We’ve all been amazed by the videos of the SpaceX rockets returning to their origin and landing on their sharply deplorable legs, looking all over the world as if drawn from a 1950s science fiction movie. On countless occasions, founder Elon Musk and president Nguyen Shotwell praised the qualities of reusable rockets, such as low operating costs and high reliability, with each booster having a flight tradition. At the moment, even NASA feels confident enough to fly on their missions and the reusable SpaceX hardware of astronauts.
Nevertheless, SpaceX’s reusability program remains an external one, as all other launch providers have postponed the course and continue to offer only costly booster rockets. Competitors like United Launch Alliance and Blue Origin have teased varying degrees of reusability for their future vehicles, but to this day they have nothing to show for it beyond some flashy computer-generated imagery. All the while SpaceX has been streamlining their process, reducing turnaround time and repair costs with each successful reuse of a Falcon 9 booster.
But that changed earlier this month, when a helicopter successfully captured an electron booster from a rocket lab in mid-air as it returned to Earth under a parachute. While calling the two companies direct competitors may be an extension due to the relative size and power of their boosters, SpaceX finally has an additional partner in the science of recycling. The Falcon 9 has already broken the space shuttle’s record turnaround time, but Rocket Lab will probably be the first to achieve the stated goal of re-launching Elon Musk’s rocket within 24 hours of recovery.
Arrest and release
Unfortunately, when the helicopter was able Caught The booster did not last long as it returned to Earth. The pilots noted that the behavior of the rocket captured at the end of the tether was inconsistent with the mass simulator they used during the exercise and decided to relax it instead of risking a fatal situation.
It is not yet clear why the flight characteristics of the original rocket differed, but one theory is that its fuel and oxidizer tanks were not completely empty and that the slushing fluid initiated an unexpected oscillation. You would think that the answer would be to run the first nine Rutherford rocket engines until all the propellants have been consumed, but allowing the turbopumps to dry could cause significant internal damage if not completely destroyed.
If it was determined that incomplete propellants were responsible, the solution could be to cut off the main engine (MECO) and flow the fuel and oxidizer tanks into the upper atmosphere after phase separation at an altitude of about 75 km (46 miles); This ensures that the rocket is in an empty and secure configuration long before the helicopter enters the capture area.
The helicopter was unable to bring the rocket back safely to the ground, but all was not lost. As luck would have it, the booster’s parachute swelled again after being released from the tether, and it eventually created a controlled splash in the ocean. While this was clearly a much tougher ride than expected, Rocket Lab CEO Peter Beck indicated that the rocket may still be in good enough condition for reuse. Photo he tweeted from the recovery ship Shows that the rocket and its valuable engine Significantly better condition, although a thorough internal examination will naturally be required before making any decision about using hardware on a future flight.
Fast is not always cheap
It should be noted that Rocket Lab’s argument for trying to reuse their electron rockets is not entirely consistent with SpaceX. Because the rocket is much smaller and cheaper than the Falcon 9, the cost of recovery, especially early in the program, probably outweighs the cost of hardware. But that’s not the point. The unique construction of electrons, including the carbon composite fuselage and the 3D printed engine, means that it currently takes about a month to build each rocket. When your competitors fly every two weeks, that’s not good enough.
As Peter Beck explained when he announced the company’s plans to re-electron in 2019, it is expected that a rescued rocket could be renewed in less time than it takes to build a new one. Even if recovery and renewal are more expensive, in the long run, extended launch cadence will be better for the bottom line of the rocket lab. With each rocket recycled only once, they would double the number of missions they could fly in a year.
SpaceX has used recycling to reduce their operating costs, with Rocket Labs looking at it as an alternative to setting up a second electron production line. It is unknown at this time what he will do after leaving the post.