Old Spacesuits are Potential Satellites

SpaceAdmiral writes "In order to determine if old spacesuits can be effective satellites, the crew on the International Space Station will be throwing one overboard on February 3rd. The SuitSat will transmit information about its condition and, if you happen to have a ham radio or a police scanner, you can tune in when it passes your city! You can use NASA's J-Pass utility to determine when it will pass above you."

Comments

Sufficiently low orbit.

[reality-bytes]

IIRC, due to the fairly low orbit of the ISS, anything cast overboard and not subject to a prograde burn will re-enter the Earths atmosphere in a reasonable ammount of time.

Re:Sufficiently low orbit.

[pranay]

True. But the time to re-entry depends heavily on 2 factors: The cross-section of the object (satellite/spacesuit) in the direction of motion and the time of launch.

The cross section decides the drag the object faces. At about 380-400km, which is the altitude of the ISS (and therefore, the ceiling for space-shuttle); the velocity of a satellite is about 7.67km/sec and drag from the thin ionosphere does matter significantly.

The time of launch is relevant because of the 11 year solar cycle, at the peak of which, the sun causes the atmosphere to expand. The expanded atmosphere causes the density at ISS altitude to increase.

If launched today, a small spacecraft with a mass of 30kg and cross section dia. of 1/2 meter would survive for about 3 months before it spirals down to earth.

This is one big reason LEO (low earth orbit) is used primarily for scientific and educational experiments. The low budgets available to researchers cause them to cut costs and inhibit the development of better instruments. A major expense in building a satellite is flight-qualifying it. Which is essentially testing it for thermal, vacuum, outgassing parameters and more importantly, safety to space-shuttle. Since the space-suits have already been in space, they are flight-tested and can bypass all those grueling stages.

Cool, but not very practical

[Rorschach1]

I talked to one of the guys responsible for the payload at a conference a few months ago. It comes down to the fact that they were going to throw an old Orlan suit away anyway, and someone thought it'd be cool to put some electronics in it. But you have to understand that all those electronics were designed and delivered specifically for that purpose, and for the same amount of delivered weight you could probably deploy a standalone microsat. The suit really doesn't add much. Except for the novelty factor, anyway.