Author Topic: SpaceX Falcon 9/Dragon CRS-2 SpX-2 MISSION GENERAL DISCUSSION (Read 379859 times)

Antares · « **Reply #380 on:** 02/28/2013 10:48 pm »

Wouldn't the phasing change if the launch moves even a day? Then Dragon would need panels.

baldusi · « **Reply #381 on:** 03/01/2013 12:51 am »

Plus, NASA actually asked for more power for their payloads.

Chris Bergin · « **Reply #382 on:** 03/01/2013 05:16 am »

Launch day thread is now on. Locked as a placeholder until the updates start arriving:
http://forum.nasaspaceflight.com/index.php?topic=31239.0

Launch day article - a really massive and awesome article by William Graham - is now live:
http://www.nasaspaceflight.com/2013/03/spacex-milestone-falcon9-launch-dragon-crs2/

sdsds · « **Reply #383 on:** 03/01/2013 06:14 am »

There's clearly some sort of disturbance stretching northward from the panhandle. I presume that's not a concern. But below that there's visible something else.... Is that the cause of the 20% no-go chances for weather?

Galactic Penguin SST · « **Reply #384 on:** 03/01/2013 06:25 am »

Quote from: sdsds on 03/01/2013 06:14 am

There's clearly some sort of disturbance stretching northward from the panhandle. I presume that's not a concern. But below that there's visible something else.... Is that the cause of the 20% no-go chances for weather?

That small bunch of clouds to the south has been dissipating for the last few hours, so not a concern. The bank of clouds to the north has been moving from the west since yesterday, but doesn't seems to be moving southward at this moment.

Peter NASA · « **Reply #385 on:** 03/01/2013 12:10 pm »

Quote from: Chris Bergin on 03/01/2013 05:16 am

Launch day thread is now on. Locked as a placeholder until the updates start arriving:
http://forum.nasaspaceflight.com/index.php?topic=31239.0

Launch day article - a really massive and awesome article by William Graham - is now live:
http://www.nasaspaceflight.com/2013/03/spacex-milestone-falcon9-launch-dragon-crs2/

Superb article. Important to remember the downs as well as the ups.

yg1968 · « **Reply #386 on:** 03/01/2013 03:16 pm »

During, the launch, I noticed that the Falcon 9 was shaking a bit before MaxQ. Is that normal?

ugordan · « **Reply #387 on:** 03/01/2013 03:18 pm »

Quote from: yg1968 on 03/01/2013 03:16 pm

During, the launch, I noticed that the Falcon 9 was shaking a bit before MaxQ. Is that normal?

You mean the camera was shaking. Watch the very first launch again.

yg1968 · « **Reply #388 on:** 03/01/2013 03:24 pm »

Quote from: ugordan on 03/01/2013 03:18 pm

Quote from: yg1968 on 03/01/2013 03:16 pm
During, the launch, I noticed that the Falcon 9 was shaking a bit before MaxQ. Is that normal?

You mean the camera was shaking. Watch the very first launch again.

Thanks. I was thinking that it might be the camera. But I wasn't sure.

Star One · « **Reply #389 on:** 03/01/2013 03:54 pm »

Do all the thrusters have to be operational for it to be allowed to approach/dock with ISS?

corrodedNut · « **Reply #390 on:** 03/01/2013 03:54 pm »

Can the Draco "pods" share propellant?

cro-magnon gramps · « **Reply #391 on:** 03/01/2013 03:56 pm »

Could it be that the Computer Safety Parameters are too stringent and that is what is causing them to Inhibit?

Robotbeat · « **Reply #392 on:** 03/01/2013 03:56 pm »

Quote from: corrodedNut on 03/01/2013 03:54 pm

Can the Draco "pods" share propellant?

I'm pretty sure they can, but recent tweets have sown a tiny seed of doubt.

Ben the Space Brit · « **Reply #393 on:** 03/01/2013 03:59 pm »

There may be no 'thruster issue' to resolve; it depends on what the MCC-X guys find when they check the data being read back. It is quite possible that all they need to do is send SpX-CRS-2's computer a command that basically says: "Don't be silly - begin the thruster start-up sequence."

Remember, SpaceX have had problems before with their on-board automation being too zealous about safety margins. This might be a similar problem.

As far as I can tell, the problem is that three of the four RMS pods reported an anomaly and the auto-sequencer aborted to a passive drift mode. They've managed to manually power up a second RMS pod and order the solar array deploy. It is possible that the other two RMS pods have exactly the same problem and just need to be manually started.

If I'm right (and post-mission analysis will doubtless confirm it, if recovery is successful), then all they need to do is re-calibrate the auto-sequencer software so that the abort criteria are not so stringent.

Nomadd · « **Reply #394 on:** 03/01/2013 04:10 pm »

Some speculation that they're pressure sensor averaging, so a down sensor brings the average down. That could just mean locking out the defective sensor if the other looks normal. Maybe an extra test maneuver or two before entering the forbidden zone.

krytek · « **Reply #395 on:** 03/01/2013 04:12 pm »

SpaceX said problem is with a valve

Ben the Space Brit · « **Reply #396 on:** 03/01/2013 04:13 pm »

I have to say that I'm very impressed by SpaceX's performance. Despite the company's somewhat laid-back attitude, they were very professional when mitigating this fault. No panic, no fuss; they simply buckled down and carried out procedure.

As I understand it, SpX-CRS-2 is now operating at the minimum level it needs to start closing with the station. They are also in the process of trying to start up the remaining thruster packs. If recovery from the fault is successful, it will be a significant feather in their caps - when things go wrong, the system, their procedures and their personnel are all capable of recovering and still delivering a mission.

Let's just remember that this is only the fourth spacecraft SpaceX have flown in-house. If there weren't any faults with a system still this new, it would be a miracle.

Jason1701 · « **Reply #397 on:** 03/01/2013 04:14 pm »

Quote from: krytek on 03/01/2013 04:12 pm

SpaceX said problem is with a valve

That doesn't necessarily mean the valve is mechanically defective - there could be a sensor on the valve giving an erroneous reading.

Star One · « **Reply #398 on:** 03/01/2013 04:16 pm »

Quote from: Ben the Space Brit on 03/01/2013 04:13 pm

I have to say that I'm very impressed by SpaceX's performance. Despite the company's somewhat laid-back attitude, they were very professional when mitigating this fault. No panic, no fuss; they simply buckled down and carried out procedure.

As I understand it, SpX-CRS-2 is now operating at the minimum level it needs to start closing with the station. They are also in the process of trying to start up the remaining thruster packs. If recovery from the fault is successful, it will be a significant feather in their caps - when things go wrong, the system, their procedures and their personnel are all capable of recovering and still delivering a mission.

Let's just remember that this is only the fourth spacecraft SpaceX have flown in-house. If there weren't any faults with a system still this new, it would be a miracle.

They appear to have dealt with the issues with this flight & the previous one in a very professional & competent way.

Jim · « **Reply #399 on:** 03/01/2013 04:37 pm »

Quote from: Star One on 03/01/2013 04:16 pm

They appear to have dealt with the issues with this flight & the previous one in a very professional & competent way.

How would you know? We have no insight into what they are doing.