Saturday, December 05, 2009

Apollo +50: Little Joe 2

This posting is a part of a continuing series celebrating the 50th anniversary of the Apollo moon program, tracing the launches that occured 50 years ago between now, and the 50th anniversary of Apollo itself.

This is a celebration of a group of people who used a method of experimentation, discovering the natural and materialistic causes of what happened to each space craft, using reason to make adjustments, and repeating the process until what started out as a repeated string of failures simply testing a capsule, became a string of repeated successes delivering a number of crews to the moon and returning them safely back to earth.

Fifty years ago, NASA 9 years, 7 months, and 12 days of launching astronauts to the moon. However, this was not its goa - not yet. It was still trying to get a man into space.

The dominant interest in space at this time was simply in being able to occupy the high ground - space - in any future conflict with any enemy such as the Soviet Union, and in denying that high ground to that enemy. It also needed to ensure the protection of its space-based assets and resources (spy satellites, weather satellites, communication satellites, etc.)

Where was NASA at this point in its journey?

It's first test was an utter failure.

In spite of a malfunction in the Atlas rocket that launched the capsule, this mission sowed that an ablation heat shield (one that carries away the heat by boiling off a resin put on the space ship) will keep a capsule from bruning up on re-entry and keep the astronaut safe.

Showed that a test rocket that NASA had built will actually perform as expected, allowing NASA to conduct future tests.

Failed in a second attempt to see if the abort system will work under the most stressful conditions in a typical launch.

In other words, it had not accomplished much.

Fifty years ago, NASA went through the fifth unmanned launch of a Mercury space capsule.

The purpose of this launch was to determine i a human could actually function in zero gravity.

What was zero gravity going to do to the way the brain functions? Would it create sensations that would simply cause the agent to go into a wild panic? Would an astronaut be able to eat or drink without gravity helping the process? Would the lack of gravity destroy eyesight? Balance? Blood flow?

Little Joe 2 was to answer these questions by carrying a monkey, SAM, (which actually stood for School of Aviation Medicine, which was conducting the research) into space to experiece four minutes of weightlessness to see how he did. SAM would be launched up to a height of about 400,000 kilometers (about 70 miles), experience about 4 minutes of weightlessness, then use the abort and recovery system to land in the Atlantic Ocean where he would be picked up, just like any astronaut would be picked up.

This launch was not just meant to test the ability of a primate to function during weightlessness. The capsule was also filled with things from nerve cells to barley seeds to test the effects of radiation. It also provided an ability for engineers to see how the capsule function at the edge of space and, of course, to test the system for recovering a capsule after a short flight or an abort.

They would not be able to rerun the tests on how a capsule performed under max-Q - maximum dynamic pressure - which was the objective of two failures prior to this date. This is because, to test the effects of weightlessness, the capsule would be going through max-Q without triggering an abort. A new test of that aspect of space flight had to be put off until January of 1960.

Well, NASA had not yet had a fully successful launch, and this one was no exception. The rocket only reached a height of 53 miles, which means that SAM did not actually enter space (officially listed as starting at 00 kilometers or slightly more than 60 miles).

However, this was good enough to give NASA scientists and engineers a good set of data on all of the things they sought to test.

SAM experienced three minutes of weightlessness instead of four as the capsule arched across the sky, before the capsule started to experience the G-forces of re-entry. The engineers still got data on how the capsule itself performed during separation from the rocket, through this long arch of weightlessness, and through re-entry and splashdown. And the astronaut recovery teams were able to test their procedures for finding and retrieving a capsule that had splashed down.

So, the mission was considered a success.

It would be possible, it seemed, to put an astronaut in SAM's place and send him on a test flight, at least through a few minutes of weightlessness, and recover the astronaut without any ill effects - as soon as the hardware was made reliable enough to do this.

Putting a human into space seemed possible. Putting a human into orbit, however, was still a matter of speculation.

From this point on, I will no longer be able to say that NASA had not accomplished much. It had shown that putting a man in space, at least, was doable. It had done much of what it needed to do with the successful launch and recovery of a monky. It now needed to do the same thing with the launch and recovery of a human.

The major sticking point here was with man-rating a launch vehicle. This meant making the launch vehicle safe enough that one would be willing to put a life human being on the end of it. That was still going to require a lot of engineering.

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