SpaceX COTS Demo 1 Updates

[Lars_J]

One crucial thing that has not been mentioned in this discussion is whether Dragon has enough consumables on board to do the fly-around check outs that ATV and HTV did on their first flights.  It could be impossible to combine the remaining Demo missions due to that limitation.

What consumables are you referring to? The next mission will have solar arrays (plus batteries), so power will not be an issue.

Fuel is the only thing that springs to mind, but the craft is designed for many months of operation. (supposedly free-flight capable of up to two years in the case of DragonLab, even if that may require future enhancements) But the tanks should be good for several months at minimum, I would imagine.

As far as the amount of fuel, Robotbeat calculated in another thread that Dragon has 700+ m/s of Delta-V (more than twice of the Shuttle OMS?) , which should be plenty for a shake-out period before an ISS docking.

The only consumable issue that kept this Dragon flight so short was battery power.

EDIT: Oops, I guess several other people beat me to the response.

[Jim]

Still not convinced this is a process issue either way.

The fact that it was was process issue has nothing to do with you being convinced.

[corrodedNut]

Never mind the fire, look at this image: http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=49739

No wonder why the left arm of the strongback was invisible in pad footage after liftoff. Looks like they have some beefing up to do.

I skimmed the thread again and didn't see this video (in regards to the T/E damage) mentioned, you can clearly see it starting at about :36 sec into the video:



Full-screen is better

[Robotbeat]

Never mind the fire, look at this image: http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=49739

No wonder why the left arm of the strongback was invisible in pad footage after liftoff. Looks like they have some beefing up to do.

I skimmed the thread again and didn't see this video (in regards to the T/E damage) mentioned, you can clearly see it starting at about :36 sec into the video:
...

Woah, you're right! That is pretty crazy.

[Namechange User]

One crucial thing that has not been mentioned in this discussion is whether Dragon has enough consumables on board to do the fly-around check outs that ATV and HTV did on their first flights.  It could be impossible to combine the remaining Demo missions due to that limitation.

What consumables are you referring to? The next mission will have solar arrays (plus batteries), so power will not be an issue.

Fuel is the only thing that springs to mind, but the craft is designed for many months of operation. (supposedly free-flight capable of up to two years in the case of DragonLab, even if that may require future enhancements) But the tanks should be good for several months at minimum, I would imagine.

As far as the amount of fuel, Robotbeat calculated in another thread that Dragon has 700+ m/s of Delta-V (more than twice of the Shuttle OMS?) , which should be plenty for a shake-out period before an ISS docking.

The only consumable issue that kept this Dragon flight so short was battery power.

EDIT: Oops, I guess several other people beat me to the response.

I'm really not seeing how what is presumably the total delta-v that the ship could provide in one "punch" is the relative metric in this case.

It really boils down to the size of the prop tanks and the flowrates of the engines versus the number of firings (and time) - by however many thrusters necessary - required to approach, rendezvous, station-keep with ISS, station-keep with ISS again when leaving, fly-around, sep-burn, any pre-deorbit maneuvers and the deorbit burn itself. 

I think you would find for a free-flight the attitude hold burns would be rather limited, especially if it can be "parked" in a semi-stable attitude. 

[Lars_J]

OV-106, I was just using the Delta-V as an illustration of the total amount of fuel available to the Draco's. (to illustrate that it should have plenty for a COTS2/3 combined mission with a shake-down) I did not mean to imply anything about "punch" or total thrust.

I agree that once you reach an orbit close to ISS, you should have to expend very little of that fuel (delta-V) to perform your station keeping tests.

[MP99]

SpaceX traced the root cause of the cracks, located in the aft end of the nozzle, to a GN2 vent line that “caused flutter of the thinnest portion of the nozzle extension, creating the cracks,” the company said in a statement.

If the nozzle is fragile enough to be damaged by a GN2 vent line, is it likely that it would also have failed under operation? I presume the stresses are substantial, even at the open end of the nozzle.

cheers, Martin

No, the stresses at the end of the nozzle are trivial. That's why the extention is so thin at the end. The crack was caused by GN2 impingement that caused "flutter", a local oscillation that was forceful enough to cause metal fatigue/cracking. SpaceX stated that the flight stresses were so low in that area of the nozzle that the cracks probably wouldn't even have caused a failure if they hadn't been caught.

One other issue I'm confused about.

I'd assumed that the closeout (and associated photography) happened in the hangar. But I would also assume that GN2 vent wouldn't be  active until Falcon is vertical on the pad.

One of those two assumptions would seem to be wrong - any thoughts on which one?

Thanks, Martin

[Kabloona]

One other issue I'm confused about.

I'd assumed that the closeout (and associated photography) happened in the hangar. But I would also assume that GN2 vent wouldn't be  active until Falcon is vertical on the pad.

One of those two assumptions would seem to be wrong - any thoughts on which one?

Thanks, Martin

I don't have any special insight into how that whole sequence went. Perhaps someone else does.

[tigerade]

Here are some awesome photos from the mission.  I'm not sure if this has been posted yet or not:

http://www.spaceflightnow.com/falcon9/002/remotes/

[Robotbeat]

Here are some awesome photos from the mission.  I'm not sure if this has been posted yet or not:

http://www.spaceflightnow.com/falcon9/002/remotes/

Yes, they have. In fact, Chris Bergin kindly gave us a link to the full-resolution photos that SpaceX released to the media:
https://send.spacex.com/bds/Login.do?id=A043517252&p1=naj20dpsbfegcidgdlgffcj20

[jabe]

This gives new meaning to the book "Who Moved my Cheese?"

I think you may be right...it seems more in line what Elon wanted to say.. (even though i like the monty python idea better )
for those who aren't familiar check here..
http://en.wikipedia.org/wiki/Who_Moved_My_Cheese

Elon wants more "Sniff and Scurry" people around!! Too many Hem and Haw's making all the noise...
jb

[cuddihy]

Still not convinced this is a process issue either way.

The fact that it was was process issue has nothing to do with you being convinced.

Sigh, I hated it when people who don't know what they are talking about continue to post.

Hey, this would be a pretty lonely forum if you had to have a KSC badge to post.

And by the way your inside access does't make you infallible either. IIRC you blamed it on a process issue without knowing what the problem was to begin with, "they built bad hardware, and put it on the vehicle," or words to that effect.

I work for the DoD, right now in IT rather than space (though I'm a space specialty and I've been a nuke in my early career.)

I've seen and participated in the full gamut of QA processes.

There are times when a problem really is processes. But I have also about had my fill of government management types who dont know how to finish anything but went to a CPI training for two weeks and thereafter think every problem is a process problem. (let me emphasize I'm not saying that's you) but I have wasted countless hours in critiques and RCAs where the cause of the problem was immediately obvious but nevertheless there we all were. I have seen  "lack of sufficient processes" used to excuse unqualified people performing incompetently, etc, just because it's too much of a pain to address the real issue.

I'm no SpaceX Koolade drinker, I've noticed their BS schedule projections, I'm skeptical about the viability of their pricing scheme, and Musk strikes me as a brilliant technical manager who's even better (or maybe just shameless) at over-selling his company's prospects. (the perfect entrepreneur for the age of Obama).

The point stands. Processes are not the cause of all failures, even if the correct process could have possibly prevented a particular failure does not mean it is the right thing to do.

[Comga]

Here are some awesome photos from the mission.  I'm not sure if this has been posted yet or not:

http://www.spaceflightnow.com/falcon9/002/remotes/

Yes, they have. In fact, Chris Bergin kindly gave us a link to the full-resolution photos that SpaceX released to the media:
https://send.spacex.com/bds/Login.do?id=A043517252&p1=naj20dpsbfegcidgdlgffcj20

So what is streaming off of or out of the second stage in Chris' photo 20101208_F9-002__1_Credit-Chris-Thompson_F01G0479_LG.jpg?  This is taken just as the fuel from the torn-away umbilical ignites.   Could it be more leaking fuel or is that a harmless condensation trail?  There is an even bigger white plume coming off of the first stage.  That is not igniting, despite being in contact with the flaming rocket exhaust, so I would think it must be condensation.

[ugordan]

Could it be more leaking fuel or is that a harmless condensation trail?  There is an even bigger white plume coming off of the first stage.  That is not igniting, despite being in contact with the flaming rocket exhaust, so I would think it must be condensation.

Ice and condensed vapor.

[Jim]

And by the way your inside access does't make you infallible either. IIRC you blamed it on a process issue without knowing what the problem was to begin with, "they built bad hardware, and put it on the vehicle," or words to that effect.

Because it has been evident in many other places wrt Spacex

[corrodedNut]

SFN article: http://www.spaceflightnow.com/falcon9/002/101209reaction/

"...the spacecraft landed right on target in the Pacific Ocean. SpaceX teams arrived at the floating capsule a few minutes later. Officials planned to load the craft on a barge steaming for California, then the company will transport the Dragon to a Texas test facility for post-flight inspections."

[Antares]

I'd assumed that the closeout (and associated photography) happened in the hangar. But I would also assume that GN2 vent wouldn't be  active until Falcon is vertical on the pad.

One of those two assumptions would seem to be wrong - any thoughts on which one?

This is a good spot to correct myself because I had made the same assumption about "closeout" photos, which I now think is the wrong term.  I'd blamed it on just-in-time inspection of closeout photos of a nozzle weld; but now that we've seen them, I think it was a routine inspection of the hardware after the weekend tests.  Then, they only took targeted photos of the obviously suspect nozzle condition - primarily to send back to folks in Hawthorne who weren't making the trip.  Something got lost in translation between the operators and the people writing the press releases.

[Kabloona]

I'd assumed that the closeout (and associated photography) happened in the hangar. But I would also assume that GN2 vent wouldn't be  active until Falcon is vertical on the pad.

One of those two assumptions would seem to be wrong - any thoughts on which one?

This is a good spot to correct myself because I had made the same assumption about "closeout" photos, which I now think is the wrong term.  I'd blamed it on just-in-time inspection of closeout photos of a nozzle weld; but now that we've seen them, I think it was a routine inspection of the hardware after the weekend tests.  Then, they only took targeted photos of the obviously suspect nozzle condition - primarily to send back to folks in Hawthorne who weren't making the trip.  Something got lost in translation between the operators and the people writing the press releases.

That makes more sense. As we saw later, the cracks were so conspicuous that they must have been seen right away upon inspection with a naked eyeball.

Maybe a more accurate press release would have said "A visual  inspection after the static fire and before final closeout of the interstage revealed cracks in the nozzle extension. The affected areas were photographed for further assessment by engineers in Hawthorne."

[docmordrid]

On another tack....what the Army sat on COTS-1 is up to -

SMDC-ONE  (Space and Missile Defense Command - Operational Nanosatellite Effect)


SatNews....

>
"The launch and deployment of the first SMDC-ONE nanosatellites is intended to demonstrate the concept of sending and receiving data from unattended ground sensors using small, low-cost, low earth orbit satellites," said Lt. Gen. Kevin T. Campbell, commanding general, Army Space and Missile Defense Command.
>
The ultimate goal is to have satellites that cost around $300,000 each and are either secondary payloads aboard other rockets — as in Wednesday's SpaceX launch —- or that could be put in orbit virtually on demand by a new class of smaller boosters....
>

[beancounter]

And by the way your inside access does't make you infallible either. IIRC you blamed it on a process issue without knowing what the problem was to begin with, "they built bad hardware, and put it on the vehicle," or words to that effect.

Because it has been evident in many other places wrt Spacex

It wasn't the first time that's happened and it won't be the last so to single out SpaceX isn't exactly fair.  I think that they're entitled to do this their way.  It's their money plus NASA's and NASA seems ok with the way they're going at this point anyway.