The Falcon 9 first stage that successfully landed on the deck of the Autonomous Spaceport Drone Ship (ASDS) barge on Friday sailed into Port Canaveral early on Tuesday. Riding atop “Of Course I Still Love You” the stage is hoping to conduct around ten static test fires ahead of SpaceX’s next reusability milestone of launching the flown stage once again on a mission in the coming months.
CRS-8 F9 S1:
Falcon 9 launched without issue, helping to push the CRS-8 Dragon uphill on a chase with the International Space Station (ISS).
Dragon concluded her two day journey to the orbital outpost via a successful berthing on Sunday, marking the return of SpaceX Commercial Resupply Service (CRS) operations following last year’s loss of the CRS-7 mission.
The successful primary mission was complimented by another achievement for SpaceX’s reusability test objectives, specifically the first-ever safe landing of the first stage on the Autonomous Spaceport Drone Ship (ASDS).
SpaceX had yet to complete a controlled landing on the barge from four previous attempts. The only attempted land-landing to date – during December’s Orbcomm launch – was achieved successfully at the first attempt.
With Falcon 9 already proving she could successfully return the first stage to the LZ-1 landing pad at Cape Canaveral, a successful – more challenging – landing on the drone ship would prove to be a huge boost.
SpaceX CEO and lead designer Elon Musk has noted the use of the ASDS fleet for first stage landings will be required on around half of future SpaceX missions.
“The rocket, at stage separation, is zooming out to sea at an incredible velocity. It doesn’t have enough propellent to zero out that velocity, boostback and land (on certain missions),” noted Mr. Musk.
“So in order to achieve effective reusability for missions that go to high orbit, you really need ocean landing.”
Notably, Dragon missions would allow for boosters to return to land, but for this mission the aim was to prove ASDS landings could be achieved.
“We wanted to do a ship landing where there’s a lot of margin,” Mr. Musk added. “(CRS-8) would have been a low margin return to land or a high margin ship landing.
“So this helped us show the ship landing can work.”
With the stage secured on the deck with steel hold downs welded on to the landing leg feet, the long journey back to Port Canaveral has taken several days, negotiating some challenging sea states and windy conditions.
The trip back to the coast was finally achieved on Tuesday morning, as the ASDS and support ships entered Port Canaveral, this time – for the first time – with a flown Falcon 9 first stage on the deck of the “Of Course I Still Love You”.
During the previous mission, the ASDS only got to show off the battlescars of the attempted landing of the SES-9 first stage, most notably a large hole, which was repaired in time for the CRS-8 objectives.
Now in port, the next phase involved the removal of the stage from the ASDS ahead of transportation. The crane used was already in position before the drone ship’s arrival.
“There’s a loading head fixture that we can put on the top of the rocket where the stage separation system attaches. Then we pick it up with the crane and then put it on a stand which attaches to the launch hold downs,” added Mr. Musk.
“We then fold the landing legs up, rotate the stage horizontal for transport and then take it to (probably) 39A and conduct test firings.
“If that all goes well I think we’ll be comfortable with an orbital flight.”
The leg process actually involved the hardware being removed from the stage, as opposed to folded up, as outlined by Mr. Musk.
The path to a second launch for the stage will only come after rigorous testing to ensure the stage and engines are ready for what will be a hugely historic milestone.
“The plan is to bring this booster back and do a series of test fires. We’re hoping to do that at the Cape, rather than transport it to Texas (SpaceX test center near McGregor).
“The thought it to fire it 10 times in a row and if that looks good it will be qualified for reuse.”
While the returned OG-2 first stage was successfully static-fired for a few seconds at SLC-40 – and now destined to be displayed in pride of place at SpaceX’s Hawthorne HQ – Mr. Musk has big plans for the CRS-8 S1.
Those plans may include a paying customer, launching a payload that has yet to be revealed.
“I think that’s likely,” noted Mr. Musk on achieving the milestone of reflying the booster on an upcoming mission. “We’re hoping to relaunch (this booster) on an orbital mission around May or June…let’s say June. In the future, we’ll be able to launch them (again) within a few weeks.”
Although the set plan is yet to be fully worked out, the likely housing of the booster for post-flight processing is set to be the Horizontal Integration Facility (HIF) at SpaceX’s Pad 39A at the Kennedy Space Center (KSC), which also opens up the potential debut use of the “new” pad for the ten test firings.
Testing at that pad was the original plan for the OG-2 booster, before switching to Falcon 9’s primary home at SLC-40.
Overall, the incremental successes now being achieved by SpaceX – since testing picked up the pace in 2013 – should not be underestimated.
The “landing of first stages” is in itself a major achievement, one which many commentators said would not be possible. Even Mr. Musk did not shy away from the potential of the technology failing to work as required.
With successful landings at both land and sea, SpaceX will now continue to refine the technology and feed it into their overall aspirations of “full and rapid” reusability that will blaze a path to reducing the costs associated with the launch phase of a mission.
“I think it’s a really good milestone for the future of space flight, it’s another step towards the stars,” Mr. Musk said.
“In order for us to open up access to space, we’ve got to achieve full and rapid reusability. Being able to do that for the booster is a huge impact on costs.”
“It’ll take a few years to make that smooth and efficient, but it’s proven it can work. There will probably be some failures in the future, but we’ll iron those out to the point where it’s routine and where the only changes to the rocket are to hose it down, give it a wash, add the propellant and fly again.
“That’s the key.”
(Images: SpaceX, Marek Cyzio (including shots from this video montage) and L2 SpaceX – including renders (Core Testing at 39A and FH Stages Returning) from L2 artist Nathan Koga – The full gallery of Nathan’s (SpaceX Dragon to MCT, SLS, Commercial Crew and more) L2 images can be *found here*)
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