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

[ulm_atms]

Did some calculations. Required delta-V from a 200 km circular orbit to 1000x20,181 km is 2184.8 m/s (2071.3 m/s for the perigee burn and 113.5 m/s for the apogee burn). I estimate the extra delta-V to get into 55° orbit from Cape Canaveral is 260.2 m/s. Total is 2445.2 m/s. The extra delta-V to get into GTO is 2454.6 m/s, so the delta-V's are very similar for these missions. Expendable Falcon 9 GTO performance is 8.3 t and 5.5 t for droneship landing. So for a 3.8 t payload, a reusable mission gives way more performance than necessary. I don't see any need for an expendable, unless the boiloff rate of LOX from the second stage causes a significant loss of performance.

If we do the higher delta-V, but shorter time to the second burn, the perigee burn is 220.0 m/s to 1000 km apogee, followed by a 2059.2 m/s burn at apogee to raise to 20,181 km. Total delta-V is 2279.2 m/s + 260.2 m/s = 2539.6 m/s. For an expendable mission, I estimate this reduced the payload to 8.0 t. That's only a 0.3 t difference, so reusable performance may reduce to 5.2 t, still way above what's required.

What would be the prop margins with a single disposal burn since S2 would be up there a long time without it.  That plus required margin for mission plus LOX boil off would be my answer for expendable.

[Raul]

In context of last Elon's tweet and fact, that this is second Fairing 2.0. on the east coast, I think we can expect water recovery of fairing during GPS IIIA-01 mission- quite near Outer Banks.

.. and USAF GPS Directorate mission patch:

[jacqmans]

First Lockheed Martin-Built GPS III Satellite Encapsulated for Dec. 18 Launch

Advanced new satellite design to help the U.S. Air Force modernize the GPS constellation

TITUSVILLE, Fla., Dec. 11, 2018 /PRNewswire/ -- The U.S. Air Force's first Lockheed Martin (NYSE: LMT)-built GPS III satellite is now encapsulated for its planned December 18 launch from Cape Canaveral Air Force Station, Florida, on a SpaceX Falcon 9 rocket.

GPS III Space Vehicle 01 (GPS III SV01) underwent pre-launch processing, fueling and encapsulation at Astrotech Space Operations, in Titusville, Florida. During encapsulation, GPS III SV01 was sealed in its launch fairing, an aerodynamic, nose-cone shell that protects the satellite during launch. In the coming days, the fairing-enclosed satellite will be mounted to the rocket as launch preparations continue.

The first Lockheed Martin-built GPS III satellite for the Air Force was encapsulated for a December 18 launch.

GPS III SV01 is the first of an entirely new design of GPS satellite which will help the Air Force modernize today's GPS constellation with new technology and advanced capabilities. GPS III has three times better accuracy and up to eight times improved anti-jamming capabilities. Spacecraft life will extend to 15 years, 25 percent longer than any of the GPS satellites on-orbit today. GPS III's new L1C civil signal also will make it the first GPS satellite broadcasting a compatible signal with other international global navigation satellite systems, like Galileo, improving connectivity for civilian users.

"The world is dependent on GPS. More than four billion military, commercial and civilian users connect with signals generated by GPS satellites every day," said Johnathon Caldwell, Lockheed Martin's Vice President for Navigation Systems. "The launch of GPS III SV01 will be the first step in modernizing the Air Force's GPS constellation with the most powerful and resilient GPS satellites ever designed and built."

Lockheed Martin developed GPS III and manufactured GPS III SV01 at its advanced $128-million GPS III Processing Facility near Denver. In September 2017, the Air Force declared the satellite "Available for Launch" (AFL) and had the company place it into storage. Last Summer the Air Force "called up" the satellite for launch and Lockheed Martin delivered it to Florida on August 20. The Air Force nicknamed the satellite "Vespucci" after Italian explorer Amerigo Vespucci.

GPS III SV01 is the first of 10 GPS III satellites originally ordered by the Air Force. GPS III SV03-08 are now in various stages of assembly and test. In August, the Air Force declared the second GPS III "AFL" and, in November, called GPS III SV02 up for 2019 launch.     

In September, the Air Force selected Lockheed Martin for the GPS III Follow On (GPS IIIF) program, an estimated $7.2 billion opportunity to build up to 22 additional GPS IIIF satellites with additional capabilities. GPS IIIF builds off Lockheed Martin's existing modular GPS III, which was designed to evolve with new technology and changing mission needs. On Sept. 26, the Air Force awarded Lockheed Martin a $1.4 billion contract for support to start up the program and to contract the 11th and 12th GPS III satellite. 

For additional GPS III information, photos and video visit: www.lockheedmartin.com/gps.

[Chris Bergin]

Naming note: GPS III-2 is the name on the range, as its the tail number of the spacecraft and not mission number. GPS III SV01 could be a good way to name this one. But we'll go with whatever SpaceX goes with (currently only "GPS III" per media accreditation).

[gongora]

Naming note: GPS III-2 is the name on the range, as its the tail number of the spacecraft and not mission number. GPS III SV01 could be a good way to name this one. But we'll go with whatever SpaceX goes with (currently only "GPS III" per media accreditation).

How is GPS III-2 the tail number of the spacecraft?  It's the first spacecraft.  GPS III-2 was the contract that SpaceX won (the second GPS III contract awarded).  Then they switched the launch order...

[docmordrid]

SpaceX ✔ @SpaceX
 Static fire test of Falcon 9 complete targeting December 18 launch of GPS III SV01 from Pad 40 in Florida.
12:24 AM - Dec 14, 2018

[LouScheffer]

OK, now we know the second stage will de-orbit in the south Atlantic about 6 hours after liftoff.

So my guess is this.  From these estimates, we think the second stage (with expendable booster) should have about 3350 m/s above LEO to play with.  How could this be used?  First, from parking orbit you can get a 250 x 20000 orbit transfer orbit for about 2060 m/s.  This is a 6 hour orbit and would give about the right re-entry time.   But it does not use full capacity of the rocket - there is about 1300 m/s left over.

So they could coast to apogee, then apply about 800 m/s to raise perigee.  Then they release the spacecraft, turn the second stage around, and apply -800 m/s to make it re-enter.  This seems like more than 1300 m/s, but the re-entry burn has no satellite mass and hence is much more efficient.  The GPS satellite ends up in a 8000 x 20000 orbit with only about 600 m/s to go.

This trajectory at least accounts for the re-entry timing, uses the full performance, and takes 3 burns of the second stage, which we know it can do.  Any better ideas?

[Zed_Noir]

....
This trajectory at least accounts for the re-entry timing, uses the full performance, and takes 3 burns of the second stage, which we know it can do.  Any better ideas?

Maybe it is convenient timing that the USAF presents an opportunity and is willing to pay for an expendable Block 5 launch to test out it's maximum mission capability.

The performance numbers posted on the SpaceX website is only an estimate after all.

With the data from this upcoming launch SpaceX could perhaps squeeze a little bit more performance out of the Block 5.

[gongora]

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.

[mlindner]

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.

[Ronsmytheiii]

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.

More like slander.

Seriously, if the USAF wanted ULA to win at all costs, then they would have picked them for the launch. They are buying the launch, and are putting the ones paying (presumably more) for an expendable launch. Ultimately doesn't effect SpaceX, as they are still launching a paying customer.

[gongora]

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.

SpaceX and ULA prices are so far apart at this performance level that $30M really doesn't even make a difference.

[rpapo]

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.

[mlindner]

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.

More like slander.

Seriously, if the USAF wanted ULA to win at all costs, then they would have picked them for the launch. They are buying the launch, and are putting the ones paying (presumably more) for an expendable launch. Ultimately doesn't effect SpaceX, as they are still launching a paying customer.

The Air Force is not monolithic. Just because one part wants SpaceX doesn't mean some other part doesn't but doesn't have control over the selection, but does have control over mission design.

The claims the Air Force themselves are making about the performance of the vehicle being somehow unknown are equally nonsensical/self-slanderous. They've already launched OTV-5 that Air Force would have data on and numerous other vehicles have launched on Falcon 9 that SpaceX has direct performance data on. They're claiming either that SpaceX doesn't know their own vehicle or that SpaceX is lying to the Air Force about the performance. Those would also be slanderous.

[RedLineTrain]

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.

More like slander.

Seriously, if the USAF wanted ULA to win at all costs, then they would have picked them for the launch. They are buying the launch, and are putting the ones paying (presumably more) for an expendable launch. Ultimately doesn't effect SpaceX, as they are still launching a paying customer.

Wasn't this the launch where ULA didn't bid, much to the dissatisfaction of the USAF?

[gongora]

The claims the Air Force themselves are making about the performance of the vehicle being somehow unknown ...

Do you know the mission requirements?  Do you know the margins for F9 completing those mission requirements?

[wannamoonbase]

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.

More like slander.

Seriously, if the USAF wanted ULA to win at all costs, then they would have picked them for the launch. They are buying the launch, and are putting the ones paying (presumably more) for an expendable launch. Ultimately doesn't effect SpaceX, as they are still launching a paying customer.

Agree, there isn’t any schenangians here.  This is learning a new vehicle, we don’t know everything about the contract requirements.  Air Force wants cheaper flights, but they want the lowest risk and longest on orbit life possible.

[gongora]

https://twitter.com/AF_SMC/status/1074439160277086209

[pb2000]

The claims the Air Force themselves are making about the performance of the vehicle being somehow unknown ...

Do you know the mission requirements?  Do you know the margins for F9 completing those mission requirements?

The question is what version of the F9 did SpaceX originally bid? the RFP closed before a F9 FT flew, so it's possible it was bid on 1.1 performance numbers which leaves plenty of gas in the tank for a B5 barge landing.

[edkyle99]

The claims the Air Force themselves are making about the performance of the vehicle being somehow unknown ...

Do you know the mission requirements?  Do you know the margins for F9 completing those mission requirements?

The question is what version of the F9 did SpaceX originally bid? the RFP closed before a F9 FT flew, so it's possible it was bid on 1.1 performance numbers which leaves plenty of gas in the tank for a B5 barge landing.

We will hopefully be able to learn the "why" on launch day, or soon after.  Perhaps this GPS-3 is going to weigh more than everyone thinks at liftoff.  Maybe it is going to a higher orbit (higher perigee) than everyone expects.  Obviously it is going to a higher inclination than the GTO missions reach, which costs performance.  Keep in mind that Block 5 has to date only lifted 5.3 tonnes to a full GTO with first stage recovery on OCISLY.  Maybe it is a two-burn second stage ascent with a higher than usual parking orbit.  Maybe there are any number of other constraints we don't know about.  Maybe the Air Force just wanted extra margin for this initial flight.   

 - Ed Kyle