by Gideon Marcus

Baby's first step… Take Four

Out in Huntsville, Alabama, Von Braun's team is busy making the biggest rockets ever conceived.  The three-stage Saturn V, with five of the biggest engines ever made, will take people to the Moon before the decade is out.  But NASA's is justifiably leery of running before walking.  Moreover, there is use for a yet smaller (but still huge!) rocket for orbital Apollo testing and, also, practice building and launching Saturn rocket components.

Enter the two-stage Saturn I, whose first stage has eight engines, like the Nova, but they are much smaller.  Still, altogether, they produce 1.5 million pounds of thrust — that's six times more than the Atlas that will put Gordo Cooper's Mercury into orbit next month.  The Saturn I's second stage will likely also be the third stage on the Saturn V.

The Saturn I has had the most successful testing program of any rocket that I know of.  It's also one of the most maddeningly slow testing programs (I'm not really complaining — methodical is good, and it's not as if Apollo's ready to fly, anyway). 

The fourth in the series lifted off March 28, and they still aren't fueling the second stage.  They've essentially all been tests of stage #1.  This particular test was interesting because they shut off one of the engines on purpose during the flight to see if the other engines could compensate for the loss.  SA-4 continued to work perfectly, zooming to an altitude of 129 kilometers.

SA-4 was the last of the first-stage-only tests.  Henceforth, we'll get to see what the full stack can do. 

A breath of very thin fresh air

We tend to ignore most of the atmosphere.  After all, the air we breathe and most of the weather are confined to the first few kilometers above the Earth.  But the upper regions of the atmosphere contain the ozone layer, which shields us from deadly radiations; the ionosphere, which bounces radio waves back to Earth; beautiful and mysterious noctilucent clouds, only visible after sunset; and of course, spacecraft have to travel through it on their way up and down.  Knowing the makeup of our atmosphere gives us clues to understand climate, the history of the Earth, the interaction of our planet and the sun, and much more.

And yet, aside from the TIROS weather satellites, which only study the lowest level of the atmosphere, there has never been a dedicated atmospheric study satellite.  Sure, we've launched probes to detect radiation and charged particles and the Earth's magnetosphere.  Some have investigated the propagation of radio waves through the ionosphere.  But none have gone into space just to sample the thin air of the upper atmosphere and find out what's up there and how much.

Until now. 

Explorer 17 is a big, sputnik-looking ball loaded with a bunch of pressure gauges and other instruments.  Its sole purpose is to measure the the pressure and make-up of the upper atmosphere, from about 170 kilometers up. 

Launched on April 3rd, in its first few days of operation, the probe has more than tripled all previous measurements of neutral gases in Earth's upper atmosphere to date.  For instance, the satellite has discovered that the earth is surrounded by a belt of neutral helium at an altitude of from 250 to 1000 miles, a belt no one was sure it existed.  We suspected it, of course — helium, produced in the Earth's crust by the natural radioactive decay of heavy elements, is very light.  Just as helium balloons go up and up, free helium's normal fate is to eventually escape Earth's gravitational influence, leaving behind the heavier gasses. 

This is the first time this hypothesis had a chance to be proven, and by measuring the density of this helium, we should be able to get an idea of how much helium is generated by the Earth each year.  This, in turn, will tell us something about how much radioactive material is left on Earth.  Isn't that neat?  We send a probe far up into space to learn more about what's going on down here.  Your tax dollar hard at work.

The Cosmos opening up for Kosmos

Pop quiz — what did the Soviets accomplish last year in the Space Race?  Right.  The Soviets made big news with the flashy dual mission of Vostoks 3 and 4.  Anything else?  Can you recall a single space accomplishment for the Communists?  In 1962, the United States launched Telstar, the Orbiting Solar Observatory (OSO), three Explorer science probes, three Ranger moon probes, Mariner 2 to Venus, and a couple dozen military satellites, not to mention the orbital Mercury flights of John Glenn, Scott Carpenter, and Wally Schirra.

This year is a different story.  We Americans haven't slackened our pace, but the Russians have finally picked up theirs.  They've got a probe on its way to Mars, as well as a new series of satellites called Kosmos.  This month, they launched three, getting up to Kosmos 16.  They are touted as science satellites, but there has been precious little data from them made public or that's worked its way into scientific papers.  This suggests that the Kosmos program is really a civilian front for a military program.  That's the fundamental difference between the Western and Eastern space efforts.  While the American military takes up its share of the national space budget, we still make sure there's room for pure science.  The Soviets have chosen between guns and science in favor of the former (though, to be fair, if we could only afford one option, would we have made the same choice?)

So why did it take so long for the Soviets to get into the groove after having such a seemingly commanding lead in the Space Race?  And just what are the Kosmos satellites really doing up there? 

According to a NASA scientist, the lack of announced flights doesn't mean the Russians didn't try.  Our Communist friends are notorious for talking only about their successes.  In fact, the Soviets were trying a new four-stage version of the booster that launched Sputnik and Vostok, and the fourth stage kept failing.  There might have been a few failed moon missions in there, too, that we never heard about.  We probably only learned about Luna 4, launched April 2, because it took off just fine — it just missed its target (the Soviet reporting after lunar flyby was notably subdued). 

As for what Kosmos is, Aviation Weekly and Space Report suggests the series is really two types of satellites based on weight and orbital trajectory.  One is a small class of probe that stays up for months.  They could be akin to our Explorers, but again, they don't produce science (whereas ours have revolutionized our knowledge of near-Earth space).  More likely, they are engineering satellites designed to test various components for future missions: communications, cameras, navigation.

The other class is big — as big as the manned Vostoks.  They only fly a few days, too, and their orbits cover most of the globe.  These could be unmanned tests of the next generation of Soviet manned spacecraft.  But they also could be repurposed Vostoks designed to conduct spy missions.  Perhaps the Soviet Union is sending up cosmonauts with camera in hand (as we have done on the Mercury missions).  Sure, it's more expensive than our Discoverer spy sats, but everything's free in a command economy, right?

In any event, the world once again has two active space superpowers.  What happens next is anyone's guess…