Author Topic: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION  (Read 625033 times)

Offline Antares

  • ABO^2
  • Senior Member
  • *****
  • Posts: 5181
  • Done arguing with amateurs
  • Liked: 371
  • Likes Given: 225
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #560 on: 10/08/2012 03:36 pm »
If you don't like armchair engineering, you should get off the internet.

The problem with a vehicle being reliable enough is that customers see videos like this and freak out, even if it's an emotional response.  Most satellite customers are not that embracing of risk.

I'll hazard a guess that launch video will prove significant in diagnosing what happened. Yet, if I am not mistaken, launch video was not a Go/No Go requirement for launch.  After they institute a fix(es) before next flight, will they also have to insist that launch video systems- and sufficiently clear weather - also be launch constraints for flight?

No.  That's what telemetry is for.  Engine parameters are more than sufficient for diagnosing problems.  Shuttle, with its heat shield in the wrong place for ascent, needed video and radar because there was not telemetry that could tell if foam was separating.

The fact that this happened after acceptance tests and a static fire with no pre-warnings of a fault would raise issues about the engine's overall reliability.

I don't think anyone outside of SpaceX and customers watching data last night know if there were leading indicators of the event.

I really think the agora needs to recalibrate what normalization of deviance means with SpaceX.  SpaceX will not take months or years to stand down like NASA would.  SpaceX will evaluate the risks, Pareto the causes, control the most likely ones and move on.  SpaceX will not correct the things that it finds to be low likelihood, unlike NASA.  It's a difference in culture that customers need to be aware of.

If SpaceX does not intend this to be the perception, then its actions need to better match its rhetoric.
If I like something on NSF, it's probably because I know it to be accurate.  Every once in a while, it's just something I agree with.  Facts generally receive the former.

Offline brettreds2k

  • Full Member
  • ****
  • Posts: 736
  • Charlotte, NC
  • Liked: 16
  • Likes Given: 41
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #561 on: 10/08/2012 03:37 pm »
You have to wonder the condition of this flight due to no information has been given since launch on the status it seems, No confirmation of the health of the craft this morning or if the doors opened as planned, etc.
Brett
www.facebook.com/brett.lowenthal1

Orbiters I have visited in retirement:

[ ] Enterprise
[X] Discovery
[X] Atlantis
[ ] Endeavour

Offline Lars_J

  • Senior Member
  • *****
  • Posts: 6160
  • California
  • Liked: 675
  • Likes Given: 195
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #562 on: 10/08/2012 03:43 pm »
*If* this was a RUD event for engine 1 - Would this be the first time a LV has survived an "engine RUD" and still delivered the payload successfully?

I'm wondering about that too.  Did we witness an historic first tonight?

No, there is nothing historic about it.

Can you give us examples of this happening before, then? Not engine shutdowns, but engine 'RUD's that did not cause LOV/LOM.

Offline mrmandias

  • Full Member
  • ****
  • Posts: 504
  • US
  • Liked: 30
  • Likes Given: 34
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #563 on: 10/08/2012 03:43 pm »
I'm sure SpaceX will take the problem extremely seriously and get a fix that will be acceptable to customers.  How long it will take depends on how long it will take.

But as a distinterested bystander, I was really impressed that their rocket survived and thrived.  Luck?  No, good engineering.

Offline brettreds2k

  • Full Member
  • ****
  • Posts: 736
  • Charlotte, NC
  • Liked: 16
  • Likes Given: 41
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #564 on: 10/08/2012 03:45 pm »
Id agree, they designed the vehicle to survive a break down of 1 engine it seems, they promised this when it was in testing. Great job to them, just wish they would give some updates on the mission
Brett
www.facebook.com/brett.lowenthal1

Orbiters I have visited in retirement:

[ ] Enterprise
[X] Discovery
[X] Atlantis
[ ] Endeavour

Offline corrodedNut

  • Full Member
  • ****
  • Posts: 1542
  • Liked: 216
  • Likes Given: 133
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #565 on: 10/08/2012 03:48 pm »
Every Falcon 9 launch to date has had anomalies. Remember the liftoff roll? The 2nd stage roll? The fireball? The fuel-rich shutdown? All of these problems got "fixed".  This one will get fixed too.

Online ugordan

  • Senior Member
  • *****
  • Posts: 8336
    • My mainly Cassini image gallery
  • Liked: 3151
  • Likes Given: 695
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #566 on: 10/08/2012 03:50 pm »
Vehicle #3 was fairly clean, at least judging by public info.

Offline douglas100

  • Senior Member
  • *****
  • Posts: 2177
  • Liked: 227
  • Likes Given: 105
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #567 on: 10/08/2012 03:52 pm »

But as a distinterested bystander, I was really impressed that their rocket survived and thrived.  Luck?  No, good engineering.

We won't know how lucky or otherwise they were until we know the cause of the failure.
Douglas Clark

Offline corrodedNut

  • Full Member
  • ****
  • Posts: 1542
  • Liked: 216
  • Likes Given: 133
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #568 on: 10/08/2012 03:55 pm »
Vehicle #3 was fairly clean, at least judging by public info.

Oh, was that early shutdown flight 2?  I thought is was flight 3.

Online ugordan

  • Senior Member
  • *****
  • Posts: 8336
    • My mainly Cassini image gallery
  • Liked: 3151
  • Likes Given: 695
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #569 on: 10/08/2012 03:55 pm »
What early shutdown?

#2 had an oxygen-rich condition at 1st stage shutdown and a truncated MVac nozzle, I'm not aware of any early shutdowns.

#3 other than burning MVac longer than published info stated (stale info or underperfomance?), was pretty uneventful.
« Last Edit: 10/08/2012 03:58 pm by ugordan »

Offline corrodedNut

  • Full Member
  • ****
  • Posts: 1542
  • Liked: 216
  • Likes Given: 133
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #570 on: 10/08/2012 03:59 pm »
What early shutdown?

Ok, my bad...it was something about fuel-rich or out-of-parameters on one engine... got over blown...the infamous e-mail and lawsuit.  Maybe it wasn't early shutdown, and I forget what flight now.

Online ugordan

  • Senior Member
  • *****
  • Posts: 8336
    • My mainly Cassini image gallery
  • Liked: 3151
  • Likes Given: 695
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #571 on: 10/08/2012 04:01 pm »
Ah, that. I think that might have been a case of someone hearing about the anomaly on #2 (oxygen-rich shutdown) and not understanding the preplanned MECO-1 cutoff, added 2 and 2 and got 5.

Back on topic, Ben Cooper's launch photos: http://launchphotography.com/SpX-1.html
« Last Edit: 10/08/2012 04:02 pm by ugordan »

Offline Genuine

  • Member
  • Posts: 3
  • Liked: 0
  • Likes Given: 0
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #572 on: 10/08/2012 04:01 pm »
Quote
4 flights does not prove a design.

Ok, Jim, I'm an engineer and a scientist. One successful launch demonstrates that a design is capable of working. Engineering is a science. Science doesn't prove anything, it demonstrates the veracity of a design, whether that design is mere langauge or a complex system. That demonstration is temporary, as all designs should be. Designing is a continuous process, and the reason this domain is in so much trouble is that people take a design and run with it ad infinitum, expecting it to work over and over again with little or no improvement. That may work for NASA and the Air Force, but it's not going to work with the new paradigm of commercial space flight if you expect progress in the timeframes of your lifetime. Still starting your car with a lead acid battery charged by an alternator are you? Got jumper cables in your trunk?

[Impolite but well deserved snark removed by Genuine]
« Last Edit: 10/08/2012 04:20 pm by Genuine »

Offline meekGee

  • Senior Member
  • *****
  • Posts: 12667
  • N. California
  • Liked: 11789
  • Likes Given: 1323
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #573 on: 10/08/2012 04:07 pm »
This video steps through the anomaly frame by frame:




This movie adds a lot of context.
In the second frame, there's what looks to me like the first piece of large debris exiting the top of the exhaust stream.  (it looks like a flame extension, but look carefully, you can see the object)

It is the largest piece, and I think it is the lower fairing.  It is shown again at about frame #6, already far outside the flow.

At this point the engine reacts, there's a lot of disturbance to the flow (~10 frames)

Only then do other large (but smaller) pieces show up a, including what is very likely the upper part of the fairing

Then, the engine shuts off.

I'm still with the torn fairing proposal then.

----

Near LOM?  maybe.  It's definitely not a ho-hum nothing-serious-happened event.   If you design reliability for a single engine-out, then this must be a rare event.  If it isn't, then you need to design reliability for a dual engine-out.

That said, they indeed flew 40 engines already, and this might not even be an engine-related problem, but loss-of-engine due to an external issue.  Time to wait and see.
« Last Edit: 10/08/2012 04:16 pm by meekGee »
ABCD - Always Be Counting Down

Offline aero

  • Senior Member
  • *****
  • Posts: 3617
  • 92129
  • Liked: 1136
  • Likes Given: 358
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #574 on: 10/08/2012 04:25 pm »
I guess that means Falcon 9 v1.0 is not quite reusable.
Retired, working interesting problems

Online Herb Schaltegger

This is an interesting time lapse from Ben Cooper's amazing set.  Does the brightening along the early part of the ascent document the Engine 1 anomaly?

http://www.launchphotography.com/SpX-1.jpg
Ad astra per aspirin ...

Online Galactic Penguin SST

This is an interesting time lapse from Ben Cooper's amazing set.  Does the brightening along the early part of the ascent document the Engine 1 anomaly?

http://www.launchphotography.com/SpX-1.jpg

I think there's an easier explaination: a cloud deck.  ;)

That said, "that thing" happened just as the F9 went throught a cloud deck....
Astronomy & spaceflight geek penguin. In a relationship w/ Space Shuttle Discovery. Current Priority: Chasing the Chinese Spaceflight Wonder Egg & A Certain Chinese Mars Rover

Offline Nomadd

  • Senior Member
  • *****
  • Posts: 8436
  • Highway Whatever
  • Liked: 57162
  • Likes Given: 1103
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #577 on: 10/08/2012 04:36 pm »
 The F9 shuts down two engines part way through the boost to keep Gs down, right? Does anybody know how an unplanned shutdown would affect the planned shutdowns?
Those who danced were thought to be quite insane by those who couldn't hear the music.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 9749
  • Everyplaceelse
  • Liked: 2246
  • Likes Given: 12569
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #578 on: 10/08/2012 04:41 pm »
Wrong, this is not a finest hour.  They just got lucky.  A performance critical mission would not have the same out come.
Let me qualify that. *If* it turns out to be an engine explosion then in term of *vehicle* design this may well be Spacex's finest hour to date.

Engine explodes.

Debris shields between engines contain damage (BTW do other LV's have this? Xcorp have talked about it for Lynx but that's sub orbital at present)

Primary payload continues to orbit. Secondary payload in backup orbit (IIRC the 2nd stage was supposed to have a 2nd burn but if it was not possible the Orbcomm satellite was to be deployed in the parking orbit which was presumably *agreed* with Orbital before it was fitted)

The fact it happened is *not* their finest hour, but how they *respond* to it (like NASA's response to Apollo 13) is likely to be a defining moment for the company.

As for "they got lucky." Well no they didn't. Having an engine (probably) blow up on you is not most peoples idea of good luck. Having it happen and still completing the mission and discovering (later) that is because the fragments hit nothing vital *would* be good luck.

But it's impossible to say if they had that either. They *prepared* for possible failure by deciding to have multiple engines (for a *benign* shutdown) and blast shields between them (for a non benign shutdown).
That's not "luck," that's engineering.

As for "performance critical" missions I'd guess they'd start by not carrying any *secondary* payloads (which, if the payload was that heavy or the orbit that difficult the primary customer would not agree to anyway). So the question becomes are there parts of the F9 payload/orbit operating envelope that are marginal with *all* engines operating normally and standard margins on propellants?

IDK. I'm not that familiar with the F9 payload manual and I'm not sure it would be *explicitly* mentioned anyway.
That's a question of how close to F9's *absolute* performance the nominal range runs. 

Do you have any *specific* examples where their indicated payload/orbit parameters are pushing the limits of the vehicles capabilities? If you don't then is there *any* reason to expect the results of such a mission to be any worse than the ones today?

I'll note it's still *possible* the contents of Dragon may be severely damaged (and were it carrying passengers they might be badly hurt or even dead) and the Orbcomm sat situation still seems unclear. But (in so far as anything *is* known) they both seem OK. Which I think is a lot better than they would be on *any* other current generation launch vehicle.
« Last Edit: 10/08/2012 05:01 pm by john smith 19 »
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022. Forward looking statements. T&C apply. "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap

Offline Garrett

  • Full Member
  • ****
  • Posts: 1122
  • France
  • Liked: 120
  • Likes Given: 97
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #579 on: 10/08/2012 05:00 pm »
I will continue to respond to your inanities until I am banned here.

Not a very nice way to introduce yourself with your first post.
Can we please be polite?

Sure, I can be polite. The question is, can Jim?
You're confusing "impoliteness" with "bluntness". If the latter offends you, then you need to consider avoiding internet forums in general, and scientific/engineering orientated forums in particular.

Oh, and welcome to the forum.
« Last Edit: 10/08/2012 05:01 pm by Garrett »
- "Nothing shocks me. I'm a scientist." - Indiana Jones

Tags:
 

Advertisement NovaTech
Advertisement SkyTale Software GmbH
Advertisement Northrop Grumman
Advertisement
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1