SpaceX Falcon 9 / Dragon 2 : SpX-DM1 : March 2, 2019 : DISCUSSION

[Roy_H]

So, would a static fire require that the strongback + crew accessway be pulled back from the stack before the fire?

The purpose of the static fire is to simulate all steps in a real launch. I think it would be a major error if they fail to retract the crew arm.

[butters]

So, would a static fire require that the strongback + crew accessway be pulled back from the stack before the fire?

The purpose of the static fire is to simulate all steps in a real launch. I think it would be a major error if they fail to retract the crew arm.

With load-and-go, wouldn't we expect the crew access arm to be retracted, and the SuperDraco abort system activated, before tanking begins at T-35m? Pad abort is definitely a no-go with the access arm extended.

[Joffan]

So, would a static fire require that the strongback + crew accessway be pulled back from the stack before the fire?

The purpose of the static fire is to simulate all steps in a real launch. I think it would be a major error if they fail to retract the crew arm.

With load-and-go, wouldn't we expect the crew access arm to be retracted, and the SuperDraco abort system activated, before tanking begins at T-35m? Pad abort is definitely a no-go with the access arm extended.

Pad abort is probably a "go" any time the system is activated. The reason to retract either the TE or the access arm earlier than normal would be to avoid the damage to those items that an abort might inflict. I 'd see the access arm as being far more vulnerable; the Dragon is above most of the TE.

So yes, I too would expect the access arm to be moved a little out of the way once the abort is armed. But perhaps not a full retraction until late in the count; an interesting point to watch.

[ejb749]

IF they are on a normal timeline, LOX load should be starting now.

[Comga]

Separate question:
From memory, for all recent Falcon launches, the strongback is retracted at T-4:00.

For Crew Dragon, including DM-1, will the strongback be retracted before fueling, at T-35:00 so that the capsule has a clear escape path?
Particularly if the umbilical retractors are designed to work from the retracted position, it seems logical that it be retracted any time the LAS is primed to pull the capsule away from a dangerous situation.
"Dangerous situations" includes failures during fueling.

Responding to my own question, it just passed T-35:00 for a 1600 local static fire time.
Fueling should have started if they are still on that schedule.
The CAA is retracted but the strongback has not yet leaned back.

edit:

LOX loading has started

It is not clear how jjyach knows this.
The strongback is still not retracted at 3:30 local (T-30:00 for 4:00 SF)

[ejb749]

With all of that wind, venting might not be too obvious until later in the count then normal.

[HelixSpiral]

Looks like there's frost forming on the first stage, so I'd say loading has started yes.

[ejb749]

Again, IF normal timing, Second stage LOX loading should be starting now.

[ejb749]

Venting!

[Craftyatom]

Heck of a lot of venting from the TE.

[Comga]

Venting!

So SpaceX did NOT retract the strongback before LOX loading.
Interesting

[ejb749]

Venting stopped.  1st stage LOX load in Pre-topping.

[ejb749]

2nd stage venting visible.

[ejb749]

Main engine chill down should have started.

[ejb749]

Strongback should start to retract soon.

[Lars-J]

Strongback is retracting

[ejb749]

Let's light this candle.

[ejb749]

Ignition!

[Craftyatom]

4:00pm Eastern on the dot!

[Comga]

Strongback should start to retract soon.

Nope!

It looks like they did the static fire without retracting the strongback