SpaceX breaks capsule 'chute world record A couple of days ago, SpaceX successfully tested its Crew Dragon capsule parachute system, as it advances towards manned vehicle certification as part of NASA's Commercial Crew Program. The Crew Dragon 'chute drop over Arizona was a quiet affair compared to the recent test of the next-generation fire-breathing Dragon 2, …
It is - different redundancy models.
Soyuz has a full parachute backup for its one and only. Apollo could land (albeit quite bumpy) after losing a chute. 4 chutes look like adding an extra redundancy +1 to the existing 3 on the unmanned one to get the required reliability for man-rated landing.
The NASA Blog talks of "The mass simulator and parachutes were released thousands of feet above the ground from a C-130 cargo aircraft. "
By 'mass simulator', do they just mean a big weight, or have they some sort of Einstein-worrying technology? If the latter, what the hell are they doing messing around with rockets?!
- https://blogs.nasa.gov/commercialcrew/2016/01/27/spacex-tests-crew-dragon-parachutes/
"until space agencies finally retire the tech"
Somehow I wouldn't want to sign the order for 'No, we don't need backup 'chutes any more, our retros are 100% reliable."
Personally, I can't see 'chute retirement in the foreseeable future ... just imagine the Congressional hearing if there was an incident and a private company exec said 'we excluded backup parachutes to save some money and weight." End of contract, end of company.
That's easy. If the chute failure happens above Congress, and then the rockets turn out to work after all, once it gets to about 50 feet say, then you've solved the Congressional enquiry problem at a stroke.
I'm torn between the flames and black helicopter icons here. If I never post again, I picked the wrong one...
"Somehow I wouldn't want to sign the order for 'No, we don't need backup 'chutes any more, our retros are 100% reliable."
To be fair, they're not claiming 100% reliability. Which is why Dragon 2 has 8 motors in pairs - a main and a spare at every point.
Of course there's no point taking parachutes to Mars (that being their end-game) because at 0.0006 atmospheres they won't save you if the rockets fail, so the rockets need to be a man-rateable level of safe and reliable.
> Somehow I wouldn't want to sign the order for 'No, we don't need backup 'chutes any more, our retros are 100% reliable."
You won't need to. Chutes are part of the design as last-ditch backups (retros are used for manouvering, so if they don't work you have enough warning to deploy chutes) and for launch escape use (retros used as an escape rocket until fuel-out, capsule comes down under chutes)
The voice over said the chutes deployed "just as they would" on a real mission (or somesuch).
That implies that the capsule is somehow going to slow to an airspeed comparable to a C-130 before deploying the chutes. That's around 300kts. That's _slow_. How is that phase (slowing from reentry speed to 300kts) going to happen?
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