A few days ago Elon Musk tweeted a photo of the Falcon 9-R(eusable) ‘advanced prototype’ on the engine test stand, nine Merlin 1D engines firing away. Despite notices to the local community that the test could last several minutes, SpaceX says it only went 10s. Rumor is that a problem with the gas generator caused an early abort, and that the company is resetting for another run in the near future.
The interesting question is just what relationship the F9-R (F-Niner) has to do with the Falcon 9 v1.1, SpaceX’s new standard rocket. The company no longer calls the rocket v1.1 — it was always a temporary handle — but has apparently not settled on a new name yet. Is the F9-R just a redubbed v1.1, or a scaled-up Grasshopper test bed?
SpaceX isn’t saying, although its quirky public relations strategy seems partly to hinge on explaining Elon Musk’s tweets and impulsive public comments. Certainly the F-Niner is using a v1.1 core stage, possibly the old stage built for testing. Musk has consistently said that his goal is to build a fully reusable rocket, which given the potential launch cost reductions is somewhat of an industry Holy Grail. Whether Grasshopper II or v1.1 redux, the F-Niner advances in that direction.
The Canadian satellite Cassiope is the next scheduled, with a liftoff date in late 2013. After the last Dragon capsule returned from space a few months ago, Musk said that the next v1.1 flight would include core stage re-ignitions after separation, one near the top of the parabola to slow the stage down and another just above the Pacific Ocean’s surface. The idea is to test re-ignitions with an eye towards one day landing it vertically back at the launch pad. The F-Niner may simply be a v1.1 with engines capable of re-igniting and limited steering capability on the way back down. The idea, Musk said, is to recover each successive launch’s stages closer and closer to the launch pad, until eventually making a pinpoint vertical landing back at its launch pad. Nothing if not ambitious, Musk said further that he expects to do so by the end of the year.
On the other hand, Musk has tweeted a picture of a carbon-fibre A-frame leg with an F-Niner caption, much like the one used on the Grasshopper test bed. Grasshopper is used specifically for vertical takeoff, hovering and landing tests, of which it has successfully conducted four. It is not a complete core stage — it’s essentially a single Merlin 1D with RP-1 and LOx tanks inside a core. The F-Niner may be a more powerful, more representative version of the Grasshopper, or even an attempt to leapfrog to an operational reusable first stage. SpaceX has recently signed a lease for space at Spaceport America in New Mexico, the airfield built for Virgin Galactic that sits under the airspace of White Sands missile test range, almost wholly unencumbered from the civilian airspace restrictions of the McGregor, Texas engine test facility. I had assumed the lease was to allow Grasshopper more flexibility — its last test did approach the edge of allowable airspace at McGregor — but it’s a great place to fly a much more capable Grasshopper II.
It is also worth noting that circumstantial evidence (and my own uninformed speculation) indicates the Falcon super-heavy design effort may be underway. As recently as last year, company officials were openly discussing a rocket known only as MCT, said to be designed around an 8m+-diameter core, and engines capable of putting out over 1 million lbs of thrust. Two things have come to my attention that indicate a formal design programme may be underway:
First, a Bigelow-written, NASA sponsored report was unveiled (the full report has not yet been released), discussing the medium-term future of commercial space, which would allow NASA to ignore those areas and focus on bigger game. To compile the report, Bigelow went to various companies, asking what they intended to do over the next decade or so. SpaceX was one such company, and at the press conference, Bigelow stated that the company is looking “into other generations besides just the heavygeneration. They’re in it for the long haul.” Not exactly a trade secret, but a formal indication TO NASA of their formal interest.
Secondly, SpaceX public affairs no longer answers questions about a super-heavy, and workers at the company have clammed up on a more informal basis. This is essentially the same thing that happened in the runup to Grasshopper’s construction. A super-heavy is many years away — SpaceX has not yet flown the first Falcon 9 Heavy — but an underway design effort is a necessary start.