Thursday, April 18, 2024

Reusability Changes Everything - the Next Chapter

In a company news update early this week, Rocket Lab announced that their first booster set to be reused is moving through the final steps of being certified for its flight, although they didn't announce a date.

Rocket Lab USA, Inc. (Nasdaq: RKLB) (“Rocket Lab” or “the Company”) today announced it is returning a previously flown Electron rocket first stage tank into the Electron production line for the first time in preparation for reflying the stage. The step is a significant milestone in Rocket Lab’s development program to make Electron the world’s first reusable small orbital launch vehicle.

If  you've been following Rocket Lab launches, you'll know that they started trying to recover boosters by catching their parachutes with a helicopter, and actually caught one, but stopped trying after a couple of more attempts. They then switched to essentially what SpaceX is doing, letting it splash into the ocean and having a nearby ship recover it. They say the previously recovered boosters have been used to develop a standardized method of refurbishing and qualifying those boosters for flight again. This booster, originally launched in January of this year.

The stage was successfully launched and recovered as part of the ‘Four of a Kind’ mission on 31 January 2024 and has already passed more acceptance tests than any other recovered Electron stage, including:

  • Tank pressurization test – a process that filled the carbon composite tank with inert gas and held it in excess of maximum operating pressure for more than 20x longer than the standard Electron flight duration;
  • Helium leak check – a stringent process that determines there are no leaks in the tank; and
  • Carbon fiber structural testing – including ultrasonic assessment and other non-destructive tests to confirm no delamination of the carbon composite tank fibers.
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“This is the exciting final piece of the puzzle before Electron goes reusable,” said Rocket Lab founder and CEO Peter Beck. “Our key priority in pushing this stage back into the standard production flow for the first time is to ensure our systems and qualification processes are fit for accepting pre-flown boosters at scale. If this stage successfully passes and is accepted for flight, we’ll consider opportunities for reflying it in the new year.”Rocket Lab has carried out iterative modifications across multiple recovery missions to hone the recovery process ahead of first reflight, including:

  • Ensuring Electron’s carbon composite structure survives the intense heat and forces of atmospheric reentry through innovative coatings, heat shields, and advanced reaction control systems to control the angle of reentry;
  • Refining the parachute system to ensure reliable deployment and smooth deceleration from more than 2,300 meters per second to 10 meters per second;
  • Honing the telemetry and tracking systems so the marine recovery team can locate the stage as soon as it splashes down;
  • Streamlining the process of collecting the stage from the water in less than an hour, then ensuring safe transit back to the Rocket Lab production complex; and
  • Successful launch of a previously flown Rutherford engine.

The booster immediately before recovery back in January. Image credit: Rocket Lab USA

Bear in mind that Rocket Lab's Electron is in an entirely different market than SpaceX's Falcon 9; the Electron isn't rated to one metric ton to Low Earth Orbit while the Falcon 9 is capable of over 22 metric tons to LEO. Rocket Lab is also working toward a heavier lift booster, the Neutron which is being designed from the start for reuse. I'll speculate that the reason reuse matters for Electron is that SpaceX is sucking up a lot of the market for small satellite launches with their ride sharing missions, Transporter and the new Bandwagon that just had its first flight.  They need to watch their costs.



2 comments:

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  2. It's interesting that SpaceX was all into carbon fiber until they did some serious stress testing, and then found that carbon fiber and composites are great until they aren't and fail spectacularly. Whereas stainless steel can be tested and checked for failures, and can be seen with a naked eye.

    I hope composite construction works for Rocketlab. Looking forward to their continuing successes.

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