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Science / Space Race

[November 18, 1968] Pioneers and Protons (a space round-up)

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by Gideon Marcus

The Interplanetary Pioneers

When you think "outer space", you don't usually think of weather.  In fact, weather in space is a bit like weather on Earth: there's wind, turbulence, a steady rain, and occasional storms.  Except that the wind and rain are the sun's ceaseless spray of charged particles along with their attendant magnetic fields.  The storms are the result of solar flares, those sudden unsettled periods when fiery prominences reach out from the sun's surface.

These phenomena can even be sensed by humans—as aurorae where the solar wind interacts with the Earth's magnetic field, and as the crackle of static on a shortwave radio.  For satellites and space travelers, the solar radiation, particularly during flares, can damage electronics and internal organs.  There are thus a lot of reasons it would be practical to have a space weather report, just as we have a daily weather report down here on Earth.


Northern Lights, 1921, by Sydney Laurence

This is why the Pioneer series of solar weather satellites, the first launched December 16, 1965 and the latest launched on November 8th of this year, was created: to serve as long-term weather sentinels in space, the interplanetary equivalent of our TIROS weather satellites.

Prior to the launch of Pioneer 6 (no relation to Pioneer 5 or its predecessors save for the name), the mapping of the solar wind had been a strictly local affair.  The Interplanetary Monitoring Platform satellites, Explorers 18, 21, 28, 33, 34, and 35, have all been launched in high Earth orbits to survey the solar wind between the Earth and the moon.  This is in service of the Apollo program.

The aforementioned Pioneer 5 and interplanetary probes like Mariner 2 have made preliminary forays into true interplanetary space beyond the Earth/moon region, but those missions only lasted a few months.  The interplanetary Pioneers will be on station for years.

Launched on Delta rockets (the direct descendants of the Thor-Able rockets that launched the first Pioneers toward the moon), Pioneers 6-9 (and eventually #10, next year), were hurled into orbits that parallel our own, but further out in the case of Pioneers 7, 8, and 9; a little closer to the sun in the case of Pioneer 6.  The outer ones orbit a little more slowly while P6 zooms a little faster.  As a result, they all spread out, making a necklace of stations around the sun.

Pioneer 6 was launched in 1965 during the lull in the sun's 11 year cycle called "the solar minimum".  The hope was that we would get continuous data as the sun increased in activity, flaring more and more often.  We have not been disappointed.  On July 7, 1966, a big shock front from a solar flare enveloped Explorer 33.  45 hours later, Pioneer 6 was hit.  Interestingly, because of the time delay, even though both probes were similar distances from the sun (but far apart in orbit, of course), it is believed those might have been the result of two different flares, or perhaps two disturbances from the same one.

When the Pioneers were launched, scientists had a basic idea of that the solar wind looked like the spiral spray of a sprinkler head, this caused by the 28-day rotation of the sun.  But the instruments onboard the sophisticated Pioneers afforded much more detailed analysis of these streams and fields.  The Pioneers have found that the local magnetic fields will suddenly flip every so often.  Their microstructure is like woven filaments, far more complicated than we had previously conceived.


High-level view of the "sprinkler" spray of the solar wind

Pioneers 7 and 8 sailed through the Earth's magnetosheath, that magnetic shadow formed as the sun's wind interacts and deflects around the Earth.  Comparing their results to the closer-in Explorer 33, they found that this shadow tail gets more diffuse, more like the background interplanetary wind at greater distances, which is what one would expect.


The Earth's magnetic field (you can see the figure 8 Van Allen Belts) and the long, trailing, magnetosheath.

The Pioneer satellites are well-placed for more than just solar science.  Pioneers 8 and 9 are equipped with cosmic-ray telescopes designed to measure the chemical composition and sprectra of the galactic wind—the higher-energy rain of particles from beyond our solar system.  But the coolest use of the Pioneers so far (to me) is when Pioneer 7 was used to measure the lunar ionosphere.  On January 20, 1967, the moon "occulted" (blocked) the space probe, as seen from Earth.  Radio waves were beamed from a 150-foot dish run by Stanford past the edge of the moon.  They found that the scattering that resulted can't be explained just by the physical rocks of the lunar surface.  There must be a tenuous "atmosphere" above the moon, at least on the sunlit side, created at high altitudes by interactions between the solar wind and the surface of the moon.

There's actually a lot more, esoteric stuff that's way above my head.  And there will be plenty more as the Pioneers will probably keep going for many more years.  Though they haven't gotten much press, I think these are some of the most exciting missions to date.  Stay tuned!

My, what big…rockets you have!

Three years ago, I made a brief announcement about the launch of a new Soviet probe, one so enormous that its size alone had ramifications for the future of the Communist space program.  Proton, launched July 16, 1965, massed a whopping twelve tons, making it the biggest single object put in orbit until the November 1967 launch of Apollo 4.  That means that the USSR has a Saturn-class rocket in its stable, which is why the concerns about an imminent moon mission have grounding.

Since Proton 1, three more Protons have been sent into orbit, the latest just two days ago on November 16th.  Proton 4 weighs seventeen tons, which will beat all records—at least until Apollo 8 goes up in December. 

Why are they so heavy?  Because they carry heavy instruments.  Protons 1 and 2 included a gamma-ray telescope, a scintillator telescope, and proportional counters.  These counters were able to determine the total energy of each super-high energy cosmic particle individually, a capability no prior satellite had possessed, measuring cosmic rays with energy levels up to 100 million electron volts.

In addition to the above equipment, the fourteen ton Proton 3 was also equipped with a two-ton gas-Cerenkov-scintillator telescope.  Its goal was to attempt to detect the "quark", a brand new theoretical sub-particle that, according to theory, makes up all atomic particles.  Presumably, Proton 4 mounts a similar device with refinements.

Unlike most Soviet satellites, whose missions are shrouded in secrecy, data from the experiements onboard the first two Protons have produced at least five scientific papers on cosmic rays.  I haven't seen anything on Proton 3, but astronauts on Gemini 11 managed to snap a picture of it in September 1966!

Will the advanced experiments on Proton 4 produce a scientific bonanza to rival that of the Pioneers?  Only time will tell.  For now, the papers are more obsessed with the rocket than the satellite.

Apparently, it's all about size.  Who knew?




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Science / Space Race

[August 26, 1968] No time for a breath (Summer space round-up)

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by Gideon Marcus

There are some months where the space shots come so quickly that there's scarcely time to apprehend them all, much less report on them!  Every other day, it seems, the newspaper has got a headling about this launch or that discovery, and that's before you get to the announcements about the impending moon missions.

So, in rapid-fire style, let's see how many exciting new missions I can tell you about on a single exhale (while you stand on one leg, no less…that's a Jewish joke).

A Pair of Yankee Explorers

On August 8th, a Scout rocket took off from Vandenberg Air Force Base (the Western Test Range) in Southern California carrying the two latest NASA science satellites.  It was a virtual duplicate of the launch nearly four years ago of Explorers 24 and 25: a balloon for measuring air density in the upper atmosphere, and a more conventional satellite with an array of instruments for surveying the Earth's ionosphere.  Affectionately dubbed "Mutt and Jeff", these two craft were sent into polar orbit (hence the Pacific launch site).  If you're wondering why NASA is repeating itself, that's because the sun has a profound effect on the Earth's atmosphere.  It is important to measure its impact throughout the 11 year solar cycle, from minimum to maximum output, to better understand the relationship between the solar wind and the air's upper layers.

Not much can go wrong with a balloon, but Explorer 40, after deploying its spindly experiment arms, suffered a malfunction.  Its solar panels are not delivering as much power as they should.  NASA is confident, however, that this will not compromise the mission, which is planned to last more than a year.

Alphabet Soup

Time was, we gave proper names to our satellites.  Now it's all acronyms and arcane jumbles of letters and numbers.  That's all right.  I can decipher them for you!

Advanced Technology Satellite (ATS) 4

August 10 marked the launch of "Daddy Longlegs" ATS 4, the fourth of seven satellites in this series.

Some of you may remember ATS-1–you may recall that ATS-1 helped relay the first worldwide "Our World" broadcast last year. 

ATS-1 is actually still working, just like its two siblings.  ATS-2, launched April 5, 1967 was judged a failure since the second stage of its carrier rocket malfunctioned, stranding it in an eccentric orbit.  Still, the several science experiments onboard have returned information on cosmic rays and such in space.  ATS-3, which went up November 5, 1967, was the last to ride an Atlas Agena D rocket.  Armed with a panoply of experiments, including two transceivers, two cameras, and a host of radiation detectors, that satellite worked perfectly, returning the first color picture of the entire Earth!

ATS-4, unlike its predecessors, is a strictly practical spacecraft, carrying no science experiments, but makes up for it in engineering marvels.  One is a a day-night Image Orthicon Camera, a teevee transmitter that would provide continuous color coverage of the world from high up in geosynchronous orbit (i.e. orbiting at the same rate as the Earth turns, keeping it more or less stationary with respect to the ground).  Another is a microwave transmitter, turning ATS into a powerful communications satellite like its progenitor

ATS-4 also was to test out a gravity gradient stabilization system, basically using the subtle gradations of the Earth's pull on the satellite's arms to keep it oriented in orbit.  Finally, ATS-4 has an ion engine aboard.  These drives, perfect for space, work by shooting out Cesium electrons.  They are incredibly economical compared to conventional rockets, but their thrust is quite low, meaning they must be fired continuously to have an appreciable effect on velocity.

Sadly, as with ATS-2, ATS-4's Atlas Centaur failed on the second stage, stranding the satellite in a low, largely useless orbit.  Well, I guess that's why you launch lots of them!

ESSA 7

We haven't given the ESSA series of satellites much love, which I suppose is what happens when a technology stops being novel and instead becomes routine, even essential.  After all, who reports on every airplane that takes off anymore?

But it's worth talking about the latest satellite, ESSA 7, launched August 16, to summarize what the system has done for us over the last several years.

There were eleven satellites in the TIROS series of weather craft, the first launched in 1960.  In February 1966, with the launch of ESSA 1, the Environmental Science Services Administration (ESSA) took over the cartwheel satellites, making the series officially operational.

All of them have worked perfectly, launched into sun-synchronous polar orbits about 900 miles up that circle the Earth from north to south as the planet rotates eastward beneath.  So perfect is ESSA 7's orbit that it will cross the equator at virtually the same time every day, drifting from that time table by only four minutes every year.

ESSA satellites have returned 3000 warnings of hurricanes, typhoons, and cyclones, reporting not just on the existence but the intensity of these dangerous storms.  As of May 27 of this year, ESSA satellites had taken a million photos of the Earth's weather–that's $42 per picture, since the total launch cost of an ESSA is $6 million.


An image of Tropical Storm Shirley taken August 19, 1968

Up in the Kosmos

If we had to cover the launch of every Kosmos (Cosmos) satellite out of the Soviet Union, we'd have to go to a daily schedule.  There's such a thing as too much of a good thing, right?

But the Russkies are putting them up on the average of one a week, so it's worth sampling them occasionally to keep tabs on all the stuff they're putting in orbit.  Especially since the Kosmos is a catch-all designator, even more broad than our Explorer series.  It includes military satellites, science satellites, weather satellites, even automatic tests of the Soyuz spacecraft.

Here's a brief outline of the launches this last month:

Kosmos 230

This is a typical Soviet launch press release:

The Soviet Union launched another Cosmos satellite today and the Sputnik was reported functioning normally, Tass, the official Soviet news agency, said.  The device, Cosmos 230, is sending information to a Soviet research center for evaluation.

We know it was launched July 5 into a 48.5 degree inclined orbit, that it soars between 181 and 362 miles above the Earth, and that it's still in orbit as we speak, circling the Earth every 92.8 minutes.

As for what it's for… well, your guess is as good as mine.  That said, it's probably not a spy satellite.  How do I know?  Read on, and I'll show you what a spy sat looks like so you can spot them yourself!

Kosmos 231

The Soviet Union has launched another satellite in its program of exploring outer space, the official Tass news agency said Thursday.  It said Cosmos 231 was launched Wednesday [July 10] and is functioning normally.  The latest Cosmos is orbiting the earth once every 89.7 minutes in a low orbit from 130 miles to 205 miles.  Its angle to the earth was 65 degrees.

Seems innocuous enough, right?  Doesn't tell you anything more than the other one.  Except…

First tip-off: the angle.  A zero degree angle would be along the equator, never leaving 0 degrees latitude.  A 90 degree angle is polar, heading due north and south.  The lower the angle, the narrower a band of the Earth a satellite covers.

A 65 degree angle is sufficient to cover a wide swathe…including all of the continental United States.

The altitude is quite low, too.  The closer, the better–if you want to look at something from orbit.

But the real kicker is this: the spacecraft reentered on July 18, just eight days after launch.  Normally, when you send a science satellite up, you want it to stay in orbit as long as possible to get more back for your buck…er…ruble.  You only deorbit a spacecraft (and make no mistake–Kosmos 231 had to have been deorbited; its orbit wasn't that low) when there's something onboard you want to get back.  Like a person…or film.

We know there wasn't anyone onboard Kosmos 231.  The Soviets would have told us.  By the way, I'm not the only one who thinks the Kosmos was a spy satellite, taking pictures in orbit and then landing the film for processing.  There's a blurb in the July 15th issue of Aviation Weekly and Space Report which says the same thing.  And they reached that conclusion before the craft even landed, just based on the orbit!

By the way, if you're wondering what the Soviet spy satellites look like, we actually have a better idea of theirs than ours!  We're pretty sure they're based on the Vostok space capsules used to carry cosmonauts.  In fact, it's an open question whether or not the spy sat was evolved from the Vostok or the other way around!

Kosmos 232

Launched July 16, its orbital parameters were as follows: 125 to 220 miles in altitude, 89.8 minute orbit, 65 degree inclination.  The newspaper article I read noted that the satellite's path was a common one, and predicted the satellite would be recovered in eight days.

Sure enough, it was on the ground again on July 24.

Sound familiar?

Kosmos 233

Here's another oddball: launched on the 18th, the Soviets didn't release news of its orbiting until at least the 20th.  It's in a near polar orbit, soaring up to 935 miles, grazing the Earth with a perigee of 124 miles.

That's no spy sat.  In fact, I'd guess this one might be a bonafide science satellite, exploring the Earth's Van Allen Belts.  But it could just as easily be the equivalent of our Transit navigational satellites or something.  We won't know until and unless the Communists publish scientific results.

Kosmos 234

Launched July 30, it soared from 130 to 183 miles up with a period of 89.5 minutes and an inclination of 51.8 degrees.  Low orbit?  Check.  Cryptic announcement describing its purpose as "the continued exploration of outer space"?  Check.  But the inclination's a bit low.  Better wait for more information.

Oh wait.  It landed August 5.  Pretty sure we know what this one was!

Kosmos 235

Up August 9, down August 17.  Orbit went from 126 to 176 miles, period was 89.3 minutes, and the inclination was exactly the same as before–51.8 degrees.

I'm not sure the significance of the different inclinations.  Maybe it's a matter of the rocket or the launch location.  Generally, the higher the inclination, the more expensive the shot in terms of fuel since the rocket doesn't get the extra boost of the Earth's rotation.

Operator?

It's been a while since we covered the Molniya communications satellites, one of the few Soviet series we do know something about.  July 5 marked the launch of the ninth comsat in the series, zooming up to a high, not quite geosynchronous, orbit, where it has a nice vantage of the whole of Asia.

This launch comes less than three months after the orbiting of Molniya H, the eighth in the series.  Whether Molniya I is replacing its predecessor, which may have been faulty, or whether the ninth Molniya is simply acting as a backup, is not certain.  The latter seems unlikely, though.  When Molniya G went up just three weeks after Molniya F, it was widely believed that the Russians had sent up two to make sure they could televise their annual November Moscow parade to the other Communist countries.

That's all folks!

That's the big news for this month.  The rest of the year is going to be really exciting, what with the upcoming launch of Apollo 7 and Zond 5.  We're about to enter a new phase of manned lunar exploration.  That said, we promise to keep covering the significant shots closer to home, too.  For us, all space missions are out of this world!


The prime crew for Apollo 7 (l-r) Astronauts Donn F. Eisele, Command Module Pilot; Walter Cunningham, Lunar Module Pilot; and Walter M. Schirra, Jr., Commander




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Science / Space Race

[May 30, 1965] Ticket to Ride (May space round-up)

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by Gideon Marcus

It's been another exciting month in the realm of spaceflight.  We're between crewed missions, what with Voskhod 2 and Gemini 3 having flown in March and the next Gemini due in a few days.  Nevertheless, it has been a field day for robotic spacecraft, with a number of civilian and military packages booking passage aboard a plethora of satellites.  Take a look:

The Shape of Things that Came

Yuri Gagarin soared into history in April 1961, becoming the first human space traveler.  His face became known worldwide. His spacecraft, on the other hand, remained shrouded in mystery. For four years, the shape of the Vostok capsule remained a secret, with only a few dubious artists' conceptions offering any clues to its configuration.

That changed suddenly last month when the Soviets displayed the complete Vostok spacecraft at an exhibition in Moscow.  Now we know that the fanciful cylinders and bullet-shaped craft were completely off the mark — Vostok was spherical.

This is significant.  A sphere is a simple shape, mathematically, and it is not hard to weight a ball such that one end always points down.  In the Vostok, that point is where its heat shield was mounted.  A similar concept was employed with America's Mercury capsule, but the back end of the Mercury is only a small arc of a circle.  That's because American rockets were too weak to loft a full sphere.  Vostok is clearly a much heavier spacecraft than Mercury, and this suggests that the Soviet Vostok rocket was much more powerful than the Atlas and certainly the Redstone that lofted the first astronauts.

The unveiling of Vostok affords us a look into a completely different space program, too.  Earlier in the year, American intelligence determined that the Vostok had been turned into a spy satellite.  Instead of cosmonauts, the new Vostok carries a camera.  After a week snapping pictures in orbit, the capsule parachutes to Earth, and the film is developed.  It's an elegant repurposing, though it has to be more expensive than the American analog, Discoverer.

While the Soviets do not announce their spy missions, it's not too hard to figure out which of their Kosmos "science satellites" are probably spy Vostoks.  Their orbits, sweeping them over Western targets of interest, and their short lifespans on the order of a week give them away.  In just the last two months, it's likely that Kosmoses 64, 65, and 66 were all spy satellites.  In a few days, we'll know if Kosmos 67, launched on May 25, is also a space shutterbug.

Softly, softly

Another probe about which the Soviets are being less than forthcoming is Luna 5.  Launched on May 9, the ton-and-a-half spacecraft was headed for the Moon.  Reportedly, it conducted a mid-course maneuver on May 10, directing it toward the Sea of Clouds — which it hit at 10:10 PM, Moscow time.  Per TASS, "During the flight and the approach of the station to the moon a great deal of information was obtained which is necessary for the further elaboration of a system for soft landing on the moon’s surface."

That might lead one to the conclusion that Luna 5 was the Soviet version of Ranger, a TV probe designed to take pictures until it crashed.  However, Western observers using telescopes saw the plume of dust that one would expect accompanying an attempt at a soft landing.  That such a landing did not occur suggests that Luna 5 was supposed to be an equivalent of our Surveyor, set to launch next year, and that things did not go as planned.  The lunar race thus remains neck and neck.

Exploring, Communicating

The last month saw two more entries into the Explorer series: Explorer 27, launched April 29, is a windmill-shaped little satellite that will measure irregularities in the Earth's shape; a secondary mission is probing the ionosphere.

Meanwhile, Explorer 28 was launched on May 28, and is the latest in the Interplanetary Monitoring Probe series, along with Explorers 18 and 21.  All three craft have high, eccentric orbits that allow them to thoroughly map Earth's magnetic field, though Explorer 18 went kaput earlier this month.

As we saw with last month's flight of Intelsat 1, space-based communications are now a fact of everyday life.  The USSR has now gotten in on the act, following up the flight of Early Bird with their own first satellite called Molniya, launched April 22, 1965.  It has a high, 12-hour orbit, not quite geosynchronous, designed to service the high latitude residents of the Soviet Union during the daytime.  European nations have already requested use of the Molniyas; they feel that the "international" Intelsat corporation too strongly favors the United States.


Finally, the Air Force's second "Lincoln Experimental Satellite," launched May 6, has been a success.  This next-generation communications satellite tests new technologies that will allow it to service hundreds of users at a time.  Its predecessor, LES-1 launched February 11, failed to fire its onboard engine that would kick it from its initial low orbit.  LES-2 had no such problems, and its orbit takes it more than 9000 miles above the surface of the Earth.

Of course, being a military satellite (as opposed to Telstar, Relay, and Syncom), it is possible that we civilians won't see immediate benefits, but I suspect they will trickle down in good time.

Another step Moonward

May 25 marked the ninth successful launch of the Saturn rocket, possibly the biggest rocket on Earth.  At its tip were boilerplates of the Apollo Command and Service Modules.  But these mock spacecraft weren't the stars of the show: inside the cylindrical Service Module was a giant satellite, the second Pegasus.  Appropriately adorned with a pair of enormous wings, Pegasus will stay in orbit for years measuring how many micrometeoroids our astronauts are likely to encounter on their way to the Moon.

The reliability of the Saturn is truly remarkable.  Remember the early days of the Space Race?  Chances were 50/50 then that any given rocket, Atlas, Juno, or Vanguard, would blow up on the launch pad, tilt off course, or otherwise fail.  We're now in an age of maturing space travel.  If Gemini's Titan rocket continues to do as well as the Saturn, I do believe that, by the 1970s, everyday citizens like you and me will be able to get tickets to ride into space. 

This week's Journey Show is a special Space Race episode!  Don't miss it!




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Science / Space Race

[Oct. 16, 1964] Three in One (The next leg of the Space Race)

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by Gideon Marcus

A whole new ballgame

It's not often that news of the next stage in the Space Race is eclipsed by an even bigger story.  Yet that's exactly what happened this tumultuous week, a handful of days so crazy that we halted publication ("STOP THE PRESSES!") to keep up with events.

It all started with "Kosmos 47", launched just after midnight (San Diego time) on October 6.  While the Soviets were typically close-lipped about its purpose, from its orbital path, it was suspected that the 24 hour flight was actually an uncrewed test of a new type of Soviet spacecraft.

Sure enough, just six days later, Voskhod ("Sunrise") #1 took off.  On board were three cosmonauts: Commander Vladimir Mikahilovich Komarov, civilian scientist Konstantin Petrovich Feoktistov, and civilian physician Boris Borisovich Yegorov.

This is huge news — both the American Mercury and Soviet Vostok space programs ended more than a year ago.  Those spacecraft only fit one person.  Since then, the United States has been hard at work on both its three-person Apollo lunar craft and its intermediate two-seat Gemini ship.  Although Gemini has already flown once, the first crewed flight won't happen until early next year.

And here are the Soviets, already throwing up a three person spaceship!  Could they be closer to a Moon mission than we thought?

On their eighth orbit, Voskhod's cosmonauts passed over the United States and radioed, "From aboard the spaceship, Voskhod, we convey our best wishes to the industrious American people.  We wish the people of the United States peace and happiness."

Interestingly, a second radio exchange was heard afterwards, during orbit sixteen: the three cosmonauts requested permission to extend the mission beyond 24 hours.  The request was denied, and the flight ended just one day after it had begun.

Why is this strange?  Well, one of the stated goals of the mission was "Extended medio-biological investigations in conditions of a long flight."  And while 24 hours is a long flight by American standards (that of Gordo Cooper in Faith 7 was about a day and a half), the Soviets have been flying day-long and longer missions since Gherman Titov's flight in 1961.  Did something go wrong with the spaceship? 

It turns out the problem was on the ground.  Even as the three cosmonauts were making history in space, the Presidium was holding a vote of no confidence, citing Khruschev's age and health as reasons for his dismissal.  Leonid Brezhnev was elevated to Secretary of the Communist Party and Andrei Kosygin was named Premier.  When the space travelers landed, they were whisked to Moscow where they must have been quite surprised to meet the new leadership!

Still, regardless of who is wearing the crown behind the Iron Curtain, there is no question that Voskhod was a tremendous accomplishment.  The question now is: What will they follow it up with?

Beep Beep, says America

Though perhaps not as impressive to some, the United States maintains the lead in automated space science.  Just this month, we launched the two latest Explorer satellites, 21 and 22.  And while those numbers seem a lot lower than what the Soviet "Kosmos" series has gotten up to, we have to remember that Kosmos conceals a wide variety of satellites, most of which have never resulted in a scientific paper.  They have probably snapped a great many photos of Midwest missile bases, though.

In contrast, the Explorer program is just one of many devoted to returning scientific data from the heavens.  Explorer 21, launched on October 4 (seven years after Sputnik) is the second of its type.  Also known as Interplanetary Monitoring Platform (IMP) B, its job is the same as that of Explorer 18, launched in last year — to measure the magnetic fields, cosmic rays, solar wind, and charged particles far from the Earth.  This helps us understand the physics of the solar system, and it lets us map the electromagnetic "terrain" of the space between Earth and the Moon.  The IMPs are blazing a trail for Apollo, making sure it's safe for people out there.

Unfortunately, the third stage on IMP-B's Thor Delta launch booster fizzled, and instead of soaring 160,000 miles from the Earth, Explorer 21 barely gets to 60,000.  This is within the hellish Van Allen radiation belts, so even though Explorer 21's nine instruments are performing perfectly, the data being returned tells nothing about the universe beyond Earth's magnetic system.

However, Explorer 22, launched October 10, is doing just fine.  It's the last of NASA's first phase of ionospheric explorers, measuring the electron density in the upper atmosphere.  Before your eyes glaze, that just means it sees how electrically charged the air is in the layer that reflects radio waves.  Such experiments help us better understand how the Sun affects our broadcasts — and allows us to make plans for unusual space weather events. 

The satellite, also known as Beacon Satellite B ("A" failed to orbit on March 29) is also the first of NASA's geodetic satellites, measuring the shape of the Earth with tremendous precision.  What's neat about Explorer 22 is that the spacecraft is actually quite unsophisticated, just three radio beacons and a laser reflector.  More noteworthy are the 80 tracking stations run by 50 scientific groups in 32 countries.  These provide a worldwide web, collecting navigational data on an unprecedented scale.

And since it's a civilian probe, we'll probably even share the information with the Communists.  You tell me who's winning the Space Race…

[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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