SpaceX’s most significant US Air Force launch contract yet is set to kick off with a (NET) December 18 launch of the first of 10 next-gen GPS satellites, known as GPS III Space Vehicle 1 (SV01). Thus far, SpaceX has won all five competitive GPS III launch contracts offered thus far by the USAF and – depending on Falcon 9’s performance this launch – could win several more.

Aside from contract victories, SpaceX’s first GPS III launch will be marked by yet another first for the company’s May 2018-debuted Falcon 9 Block 5 rocket. This first is not quite as desirable, though: sans landing legs and titanium grid fins, the new Block 5 booster will be expended after launch and will make no attempt to land.

Via @USAirForce: First GPS III satellite, AKA “Vespucci,” encapsulated in fairing on 12/7 ahead of #SpaceX Falcon 9 launch NET 12/18. This is the company’s first GPS mission and is expendable, so there will be no booster recovery. (?: @LockheedMartin) pic.twitter.com/5aOWy1tI5k — Emre Kelly (@EmreKelly) December 11, 2018

At this point in time, the first official confirmation that Falcon 9 will be flying in an expendable configuration was given in a handful of comments made by Vice President of Launch and Build Reliability Hans Koenigsmann at a Dec. 5 press conference. While focused primarily on the topic at hand (SpaceX’s successful launch of the CRS-16 Cargo Dragon), members of the press managed to squeeze in a few minimally related questions which Hans graciously answered. Speaking about SpaceX’s imminent GPS III launch, Hans noted that,

“GPS is not landing a booster. It doesn’t have the landing hardware, or the majority of the landing hardware. … I looked at the booster yesterday, it’s in great shape and getting integrated in the hangar.

GPS III SV01 is encapsulated in Falcon 9’s fairing. (SpaceX) GPS III SV01 is encapsulated in Falcon 9’s fairing. (SpaceX) GPS III SV01 is encapsulated in Falcon 9’s fairing. (SpaceX) Spotted by local photographer Tom McCool on November 27th, this 39A-located Falcon 9 booster is the likeliest candidate for the first GPS III launch. (Tom McCool)

Hans also told members of the audience that he believed the expendable profile had stemmed from a customer (i.e. USAF) requirement based on a need for extra performance:

“Regarding GPS not landing, I think this is a customer requirement to have all the performance for the mission. It’s a challenging mission.“

While there was previously some doubt as to whether Falcon 9 was actually incapable of attempting a booster landing after launch, Mr. Koenigsmann’s offhand suggestion that GPS III launches would be “challenging mission[s]” makes it far more likely that the USAF’s given mission profile genuinely demands all of Falcon 9’s performance – not enough propellant will remain for Falcon 9 to attempt recovery. There is, however, still some ambiguity in Hans’ answer.

If Falcon 9 will be expended solely as a consequence of mission performance requirements despite the oddly low payload mass (~3800 kg) and comparatively low-energy orbit (~20,000 km), the only possible explanation for no attempted recovery would be the need for Falcon 9’s upper stage to perform a lengthy second burn after a long coast in orbit. However, the mission parameters the USAF shopped around for would have placed the GPS III satellite into an elliptical orbit of 1000 km by 20,181 km, an orbit that would unequivocally allow Falcon 9 to attempt a drone ship recovery.

Falcon 9 B1047.2 is seen here conducting its second successful drone ship landing. (SpaceX) In a more perfect world, Falcon 9 would have been responsible for the rainbow. (SpaceX) Lockheed Martin’s GPS III (SV 01-10) satellite. A GPS III spacecraft spreads one of its solar array wings. (USAF)

The reasoning behind this is simple: SpaceX routinely recovers Falcon 9 boosters after far more energetic launches. For example, Falcon 9’s November 15th launch placed the 5300 kg Es’hail-2 satellite into an orbit of 200 km by 37,700 km, after which Falcon 9 B1047.2 performed its second successful landing on drone ship Of Course I Still Love You. A prevailing second theory for the expendable mission lies in the Air Force’s notoriously stodgy and sometimes irrational revulsion at the slightest hint of risk or change – to minimize perceived risk, the USAF could have thus demanded that SpaceX expend Falcon 9 regardless of whether it was capable of doing so.

For GPS III SV01, it appears that only time will tell whether the satellite ends up in an orbit that can properly explain the booster’s premature demise. Given that SpaceX has a full four additional GPS III launches currently on the books, it will be a shame to see a veritable fleet of Falcon 9 Block 5 boosters tossed into the sea after just a single launch each.

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