SpaceX Pad Abort Test
Why Hacker News recommends it
HN commenters cite it as evidence that Dragon's built-in launch escape system works and that a failed launch need not kill the crew.
What it is
A short SpaceX video of the Dragon 2 pad abort test, in which the capsule's thrusters fire to carry it away from the launch pad. It also shows the pad deluge system.
Recommended by 0 HN commenters across 0 different months, 2015 to 2018.
What Hacker News said
Cites toomuchtodo · 2015-11 · on “NASA Orders SpaceX Crew Mission to International Space Station”
I'm assuming NASA is pretty confident in SpaceX's SuperDraco thrusters after the unmanned pad abort test [1]. With regards to the second comment, I can find out if you're interested. [1] [this video]
Cites ansible · 2016-01 · on “SpaceX successfully tests parachute for bringing astronauts back [video]”
They also need the parachutes because if there is an emergency during launch, the thrusters will be used to separate the capsule from the launch vehicle. They demonstrated this with their pad abort test: [this video] Perhaps later this year we will also see an in-flight abort test, which will be very exciting.
Cites mikeyouse · 2016-05 · on “SpaceX lands rocket at sea second time after satellite launch”
Since they don't have to deal with the insulation issues like the shuttle did, the most dangerous phase of flight for a crew is during launch. Last Spring, SpaceX demo'ed their launch abort system which in theory should be able to protect the astronauts against any launch problems; [this video]
Cites rory096 · 2016-09 · on “A SpaceX Falcon 9 rocket has exploded at Cape Canaveral”
Actually they specifically plan to load astronauts before fueling begins. If they're in the capsule the launch escape system (LES)[1] can propel them away from any on-pad disaster; not so if they're still walking across the gantry. That said, NASA has raised concerns about loading crew pre-fueling as part of the NASA-SpaceX Commercial Crew development contract (CCDev). [1] Here's a video of the LES test for Dragon 2: [this video]
Cites rst · 2016-09 · on “A SpaceX Falcon 9 rocket has exploded at Cape Canaveral”
The point of those systems was to limit damage from vibration and rocket exhaust on a normal launch, not to allow the pad to withstand an explosion. (And SpaceX does have them as well; the pad deluge system is more visible than usual in this video of the Dragon pad-abort test, which was conducted at the same launch pad they use for Falcon 9s, though without the rocket itself or any of its mobile support equipment: [this video] -- the large streams of water kick in a few seconds before the Dragon abort thrusters kick off.)
Cites GenerocUsername · 2016-09 · on “SpaceX is using Boeing's 1920s strategy to get to Mars”
A failed launch does not necessarily imply death. [this video] However, your point stands. Space travel will never catch on if it combines "Extreme Sport" mortality rates with C-level costs.
Cites rwh86 · 2018-05 · on “NASA advisers say SpaceX rocket technology could put lives at risk”
I think the more relevant videos are: Pad abort test: [this video] Pad abort test (POV): [LINK] Stream of the same test: [LINK]
Cites ceejayoz · 2018-10 · on “Astronauts escape malfunctioning Soyuz rocket”
SpaceX's crewed Dragon is the escape system. It's built into the capsule, and has been successfully tested. [this video] The BFR, to my knowledge, lacks one. Not sure if Musk has commented on that; I'd imagine his likely argument is that airliners don't either.