Small Object Hit Space Shuttle Last Month

UglyTool writes "A small object, possibly a micrometeoroid, hit a radiator panel on the Space Shuttle Atlantis in September. The impact also damaged a one-inch (2.5-centimeter) area in the radiator's honeycomb-like aluminum mesh, but did not sever any of the panel's 26 vital coolant tubes as it passed through the half-inch wide panel. This brings up some interesting questions. Is there a better way to protect the shuttle in orbit? Will a serious mishap in space be the end of our manned space program?" From the article: "The impact left a hole about one-tenth of an inch in diameter, NASA reported Thursday on its Web site. The damage 'didn't endanger the spacecraft or the crew, nor did it affect mission operations,' NASA said. The radiators were brought inside the bay before the shuttle's landing last month, so the damaged area did not encounter searing heat during re-entry through Earth's atmosphere."

Comments

Re:Deflector Shields

[abandonment]

This is exactly what i was thinking - they can come up with deflector shields for tanks these days, why not apply this to space-based craft? while they aren't technically 'shields' - at least they would suffice for protecting a craft from objects large enough to potentially damage them...if they can pick out rpg's, why not a piece of space debris...

mind you, space debris is typically flying a LOT faster than an rpg...

Whipple Shields

[TTK Ciar]

qv: Whipple Shields

The idea behind whipple shields is that you put several thin barriers in front of a hypervelocity threat, and the shock waves induced inside the moving body (from rapidly loading and unloading it with compressive forces) tears it apart. What emerges from the other side of the whipple shield is a cloud of dust rather than a rock (or steel bolt, or whatever), and this cloud of dust is incapable of penetrating the side of your spacecraft.

The document linked above describes research which demonstrates that the strength and thickness of the individual barriers is much less important than the number of barriers, and the ratio of barrier thickness vs space between the barriers. Thus whipple shields can have extremely high mass efficiency against hypervelocity threats, equivalent to 0.6 of the same thickness of hardened steel. A foamed polystyrene solution (where the cell foam wall thicknesses are tuned to the correct ratio of foam cells' widths) could therefore provide the same level of protection as ~135 times its weight in hardened steel plate.

This technology is being actively developed for protecting battletanks from shaped charges (which generate explosively-formed penetrators moving at high hypervelocity speeds of 8,000m/s and more), but its relatively low thickness efficiency (0.6x, as opposed to ~3x-4x for some modern composite armor systems) limits its usefulness in this role, as battletanks have limited space to play with. Spacecraft are much less limited in this respect.

Other so-called "Active Defenses" developed for battletanks might also be applicable.

-- TTK

Re:Whipple Shields

[Guysmiley777]

Other so-called "Active Defenses" [ciar.org] developed for battletanks might also be applicable.

Maybe, but these objects are an order of magnitude faster than an RPG round. And they work by firing off a charge to intercept the incoming round. You think the debris problem is bad not? Try setting off a few of these in the ISS's orbit. "Cleanup in aisle 5"...

Re:That's part of what makes astronauts still cool

[sm62704]

That's their design for the shuttles successor.