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NASA Supports SpaceX Plan To Fuel Rockets With Astronauts On Board (engadget.com)
For years, NASA has been debating whether to allow SpaceX to fuel its spacecraft with super-cold propellant after astronauts have boarded. While the company typically fuels its rockets shortly before launch in order to prevent the coolant from warming up too much, the practice has been deemed "a potential safety risk" by NASA safety advisers due to the high risk of an explosion. Now, according to Engadget, NASA has "decided that it will move forward with the SpaceX plan to fuel rockets after astronauts have already boarded." From the report:
"To make this decision, our teams conducted an extensive review of the SpaceX ground operations, launch vehicle design, escape systems and operational history," Kathy Lueders, manager of NASA's Commercial Crew Program, said in a statement. "Safety for our personnel was the driver for this analysis, and the team's assessment was that this plan presents the least risk." SpaceX will have to prove its system is safe, however. The company will have to demonstrate the fueling procedure five times prior to its first crewed flight and afterwards, NASA will assess any remaining risk before certifying SpaceX's system. In September 2016, a Falcon 9 rocket exploded on the launchpad while it was being loaded with propellant. No injuries were reported, but it didn't look good to NASA which was already reviewing the fueling procedure.
Is it safer to do a whole lot of manipulation (as required with the boarding procedure, climbing the launch tower, sealing the hatch etc) around a rocket that is already filled with potentially explosive material, and might blow up at any point consuming in a ball of fire anything within the area that can't get away fast enough?
Or would it be safer to enter the capsule while the rocket is just an inert tube, buckle up, and wait till the rocket is filled up, sitting comfortably in a hermetic capsule equipped with a launch escape system - capable of getting away from the explosion fast enough to be safe?
Paradoxically, before the launch, the crew compartment is the safest of all places near the rocket.
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The 2016 explosion didn't rip the fairing apart. There's the entire service module (trunk) as a buffer between the launcher and the capsule. The engines are on the sloped sides, not beneath the capsule. And in the end, after analyzing the incident, Musk announced "Dragon would have been fine"
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out of there with extreme rapidity with a twist of the wrist
And it doesn't even take that much. There is an automatic process which can trigger the LES upon loss of connectivity through a wire that runs the length of the rocket. The moment that wire is broken, the LES can fire, and this can react faster than any human could.