SpaceX’s reusability aspirations will receive further testing at Spaceport America, in the shape of the first successfully recovered Falcon 9 first stage. The New Mexico spaceport will host the recovered booster – potentially the core stage from the upcoming CRS-6 mission, if recovered – for an additional flight to find hardware limits, paving the way for the first full reuse of a stage during a future launch in 2016.
The path towards launching, recovering and reusing a first stage booster is part of a plan unveiled by SpaceX founder Elon Musk back in September of 2011 – initially featuring first and second stages that would fly back to the launch site under their own power. Mr Musk had previously hinted at such an ambition as early as 2009.
While efforts to achieve this goal are in the pipeline for the Upper Stage, milestones have already been achieved with the booster, via incremental advances during the life of the upgraded Falcon 9 v1.1.
The debut of the Falcon 9 v1.1 – carrying the CASSIOPE satellite – involved the first “boost back” test of the first stage, while there was also a boost back test during the SES-8 mission, or at least the restart of the first stage post staging.
More testing was involved on the F9 v1.1 mission that successfully lofted the Thaicom-6 satellite.
These attempts allowed SpaceX to further refine their approach – such as adding strength to the baffles in the first stage tanks, prior to adding landing legs in anticipation of a stage “landing on her feet“.
Those legs on the aft of the stage debuted during the Falcon 9 v1.1 launch of the CRS-3/SpX-3 Dragon.
The stage touched down on the Atlantic Ocean in impressive style – as much as high seas soon destroyed and swallowed the hardware.
Footage, which required a huge crowdsourcing effort by NASASpaceFlight.com members – earning the thanks of Mr. Musk – showed the stage conducting the required burns and deploying the legs, as planned.
Further ocean landing attempts helped develop additional aids, such as the grid fins for stability, prior to the next stage of testing.
This involved the debut of the Autonomous Spaceport Drone Ship (ASDS), which was deployed ahead of the small possibility the first stage from the CRS-5/SpX-5 launch could make a successful landing attempt.
The landing attempt was “close, but no cigar” as the stage returned with too much velocity and lost some of its required stability due to the grid fins running out of hydraulic fluid right before landing.
The stage still managed to find the deck, albeit at an angle, before crashing over the side of the deck into the ocean.
The ASDS only suffered relatively minor damage from its meeting with the stage, while SpaceX used the data to provide the next stage with additional hydraulic fluid to mitigate the CRS-5 stage’s shortcomings.
The following attempt, with the first stage that had successfully completed its role as part of lofting the Deep Space Climate Observatory (DSCOVR) spacecraft into orbit, showed progress had been achieved, as the stage returned through its re-entry and landing burns with good stability.
However, poor sea conditions impacted on the ASDS’ role of being in position to receive the stage, resulting in SpaceX opting to call off the landing attempt, instead allowing the stage to conduct a soft landing in the ocean.
It was later noted that the landing was stable and precise – and may have resulted in a good landing had the ASDS been able to receive it.
While work was recently conducted to make the ASDS more battle-hardened – with the addition of a barrier to deal with tough sea conditions – SpaceX’s next landing attempt was moved to the CRS-6/SpX-6 Dragon mission.
That was the next landing attempt because both of the preceding launches – with Asia Broadcast Satellite’s ABS-3A spacecraft and Eutelsat 115 West B, along with the upcoming TurkmenistanSat mission – were classed as requiring all of the juice available in the Falcon 9’s propellant tanks, thus negating spare fuel for the return leg of the first stage.
Interestingly, that most recent mission resulted in impressive performance from the launch vehicle, with source information noting the upper stage shut down on reaching the “apogee maximum limit”, still with propellant available for additional performance, had it been required. The contracted minimum apogee was actually many thousands of miles less than what was actually achieved.
The TurkmenistanSat mission was to be the next launch, prior to an issue with “bad trends” in the data relating to the helium tanks aboard the rocket. Following a review, it was decided that this launch will be slipped until at least April 24.
As a result, the next SpaceX mission to launch will be the CRS-6 mission with Dragon, set for another cargo run to the International Space Station (ISS). As had been previously planned, this Falcon 9 will have legs and will attempt to land on the ASDS.
Although the probability of a successful landing is still in the balance, the historic milestone of a Falcon 9 first stage landing on the deck of the ASDS – prior to being secured via chains around the aft, and triumphantly being shipped back to the coast – would initiate an additional test program.
That plan, it is understood, would result in the recovered stage being safed and shipped to Spaceport America in New Mexico.
SpaceX already has a small base of operations at the spaceport, which will be the primary site for Virgin Galactic’s SpaceShipTwo.
The original plan was to use the site for test flights of the second F9R Development Vehicle, known as F9R Dev2, a follow on vehicle from the impressive Grasshopper and F9R Dev1 vehicles that paved the way for the propulsive landing attempts.
Those vehicles were tested at SpaceX’s McGregor test site in Texas, but were restricted by an altitude ceiling, resulting in the decision to conduct tests at Spaceport America, at much greater altitudes.
Now, based on the advances made during recent missions, it appears SpaceX is hoping to promote the role of Spaceport America, specifically to put the first recovered stage through its paces.
Those tests will be used to find hardware limits, such as how many cycles can be put on a stage, while the second successfully recovered booster would provide the role of qualification testing.
Should the recovery efforts progress, the first launch of a reused booster is likely to occur in late 2016.
Another major milestone in the reusability path will be a stage returning to land, with the earliest planned attempt – should all testing go to plan ahead of the mission – being the Jason-3 launch in the summer.
This would result in the stage returning for a landing at SLC-4 at Vandenberg Air Force Base in California. This will be at the mercy of SpaceX’s confidence levels, and a second ASDS, based on the West Coast, has already been confirmed.
SpaceX is also planning to land stages on the East Coast, at Cape Canaveral’s SLC-13.
Returning to land is not only important to SpaceX for the eventual turnaround flow schedules, but it also mitigates the loss rate expected from landings involving sea recovery, not least due to weather variables associated with the ASDS.
These advances will then feed into SpaceX’s Falcon Heavy rocket, which will be aiming to return three cores per mission. Technically, it has been argued, that returning all three cores from Falcon Heavy flights could result in the rocket becoming cheaper to operate than an expendable Falcon 9.
(Images: via L2’s SpaceX Section, including renderings created by L2 Artist Nathan Koga – Click here for full resolution F9, F9-R, FH and BFR renderings and more – these are not official SpaceX images. Other images from SpaceX)
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