SpaceX Falcon 9/Dragon COTS Demo (C2+) GENERAL DISCUSSION

[sanman]

Can someone tell me why the solar panels on Dragon look white in those images? It doesn't appear to be caused by the lighting/angle.

Backside

Ah, didn't realize they were one sided. silly me.

Do they have to be one-sided? Can future versions maybe have both sides being photovoltaic, for more power? Or is that impractical?

[dasmoth]

Do they have to be one-sided? Can future versions maybe have both sides being photovoltaic, for more power? Or is that impractical?

One side is all you need if you keep it facing towards the sun.

Even if you can't point them perfectly, double-sided will only offer an advantage for a fraction of the time.  Not worth it.

[MP99]

1) Is it likely the mixture-adjustment hardware could compensate for a LOX-rich bias in an engine, at least to carry it through the first seconds of flight until the point where the Falcon can struggle on with eight engines? I'm guessing not, as I assume the actual adjustment range would be quite small.

2) Also, how does the stage determine the remaining prop levels - does it just integrate the flow levels? If so, would the flow be measured per-engine or before the octopus? If flow is measured per-engine, I guess that would be a useful indication to the engine controller of a problem.

1) Hard to say.  If there's closed-loop engine control, maybe.  Too many branches of the fault tree to say for sure.  Not sure it's even desirable to try and fly through it.  Abort may be the better choice.

2) Tank bottom pressure.  Flight computer solves for h in P_b = P_ull + rho*g*h.  There are patents on it that are available with a web search.

During launch we heard "stage one propellant utilization is active", and same for stage 2.

I presume that would be the start of monitoring in preparation for mixture adjustment?

cheers, Martin

Edit: lunch? Pchaw.

[Ronsmytheiii]

Silly question, does Dragon use Ku-band or only S-band?  Think it is the latter.

[Nahavandi]

[Ronsmytheiii]

Silly question, does Dragon use Ku-band or only S-band?  Think it is the latter.

and it is :

Dragon can also communicate on S-band via
either tracking and data relay system
(TDRSS)
or ground stations.

http://www.spacex.com/downloads/COTS-2-Press-Kit-5-14-12.pdf

[Norm38]

I didn't get to see it live, does anyone have a video link to the post launch press conference?  I found Bolden's comments, but can't find the full press conference.

Bolden's speech is here:  http://www.youtube.com/user/SpaceRefOnOrbit

[Rex Chan]

I didn't get to see it live, does anyone have a video link to the post launch press conference?  I found Bolden's comments, but can't find the full press conference.

Bolden's speech is here:  http://www.youtube.com/user/SpaceRefOnOrbit

[kirghizstan]

After mvac ignition there is seems o be a fluid coming from above the nozzle, is this just melting ice as it is a significant amount at first then tapers down to only occasional drops?

[Longhorn John]

Why are you not following the live thread Norm?? All these videos are already on there.

[corrodedNut]

After mvac ignition there is seems o be a fluid coming from above the nozzle, is this just melting ice as it is a significant amount at first then tapers down to only occasional drops?

The ice that has formed around the 2nd stage combo-umbilical disconnect melts and drains after staging. It's happened on the previous flights.

[Norm38]

I didn't see the press conference on the live thread, must have missed it, and didn't want to clutter it up with a question.  Airlock posted it there right after I asked here.

[Danderman]

This is a pleasant surprise, I didn't think that SpaceX would get this far this year.

[bad_astra]

Wish they'd launched Saturday morning while we were there, but it looked fantastic from what I saw last night on nasa tv (kept getting problems with the stream, and it was delayed a minute or so for some reason). Can't wait to see Cygnus get it's first flight too!

[Jim]

AirmanPika,
Nice pic - It looks like a more significant payload processing area extension than I thought.

The added height - perhaps they want to be able to do vertical payload processing, at least for the payload and fairing?

Just vertical encapsulated payload receiving and breakover.  Payload might still be processed at another facility.

[avollhar]

Seeing the SpaceX staff crowd cheering when the solar panels deployed was awesome! Politics aside, these young motivated people certainly deserve this mission to be successful.

[MP99]

AirmanPika,
Nice pic - It looks like a more significant payload processing area extension than I thought.

The added height - perhaps they want to be able to do vertical payload processing, at least for the payload and fairing?

Just vertical encapsulated payload receiving and breakover.  Payload might still be processed at another facility.

Is that the sort of service that Astrotech would provide?

cheers, Martin

[Lar]

I didn't get to see it live, does anyone have a video link to the post launch press conference?  I found Bolden's comments, but can't find the full press conference.

Bolden's speech is here:  http://www.youtube.com/user/SpaceRefOnOrbit

Anyone know where there's a transcript of Bolden's remarks? For speeches, sometimes just reading the transcript is faster and more efficient.

Thanks!

[Tnarg]

Is there any map or something where one can see where Dragon is right now?

Maybe this http://www.n2yo.com/?s=77777 ?

Dragon chasing ISS:-

http://www.n2yo.com/?s=25544|77777

cheers, Martin

link seems to of stopped working.  Heres a new one

http://www.n2yo.com/?s=25544|38348

[IRobot]

This is a pleasant surprise, I didn't think that SpaceX would get this far this year.

Did you really expect them to be on the launch pad for the next 7 months? Time to give them some credit!