, the USSR still celebrated it as an achievement on its 1964 Cosmonauts Day stamp.

Mariner IV was launched on an Atlas Agena rocket from Cape Canaveral at 12:22 GMT on November 28, last year. It has an octagonal magnesium frame, 50 inches across the diagonal and 18 inches high, which houses the electronic equipment, propulsion system and attitude control gas supplies and regulators. Four solar panels, containing a total of 28,224 solar cells, are attached to the top of the frame. They are able to generate 310 watts of power at the distance of Mars from the Sun. Mariner also has two antennae for transmitting data back to Earth: An elliptical high-gain parabolic antenna and an omnidirectional low-gain antenna, mounted on a seven-foot, four-inch-tall mast next to the high-gain antenna.

Mariner IV is an incredibly sophisticated space probe for its size, packed with scientific instruments, plus its television camera system. Its design is a radical departure from the conical design used for the Ranger Moon probes and NASA's successful Mariner II mission to Venus.

Deep Space Laboratory

For its relatively small size, Mariner IV is a spacegoing scientific laboratory, designed to measure the conditions in deep space between Mars and the Earth and in the vicinity of Mars itself. Its scientific instruments include a helium magnetometer to measure the characteristics of the interplanetary and planetary magnetic fields; an ionization chamber/Geiger counter, to measure the charged-particle intensity and distribution in interplanetary space and in the vicinity of Mars; a cosmic ray telescope, to measure the direction and energy spectrum of protons and alpha particles; a solar plasma probe, to measure the very low energy charged particle flux from the Sun, and a cosmic dust detector, to measure the momentum, distribution, density, and direction of cosmic dust. Although the Geiger counter failed in February and the plasma probe's performance is degraded, the other instruments are all working well.

Mariner IV's 'endless loop' magnetic tape recorder. Its 330ft of tape has a storage capacity of 5.24 million bits – right at the cutting-edge of recording technology!

Probably the most important instrument on Mariner IV, and certainly the one of the most interest to the public, is its television camera, designed to obtain close-up images of the Martian surface. The camera is mounted on a scan platform at the bottom centre of the spacecraft and consists of 4 parts: a Cassegrain telescope with a 1.05° by 1.05° field of view; a shutter and red/green filter assembly with 0.08s and 0.20s exposure times; a slow scan vidicon tube which translates the optical image into an electrical video signal, and the electronic systems required to convert the analogue signal into a digital signal for transmission. During the fly-by of Mars, all the television images and the data gathered by the scientific instruments were stored on an ‘endless loop’ four-track magnetic tape recorder for later transmission back to Earth. 

First Pictures from Another World

On July 15 Mariner 4 passed within 6117 miles of Mars, spending just 25 minutes doing visual observations of the planet’s surface. During that brief time, its television camera captured 21 full pictures and part of a 22nd, the first ever close-up images of the surface of another planet. Each photo covers an area of about 77 square miles. It takes about 10 hours to transmit each image back to Earth and each picture is being transmitted twice to ensure that all the data is correctly received.

The second Mariner IV image released by NASA shows the border of Elysium Planitia and Amazonis Planitia. Taken from around 9,940 miles, the picture is about 310 miles across and 560 miles from top to bottom because the surface is curving away. North is up and the sun is illuminating the area from the southeast.

Only three of the Mariner Mars images have so far been released, but already they have disappointed scientists and the public alike by putting an end to any hope of finding intelligent life on the Red Planet. What they have so far revealed is a world that looks more like the Moon than the Earth, with no signs of water, vegetation or animal life. When this is coupled with the findings of the scientific instruments, which show that Mars has an atmosphere of carbon dioxide with only a very low atmospheric pressure (only a fraction of that found on Earth, which was quite a surprise to scientists), a daytime temperature of -148 degrees F and no magnetic field (meaning that the surface of the planet is bombarded by the solar wind and cosmic radiation), it means that the prospects for any kind of life on Mars are very small indeed. However, Mariner’s images only cover just 1% of the Martian surface, so perhaps we should not entirely give up hope that future missions will find Mars more exciting and scientifically interesting than it seems right now. After all, the pictures have not yet revealed the cause of the apparent seasonal changes observed from Earth….

The third image we have seen so far shows the Orcus Patera region in western Amazonis Planitia. It was taken with the sun only 13 degrees from vertical, so the topography is hard to make out, although some raised areas can be seen at upper left. The image is 202 miles across and 319 miles from top to bottom. The resolution is about 1.9 miles and north is up.

Australia Plays Its Part

Australia has played a crucial role in the Mariner IV mission, with its first images being received at the Tidbinbilla tracking station outside Canberra. NASA’s second Deep Space Network station in Australia, Tidbinbilla became operational in December 1964 so that it could support the Mars mission. As the signal from Mars is very weak, the station asked the civil aviation authorities to divert any aircraft that might interfere with the reception of the signals from Mariner at the time of the fly-by. This resulted in an amusing incident: at the critical time, just when Mariner 4 had gone behind Mars, the direct phone from Canberra Airport rang and the station was asked if it was experiencing interference from a UFO! It now seems that the offending object was a weather balloon and not a Martian saucer come to check on what the Earthmen are up to.


Nestled in a secluded valley, for protection from radio interference from nearby Canberra, NASA's Tidbinbilla Deep Space Network Station received the first images of Mars from Mariner IV. Australia is host to a growing number of NASA tracking stations covering all its space tracking networks.

A Role for a Radio Telescope

Australia’s Parkes radio telescope, the largest fully steerable radio telescope in the world, also played a role in receiving Mariner IV’s Mars images. NASA is basing the design of its new 210 ft antennae for the Deep Space Network on that of the Parkes telescope. As a demonstration of its tracking capabilities, Parkes has also tracked Mariner IV and received some of its images from Mars. Its greater antenna size, and therefore better reception capabilities, mean that its images will be more detailed than those received by the 85 ft dishes at Tidnbinbilla and other NASA stations and they will enhance the overall quality of Mariner IV’s Mars pictures when the Parkes and Tidbinbilla images are combined. I hope that NASA will release the rest of the Mariner images soon: even if they have dashed almost a century of Martian fantasies, they are revealing a planet that is very different from what we have expected and I wonder what further surprises might be in store for us as we explore more of Mars and the rest of the Solar System….

The world-leading radio telescope developed by the Commonwealth Scientific and Industrial Research Organisation, Australia's national civil scientific research body. Located near Parkes, New South Wales, this astronomical instrument is also proving its value as a space tracking facility and I'm sure that NASA will call on it again in the future for further tracking support




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Book, Magazine, Science / Space Race, Serial

[December 5, 1964] Steady as she goes (January 1965 IF)

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by Gideon Marcus

A tale of two missions

Mariner 4, launched November 28, 1964, is on its way to Mars.  Shortly after launch, the smart folks at Jet Propulsion Laboratory (some of whom I met last weekend!) determined that Mariner was going to miss its destination by some 200,000 kilometers.  So they calculated the nudge it would take to deflect the ship toward a closer rendezvous with the Red Planet.  This morning, the little spacecraft was ordered to fire its onboard engines for a 20 second burn, and it now looks like Mariner will come within just 10,000 kilometers of its target!

On the other side of the world, the Soviets have informed the world that their Zond 2 probe, launched two days after Mariner 4, needs no course correction.  On the other hand, on Dec. 2, it was reported that the probe is only generating half the power it's supposed to.

Similarly, in the science fiction magazine world, no fewer than three magazines got new editors this year (Fantasy and Science Fiction, Science Fantasy, and New Worlds), and two of them have the same editor with a different name (Amazing's and Fantastic's Cele Goldsmith is now Cele Lalli).

But in Fred Pohl's trinary system of Galaxy, Worlds of Tomorrow, and IF, not only is leadership unchanged, but so is content.  Nowhere is that clearer than in the January 1965 issue of IF, which like its predecessors, is an uneven mix of old and new authors, old and new ideas, and generally inferior but not unpleasant work. 

In other words, on course, but running on half-steam.

The Issue at Hand


by Gray Morrow

In many ways, this is not the issue Pohl wanted on the news stands.  The cover doesn't illustrate any of the contents of the issue; it's supposed to go with Jack Vance's novel, The Killing Machine.  But since that story ended up in book print before it could be serialized, it was pulled from appearing in the magazine.  Instead, we got the sequel to Fred Pohl's and Jack Williamson's The Reefs of Space, which had the virtue of being an IF-exclusive series and co-written by the editor. 

It's a good thing Pohl had it in his back pocket!

Starchild (Part 1 of 3), by Frederik Pohl and Jack Williamson


by Gray Morrow

Hundreds of years from now, the solar system is ruled by the Plan of Man, a computer-led collective in which everyone's lives are ordered, and dissent is rewarded with a quick trip to the body banks for organ harvesting.  But out in the stellar outskirts, in the frigid birthplace of comets, the steady creation of matter in the universe provides rich feeding grounds for the fusorians.  These cosmic plankton eaters in turn create vast reefs in space, homes to the seal-like spacelings and their predators, the dragonesque pyropods.  These reefs have also become shelters for Terran dissidents yearning to be free.  The Reefs of Space told the tale of their first human visitors.

Starchild is the story of Machine Major Boysie Gann, a spy sent to Polaris station to suss out traitors to the Plan.  He ends up kidnapped to the Reefs and then made a messenger to the Planner, the human liaison with the Planning Machine.  Mysteriously teleported back to Earth, Boysie bears with him The Writ of Liberation: if the Plan of Man does not end its attempts to subjugate the free people of the Reefs, the "Starchild" will blacken the Sun…

I was a bit chary of this serial at the beginning.  Williamson is a pulp writer from the way-back, and it shows.  Pohl can be brilliant, but Reefs was more pedestrian (except for the gripping middle section).  But Starchild kept me going the whole way, sort of a Cordwainer Smith "Instrumentality" story, though with less poetry.

Four stars so far.

Answering Service, by Alma Hill

A Boston fan and writer, Hill is new to my ken but has apparently been published since 1950. Service shows us a world where the SPCA has won, cats and other "aggressive" animals are tolerated only in zoos, and mice are overrunning the world without check.  One man is determined to reverse this situation.

Utterly forgettable.  Two stars.

The Recon Man, by Wilson Tucker


by Nodel

A young man wakes up from an amnesiac coma with a push to his back out the door of a house.  Onto a Heinlein moving road he goes, along with dozens of other male commuters to some mysterious labor destination.  A spitfire, himself, the other drones are so many zombies.  Only the pink jumpsuited women have any personality; they seem to run the show.

The man is harnessed to a machine, tasked with creating bacon by conceptualizing it so it can materialize in front of him.  He soon gets bored with this role and makes neckties and carpentry tools instead.  This shuts down the assembly line early, and one of the female supervisors takes him home to see what's wrong with him. 

Slowly, memories of a fatal car crash, centuries before in 1960, coalesce in the man's mind.  How did he get to this strange world?  For what purpose?  And how long does he have to live?

Recon Man is a neat little mystery with a truckload of dark implications.  I liked it a lot.  Four stars.

Vanishing Point, by Jonathan Brand


by Gray Morrow

This is the second outing by Brand, his first being a disappointment.  He fares better with this one, a space story within a bedtime story (the framing is cute but not particularly necessary) about Earth travelers on the first emissary mission to an alien race.

The place chosen for first contact is a sort of mock-Earth made by the aliens, a beautiful park of a world stocked with all sorts of game.  It even has a centenarian, human caretaker.  But neither the park, nor the old man, are what they seem.

Not bad.  Three stars.

The Heat Racers, by L. D. Ogle

Then we come to our traditional IF "first", the piece by a heretofore unpublished author (or at least an unpublished pseudonym).  This one is a vignette about a race of anti-grav sailboats.  I think.  The motive force and levitative technologies are never really explained.

Another trivial piece.  Two stars.

Retief, God-Speaker, by Keith Laumer


by Jack Gaughan

And last up, we have yet another installment in the increasingly tiresome saga of Retief, the diplomatic superspy of the future.  This one involves a race of money-grubbing, seven-foot, theocratic slobs, and the diminutive, subterranean aliens they mean to wipe out like vermin.  Can Retief establish formal relations with the former while saving the latter?

By the end of the novelette, you probably won't care.  This is easily the goofiest and most heavy-handed entry in the series.  I think it's time for Laumer to cut his losses.

Two stars.

Summing Up

All told, this month's issue is more "half a loaf" than "curate's egg".  The parts I liked were lots of fun, and as for the dreary bits, at least they made for quick reading.  I've said before that Pohl doesn't really have enough good material for three mags, but he could have a dynamite pair.

On the other hand, IF is a place to stick new authors and off-beat stories.  I just wish they were more consistently successes!

Maybe 1965 will be the year IF gets a mid-course correction…

[Come join us at Portal 55, Galactic Journey's real-time lounge! Talk about your favorite SFF, chat with the Traveler and co., relax, sit a spell…]




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Science / Space Race

[December 1, 1964] Planet Four or Bust! (What we know about Mars)

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by Gideon Marcus

Mars or Bust

This week, humanity embarked on its most ambitious voyage to date.  Its destination: Mars.

I use the term "humanity" advisedly, for this effort is a global one.  On November 28, 1964, the United States launched Mariner 4 from Cape Kennedy.  And just yesterday, the Soviet Union's Zond hurtled into space.  Both are bound for the Red Planet, due to arrive next summer. 

That both missions commenced so close to each other was not a coincidence.  Every two years, Earth and Mars are situated in their orbits such that a minimum of energy can be used to get from one planet to the other.  This favorable positioning applies equally to democracies and communist states.

Mariner 4 and Zond are not the first Martian probes: identical Mariner 3 was lost a few weeks ago, and Zond's predecessor, Mars 1, failed a couple of months before it could reach its target.  Let us hope these new spacecraft have more luck.  So far so good!

It is possible that these two probes will revolutionize our understanding of Mars, just as Mariner 2 changed our view of Venus forever.  It is, therefore, appropriate that I summarize our knowledge of the planet on the eve of collecting this bonanza of new information.

Another Earth?

Mars has been known to us since ancient times.  Because it wanders through the constellations throughout the year, it was classified as a "planet" (literally Greek for wanderer).  When it is in the sky, it is one of the brightest objects in the sky, with a distinct reddish tinge, which is why it has been associated with the bloody enterprise of war.

Until the invention of the telescope, all we knew about the fourth planet from the Sun was its orbital parameters: its year is 687 days, its path around the sun very circular, and its average distance from the Sun is around 141,600,000 miles. 

Even under magnification, Mars can be a stubborn target; at its nearest, about 35 million mies away, the planet measures just 25 seconds of arc from limb to limb (compared to the Moon, which subtends 1860).  Still, early telescopes were good enough to resolve light red expanses, darker expanses (believed to be seas), and bright polar caps.  Said caps waxed and waned with the Martian seasons, brought on by the planet's very Earthlike tilt of 25 degrees.  Because the Martian surface was visible, unlike those of Venus or Mercury, the day was calculated to be just over 24 hours long.  Indeed, Mars appeared to be a world much like Earth.

Mars for the Martians

In 1877, our understanding of the planet broadened.  Astronomer Asaph Hall discovered two tiny moons, named Phobos and Deimos, and we were able to deduce the mass of Mars — about 10.7% that of Earth.  Combined with the planet's diameter of 4200 miles, that meant Mars' density was about four times that of water.  This is only two thirds that of the Earth, which suggests that the planet is poorer in heavy metals, and/or that, because the planet is less massive overall, its layers are not so tightly bound together with gravity.  From Mars' measured mass and diameter, we learned that the surface gravity is 38% that of Earth; sprinting and jumping should be much easier there.  Flying…well, more on that in a moment.

1877 was also the year that Mars came into our public consciousness in a huge way — all because of a silly mistranslation.  Giovanni Schiaparelli turned his 'scope to Mars and saws something remarkable: dozens of fine straight streaks crisscrossing the planet that seemed to link up the dark patches (which were, if not oceans, at least areas of vegetation suggesting the existence of water).  He called them canali, which is Italian for "channels".  But to English ears, it came out as "canals", which strongly connotes construction by intelligent beings.

Well, you can see what an uproar that would make.  Very soon, folks like Wells and Burroughs were writing tales of Martian aliens.  And not just aliens — civilizations beyond those found on Earth.  The thinking went that the planets' ages corresponded to their distance from the Sun.  Hence, Mercury was a primordial hunk of magma.  Venus, shrouded in clouds, was probably a steamy jungle planet on which Mesozoic monsters roamed.  And beyond the Earth, Mars was a cold, ancient world, its verdant plains dessicated to red deserts.  To avoid catastrophe, the Martians built planet-spanning canals to bring water to their cities.  Being so advanced, it was obvious that they had mastered space travel, and had either visited us or were on the verge of doing so.

Even the more practical-minded scientists were hungry for evidence of life, even primitive stuff, existing off of the Earth.  Mars seemed like the prime location for extraterrestrial creatures to be found.  For one thing, the planet clearly had an atmosphere, wrapping the planet's edges in a haze and producing a marked twilight. 

Originally thought to be a touch thinner than Earth's, more recent measurement of the polarization of Martian light (the vibration angles of light reflected off the atmosphere) suggested that the surface air pressure was about 8% that of Earth.  That was too thin for easy breathing, but not too thin for life.  If there was enough oxygen in the mix, perhaps a person could survive there. 

Mars Today

Such was our understanding of the planet perhaps a decade ago.  Recently, ground-based science has made some amazing discoveries, and it may well be that Mariner and Zond don't so much revolutionize as simply enhance our understanding of the planet.

I just read a paper that says the Martian atmosphere is about a quarter as dense at the surface that thought.  This isn't just bad for breathing — it means NASA scientists have to rethink all the gliders and parachutes they were planning for their Voyager missions scheduled for the next decade.  Observations by spectroscope have found no traces of oxygen and scarcely more water vapor.  The planet's thin atmosphere is mostly made up of nitrogen and carbon dioxide.  The ice in the polar caps may well be mostly "dry".

Because of the lack of water and the thin air, erosion is probably much less of a factor on Mars.  In a recent science article in Analog, George Harper says that the planet's surface may be riddled with meteorite craters that never got worn away.  Close up, Mars may end up looking more like the Moon than the Earth!

And those canals? Telescopic advances in the late 40s made it possible to examine Mars in closer detail than ever before. The weight of astronomical opinion now disfavors the existence of canals.

Still, old dreams die hard.  I imagine we will cling to our visions of Martian life and even civilizations long after such notions are proven unworkable.  To kill such fancies, it'll take a blow as serious as that delivered by Mariner 2, which told us that it's hot enough to melt lead on the surface of Venus.

We'll find out, one way or another, in July 1965!

[Come join us at Portal 55, Galactic Journey's real-time lounge! Talk about your favorite SFF, chat with the Traveler and co., relax, sit a spell…]




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Science / Space Race

[August 29, 1963] Why we fly (August Space Round-up)

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by Gideon Marcus

We've become a bit spoiled of late, what with space spectaculars occurring on a fairly regular basis.  So, I was not too surprised when a friend buttonholed me the other day and exclaimed, "When is the Space Race gonna get interesting again?"  After all, it's been a whole two months since the Vostok missions, three since the last Mercury mission, and even satellite launches have been few lately.

Oh ye of little faith.  The real work doesn't happen when the rockets go up, but after their payloads are aloft.  A lot happened in the arena of space this month — you just have to dig a little to learn about it.  Here are the exciting tidbits I gleaned (and the journos missed) in NASA's recent bulletins and broadcasts:

Bridging the Continents

Communication satellites continue to make our world a smaller place.  Syncom, built by Hughes and launched by NASA late last month, is the first comsat to have a 24-hour orbit.  From our perspective on the Earth's surface, it appears to do figure eights around one spot in the sky rather than circling the Earth.  This means Syncom can be a permanent relay station between the hemispheres.

It's already being used.  On August 4 the satellite allowed Nigerian journalists and folks from two U.S. services to exchange news stories as well as pictures of President Kennedy and Nigerian Governor General Dr. Nnamdi Zikiwe.  Five days later, voice and teletype was exchanged between Paso Robles, California and Lagos, Nigeria.  This 7,700 mile conversation represents the longest range real-time communication ever made.

And, on the 23rd, Syncom carried its first live telephone conversation — between President Kennedy and Nigerian Prime Minister Sir Abubaker Tafawa Balewa, as well as several other official conversations.  One has to wonder if the whole scheme wasn't hatched just so Jack could expand his pen pal list to West Africa…

More comsat news: RCA's Relay 1 is still alive and kicking, having been used in 930 wideband experiments, 409 narrowband transmissions, and 95 demos of TV and narrowband broadcasts.  And in a stunning imitation of Lazarus, AT&T's Telstar 2 came back on-line after having been silent since July 16.  I understand there will be an unprecedented experiment next month: NASA is going to use Relay and Syncom to bounce a message from Brazil to Africa.  Expect that kind of satellite ping-pong to become common in the future.

Finally, NASA's passive comsat, Echo 1, continues to be used for tests.  Come winter, it will be joined by Echo 2.  Because if there's anything space needs, it's more balloons.


First pass of Echo 1 satellite over the Goldstone

Predicting the Weather

Mariner 2, the Venus probe that encountered the Planet of Love last December, went silent early this year.  Yet its reams of data are still yielding discoveries.  During the spacecraft's long flight toward the sun, it took continuous measurements of the solar wind — that endless stream of charged particles cast off from the roiling fusion reactor of our nearest star.  These measurements were then compared to readings made on Earth and in orbit.  Scientists have now determined that the sun's radioactive breeze blows in gusts from 500 to 1350 kilometers per second, the bursts correlated with expansions in the solar corona.  When a particularly strong stream of electrons and protons, sizzling at a temperature of 500,000 degrees F., slams into the Earth's magnetic field, it causes disruptions in broadcasts and communications.

Closer to home, Explorer 12 soared far from Earth in its highly eccentric orbit, charting long-lived solar plasma streams in interplanetary space.  The satellite determined that these gouts of plasma caused geophysical disturbances more than twenty days after their creation.

One can imagine a constellation of satellites being deployed to provide solar system-wide space weather reports.  Not only would they help keep astronauts safe as they journeyed from planet to planet, but they'd also let radio operators on Earth know when to expect static in their broadcasts.

And speaking of weather forecasts, Tiros 6 and 7 continue to be our eyes in the sky, tirelessly shooting TV of Earth's weather.  They've already tracked the first hurricane of the season, Arlene.  Who knows how many lives and dollars they will save with their early warnings?

Previews of Coming Attractions

The ill-starred lunar probe, Ranger, has failed in all five of its missions.  In fact, NASA is 0 for 8 when it comes to moon shots since 1959.  Perhaps Ranger 6, set for launch around Thanksgiving, will break this losing streak.  It will be the first of the Block 3 Rangers, lacking the sky science experiments that flew on Rangers 1 and 2, and the big seismic impactors carried on Rangers 3-5.  The new Rangers will just shoot TV pictures of potential Apollo landing sites.  This sacrifice of science in deference to the human mission has not gone without protest, but given the dismal track record of the program, the labcoat crowd will have to take what they can get.

A full year after Ranger (hopefully) reaches the Moon, a pair of Mariners will set sail for Mars.  Unlike last year's Mariner 2, Mariners 3 and 4 will carry cameras to provide our first close-up view of the Red Planet.  Let's just hope neither of these upcoming probes meet the same fate as Russia's Mars 1, which died last March.

At some point in the mid-60s, even bigger Mariners will fly to the planets, carried by the big liquid oxygen "Centaur" second-stage.  The first successful test fire took place on August 17 just down the way from my house — at General Dynamics/Astronautics San Diego

And finally, another 271 space candidates applied to NASA this year.  They have been screened to 30, and out of them, 10-15 will be selected in late October to comprise the third group of astronauts.  None of them are women yet, but perhaps there will be some in time for Group Four.


Pilots Jerrie Cobb and Jane Hart testify before the Subcommittee of the House Committee on Science and Astronautics, July 1962.  That's an Atlas Centaur model next to them.

Who knows?  Maybe you'll be one of them!

[Want to talk to the Journey crew and fellow fans in real-time?  Come join us at Portal 55! (Ed.)]

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Science / Space Race

[March 24, 1963] Bumper Crop (A bounty of exciting space results)

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by Gideon Marcus

February and March have been virtually barren of space shots, and if Gordo Cooper's Mercury flight gets postponed into May, April will be more of the same.  It's a terrible week to be a reporter on the space beat, right?

Wrong!

I've said it before and I'll say it again.  Rocket launches may make for good television, what with the fire, the smoke, and the stately ascent of an overgrown pencil into orbit…but the real excitement lies in the scientific results.  And this month has seen a tremendous harvest, expanding our knowledge of the heavens to new (pardon the pun) heights.  Enjoy this suite of stories, and tell me if I'm not right…

How hot is it?

Mariner 2 went silent more than two months ago, but scientists are still poring over the literal reams of data returned since its rendezvous with Venus.  The first interplanetary mission was a tremendous success, revealing a great deal about the Planet of Love, whose secrets were heretofore protected by distance and a shroud of clouds. 

Here's the biggie: Preliminary reports suggested that the surface temperature of "Earth's Twin" is more than 400 degrees Fahrenheit.  It turns out that was a conservative estimate.  In fact, the rocky, dry landscape of Venus swelters at 800 degrees — possibly even hotter than the day side of sun-baked first planet, Mercury.  It's because the planet's dense carbon dioxide atmosphere acts like a heat blanket.  There's no respite on the night side of the hot world either; the thick air spreads the temperatures out evenly.

Thus, virtually every story written about Venus has been rendered obsolete.  Will Mariner 3 destroy our conception of Mars, too?

Just checking the lights

On February 25, the Department of Defense turned little Solrad 1 back on after 22 months of being off-line.  The probe had been launched in conjunction with a navigation satellite, Transit, back in June 1960.  For weeks, it had provided our first measurements of the sun's X-ray output (energy in that wavelength being blocked by the Earth's atmosphere and, thus, undetectable from the ground).  DoD has given no explanation for why the probe has been reactivated, or why it was turned off in the first place.  Maybe there's a classified payload involved?

Radio News from the Great White Spacecraft

Last September, the Canadians launched their first satellite — the "top-sounder," Alouette, whose mission was to measure the radio-reflective regions of our atmosphere from above.  The results are in, and to any HAM or communications buff, its huge news.

It turns out that the boundaries of the ionosphere are rougher at higher latitudes than at lower latitudes.  Moreover, Alouette has determined that the Van Allen Belts, great girdles of radiation around our planet, dip closer to the Earth at higher latitudes.  This heats up the ionosphere and causes the roughness-causing instability. — the more active the electrons, the poorer the radio reflection.  Now we finally know why radio communication is less reliable way up north.  The next step will be learning how to compensate for this phenomenon so that communication, both civil and military, can be made more reliable.

Sun Stroke Warning

After a year in orbit, NASA's Orbiting Solar Observatory is still going strong, with 11 of 13 experiments still functioning.  The satellite has probably returned more scientifically useful data than all of the ground-based solar observatories to date (certainly in the UV and X Ray spectra, which is blocked by the atmosphere).

Moreover, OSO 1 has returned a startling result.  It turns out that solar flares, giant bursts of energy that affect the Earth's magnetic field, causing radio storms and aurorae, are preceded by little microflares.  The sequence and pattern of these precursors may be predictable, in which case, OSO will give excellent advance warning of these distruptive events.

Tax money at work, indeed!

Galaxy, Galaxy, Burning Bright

In the late 1950s, astronomers began discovering some of the brightest objects in the universe.  It wasn't their visible twinkle that impressed so much as their tremendous radio outbursts.  What could these mysterious "quasi-stellar sources" be?

Now we have a pretty good guess, thanks to a recent scientific paper.  Cal Tech observers using the Mt. Wilson and Mt. Palomar observatories turned their gaze to object 3C 273, a thirtheenth magnitude object in the constellation of Virgo.  It turns out that 3C 273's spectrum exhibits a tremendous "red shift," that is to say, all of the light coming from it has wavelengths stretched beyond what one would expect.  This is similar to the decrease in pitch of a railroad whistle as the engine zooms away from a listener.

The only way an object could have such a redshift is if it were of galactic proportions and receding from us at nearly 50,000 km/sec.  This would place it almost 200,000,000 light years away, making it one of the most distant (and therefore, oldest) objects ever identified.

At some point, astronomer Hubble's contention that the universe is expanding is likely to be confirmed.  These quasi-stellar objects ("quasars"?) therefore represent signposts from a very young, very tiny universe.  What exciting times we live in!

Five years of Beep, Beep

St. Patricks Day, 1958 — Vanguard 1 was the fourth satellite in orbit, but it was the first civilian satellite, and it is the oldest one to remain up there.  In fact, it is the only one of the 24 probes launched in the 1950s that still works.

What has a grapefruit-sized metal ball equipped with a radio beacon done for us?  Well, plenty, actually.  Because it has been tracked in orbit so long, not only have we learned quite a bit about the shape of the Earth (the variations in Vanguard's orbit are due to varying gravities on the Earth, the measurement of which is called "geodetics"), but the satellite's slow decay also tells us a lot about the density of the atmosphere several hundred miles up.

So, while Sputnik and Explorer might have had the first laughs, Vanguard looks likely to have the last for a good long time.

Telstar's little brother does us proud

RCA's Relay 1, launched in December, is America's second commercial communications satellite.  It ran into trouble immediately upon launch, its batteries producing too little current to operate its transmitter.  Turns out it was a faulty regulator on one of the transponders; the bright engineers switched to the back-up (this is why you carry a spare!), and Relay was broadcasting programs across the Atlantic by January.  660 orbits into its mission and 500 beamed programs later, NASA announces that Relay has completed all tests. 

Nevertheless, why abandon a perfectly good orbital TV station?  Relay will continue to be used to transmit shows transcontinentally, especially now that Telstar has finally gone silent (February 21).  There is even talk that Relay could broadcast the Tokyo Olympics in 1964, if it lasts that long!

In a sea of Blue, a drop of Red

On March 12, 3-12 at the Spring Recognition Dinner of Miracle Mile Association, in Los Angeles, Cal Tech President, Lee DuBridge, noted that the United States has put 118 probes into space, while the Russians have only lofted 34 (that we know of).  He also pointed out that virtually no scientific papers have resulted from the Soviets' "science satellites." 

As if in reply, on March 21 the Soviets finally, after 89 days without a space shot, launched Kosmos 13.  (To be fair, it's been kind of quiet on the American side, too).  The probe was described as designed to "continue outer space research."  No description of payload nor weight specifications were given.  Its orbit is one that allows it to cover much of the world.  While it may be that some of the Kosmos series are truly scientific probes, you can bet that, like America's Discoverer program, the Kosmos label is a blind to cover the Russians' use of spy satellites.  Oh well.  Turnabout is fair play, right?

[Next up, don't miss Mark Yon's spotlight of this month's New Worlds!  And if I saw you at Wondercon, do drop me a line…]

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Science / Space Race

[January 15, 1963] Venus' true face (Scientific Results of Mariner 2)

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[if you’re new to the Journey, read this to see what we’re all about!]


by Gideon Marcus

Remember five years ago, when Explorer 1 was launched?  At first, the big news was that America had answered Sputnik and joined the Space Age, but it soon became clear that the flight had larger significance.  For Explorer discovered the giant bands of hellish radiation that girdled the Earth, particles trapped by the Earth's magnetic field.  Until 1957, these "Van Allen Belts" had been virtually unsuspected.  With one flight, our conception of the universe had drastically changed.

It's happened again.

Mariner 2 is humanity's first successful mission to another planet, and the scientific harvest is absolutely enormous.  Moreover, thanks to recent changes in policy, the initial results of this harvest were released unprecedentedly quickly (scientists are now reporting upon submission and acceptance of papers rather than publication).  Just one month since the probe's encounter with Venus, the flood of information has been almost too much to parse; nevertheless, I think I've gotten the broad strokes:

Getting there is half the fun

Before I talk about Mariner's encounter with Venus, it's important to discuss what the spacecraft discovered on the way there.  After all, it was a 185 million mile trip, most of it in interplanetary space charted but once before by Pioneer 5.  And boy, did Mariner learn a lot!

For instance, it has finally been confirmed that the sun does blow a steady stream of charged particles in a gale known as the "Solar Wind."  The particles get trapped in Earth's magnetic field and cause, among other things, our beautiful aurorae. 

Mariner also measured the interplanetary magnetic field, which is really the sun's magnetic field.  It varies with the 27-day solar rotation, and if we had more data, I suspect the overall map of the field would look like a spiral. 

Why is all this important?  Well, aside from giving us an idea of the kind of "space weather" future probes and astronauts will have to deal with, these observations of the sun's effect on space give us a window as to what's going on inside the sun to generate these effects. 

One last bit: along the way, Mariner measured the density of "cosmic dust," little physical particles in space.  It appears that there's a lot of it around the Earth, perhaps trapped by our magnetic field, and not a lot in space.  It may be that the solar wind sweeps the realm between the planets clean.

Unattractive planet

Given how magnetically busy the Earth is, and since Jupiter fairly crackles on the radio band thanks to its (likely) magnetic dynamo, one would expect Venus to impact its local space environment.  Nope.  In fact, Mariner 2 flew past the second planet without detecting a trace of Venusian magnetic field, nor any concentration of space dust around the planet.  Now, it's possible that Venus has a weak field, or that its field is so oddly shaped that Mariner just hit a low patch, but the simplest explanation is usually the right one — Venus has no magnetic field.

Taking her temperature

Right up until December 14, some scientists (and many writers!) had held out hope that the thick clouds of Venus hid a reasonably hospitable surface, potentially teeming with life.  Earth-based sensors had indicated that the Venus was unbearably hot, but such could be explained by an unusually active Venusian ionosophere.  But as Mariner 2 turned its microwave and infrared radiometers across the face of Venus, it was clear that the edges of the planet were cooler than the center.  This is what one would expect from a hot surface, cooler atmosphere; the reverse would be expected of the "hot ionosphere" model.

So how hot is Venus?  At least 400 degrees Kelvin (260 degrees Fahrenheit), and probably a lot more.  There's no way there is any liquid water under that hellish greenhouse of carbon dioxide.  Moreover, it's not any nicer at night time.  There appears to be no real difference in temperature between the illuminated and dark halves of Venus, probably for the same reason the Earth's oceans run a fairly consistent temperature – Venus' atmosphere is thick enough for efficient distribution of warmth. 

Amtor dispelled

Mariner 2 and terrestrial radar have determined that the Venusian day incredibly long (~250 days, backward with respect to the other planets), but the Venusian winds blow across the planet far faster than the planet rotates; clouds have been seen racing around the disk of Venus in just 4-5 days.  Recent radar observations indicate that Venus's surface is smoother than that of the Earth or the Moon. 

This, then, is our new picture of Venus.  It is a truly hellish place, more worthy of its less common moniker, Luciferos — a bleak, half-lit world scoured by hurricane-strength sandstorms hot enough to melt lead.  Bradbury's All Summer in a Day, not to mention Burroughs' "Venus" series', will need some serious revision. 

Details, details

One of the nice things about sending a probe far from Earth is it allows for more accurate measurement of basic units – like the distance of the Earth and Venus from the sun.  This will help in future expeditions, manned and unmanned.  Another bit of bounty from Mariner's flight is a refinement of the mass of Venus.  It is 81.485% that of Earth – one of the few ways Venus remains "Earth's Twin."

What's next?

Opportunities to explore Venus occur every 19 months, when the second and third planets of the solar system are aligned in their orbits for easy travel.  Mariner 2 was so successful in its mission that NASA has canceled plans for a repeat flight in 1964.  Rather, the space agency will focus on Mars that year and follow up with Venus later, perhaps 1965. 

One reason to launch a new probe to Venus sooner rather than later is, despite the wealth of information passed back by Mariner 2, we did not get a single photograph of the planet.  That's because the spacecraft was too small to carry the transmitting equipment required to send back pictures from so far away.  But by '65, the new Centaur booster stage will have replaced the weaker Agena, which will allow a beefier payload. 

In the meantime, telemetry is worth a thousand pictures.  For now, let us revel in this scientific bonanza. Venus may not be a great place to live, but visiting has paid off tremendously.


(that's rolls of data, not paper towels)

[P.S. If you registered for WorldCon this year, please consider nominating Galactic Journey for the "Best Fanzine" Hugo.  Check your mail for instructions…]




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Science / Space Race

[December 14, 1962] Hot Stuff (Stop Press report on Mariner 2)

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[if you’re new to the Journey, read this to see what we’re all about!]


by Gideon Marcus

The Space Race has given us a lot of firsts to report on in the last five years.  Today marks perhaps the most significant: for the first time, a spacecraft is reporting back to Earth on another world.  Mariner 2, launched on August 27, has traveled 182 million miles to fly by the second planet out from the sun, Venus.

It has been a perilous trip the entire way — even before the spacecraft ever left the ground!  Firstly, the mission almost didn't leave the drawing board.  The original Mariner probe was a robust and heavy craft with a huge panoply of experiments.  But the beefy Atlas-Centaur booster wasn't going to be ready in time for the next favorable orbital alignment of Earth and Venus, such occurring every 19 months.  Unless NASA wanted to wait until 1964…and risk being beat by the Russians, an alternative had to be found.

Luckily, the Ranger series of moon probes, half the size of the original Mariner and designed to fit on the smaller Atlas-Agena, was available.  Two new Rangers were adapted into "Mariner Rs" posthaste to meet the Summer 1962 deadline.  By July, Mariner 1 was on the launchpad.  This is where the second hurdle was met.

On July 22, Mariner 1's Atlas soared into the sky.  93 seconds into the flight, the guidance antenna on board the rocket stopped hearing commands from ground control.  This was not immediately fatal; after all, the Atlas has its own computer with a program designed to keep the booster on course even without external direction.  Unfortunately, something was wrong with the program, too — probably a misprogrammed equation led the Atlas to make increasingly jerky maneuvers on its yaw axis.  Five minutes into the mission, ground control had to send a destruct order, blowing the rocket up in midflight.

A tense month went by.  Would the Russians beat us to the punch?  We'd gotten a reprieve the year before, when the Soviet probe Venera 1 sailed silently past the Planet of Love, its systems having died in flight.  On August 25, there were reports of a Soviet launch but no subsequent announcement of a new Venus mission.  Was it just a false alarm?  Or had our adversaries had troubles of their own?

Then Mariner 2 successfully launched, on August 27.  It made it through a mid-course correction on September 4 that put it on a course with destiny.  Now it just had to survive the journey, longer than any that had been managed before.  Given the track record of the Rangers (0 for 5), the odds weren't good.

In fact, Mariner almost didn't make it.  On Halloween, one of Mariner's solar panels shorted out.  It came back on a week later only to short out for good on November 15.  Still, the crippled ship soldiered on closer to the sun, its remaining panel absorbing sufficient energy to power all instruments.  Mariner 2 set a record en route, continuing to send data past the point that Pioneer 5's transmission faded away two years ago.  As the craft approached Venus, the temperature inside was close to boiling.

Nevertheless, little Mariner pulled through!  Passing just over 20,000 miles over the surface of Venus, Mariner 2 is sending back information, all experiments functioning.  As we speak, JPL engineers are poring through the data.  In just a few short weeks, we will finally have answers to some big questions: Is Venus really a roiling inferno?  How long is a Venusian day?  What is the nature of Venus' magnetic field? 

Humanity has waited 100,000 years to learn the answers.  By January, we should have them.

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