Last Thursday, SpaceX performed its first full-blown fairing recovery test during the Falcon 9 launch of PAZ and two Starlink demonstration satellites. The attempt involved a new addition to the SpaceX recovery fleet, Mr. Steven, complete with a giant net that is designed to catch returning fairings. While the catch during the PAZ mission was unsuccessful, the other phases of the recovery process showed significant progress.
The fairing is a nose cone structure which encapsulates the payloads on the rocket. It not only protects the payloads during ascent, but it also keeps the vehicle aerodynamic. Once the rocket is in the vacuum of outer space, the fairing is no longer needed. Therefore, it separates into two halves and falls back to Earth.
To reduce the cost of launch, SpaceX hopes to recover and reuse the fairing which represents an estimated $6 million – about 10% of the Falcon 9’s launch cost. Since the five meter diameter fairing splits into two halves when jettisoned, two recoveries are required per launch – with each saving about $3 million worth of hardware.
Currently, SpaceX’s fairing recovery routine works as follows.
Shortly after separation, the two fairing halves use cold gas thrusters and a guidance system to control themselves as they plummet back to Earth at up to eight times the speed of sound.
After entry into Earth’s atmosphere, a parafoil is deployed. The fairing halves are then able to steer themselves towards a general location in the ocean.
The parafoil has been one of the largest challenges with fairing recovery. Just a few weeks ago, SpaceX CEO Elon Musk stated, “It turns out that when you pop the parachute on the fairing, you’ve got this giant awkward thing. It tends to interfere with the airflow on the parachute. It gets all twisty.”
The final portion of recovery involves a vessel. The boat is tasked with positioning itself beneath the fairing, in order to catch it with a net located on the deck. This prevents the fairing from entering the corrosive salt water environment.
The first significant sign of progress came during the Falcon 9 launch of SES-10 in March of 2017. Due to the historic nature of the launch – it was the first reflight of a Falcon 9 booster – SpaceX held a post-launch press conference usually reserved for NASA launches such as Dragon missions. During the conference, Musk announced that not only had SpaceX successfully reused and recovered a Falcon 9 first stage, but they had also successfully recovered a portion of the fairing.