SpaceX Falcon 9 : GPS III SV01 : SLC-40 : Dec. 23, 2018 - DISCUSSION

[Lar]

Supposition: The Air Force is intentionally forcing SpaceX to expend their vehicle despite having performance to land. They are doing this because some insider is trying to support ULA so that SpaceX and ULA prices are more comparable.

Disagree: As far as I know, SpaceX has yet to publish launch prices which take into account whether or not they expect to recover the first stage, or whether the first stage is being reused from a prior mission.  In fact, the public statements so far have been "maybe later, after we've recovered some of the R&D costs."

That would mean that as far as public pricing is concerned, there is no discount to the customer for not expending the stage.  Therefore, the price SpaceX is charging is not any higher (or less competitive) than usual.

Whether this means less profit for SpaceX is immaterial for this discussion.

Why is it immaterial? Not recovering a stage definitely cuts their profit. I've predicted elsewhere that SpaceX will start writing contracts that require stage recovery OR that have higher pricing if it is precluded ... we will probably never know if my prediction is correct.

[Jarnis]

My educated guess:

SpaceX was paid for a contract that does not require a booster recovery, or in other words the price is "expendable" to start with. SpaceX would naturally want to recover the booster anyway, but that is up to the requirements of the payload orbit.

Air Force wanted to use this flight also to get good data for their own analysis of what F9 Block 5 can actually do "maxed out". So they designed the mission to use the full theoretical performance, with a good chunk going first to raising perigee of the orbit (shortfall not a massive deal, sat can fill in) and then to the deorbit the second stage.

If everything performs as advertised, the sat gets extra lifetime and they can use the real figures for planning future launches that do include droneship landings. If the performance is not quite as advertised, the mission is easily secure either way. If the sat really costs $600M, the launch cost is a fairly small bit of the overall bill. If going expendable and possibly foregoing some low double digit million discount, that might not even be worth it vs. the potential extra service life of the sat.

Air Force is conservative. They'll happily take lower launch costs once everything is "proven" to their satisfaction, but they're not there yet.

[RDMM2081]

If excess performance of the first stage is only reserved for margin, could SpaceX still execute entry and landing burns, sans ASDS, as an “I told you so”?

[FutureSpaceTourist]

Cross-posting from ‘customer views on reuse’ thread:

It seems at least part of USAF’s uncertainty over flight proven boosters is whether the performance lost to recover the booster significantly affects the chances of carrying out their missions:

Air Force open to reusable rockets, but SpaceX must first demonstrate performance
by Sandra Erwin — December 16, 2018

The Air Force will need time to review SpaceX’s performance as it executes EELV launches before it would consider flying military payloads on reusable rockets.

https://spacenews.com/air-force-open-to-reusable-rockets-but-spacex-must-first-demonstrate-performance/

[Celestar]

If excess performance of the first stage is only reserved for margin, could SpaceX still execute entry and landing burns, sans ASDS, as an “I told you so”?

Not sure that's a good idea. If the past is any indication, they might end up with a booster somewhere in the middle of the Atlantic that needs some form of recovery ...

Celestar

[tyrred]

Cross-posting from ‘customer views on reuse’ thread:

It seems at least part of USAF’s uncertainty over flight proven boosters is whether the performance lost to recover the booster significantly affects the chances of carrying out their missions:

Air Force open to reusable rockets, but SpaceX must first demonstrate performance
by Sandra Erwin — December 16, 2018

The Air Force will need time to review SpaceX’s performance as it executes EELV launches before it would consider flying military payloads on reusable rockets.

https://spacenews.com/air-force-open-to-reusable-rockets-but-spacex-must-first-demonstrate-performance/

Interesting.  Do we know, are they counting only DOD missions in their overall demonstration criteria, and don't consider the sample set enough data yet?  Or are they not yet confident that recovery attempts thus far haven't affected primary mission performances?

If initial core-flight recovery of the booster hasn't adversely affect primary mission payload, taking into account necessary return propellant margins, how many more successes are needed to demonstrate performance?  Am I forgetting a mission that has been lost and has been attributed to landing attempt?

[Raul]

I think there is three possibilities especially for S2 trajectory:

1. Optimal F9 trajectory with 3 burns of stage 2
- 1st long burn with apogee to 20181km, coast to apogee, 2nd short burn to raise (maximize) perigee, separation, 3rd short burn to deorbit, re-entry at ~T+6hrs - could be a problem, because the stage would not have enough time to get away the spacecraft safely before deorbit ignition.

2. Less optimal F9 trajectory with 3 burns of stage 2
- 1st burn with apogee to 1000km (or higher), coasting, 2nd burn to raise apogee to 20181km, separation, 2nd coast to apogee, 3rd short burn to deorbit, re-entry at ~T+6hrs50min (in middle of window for S2 reentry) -  disadvantage of two coasting

3. Not too efficient F9 trajectory with lower margin, but safer profile with 2 burns only - single burn for primary mission
- 1st long burn with very high lofted trajectory to reach altitude above 1000km before SECO-1 with final orbit parameters >1000/20181km, separation, 2nd short burn to deorbit, re-entry at ~T+6hrs.

In the past, with relatively light satellites and high F9 margin, single burn of the second stage already reached circular orbits in 500-725km (in case Formosat-5, Paz, SAOCOM-1A, SSO-A).
Although Argument of Perigee can be specified at 270 deg for orbit insertion requirement, it's still not final orbit for spacecraft, so I think it can be flexible.

It seems to me that the USAF rather prefers a safe flight profile, compared to optimal F9 trajectory, which can allows booster recovery or maximizing perigee of the orbit.

[CorvusCorax]

If excess performance of the first stage is only reserved for margin, could SpaceX still execute entry and landing burns, sans ASDS, as an “I told you so”?

No. That's not how it works. You always transfer your margins, aka you impart as much velocity to the second stage as possible to cover for an eventual 2nd stage or satellite performance shortfall.

Retaining landing fuel on the 1st stage would mean that delta-v is no longer available to the second stage, which means it will not be margin at all if needed due to whatever reason (larger boiloff, premature cutoff, thrust issues with the sat itself, ...)

The way I interpret the minimum requirements for this launch is, the airforce wants the sat deployed in an orbit that would be stable (or at least not reentering) for decades right from the get-go. That means even if the main propulsion on the sat fails completely, they could possibly still operate it in this less-than-optimal orbit (similar to what was done with some Gallileo sats) as long as the sat is alive.

Likely they also have a severe 2nd stage underperformance covered (as in, "fails to relight") - just in case - with enough fuel on their sat to get it to a useful orbit anyway.

But with a conservative approach like that, they would want every cm/s of deltaV they can squeeze out of the 1st stage, so they can keep this margin for a potential later underperformance. And that means minimum residual shutdown. No reentry burn, no landing burn, no landing gears, grid fins or extra plumbing for 1st stage relights, but the rocket as light as possible, etc...

The fact that SpaceX made the rocket more powerful since contract signage? Perfect. This customer will take every ounce of extra performance greedily as extra margin all the way to deployment -- to make sure they have a working satellite, even if they don't have a working satellite.

[ChrisGebhardt]

Just a question on classification of this mission:

The US Air Force says this is the first national security launch for SpaceX.  What about NROL-71 and OTV-5?  Is this an admission that, while classified, they weren't national security?  Or is it more proper to say that GPS III SV01 was SpaceX's first competitively won national security mission?

Just trying to keep this straight with what the company's launched since this contract was bid on (2015) and awarded (April 2016).

[GWR64]

I think there is three possibilities especially for S2 trajectory:

1. Optimal F9 trajectory with 3 burns of stage 2
- 1st long burn with apogee to 20181km, coast to apogee, 2nd short burn to raise (maximize) perigee, separation, 3rd short burn to deorbit, re-entry at ~T+6hrs - could be a problem, because the stage would not have enough time to get away the spacecraft safely before deorbit ignition.

2. Less optimal F9 trajectory with 3 burns of stage 2
- 1st burn with apogee to 1000km (or higher), coasting, 2nd burn to raise apogee to 20181km, separation, 2nd coast to apogee, 3rd short burn to deorbit, re-entry at ~T+6hrs50min (in middle of window for S2 reentry) -  disadvantage of two coasting

3. Not too efficient F9 trajectory with lower margin, but safer profile with 2 burns only - single burn for primary mission
- 1st long burn with very high lofted trajectory to reach altitude above 1000km before SECO-1 with final orbit parameters >1000/20181km, separation, 2nd short burn to deorbit, re-entry at ~T+6hrs.

In the past, with relatively light satellites and high F9 margin, single burn of the second stage already reached circular orbits in 500-725km (in case Formosat-5, Paz, SAOCOM-1A, SSO-A).
Although Argument of Perigee can be specified at 270 deg for orbit insertion requirement, it's still not final orbit for spacecraft, so I think it can be flexible.

It seems to me that the USAF rather prefers a safe flight profile, compared to optimal F9 trajectory, which can allows booster recovery or maximizing perigee of the orbit.

I could imagine that apogee should be above the northern hemisphere.
So that the Satellite during the raising maneuvers directly can be observed.
But why exactly Argument of Perigee at 270 deg?

[gongora]

Just a question on classification of this mission:

The US Air Force says this is the first national security launch for SpaceX.  What about NROL-71 and OTV-5?  Is this an admission that, while classified, they weren't national security?  Or is it more proper to say that GPS III SV01 was SpaceX's first competitively won national security mission?

Just trying to keep this straight with what the company's launched since this contract was bid on (2015) and awarded (April 2016).

It's the first flight they're officially doing under the EELV program.  I think this is kinda like flying Crew-1 after they've gotten DM-1 and DM-2 out of the way.

[ChrisGebhardt]

Just a question on classification of this mission:

The US Air Force says this is the first national security launch for SpaceX.  What about NROL-71 and OTV-5?  Is this an admission that, while classified, they weren't national security?  Or is it more proper to say that GPS III SV01 was SpaceX's first competitively won national security mission?

Just trying to keep this straight with what the company's launched since this contract was bid on (2015) and awarded (April 2016).

It's the first flight they're officially doing under the EELV program.  I think this is kinda like flying Crew-1 after they've gotten DM-1 and DM-2 out of the way.

That's what I was thinking.  So perhaps best to stick with the "first EELV" official line then talk about national security in the article, then.

[John Santos]

[...]

The fact that SpaceX made the rocket more powerful since contract signage? Perfect. This customer will take every ounce of extra performance greedily as extra margin all the way to deployment -- to make sure they have a working satellite, even if they don't have a working satellite.

SpaceX contracted to deliver a satellite to a particular orbit with a particular amount of margin.  If the Air Force wants more, don't they have to pay more?  Otherwise any excess performance belongs to SpaceX, not the Air Force and the Air Force has no right to demand it.

Secondly, SpaceX's goal is to reduce the price of launches through reuse.  Assuming they do reduce the price of recoverable launches eventually, there is a fleet of identical GPS satellites.  Wouldn't it be cheaper for the Air Force to accept the original performance (without margins) and, if one of them fails to reach the original contract orbit, build an extra satellite and launch it on SpaceX's dime?  Even though it could have done so if SpaceX hadn't reserved fuel for recovery?  The Air Force would get a whole bunch of cheaper launches in return, saving millions of dollars in launch costs.

[ChrisGebhardt]

One more question:

All of the competitively bid contracts have gone to SpaceX for the fleet of GPS III spacecraft whose launches have been secured.  The 2nd satellite (originally the first) that's launching next year on the Delta IV M+ is a holdover of an Air Force block buy from ULA or was not a competitive bid process, correct?

[woods170]

[...]

The fact that SpaceX made the rocket more powerful since contract signage? Perfect. This customer will take every ounce of extra performance greedily as extra margin all the way to deployment -- to make sure they have a working satellite, even if they don't have a working satellite.

SpaceX contracted to deliver a satellite to a particular orbit with a particular amount of margin.  If the Air Force wants more, don't they have to pay more?  Otherwise any excess performance belongs to SpaceX, not the Air Force and the Air Force has no right to demand it.

Yes, the USAF has a right to demand it. It is contractually covered, according to one of my SpaceX sources.

[gongora]

One more question:

All of the competitively bid contracts have gone to SpaceX for the fleet of GPS III spacecraft whose launches have been secured, yes?  The 2nd satellite (originally the first) that's launching next year on the Delta IV M+ is a holdover of an Air Force block buy from ULA or was not a competitive bid process, correct?

Yes.

[Norm38]

Air Force Magazine

“For this first flight, we’re going through making sure we’re taking care of the spacecraft … Everything we do, we’re making sure we treat it safely,” said Walter Lauderdale, mission director of SMC’s launch enterprise systems directorate. After launch, he said USAF, Lockheed Martin, and SpaceX will “come back together as a team and look for opportunities to see if we can get performance back that will enable SpaceX to recover their vehicle.”
...
Whitney said he anticipates OCX Block 1, which would enable M-Code capability, to be delivered in the 2021-2022 timeframe.

Once launched it could take as long as six to nine months to check out the satellite on orbit and then another six to nine months to integrate the GPS III satellite with the rest of the constellation, officials said.

I read this quote differently.  They are concerned about the spacecraft, treating it with kid gloves.  Then after launch, USAF and LM will look for performance gains.  Those two organizations are not in a position to increase the performance of the F9, only the payload.  Thus it appears to me that either they doesn't know what the satellite's propulsion performance will be, they aren't happy with their numbers and think they can do better on the next version, or they are prepared to increase the time for orbital maneuvers to be more fuel efficient.

I don't know how else the team would be able to "get performance back".  Get it back from where?

[envy887]

Air Force Magazine

“For this first flight, we’re going through making sure we’re taking care of the spacecraft … Everything we do, we’re making sure we treat it safely,” said Walter Lauderdale, mission director of SMC’s launch enterprise systems directorate. After launch, he said USAF, Lockheed Martin, and SpaceX will “come back together as a team and look for opportunities to see if we can get performance back that will enable SpaceX to recover their vehicle.”
...
Whitney said he anticipates OCX Block 1, which would enable M-Code capability, to be delivered in the 2021-2022 timeframe.

Once launched it could take as long as six to nine months to check out the satellite on orbit and then another six to nine months to integrate the GPS III satellite with the rest of the constellation, officials said.

I read this quote differently.  They are concerned about the spacecraft, treating it with kid gloves.  Then after launch, USAF and LM will look for performance gains.  Those two organizations are not in a position to increase the performance of the F9, only the payload.  Thus it appears to me that either they doesn't know what the satellite's propulsion performance will be, they aren't happy with their numbers and think they can do better on the next version, or they are prepared to increase the time for orbital maneuvers to be more fuel efficient.

I don't know how else the team would be able to "get performance back".  Get it back from where?

Get it back from margin reserves.

[gongora]

Remember this isn't just the first flight of F9 under EELV.  It's the first flight of a new satellite constellation that is very far behind schedule and over budget.

[Norm38]

I don't know how else the team would be able to "get performance back".  Get it back from where?

Get it back from margin reserves.

That's what I'm saying, SpaceX already knows their margin reserves.  USAF and LM are saying they need this flight to determine how much lift they actually need.  They're lucky the F9 has margin to spare.  Since it seems that they don't have hard numbers yet.
Or to Gongora's point, they're not willing to take any chances with this bird, but will take more risks with later flights.