Sunday, May 10, 2009

A Tale of Two Shuttles

Two space shuttles sitting on the pad at the same time is a rare sight. But the reason behind this picture is the stuff of summer blockbusters.

Sometime tomorrow afternoon, the shuttle Atlantis will lift off on the last mission to service the Hubble Space Telescope. This is a mission that was actually taken off the flight schedule after Columbia tragedy because it was deemed too risky.

Every shuttle mission since Columbia has been to the International Space Station. The shuttle always rotates in front of a view port before docking and high resolution pictures are taken of the heat shield tiles and leading edges to inspect for damage.

If the shuttle were damaged and unable to survive reentry, the shuttle crew could just camp out in the ISS, for months if necessary, until a ship could be launched to bring them back.

The HST orbits the Earth about 100 miles higher than the International Space Station. The space shuttles do not have enough fuel on board for the change in orbit that would be necessary to get to the ISS from the HST. If the shuttle sustained damage during lift off and were unable to come home, they would be stranded in space. Consumables such as food and breathable air would be gone in a matter of days. A couple of weeks at most.

That's where the second shuttle, Endeavour comes in. Should the worst happen, Endeavour would be launched in a matter of days to rendezvous with Atlantis. The last time the United States has had two manned space craft flying in close formation was during the Gemini 6 and Gemini 7 missions in 1965.

But during those missions, all they did was rendezvous, maneuver around each other, take some pictures, and go their separate ways.

This is very, very different.

As I understand it, the plan would be for Endeavour to come close enough to Atlantis that Endeavor could reach out with its robotic arm and latch onto Atlantis. At this point they would be facing each other cargo bay to cargo bay.

A tether would be strung between the two shuttles. Over the course of 2-3 days, using extra spacesuits carried up by Endeavour, the Atlantis astronauts would pull themselves, hand over hand, 350 miles up, over to Endeavour.

Before leaving the Atlantis, the commander would configure the flight deck so that it could be controlled from the ground.

After the Atlantis astronauts were safely aboard the Endeavour, ground controllers would put the Atlantis on a de-orbit burn that would destroy the Atlantis over the ocean.

I hope it doesn't come to that. But if it does, it will be high drama that will capture the world's attention, with a guarantee of a big budget movie to follow.


m.v. said...

I read the story and I don't get why they won't attempt to fix tiles and why they wouldn't just try to land it remotely,like the Russian shuttle-knock-off Buran did many years ago.

Xavier Onassis said...

m.v. - NASA developed and experimented with a tool kit to repair tiles in orbit. They think it might work for small damage, but they have never attempted to repair actual damage, in space, and then see if it works with astronauts aboard during reentry.

Bringing the shuttle in remotely ala Buran is certainly possible. But doing so requires a reentry path over populated areas. If Atlantis has been damaged to the extent that it was necessary to evacuate the crew, it would be too risky to attempt to bring it in remotely.

Lastly, with the shuttles due to retire to Air & Space museums in a few years, how much effort and risk is justified?

The shuttles are cool, but the Soviets/Russians got it right. With the notable exception of Buran's single, unmanned flight.

The Soyuz is the safest, most reliable spacecraft ever flown. It works. It's dependable. Why fuck with it? It doesn't need to be shiny and it doesn't need fins.

Which is exactly why you see us returning to Apollo v2.0 with upgraded electronics and a little more elbow room.

Necessity is the mother of invention and function is the father of design.

Keep it simple, build in lots of redundancy, and have a low tolerance for risk.

That approach will get your astronauts/cosmonauts/taikonauts home more often than not.

m.v. said...

That all sounds reasonable but what's the plan C -if both ships are damaged? I also agree about safety vs. effort and cost, after all Russians let space station Mir drop into the ocean and some said it still had few good years left in it.

Xavier Onassis said...

m.v. - MIR was definitely euthenized prematurely. As I recall, I think it was more political than technological and was a U.S. prerequisite for Russian participation in the ISS.


The Apollo era Skylab still had a lot of potential too! How much could it have cost to boost MIR and Skylab into a "mothball orbit" to reserve them for possible future use?

As for a Plan C, I haven't heard of one. If Atlantis and Endeavour are both damaged on liftoff, they are both FUBARed.

We would have dead astronauts in expensive, high tech coffins orbiting the Earth for hundreds of years as yet more space junk. If somewhat more revered.

But if I were in charge (as we all know I should be), I'd have Russia cranking out Soyuz spacecraft and boosters as fast as possible.

Russia can mass produce Soyuz spacecraft like Detroit can crank out the Ford Focus.

If we had to stack, fuel and launch a Soyuz for every stranded astronaut, we would do it. A launch, rescue and reentry a day.

That would be my Plan C.

Faith said...

Woohoo! Endeavour/Atlantis 69er in the sky! That is HOT, man. (I was thinking about you as I heard them talking about the Hubble mission on the news. I knew you were gonna post something about it! And see, you did. And guess what? I learned way more from you than I did on the news. Because they totally did not talk about the possibility of the shuttles 69ing each other.)

Xavier Onassis said...

Testing a reported problem.