SpaceX has retracted and stowed all four landing legs of a Block 5 Falcon 9 booster for the first time. The milestone could shave days off the time it takes teams to recover and prepare a booster for its next flight.
On May 4, a Falcon 9 was launched from Cape Canaveral carrying the CRS-17 Dragon spacecraft destined for the International Space Station. Following stage separation, the rocket’s first stage booster, identified as B1056 returned to Earth and touched down on one the company’s droneships stationed off the coast of Florida.
Once the booster was towed back to Port Canaveral, recovery teams then proceed to retract and stow the booster’s four landing legs one at a time. Although this is not the first time the retraction of a Block 5 booster’s landing legs has been attempted, it is the first time the operation has been completed successfully. Previous attempts had been abandoned without any details from the Calfornia-based launch provider. In these instances, the legs had to be completed removed and then reattached during the refurbishment and preflight preparation phases.
SpaceX has completed the first landing leg retraction, crews locked it in place and removed the cable.
This is one of the upgraded features on Falcon 9 Block 5, for rapid reusability.
— TomCross (@_TomCross_) May 7, 2019
The process of retracting and stowing the B1056 boosters landing legs was captured by photographer Tom Cross. In response to a post describing the process taking no longer than 15 minutes a leg, SpaceX founder and CEO Elon Musk adding that the accomplishment is a huge step to improving reusability.
“One of the biggest reusability improvements was fast leg stow. Version 1 sometimes took days.” tweeted Musk.
Each of a Block 5 Falcon 9 booster’s four legs measure around 10 meters (33 feet) and weigh around 600 kilograms (1,300 pounds). It uses a carbon fibre telescoping deployment mechanism that gives the leg enough strength to support the weight of the booster during a touchdown. However, to ensure the mechanism’s reliability, it’s simple and has no built-in way of retracing itself, thus the need for recovery crews to do so manually.