Krugerrand
Meow
It might be simpler to code: "In case of fire, eject." And maybe a second line of code: "Prior to self-destruct, eject." Followed by: "Once ejected, follow landing procedures." :smile:
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It might be simpler to code: "In case of fire, eject." And maybe a second line of code: "Prior to self-destruct, eject." Followed by: "Once ejected, follow landing procedures." :smile:
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mknox
Well-Known Member
Actually, Apollo had a very robust series of abort modes. The Shuttle, after Challenger, proposed a number of abort procedures which included having the astronauts jump out with parachutes.
But yes, I think a Dragon 2 would have been okay in this scenario. The Dragon capsule used in these supply missions does not have the Draco abort/landing engines that the crewed version does.
Snowball's chance in hell they'd ever use that one. There was no plausible abort sequence short of waiting for the solids to burn out and then either abort to orbit or flip over and decelerate and land in Europe. Either way the shuttle had to be mostly working, not exploding.
Apollo was much better, but some of the scenarios after jettisoning the escape tower look hairy. They assume the problem occurred down where the engines are firing, not that the upper stage disintegrated... which is what happened here.
Yes it seems plausible that the abort would have worked successfully with a crewed dragon.
chickensevil
Active Member
Of course the crew dragon still makes the assumption that the problem isn't with dragon itself. So the aborts even with the dragon aren't fail proof entirely, which goes toward the shuttle breaking away and assuming that the problem isn't with the shuttle itself. That being said, I don't know how quickly/easily they could have jettisoned the boosters and the big fuel tank should there be a problem with just one of those two and not with the shuttle itself. Especially after the last accident which the wouldn't have noticed/called off in time to abort without them already making it out of the atmosphere (and therefore still going up in flame). The only fix in that type of situation is to launch a totally other ship and go collect them while they stay in orbit (assuming you can launch quick enough and meetup with them before something bad happened.
So in a worst-case scenario of "Problem with dragon", assuming the problem isn't catastrophic enough to cause it to blow up entirely or lose containment in orbit (thereby killing everyone as it implodes on itself)... then the only fix would be hoping the problem isn't big enough to prevent them from using it to abort and land quickly, or if already in space, they can stay up there until they can launch another ship.
At some point though, I think they are just going to have to determine if it is "safe enough" and from everything I can gather the crew dragon is being designed with as many redundancies and backups and various safeties as possible, more than any other ship in the history of space flight. In this instance, a crew dragon should have had plenty of time to push away from the exploding rocket and return to land (or parachute into the ocean).
So in a worst-case scenario of "Problem with dragon", assuming the problem isn't catastrophic enough to cause it to blow up entirely or lose containment in orbit (thereby killing everyone as it implodes on itself)... then the only fix would be hoping the problem isn't big enough to prevent them from using it to abort and land quickly, or if already in space, they can stay up there until they can launch another ship.
At some point though, I think they are just going to have to determine if it is "safe enough" and from everything I can gather the crew dragon is being designed with as many redundancies and backups and various safeties as possible, more than any other ship in the history of space flight. In this instance, a crew dragon should have had plenty of time to push away from the exploding rocket and return to land (or parachute into the ocean).
mknox
Well-Known Member
That was the big problem with the shuttle. The crewed compartment (i.e. the orbiter) was strapped to the side of the launch vehicle, not placed on top where it could (possibly) be pulled clear in an accident.
The Challenger shuttle didn't actually explode. When the SRB seal leaked, the resulting flame cut through the SRB to tank support bracket causing the SRB to rotate into the tank causing it to rupture. Lots of fire from the external tank exploding, but the orbiter (Challenger) broke free, but disintegrated when it hit the atmosphere sideways at supersonic speed. The still flying SRBs were destroyed remotely from the ground before they could possibly fly back over land. There really was not a good way to separate a winged vehicle that large, and going that fast, from the external tank and SRBs.
Another catastrophic shuttle failure scenario, which thankfully never happened, was if one SRB failed to start. Those things, once lit, have to burn themselves out. If only one lit, it would be a very bad pad accident.
chickensevil
Active Member
Which makes me shudder to think that whichever company it was that is part of the Orion project is planning on using SRB's... They are horribly expensive for fuel, and don't strike me as the safest option...
mknox
Well-Known Member
The difference there, however, is that the SRBs are strapped to the side of the SLS's first stage and the Orion capsule sits atop just like the old Apollo capsules. In a catastrophic failure scenario, the launch escape tower could, in theory, pop the Orion capsule off the top and fly it to safety. Not an option with a shuttle strapped to the side.
hockeythug
Active Member
Great article on the Return To Launch Site (RTLS) abort.
http://www.tested.com/science/space/460233-space-shuttles-controversial-launch-abort-plan/
Wow, sketchier than I imagined. I figured flipping the orbiter over would be the killer, but it's just one of the stunts involved.
swaltner
Active Member
Got a chuckle out of the following clip from @Midnight. Even with the bleeps, this is NSFW.
Live Challenge - Rocket to the Crypt - @midnight Video Clip | Comedy Central
Live Challenge - Rocket to the Crypt - @midnight Video Clip | Comedy Central
Smarter Every Day discusses the failure and puts it into context. I really liked this one.
SpaceX-PLOSIONS: Why It Matters - Smarter Every Day 138 - YouTube
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gg_got_a_tesla
Model S: VIN 65513, Model 3: VIN 1913
Thank goodness the Russian Progress has made it safely to space. The ISS's supplies are not in jeopardy, assuming docking will happen smoothly.
tinm
2020 Model S LR+ Owner
Indeed. I stayed up late to watch the Progress launch, biting my nails right up until the 3rd stage separation and solar panels deployed. Whew.
Buzz Aldrin giving his 2 cents on the F9 failure. He has a very positive view:
Buzz Aldrin: SpaceX Failure Shows We Need More Commercial Space Travel
"Indeed, back in 2012, when the first SpaceX cargo vehicle docked with the space station, that event signaled the first delivery of logistics supplies to the International Space Station by a U.S. commercial space company. That first occasion, and others that followed, remind us that where the entrepreneurial interests of the private sector are aligned with NASA’s up-top mission to explore space, it creates a bottom line: America wins."
Buzz Aldrin: SpaceX Failure Shows We Need More Commercial Space Travel
"Indeed, back in 2012, when the first SpaceX cargo vehicle docked with the space station, that event signaled the first delivery of logistics supplies to the International Space Station by a U.S. commercial space company. That first occasion, and others that followed, remind us that where the entrepreneurial interests of the private sector are aligned with NASA’s up-top mission to explore space, it creates a bottom line: America wins."
I think, unless I'm wrong that is a complete turn around from his former position. Unless I'm wrong!
