Reusability in spaceflight is increasing. While SpaceX has been able to reuse the first stage of its Falcon 9 rocket by landing them, Rocket Lab is taking a different sort of approach with its Electron rocket: deploying a parachute and using a helicopter to scoop them out of the air.
It’s certainly a different approach than landing, but Rocket Lab teams are hard at work making this reusability a reality.
While Rocket Lab has plans to land the first stage of its Neutron vehicle, much like SpaceX does with the Falcon 9, the company’s Electron rocket was not designed with reusability in mind.
Rocket Lab CEO Peter Beck had to eat his hat as the company started working towards reuse.
Reusing rockets come with both challenges and advantages. By reusing the first stage, the company only has to perform some repairs and could dramatically lower the cost of each flight.
However, in order to reuse a rocket, recovery systems must be designed and implemented, systems that add both weight and complexity.
The more mass on the rocket, the less payload can be delivered to orbit. The most efficient stage to reuse is the first stage of the rocket, where the added mass has a minimal decrease in the payload capacity. As you move to the final stage of the rocket, the maximum payload mass decreases at a rate of roughly one-to-one to the mass added by recovery systems. This is one of the reasons most space companies are focusing on reusing the first stage, rather than fully reusable rockets.
Catching rockets with helicopters
It sounds like, quite frankly, a crazy idea. But it seems promising, and it’s not like mid-air retrieval was invented by Rocket Lab. Mid-air retrievals have been taking place for almost 70 years.
One of the more well-known examples of this retrieval method is the recovery of film capsules from reconnaissance satellites in the 1960s. The Corona keyhole satellites would eject the film canisters, which floated down on parachutes and were retrieved mid-air by C119s then JC-130s. In order to be able to catch the canisters, the teams would train regularly.
That is where Rocket Lab is now – training teams to catch the floating boosters.
Rocket Lab CEO Peter Beck shared a photograph of the tests on Twitter.
The company later shared video of the practice on social media.
Rocket Lab has already done some recovery, with the first stages being scooped out of the water after parachuting down, but it is the helicopter recovery that will allow the company to truly reap the benefits of reuse.
Rocket Lab isn’t the only company looking at mid-air recovery to facilitate reuse. ULA aims to implement “SMART” reuse with its upcoming Vulcan rocket. With this reuse, the BE-4 engines on rockets first stage would be ejected, with an inflatable heat shield to protect them. They would then be caught mid-air to be installed on a new Vulcan first stage.