SpaceX Land First Stage Falcon 9 at Sea

first stage CRS8 safe

SpaceX have at last successfully landed a first stage Falcon 9 rocket at sea. It was the pioneering company’s fifth attempt. The event means that SpaceX have now successfully demonstrated their Falcon 9 first stage capable of landing both at sea and on land (a recovery first performed in December).

It’s a monumental achievement — something SpaceX have been chasing for years.

The ability to recover a first stage rocket (i.e. the lower rocket responsible for launch) means greatly reduced operating costs for SpaceX. More importantly perhaps, it’s also an important foundational technology that’ll be required for ambitions for going to, and returning from, another planet such as Mars. In the simplest of terms, reusability stands to dramatically accelerate access to space.

The landing came as part of the CRS-8 Mission of April 8 which involved SpaceX’s Falcon 9 rocket launching a Dragon spacecraft into low Earth orbit to deliver cargo to the International Space Station (ISS) for NASA. It’s the eighth mission in a series of twenty or so that SpaceX have undertaken as part of the Commercial Resupply Service (CRS) contract with NASA.

CRS8 launch

Like so many of SpaceX’s recent launches, however, all attention was on the attempted landing of the first stage rocket. That moment of success came just 8 minutes and 35 seconds after a nominal launch.

first stage CRS8 approach

The first stage on approach to the drone ship ‘Of Course I Still Love You’, having descended from an altitude of some 200 km and maintained control through speeds in excess of six times the speed of sound. Image via SpaceX.

first stage CRS8 landing

The first stage close to approach with landing legs deployed. Image via SpaceX.

first stage CRS8 safe

Safe and sound. The first stage rests. Image via SpaceX.

The landing was made offshore, at the autonomous ship ‘Of Course I Still Love You’ floating somewhere out in the Atlantic Ocean off the coast of Florida.

Significance

This was a really good milestone for the future of spaceflight. This is another step to the stars.

Elon Musk

The reason why landing offshore is such a big deal is because it’s not always possible to land at a site of choice, say at a custom built landing pad as was the case in December. Depending on mission parameters, the first stage rocket might not have enough fuel left over to enable it to return to land. This is is often the case with missions requiring payload delivery into higher orbits, since they require more fuel.

Positioning a floating landing pad out at sea — essentially at a location convenient for where the first stage’s launch trajectory has taken it — means that the first stage can land, even with the limited fuel it has left over after launch.

SpaceX’s motivation for developing this sort of landing technology is plain, simple economics — ditching rockets after a single use is a costly affair and in consequence a massive barrier to fostering greater space endeavours.

Relative to the costs of manufacturing a rocket, the fuel costs of a launch are almost insignificant: around $200,000 in fuel and oxygen make up just 0.35% of Falcon 9’s $61 million launch costs. By re-using a first stage, that launch cost may be reduced to $43 million.

In the longer term, SpaceX plan for “rapid and complete reusability” of both first and second stage rockets. President and COO Gywnne Shotwell, has previously said (in interview) that to recover, refurbish and re-use rockets would result in slashing of launch costs down to something between $5 to $7 million.

Drone ship 'Of Course I Still Love You'. Image via SpaceX.

Drone ship ‘Of Course I Still Love You’. Image via SpaceX.

What Comes After Landing?

Safely landing and recovering the first stage is of course not the end of the story. What SpaceX really need to demonstrate is that the recovered first stage is capable of being scrubbed up, and made ready for another launch. Critically, the process has to cost-efficient and relatively quick.

NASA’s space shuttle was always envisioned as a re-usable space launch vehicle. But in reality the massive costs and labour required for this after each mission meant that the space shuttle failed to live up to expectations.

So what about the Falcon 9? Well, the first stage recovered in December provides some indication on the state of play. Although it’ll never fly again — it will instead sit outside SpaceX headquarters –, it was cleaned up and put through some tests. A static fire (where the rocket is held down and ignited) went mostly well, though SpaceX did report thrust fluctuations in one of the rocket’s nine Merlin engines.

23789045829_c139b832df_k

The first stage recovered in December. Image via SpaceX.

Friday’s first stage rocket is planned for an enhanced battery of tests, including 10 static fires. Asked if the booster will be launched again, Elon Musk said: “I think that’s likely. If things look good it will be qualified for re-use. We’re hoping to relaunch it on an orbital mission, let’s say by June,”.

 

About the CRS-8 Mission

Friday’s launch took place from Pad 40 at Cape Canaveral, Florida. Ten minutes after launch — with the first stage already landed — the Dragon spacecraft was deployed successfully. Two days after launch the Dragon spacecraft then successfully docked with ISS — an operation involving ISS crew members using a 17.6 meter (57.7 foot) robotic arm to capture the Dragon. The spacecraft will stay there for a little over a month before it’s released, and burns it’s way back to Earth, to splash down in the Pacific Ocean.

Dragon sits atop Falcon 9 in preparation for launch of the CRS-8 mission for NASA, Cape Canaveral. Image via SpaceX.

The Dragon cargo spacecraft sits atop Falcon 9 prior to launch of the CRS-8 mission for NASA, Cape Canaveral. Image via SpaceX.

The cargo contained within the Dragon is not insignificant (for a look at the inventory, see, NASA).

Notably it contained a prototype expandable module that will be connected onto the ISS. It’s called the Bigelow Expandable Activity Module (or BEAM), and has been developed by Bigelow Aerospace. Once in place, the module will be expanded to a rigid, multi-purpose structure that astronauts can work in. The design is unique — all existing ISS modules are of an inflexible metallic design. The expandable characteristic means that while BEAM measures just 2.4 meters (8 feet) wide while it’s being transported as cargo, once it’s deployed it will add 16 cubic meters (565 cubic feet) of volume to ISS.

It’s the kind of technology that’ll be crucial to missions further into space, and setting up colonies on Mars.

Expandable habitat from Bigelow Aerospace being lifted into Dragon's trunk for a ride to the space station. Image via SpaceX.

Expandable habitat from Bigelow Aerospace being lifted into Dragon’s trunk. Image via SpaceX.

The Year Ahead

Anyone keeping up with Phlebas’ coverage of SpaceX endeavours knows that the year ahead is a big one for the company.

Having been delayed, it’s not until the end of the year that we now hope to see the maiden flight of the mammoth Falcon Heavy rocket. Falcon Heavy is being built from three Falcon 9 first stages, with a second stage atop the middle lower stage.

On January 30, Elon Musk remarked that the Falcon Heavy “is supposed to launch toward the end of this year. I’d say maybe late September,” (Spacenews.com).

On the plus side, in the months leading up to Falcon Heavy’s debut SpaceX plan on increasing the cadence of launches. Ars Technica report that last month SpaceX’s president, Gwynne Shotwell, stated SpaceX’s plan was to launch 18 missions this year. Friday’s was the third launch of 2016.

Certainly SpaceX have the customers — all of whom are lined up for SpaceX’s much reduced costs compared to the competition. Those customers are a diverse bunch: NASA — obviously — with the commercial space station resupply missions (which will continue under a second contract until 2024); private telecommunications firms needing their satellites launched; and the US government with science and national security missions.

It’s an exciting proposition — with some speculating over as many as one launch every two weeks by the end of the year.

SpaceX’s next launch is planned for later this month, with another in the beginning of May. Within those launches we can anticipate more first stage recoveries — both at sea and on land. One of those missions is very likely to feature a first stage rocket being re-used.

Complete SpaceX webcast of the Falcon 9 CRS-8 launch and first stage landing:

SpaceX CRS-8 Mission Press Kit

Read more from Phlebas about SpaceX’s plans — Successes & Delays: SpaceX’s Pursuit of Re-Useable Rockets