NASA LDSD ("ballute")

[fredymac]

NASA keeps working on inflatable balloon decelerators for atmospheric re-entry. One day they may finally try using one for real.




https://www.youtube.com/watch?v=_iu-k-CtPj4

 

[sferrin]

Any idea why this thing keeps failing? We've been designing parachutes for supersonic deployment, under way more stressful conditions than this, since the 60s. (See supersonic, low altitude deployment of nuclear bombs.)

 

[TomS]

The LDSD chute is considerably larger and likely much lighter (at least on a weight per area basis) than the drag chutes on nuclear weapons. A B83's chute is 46 feet in diameter, the LDSD chute is 110 feet, for example.

 

[sferrin]

The LDSD chute is considerably larger and likely much lighter (at least on a weight per area basis) than the drag chutes on nuclear weapons. A B83's chute is 46 feet in diameter, the LDSD chute is 110 feet, for example.

Sure, but the principles are the same. Also, where the air is so much thinner the load per ft.^2 should be lower. Maybe it's not an exact science, and it took many attempts to get the B83's chute reliable as well. On the other hand, there's a picture in Chuck Hansen's nuke book of a B77 deploying it's chute at 1000mph at ground level IIRC, and I doubt they made many of those considering the bomb itself was cancelled. Oh well. Try again.

 

[Byeman]

Sure, but the principles are the same.

Not true. LDSD is larger and is going much faster and at lower densities.