SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION

[thomson]

What's going to happen with this dragon once it get back? NASA wants new spacecraft on every CRS flight. When SpX-1 gets back, does it mean that SpaceX will have a small fleet of 3 dragons?

Yay for building a second space fleet (the first one was STSes)!

[Garrett]

1. The primary mission was a successful failure. An engine failed explosively, but did not destroy the vehicle or initiate and FTS abort, so the primary goal of getting dragon into orbit was met.

Grrr! Only SpaceX and/or NASA get to call the engine issue an "explosion". They haven't, ergo it did not fail "explosively". Saying it looked like an explosion, or "pressure release" is code for explosion doesn't cut it.

2. The secondary mission failed. As a result of the loss of engine one the second stage was unable to execute a restart and the Orbcomm payload will likely not be usable to Orbcomm.

"unable to execute" is a bit strong. "chose not to execute" is the way I understood it. Of course, it made that choice because it figured out that it was not in a position to complete its mission.

3. While the spaceflight industry and community are indeed changing, as we (hopefully) move towards private spaceflight and exploration, the bottom line is that failures like this are not a good thing and should not be downplayed. They are not routine and are not acceptable.

Who's downplaying? SpaceX? NASA? Nope. Only some folks on the internet. Failures are not acceptable, but it'll be a long while yet before they are not routine at a price tag smaller than a bank bailout.

4. Spacex was lucky. Given the nature of this failure it "should" have probably resulted in a LOM.

There is no evidence to support your statement. The fact that it didn't result in LOM is in itself proof to the contrary. So is SpaceX's assertion that the F9 has engine out capability. There is also evidence that SpaceX engineered protection mechanisms against such an event: kevlar shielding and ejectable panels.

My guess is that the emergency system caught the failure in progress and terminated fuel/oxidizer flow to the engine as it was failing,...

Or maybe one could simply read the SpaceX statement to figure that out: "... an engine shutdown command was issued."

Hopefully, this was just a manufacturing flaw unique to that engine and it doesn't cause delays or a stand down.

Hopefully that isn't the source of the problem! A manufacturing flaw would suggest an issue with quality control which would be a VERY serious problem. I hope it's a fundamental design issue that only pops up in a real launch scenario. There's much less shame in having your engineering skills being slapped by the reality of physics.

Edits: minor grammar

[Robotbeat]

SpaceX wasn't lucky. Those redundant systems didn't just appear by luck. It was engineered to work in case of engine failure and it did. It is launch vehicles WITHOUT engine-out capability that reach orbit which are lucky that this time wasn't the time when an engine would fail.

[Cherokee43v6]

Okay... having read the back and forth for three days now there seems to be this fixation of stage 2 fuel...

From this layman's perspective it has little or nothing to do with fuel.

If you blow a tire on your car on the ramp to the highway, do you merge with traffic or pull to the side and stop???

NASA put strict rules in place for the secondary payload due to the potential for risk to the ISS and her crew.

From my perspective, what I've read so far indicates that if this same incident had occured on a pure-play satellite launch mission it is very likely that all payloads could have been successfully deployed to usable orbits.  It was the potential risk to Space Station that restricted the secondary mission.

[ugordan]

SpaceX wasn't lucky. Those redundant systems didn't just appear by luck. It was engineered to work in case of engine failure and it did.

So, let's say the engine gave up not 80 seconds but 10 seconds after liftoff and F9 US had to spend all of its propellant while still not managing to raise the perigee above the atmosphere.

Are you willing to claim that you know there was sufficient margin to complete the primary mission for any engine out condition? If not, then you have no basis for claiming they weren't "lucky" in that they were lucky the engine-out condition happened late enough to be covered by available propellant reserve.

The thing to keep in mind is the actual underperformance cost around 15 seconds of 2nd stage burn time. Orbcomm most likely needed no more than 2 seconds burn time given the huge T/W ratio of an almost empty upper stage. Call it 3 seconds for additional margin. It obviously didn't have those 3 extra seconds, otherwise Orbcomm burn wouldn't have been inhibited. Are you saying an engine out earlier than 80 sec would have been covered by those 3 secs?

[Mader Levap]

Are you willing to claim that you know there was sufficient margin to complete the primary mission for any engine out condition?

SpaceX claims F9 is capable of single engine-out at any stage of launch and still deliver. (at least primary cargo, as we see with CRS-1 launch) So, if you believe SpaceX, they would manage with engine-out at 10 second.

[Nice loaded question with numbers pulled out of nether regions]

Some people here claims that Orbcomm failure, while related to engine-out, was unrelated to amount of fuel in reserve left after whole RUD/EPR/blowout/implosion/explosion/whatever business.

[2552]

That's

Are you willing to claim that you know there was sufficient margin to complete the primary mission for any engine out condition?

SpaceX claims F9 is capable of single engine-out at any stage of launch and still deliver. (at least primary cargo, as we see with CRS-1 launch) So, if you believe SpaceX, they would manage with engine-out at 10 second.

That's likely meant for the F9 v1.1. It would probably explain the difference between the 16 ton LEO performance SpaceX submitted to NASA and the 13 ton performance SpaceX list on their website.

[peter-b]

Are you willing to claim that you know there was sufficient margin to complete the primary mission for any engine out condition?

SpaceX claims F9 is capable of single engine-out at any stage of launch and still deliver. (at least primary cargo, as we see with CRS-1 launch) So, if you believe SpaceX, they would manage with engine-out at 10 second.

A source for this would be useful, thanks!  I couldn't remember what info SpaceX had given out about the exact engine-out tolerances on Falcon 9, so if you have a link I would be interested to find out more.

[ugordan]

SpaceX claims F9 is capable of single engine-out at any stage of launch and still deliver. (at least primary cargo, as we see with CRS-1 launch) So, if you believe SpaceX, they would manage with engine-out at 10 second.

They also claim it can boost 10 tons to LEO. Which it obviously can't. They have a tendency to "forget" mentioning details like "BTW, that's for the Block 2/v1.1 upgrade, not the currently flying vehicle", but hey, if you believe all their PR, feel free to believe F9 has engine out capability that early.

[Nice loaded question with numbers pulled out of nether regions]

Some people here claims that Orbcomm failure, while related to engine-out, was unrelated to amount of fuel in reserve left after whole RUD/EPR/blowout/implosion/explosion/whatever business.

What you call numbers pulled out of nether regions, I call reasonable inferences from available data. If you have better information, other than dismissing this as clearly irrelevant, feel free to share it with us.

Which people claim it had nothing to do with fuel in reserve? L2 says otherwise and I trust L2 more than "some people".

[R.Simko]

A few thoughts on this mission.

1.  The engine failure on the F9 first stage has highlighted the risks that companies take when they sign up as a secondary payload.  But it has also shown SpaceX's ability to still deploy a secondary payload in spite of this engine failure, although, not in the preferred orbit.

2.  Companies know that they run a higher risk by being a secondary payload, but they also get a better price.  Secondary payloads are good for companies like SpaceX, because it increases revenue.  So what can be done to make this a win-win for both the company that puts a secondary payload on a F9 and for SpaceX also?

3.  My thought is, would it be financially smart to increase the fuel capacity and fuel load of the secondary satellite, so that if it gets dropped off in too low an orbit, it can then raise itself to a functional orbit, thereby saving itself and the secondary mission?

[Cherokee43v6]

A few thoughts on this mission.

1.  The engine failure on the F9 first stage has highlighted the risks that companies take when they sign up as a secondary payload.  But it has also shown SpaceX's ability to still deploy a secondary payload in spite of this engine failure, although, not in the preferred orbit.

2.  Companies know that they run a higher risk by being a secondary payload, but they also get a better price.  Secondary payloads are good for companies like SpaceX, because it increases revenue.  So what can be done to make this a win-win for both the company that puts a secondary payload on a F9 and for SpaceX also?

3.  My thought is, would it be financially smart to increase the fuel capacity and fuel load of the secondary satellite, so that if it gets dropped off in too low an orbit, it can then raise itself to a functional orbit, thereby saving itself and the secondary mission?

Number 3 would not work on a CRS mission.  NASA would most likely not allow the satellite to cross the ISS orbit due to potential threat of collision with ISS should the boost fail, which is the primary reasoning on disallowing the stage 2 burn after the stage one engine-out.

[kevin-rf]

Imagine that your next United or Southwest flight to Chicago was forced to land in Milwaukee or Rockford or Cleveland instead, but the airline refused to refund your ticket, calling the flight a "success" because the airplane didn't crash.   

What if they get me to where I want to go, but they send my luggage somewhere else for a week?

I think you just summed up this launch to the T. +1

The luggage was placed in the wrong orbit.

There have been launches where the hitchhikers have failed to separate in the past, wasn't there one recently where two of the little blood suckers managed to get attached to each other?

The last time an Atlas dumped a pair of NOSS's in the wrong orbit Ed counted it as a failure. We had pages of and pages of debate on if it was a failure. Even though the Customer and ULA spin it as a success, Ed will not budge.

[yg1968]

A few thoughts on this mission.

1.  The engine failure on the F9 first stage has highlighted the risks that companies take when they sign up as a secondary payload.  But it has also shown SpaceX's ability to still deploy a secondary payload in spite of this engine failure, although, not in the preferred orbit.

2.  Companies know that they run a higher risk by being a secondary payload, but they also get a better price.  Secondary payloads are good for companies like SpaceX, because it increases revenue.  So what can be done to make this a win-win for both the company that puts a secondary payload on a F9 and for SpaceX also?

3.  My thought is, would it be financially smart to increase the fuel capacity and fuel load of the secondary satellite, so that if it gets dropped off in too low an orbit, it can then raise itself to a functional orbit, thereby saving itself and the secondary mission?

I sort of wonder. Maybe SpaceX shouldn't have secondary payloads until the Falcon 9 version 1.1 is ready.

[ugordan]

Maybe SpaceX shouldn't have secondary payloads until the Falcon 9 version 1.1 is ready.

Hindsight is always 20/20. Put yourself in their position. They were reasonable to expect no engine failures on the way up as 30 or so engines already flew successfully and the engines themselves were test-fired at least 4 times. With that reasonable assumption their propellant allocation would ensure mission success.

[Garrett]

What if they get me to where I want to go, but they send my luggage somewhere else for a week?

I think you just summed up this launch to the T. +1
The luggage was placed in the wrong orbit.

Bad analogy. The luggage belonged to somebody else.

[yg1968]

Out of curiosity, had Dragon not been able to get to ISS after the engine failure on the Falcon 9, would Dragon have come back safely to Earth?

I am assuming that it would have. But I am not an engineer, so I prefer to ask then to assume that it would.

[yg1968]

Maybe SpaceX shouldn't have secondary payloads until the Falcon 9 version 1.1 is ready.

Hindsight is always 20/20. Put yourself in their position. They were reasonable to expect no engine failures on the way up as 30 or so engines already flew successfully and the engines themselves were test-fired at least 4 times. With that reasonable assumption their propellant allocation and reserve ensured mission success.

Yes, I agree. I wasn't suggesting that it was a bad decision for CRS-1. I am just saying that perhaps the CRS-2 flight should avoid having a secondary payload.

[R.Simko]

A few thoughts on this mission.

1.  The engine failure on the F9 first stage has highlighted the risks that companies take when they sign up as a secondary payload.  But it has also shown SpaceX's ability to still deploy a secondary payload in spite of this engine failure, although, not in the preferred orbit.

2.  Companies know that they run a higher risk by being a secondary payload, but they also get a better price.  Secondary payloads are good for companies like SpaceX, because it increases revenue.  So what can be done to make this a win-win for both the company that puts a secondary payload on a F9 and for SpaceX also?

3.  My thought is, would it be financially smart to increase the fuel capacity and fuel load of the secondary satellite, so that if it gets dropped off in too low an orbit, it can then raise itself to a functional orbit, thereby saving itself and the secondary mission?

Number 3 would not work on a CRS mission.  NASA would most likely not allow the satellite to cross the ISS orbit due to potential threat of collision with ISS should the boost fail, which is the primary reasoning on disallowing the stage 2 burn after the stage one engine-out.

Thanks for the response.  I was afraid the response would be something like that.  Do you or anyone else have any other thoughts how how a mission like this could be saved in the future?

[ugordan]

Out of curiosity, had Falcon 9 not been able to get to ISS after the engine failure, would Dragon have come back safely to Earth?

Falcon 9 doesn't/didn't go to ISS. If Dragon achieved a minimal orbit, there was a contingency recovery zone near California after nearly one orbit that would allow recovery, probably also in case of failed solar deploy.

If it didn't manage to get into any kind of orbit, I'm not sure what the options were. Probably would drop somewhere near Europe in the Atlantic.

[ugordan]

I am just saying that perhaps the CRS-2 flight should avoid having a secondary payload.

In light of the facts now, I would agree, but with an additional qualification that it should avoid carrying payloads that require any additional burns. Secondaries can mean things like sats dropped off from Dragon's trunk, etc.