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The first failure was a secondary payload. The Falcon 9 had less spare fuel than expected because one of the first stage engines failed.[1] The primary (NASA) m
by ggreer 11y ago
The first failure was a secondary payload. The Falcon 9 had less spare fuel than expected because one of the first stage engines failed.[1] The primary (NASA) mission went fine. The secondary mission had a 95% chance of success, but NASA vetoed it.
The second failure was a second stage exploding. Had the payload been a crewed Dragon V2, those inside would have survived. Even without a launch escape system, the Dragon V1 was fine[2]:
> The Dragon CRS-7 capsule was ejected from the exploding launch vehicle and continued transmitting data until impact with the ocean. SpaceX officials stated that it could have been recovered if the parachutes deployed, however the software in the capsule did not include any provisions for parachute deployment in this situation.
Overall, it's a much safer design than the Shuttle. The crew vehicle is on top of the stack instead of along side it. If anything goes wrong, the capsule can GTFO and land with parachutes.
1. https://en.wikipedia.org/wiki/SpaceX_CRS-1 https://en.wikipedia.org/wiki/SpaceX_CRS-1
2. https://en.wikipedia.org/wiki/SpaceX_CRS-7 https://en.wikipedia.org/wiki/SpaceX_CRS-7
- ForHackernews 11y ago> however the software in the capsule did not include any provisions for parachute deployment in this situation. That seems like a pretty significant oversight?
- arcticfox 11y agoNot necessarily, if there was no reason to recover it (I'm not sure if there was a reason or not)
- ggreer 11y agoIt wasn't an oversight. It was intentional. The Dragon v1 is designed solely for cargo. It has no launch escape system and its software does nothing while it's going up[1]: > The software in this cargo version of Dragon (Dragon 1), Musk explained, is inert on ascent and was not programmed to release the parachute in the event of a failure. Software in the version of Dragon under development for taking people into space (Dragon 2 or Crew Dragon) is programmed to do just that. While it sounds like simple thing, remote control of the 'chutes would add significant complexity and cost. 1. http://www.spacepolicyonline.com/news/failed-strut-likely-cause-of-falcon-9-failure-but-investigation-continues http://www.spacepolicyonline.com/news/failed-strut-likely-ca...
- erikpukinskis 11y agoAlso, you generally want as many systems "off" as you can manage during the flight. There's just less that can go wrong if there is less going on.
- oconnor663 11y agoAnd remember to set your SCE to aux.
- eblume 11y agoI know what that is!!!!
- joering2 11y agoThat was actually a very interesting read. http://motherboard.vice.com/read/john-aaron-apollo-12-curiosity-luck-and-sce-to-aux http://motherboard.vice.com/read/john-aaron-apollo-12-curios...
- DrScump 11y ago"But Bean, who was sitting in the right seat, just in front of the switch, remembered it from the sim the previous year." I guess we can forgive Bean for frying the color TV camera, then.
- Retric 11y agoWater landings only work if you design for them which is a lot of extra weight. Catching the thing in the air is difficult because you get very little warning and they can land in a huge area. Net result, failed launches are not really worth trying to recover unless it's people. Though, deploying parachutes may have marginally reduced the risks to a passing boat.
- lutorm 11y agoDragon already lands on water, so there's no technical reason it couldn't do it after a launch vehicle failure, if the event was survivable. Now we know that such a scenario exists, but that was not obvious before.
- Retric 11y agoMy understanding is Dragon 1 does not float fully loaded. It can get 3,10 kg ISS used and dispose of 3,10 kg of waste, but only to recover ~2,500 kg. https://en.m.wikipedia.org/wiki/Dragon_(spacecraft) https://en.m.wikipedia.org/wiki/Dragon_(spacecraft)
- robryk 11y ago> Though, deploying parachutes may have marginally reduced the risks to a passing boat. Didn't it fall in the range safety exclusion zone, which ships were warned away from?
- hoorayimhelping 11y agoIt wasn't an oversight - they launched the mission with the understanding that their parachute software wasn't ready and the risk was acceptable since it was uncrewed. I seem to remember reading that their parachute hardware was ready to go if absolutely necessary, but they wanted to make sure the software was locked down.
- JshWright 11y agoNo one expected Dragon to survive those conditions, so they never bothered adding that code. It's just a cargo ship, so it doesn't really matter. After having learned in real world conditions that it can handle those sorts they figured, what the heck... might as well add it. The crewed Dragon (Dragon 2) uses powered thrusters to push itself away from a failing rocket.
- tomaskafka 11y agoMove fast and crash things!