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

[edkyle99]

Antares isn't small... It's medium (by industry standards, I'd argue), in the Delta II class.

And I'm not convinced that it can correctly be classified as a "U.S." launch vehicle - and that really should be a discussion for another thread!

 - Ed Kyle

[tigerade]

Are we considering this a 4th successful launch for SpaceX?  Primary mission successful, secondary payload failed.  What is the definition of a successful launch in rocket engineering?

[Kabloona]

Are we considering this a 4th successful launch for SpaceX?  Primary mission successful, secondary payload failed.  What is the definition of a successful launch in rocket engineering?

As with many things, it depends on who you ask. SpaceX can call it a success, because they got their primary payload to orbit. NASA can call it a success, because Dragon reached ISS. ORBCOMM can call it a partial success, because although they didn't reach their intended orbit, they were able to deploy and check out some systems on their satellite. Otherwise, there is no textbook formula for "success." It's generally just getting your payload, intact, to the correct orbit.

In the case of secondary payloads, it's understood that the primary payload has priority, and as a secondary payload you have to live with the consequences of getting the short end of the stick in cases like this. Which is why secondary payloads pay only a fraction of what the primary payload pays (and because secondaries are typically much lower mass and require fewer services).

[QuantumG]

Are we considering this a 4th successful launch for SpaceX?  Primary mission successful, secondary payload failed.  What is the definition of a successful launch in rocket engineering?

Well, SpaceX certainly think so:

The goal of this mission was to transport cargo to the international space station for NASA,” SpaceX’s Oct. 11 statement said. “Orbcomm requested that SpaceX carry one of their small satellites (weighing a few hundred pounds, vs. Dragon at over 12,000 pounds) on this flight so that they could gather test data before we launch their full constellation next year.

“The higher the orbit, the more test data they can gather, so they requested that we attempt to restart and raise altitude. NASA agreed to allow that, but only on condition that there be substantial propellant reserves, since the orbit would be close to the space station.

“It is important to appreciate that Orbcomm understood from the beginning that the orbit-raising maneuver was tentative. They accepted that there was a high risk of their satellite remaining at the Dragon insertion orbit. SpaceX would not have agreed to fly their satellite otherwise, since this was not part of the core mission and there was a known, material risk of no altitude raise.”

via http://spacenews.com/satellite_telecom/121011-orbcomm-craft-falls-out-orbit.html

Makes me wonder how this will affect Orbcomm's insurance claim.

[rickl]

Are we considering this a 4th successful launch for SpaceX?  Primary mission successful, secondary payload failed.  What is the definition of a successful launch in rocket engineering?

I like jcm's formula:

I'm trying to quantify that to have a metric that I can apply fairly
to other companies' launches. I'm come up with the following strawman scheme, and welcome comments:

 Primary payloads reach some orbit and separate from LV -  30 percent
 Primary payload orbit is usable, not necessarily perfect      -  25
 Primary payload orbit is as planned (within quoted sigmas)  -  20
 Secondary payload separated in orbit -                              10
  Secondary payload orbit usable -                                     10
  Secondary payload orbit as planned -                                 5

by this metric, the Falcon 9 launch scores 85 percent

For a launch with no secondary payloads, add the corresponding secondary scores to the primary, so 40/35/25

For a launch with multiple primary payloads, divide scores evenly


one might tweak this to cover cases where the LV damages the
satellite in some way - limited damage, subtract 20 percent,
satellite inoperable scores same as failure to orbit (i.e. total 0)

That's as good a metric as I've seen.  85% sounds about right for this launch.  If there were no secondary payload, then it would have been 100% successful.  SpaceX has proven that they do indeed have engine-out capability with the Falcon 9, just as they have always claimed.

[Antares]

Otherwise, there is no textbook formula for "success." It's generally just getting your payload, intact, to the correct orbit.

Um, yes there is.  It's called the ICD (Interface Control Document).  It specifies the acceptable limits for environments and orbits seen prior to spacecraft separation and CCAM.

[Kabloona]

Otherwise, there is no textbook formula for "success." It's generally just getting your payload, intact, to the correct orbit.

Um, yes there is.  It's called the ICD (Interface Control Document).  It specifies the acceptable limits for environments and orbits seen prior to spacecraft separation and CCAM.

The ICD is not a "textbook," it's a mission-specific document describing the interfaces, services, and environments the payload will get from the LV, and it describes succces just as I said: getting the payload to orbit "intact"  ( ie within acceptable vibe, shock, and thermal limits, etc). Every ICD is different based on different payload needs and launcher environments.

So my point was, there's no "Launch Vehicle Design and Operations" textbook that one can open and find a universal definition of "success," AFAIK. If there were, we wouldn't have people like Ed Kyle and jcm here coming up with their own metrics.

[Antares]

The universal definition of success is meeting a mission ICD.  I don't understand why some are looking for a different one, even if its the typical and oddly frequent motive for wanting to know things that are proprietary or otherwise restricted.  There are bright lines between success and failure for each requirement in an ICD.  When those are exceeded, typical claims or final payments are proportionate to the number of unfunctional payloads or loss of on-orbit life.

[Kabloona]

The universal definition of success is meeting a mission ICD.  I don't understand why some are looking for a different one, even if its the typical and oddly frequent motive for wanting to know things that are proprietary or otherwise restricted.  There are bright lines between success and failure for each requirement in an ICD.  When those are exceeded, typical claims or final payments are proportionate to the number of unfunctional payloads or loss of on-orbit life.

Not disagreeing with anything you said. I was simply trying to answer tigerade's question "when is a launch considered a success?" And, as you well know, some launches have been called "successful" even when the payload was placed in the wrong orbit (e.g. Pegasus F1).

[MikeAtkinson]

The universal definition of success is meeting a mission ICD.  I don't understand why some are looking for a different one, even if its the typical and oddly frequent motive for wanting to know things that are proprietary or otherwise restricted.  There are bright lines between success and failure for each requirement in an ICD.  When those are exceeded, typical claims or final payments are proportionate to the number of unfunctional payloads or loss of on-orbit life.

That is a purist way of defining success, but I'm not sure it is much use for outside observers (i.e. us).

I have seen many payload guides, but I don't think I've ever seen a ICD for a specific payload, are they freely available? I also have never seen the full actual performance of a launcher (vibration, shock, power, temperature, acceleration, etc.). Without those it is impossible to say whether any particular launch meets the ICD.

Added complications come with multiple payloads, particularly if they have different ICD.

A launch could have some parameters outside the ICD and yet have the payload(s) be 100% successful in their mission objectives.

Taking such a purist view is not helpful or useful, in my opinion, except for the launcher's engineering teams - as any exceeding of ICD parameters needs to be investigated and fixed (even if the fix is to change future ICDs).

[edkyle99]

Are we considering this a 4th successful launch for SpaceX?  Primary mission successful, secondary payload failed.  What is the definition of a successful launch in rocket engineering?

It is a launch failure, resulting in loss of secondary payload.  Orbcomm reentered and was declared a total loss by its owner. 

The primary payload and mission have to date succeeded.  This is similar to several missions that reached orbit despite launch failures, but still failed to achieve all of the basic mission goals. 

For those who can't abide all-or-nothing categorization, I would propose a judging based on payload mass.  In this case, the 7 tonne primary payload insertion was a success while the 0.165 tonne second payload insertion failed.  That's 7/7.165 = 0.977. 

Another option might be to compare total delta-v delivered versus total delta-v expected.  In this case, the number might be something like 9200/9350 meters/sec = 0.984.  Note that the two results are similar, and that both can be rounded off to 0.98!

Another, more simplified method would be to note that the flight had two payloads, one inserted successfully and one unsuccessfully for a 0.5 result - the "partial failure" so often discussed.  Of course we must remember that for Orbcomm, this was total and it was failure - and future potential customers are going to take note.

 - Ed Kyle

[Robotbeat]

I think it should simply be done based on primary versus secondary success. If you're a customer for the primary payload such as for human spaceflight or ISS cargo missions then this flight is absolutely and unequivocally a success. And let's just be honest most of the people coming to this site care about that figure.

If you're looking to fly a secondary on a flight that is also scheduled to deliver to the international space station then absolutely you should take this flight into consideration as a failure to deliver to your proper orbit. But there's only one more version of this rock that is set to fly. if I were flying a secondary on Dragon cargo flight I would be negotiating with space X right now to see how much margin they've allowed to ensure secondary payload success. But as Ed noted this secondary was incredibly small compared to the primary payload. If Spacex's were just wanting a couple cube sats with this also be considered a launch failure?

[marsman2020]

I don't understand how Orbcomm's insurance can pay out.

It was stated this was a "prototype" and Orbcomm had accepted the risk of ending up in the lower orbit before the launch.  Also, the engineering checkouts of the "prototype" were completed before it re-entered.

Yet they file an insurance claim for a total loss, when SpaceX says the requirements were met.  How is that possible?  If it wasn't acceptable to end up in that lower orbit and just get 2-3 days of engineering data, they shouldn't have flown.  Otherwise this is a little like burning down your own house and then claiming insurance on it.

The reality is that these 18 satellites were originally manifested as the *primary* payloads on their own F1Es with launches expected to start in 2010.  I'm sure all 18 are in a pretty advanced stage of construction, if not sitting in clean rooms 100% complete at this point.  Flight testing of prototypes of communications satellites is *not* the industry standard.

Orbcomm has their own investors to answer to, and flying this "prototype" was probably mostly to keep those investors happy and save face for SpaceX's inability to fulfill their contract even 2 years behind schedule.  Other then that, I bet it is a "prototype" in name only.  Certainly it's very late in the game to make any changes to the other 17 that were supposed to start flying 2 years ago.

[edkyle99]

Yet they file an insurance claim for a total loss, when SpaceX says the requirements were met.  How is that possible? 

This is a prime example of something I discussed previously.  The launch vehicle manufacturer naturally emphasizes success and minimizes, or even omits, discussion of failure.  For a fair analyses of a launch result, then, any statements by the launch vehicle manufacturer should be taken with that self-promotion bias in mind.  A launch is not a full success just because SpaceX, or ULA, or Orbital, etc., says that it is a success.

 - Ed Kyle

[Robotbeat]

Yet they file an insurance claim for a total loss, when SpaceX says the requirements were met.  How is that possible? 

This is a prime example of something I discussed previously.  The launch vehicle manufacturer naturally emphasizes success and minimizes, or even omits, discussion of failure.  For a fair analyses of a launch result, then, any statements by the launch vehicle manufacturer should be taken with that self-promotion bias in mind.  A launch is not a full success just because SpaceX, or ULA, or Orbital, etc., says that it is a success.

 - Ed Kyle

And neither are they full launch failures.

[upjin]

I don't understand how Orbcomm's insurance can pay out.

It was stated this was a "prototype" and Orbcomm had accepted the risk of ending up in the lower orbit before the launch.  Also, the engineering checkouts of the "prototype" were completed before it re-entered.

Yet they file an insurance claim for a total loss, when SpaceX says the requirements were met.  How is that possible?  If it wasn't acceptable to end up in that lower orbit and just get 2-3 days of engineering data, they shouldn't have flown.  Otherwise this is a little like burning down your own house and then claiming insurance on it.

The reality is that these 18 satellites were originally manifested as the *primary* payloads on their own F1Es with launches expected to start in 2010.  I'm sure all 18 are in a pretty advanced stage of construction, if not sitting in clean rooms 100% complete at this point.  Flight testing of prototypes of communications satellites is *not* the industry standard.

Orbcomm has their own investors to answer to, and flying this "prototype" was probably mostly to keep those investors happy and save face for SpaceX's inability to fulfill their contract even 2 years behind schedule.  Other then that, I bet it is a "prototype" in name only.  Certainly it's very late in the game to make any changes to the other 17 that were supposed to start flying 2 years ago.

The point about what flying a "prototype" means is a very good one.  A prototype means that you are a lot less concerned about it.  Even if "prototype" in name only, giving it that label means less concern and more acceptance of risk.

For any company, being a "secondary payload", means accepting a certain level of risk and accepting increased levels of potential failure.

Irregardless of how "purists" may categorize issues with the recent secondary payload, it is likely that companies will continue to take the risk.  Believing that it will more likely pay off for them, than to fail.

In the bigger view, it remains to be seen if this will have any affect on SpaceX's business, and so far those affects look minimum.

[Kabloona]

I don't understand how Orbcomm's insurance can pay out.

It was stated this was a "prototype" and Orbcomm had accepted the risk of ending up in the lower orbit before the launch.  Also, the engineering checkouts of the "prototype" were completed before it re-entered.

Yet they file an insurance claim for a total loss, when SpaceX says the requirements were met.  How is that possible?  If it wasn't acceptable to end up in that lower orbit and just get 2-3 days of engineering data, they shouldn't have flown.

SpaceX told Orbcomm, as part of their launch contract, that there was some probability that they would not be able to do a second burn to get OG2 into the higher orbit.  Orbcomm then had their insurance policy written such that, if OG2 was not boosted to the higher orbit, the insurance company would pay for its loss. So the possibility of this outcome was known in advance to all parties, and insured against. No mystery there.

SpaceX is saying they met their minimum commitment to OG2, which was to get it into the lower orbit intact, which they did.

As for what's "acceptable" to Orbcomm, of course they would have liked to get to the higher orbit. But they knew there was a chance of not making it, and getting only a few days in a lower orbit. That's what happens when you're a secondary payload...you get a much less expensive ride, and you don't get priority. The risks were known by all ahead of time, and insured against.

[QuantumG]

In an ideal world that's probably true. I expect it's not actually that clear cut.

[marsman2020]

I don't know what insurance company would write a policy where both of the other parties involved claim success - SpaceX delivered the payload to an agreed upon orbit and Orbcomm got their engineering data on their "prototype" - but the insurance company still pays out.

Seems very fishy to me. 

[Kabloona]

I don't know what insurance company would write a policy where both of the other parties involved claim success - SpaceX delivered the payload to an agreed upon orbit and Orbcomm got their engineering data on their "prototype" - but the insurance company still pays out.

Seems very fishy to me. 

The insurance company, and the law, doesn't give a rat's behind what the insured party says publicly in their press releases. The insurance company wrote a policy to reimburse them for certain cases, calculated the odds of those cases, and charged Orbcomm a premium priced accordingly. Since one of the insured events occurred (OG2 not reaching the higher orbit) they'll have to pay out. That's how the insurance business works.

Orbcomm got their satellite into a low orbit, turned it on, ran some tests on it, and verified it worked. So they wrote a press release worded as positively as they could. That's how public relations works. They want to reassure their investors and customers. They can say anything they want in public, and it has nothing to do with the terms of their insurance contract.