Space Shuttle Heading Home

Reuters is reporting that the shuttle has been prepping for a return to Earth, stowing gear and checking systems. Their expected return is tomorrow morning, around 9am EDT. From the article: "During tests on Sunday a leaking power unit for the shuttle flight control system appeared to be in good enough shape for landing and the jets that steer the spacecraft worked fine, NASA engineers said. The shuttle crew was still awaiting word on whether Discovery's heat shield had passed a final inspection performed on Saturday, but scans conducted with cameras and sensors throughout the flight had so far turned up no damage."

Comments

Operating a freezer in space...

[posterlogo]

One of the mission goals was to set up a -80 C freezer on the ISS. We have a couple in our lab (most bio labs do) -- they're primarily used to store biological samples. The -20 C freezer and 4 C refridgerater are also standard operating equipment in biology (or chemistry, I suppose), so it looks like they're gearing up to do some life sciences work.

Now, this brings up an interesting issue -- How do you operate refrigeration equipment in space? Especially that -80 C...it's a real power hog and probably outputs a lot of heat (in a closed air environment, is this a problem?). Does anyone know how cooling is done in space? Is it still based on condenser coils? Can they somehow utilize the "cold" of space for this purpose?

Re:shoot the white elephant

[FSWKU]

The shuttle can land itself without any hassle whatsoever. What prevents this from being done is the fact that the landing gear is manually activated. This was an intentional design element, as once the landing gear is activated there is no way to reverse the process. The fear was that if the computers fouled up and dropped the landing gear early, the excess drag would cause the shuttle to fall short of the runway. For this reason, they wait until the last minute (approx. 300 feet) to activate the system. As far as I know, the landing gear still requires an actual human to give the command, but the cable they installed allows this to be done remotely if the need should arise.