Quote from: TGMetsFan98 on 01/22/2019 12:40 pmI feel like I’m missing something. How does having Dragon mated to F9 help certify F9’s fueling procedures? Unless it’s having the abort system fueled and armed?It shows confidence that the (human rated) booster won't blow up.
I feel like I’m missing something. How does having Dragon mated to F9 help certify F9’s fueling procedures? Unless it’s having the abort system fueled and armed?
Quote from: jpo234 on 01/22/2019 12:51 pmQuote from: TGMetsFan98 on 01/22/2019 12:40 pmI feel like I’m missing something. How does having Dragon mated to F9 help certify F9’s fueling procedures? Unless it’s having the abort system fueled and armed?It shows confidence that the (human rated) booster won't blow up.Is the NASA cargo for DM-1 packed in the Crew Dragon already? If not, then there is no customer payload on the vehicle, and so no point in demating for the static fire.
Quote from: envy887 on 01/22/2019 01:21 pmQuote from: jpo234 on 01/22/2019 12:51 pmQuote from: TGMetsFan98 on 01/22/2019 12:40 pmI feel like I’m missing something. How does having Dragon mated to F9 help certify F9’s fueling procedures? Unless it’s having the abort system fueled and armed?It shows confidence that the (human rated) booster won't blow up.Is the NASA cargo for DM-1 packed in the Crew Dragon already? If not, then there is no customer payload on the vehicle, and so no point in demating for the static fire.Except the risk of damaging Dragon itself...Obviously no one expects F9 to have an issue. But there’s a reason they’ve been conducting static fires without payloads mated. “Showing confidence” by firing with payload on board is no different for Dragon than any other payload.
afety requirements). ... there is an abort system to save the crew during a catastrophic failure. I'd be curious to know if they arm this system during a static fire to save the capsule.
It will be interesting to watch the access arm movements if any for the SF.
Quote from: mjcrsmith on 01/22/2019 04:46 pmIt will be interesting to watch the access arm movements if any for the SF. It would be seriously impressive to extend this static fire to include a full-up launch rehearsal. Board the astronauts, arm the Dragon abort, run the fuel loading and stop at T-zero (that is, after ignition). Then disembark the astronauts, recycle the countdown and run the full static fire - that's the only part of the process that would never have a crew present.There might well be technical reasons why this is difficult or impossible as simply stated, so take this as a concept to vary for as much experience gathering as possible.
(...nice description of various rehearsal levels...)Edit of Edit: I missed the part where you suggested putting crew on. This is an uncrewed launch, so not this time, but they could put dummies on to pretend to have a crew. And yes, it would make sense to have that part of the dress rehearsal too. Might actually be.
It would be seriously impressive to extend this static fire to include a full-up launch rehearsal. Board the astronauts, arm the Dragon abort, run the fuel loading and stop at T-zero (that is, after ignition). Then disembark the astronauts, recycle the countdown and run the full static fire - that's the only part of the process that would never have a crew present.
Not to mention that the pad egress system isn't functional as of today. (Or at least I still don't see the wires for the baskets installed in today's photos)
Worth noting something that a few people are forgetting about the discussion, RP-1 and LOX loading is the same for every Falcon 9 mission now however helium loading changes for crewed missions. The COPV's are loaded 2 hours before launch, then the crew will board inside the capsule and then at T-35minutes the normal propellant loading sequence will begin
Quote from: Alexphysics on 01/22/2019 06:45 pmWorth noting something that a few people are forgetting about the discussion, RP-1 and LOX loading is the same for every Falcon 9 mission now however helium loading changes for crewed missions. The COPV's are loaded 2 hours before launch, then the crew will board inside the capsule and then at T-35minutes the normal propellant loading sequence will beginThat does not seem possible.The He COPV's are inside the LOX tank so that they can load more He as it gets to cryogenic temperatures. They can only put in a fraction of the flight He load at ambient temperature.We can assume that SpaceX will bring the He COPVs to full pressure before the astronauts board.Then, as the LOX is loaded, the He pressure will drop, and they will continue to add He to maintain the flight pressure.That should avoid the stretching that contributed to the AMOS-6 static fire failure.
Quote from: Joffan on 01/22/2019 05:03 pmIt would be seriously impressive to extend this static fire to include a full-up launch rehearsal. Board the astronauts, arm the Dragon abort, run the fuel loading and stop at T-zero (that is, after ignition). Then disembark the astronauts, recycle the countdown and run the full static fire - that's the only part of the process that would never have a crew present.There might well be technical reasons why this is difficult or impossible as simply stated, so take this as a concept to vary for as much experience gathering as possible.Did you mean before ignition?Your proposal seems to combine the worst aspects of load-and-go and early-fueling.* Crew onboard during fueling, though protected to some degree by an armed capsule abort system.* Abort system then disarmed allowing support personnel to arrive, disembark crew, and clear pad, working next to a fully fueled vehicle.* A long pause to allow sub-cooled propellants time to warm up.
It would be seriously impressive to extend this static fire to include a full-up launch rehearsal. Board the astronauts, arm the Dragon abort, run the fuel loading and stop at T-zero (that is, after ignition). Then disembark the astronauts, recycle the countdown and run the full static fire - that's the only part of the process that would never have a crew present.There might well be technical reasons why this is difficult or impossible as simply stated, so take this as a concept to vary for as much experience gathering as possible.
No, T-zero is after ignition, which occurs 2-3 seconds earlier. We have seen countdown aborts after ignition before. ...