With Rocket Lab’s Daring Midair Catch, Reusable Rockets Go Mainstream

We’ve all marveled at the videos of SpaceX rockets returning to their point of origin and landing on their spindly deployable legs, looking for all the world like something pulled from a 1950s science fiction film.  On countless occasions founder Elon Musk and president Gwynne Shotwell have extolled the virtues of reusable rockets, such as lower operating cost and the higher reliability that comes with each booster having a flight heritage. At this point, even NASA feels confident enough to fly their missions and astronauts on reused SpaceX hardware.

Even so, SpaceX’s reusability program has remained an outlier, as all other launch providers have stayed the course and continue to offer only expendable booster rockets. Competitors such as United Launch Alliance and Blue Origin have teased varying degrees of reusability for their future vehicles, but to date have nothing to show for it beyond some flashy computer-generated imagery. All the while SpaceX continues to streamline their process, reducing turnaround time and refurbishment costs with each successful reuse of a Falcon 9 booster.

But that changed earlier this month, when a helicopter successfully caught one of Rocket Lab’s Electron boosters in midair as it fell back down to Earth under a parachute. While calling the two companies outright competitors might be a stretch given the relative sizes and capabilities of their boosters, SpaceX finally has a sparing partner when it comes to the science of reusability. The Falcon 9 has already smashed the Space Shuttle’s record turnaround time, but perhaps Rocket Lab will be the first to achieve Elon Musk’s stated goal of re-flying a rocket within 24 hours of its recovery.

Catch and Release

Unfortunately, while the helicopter was able to catch the booster as it returned to Earth, it wasn’t able to hold onto it for long. The pilots noted that the behavior of the captured rocket at the end of the tether was inconsistent with that of the mass simulator they had used during the practice runs, and rather than risk a deadly situation, they made the decision to cut it loose.

It’s still not clear why the flight characteristics of the real rocket were different, but one theory is that its fuel and oxidizer tanks were not fully empty, and the sloshing liquid introduced unexpected oscillations. You might think the answer would be to simply run the first stage’s nine Rutherford rocket engines until all propellants were expended, but allowing the turbopumps to run dry would likely lead to significant internal damage, if not complete destruction.

Should it be determined that unburned propellants were to blame, the solution would likely be to vent the fuel and oxidizer tanks into the upper atmosphere after main engine cutoff (MECO) and stage separation at an altitude of approximately 75 kilometers (46 miles); thus ensuring the rocket is empty and in a safe configuration long before the helicopter enters the capture area.

Even though the helicopter wasn’t able to bring the rocket back down to the ground safely, all was not lost. As luck would have it, the booster’s parachute reinflated after it was released from the tether, and it ultimately made a controlled splash down in the ocean. While it obviously had a far rougher ride than anticipated, Rocket Lab CEO Peter Beck has hinted that the rocket may still be in good enough condition to reuse. Pictures he tweeted from the recovery ship appear to show that the rocket and its valuable engines are in remarkably good shape, though a thorough internal examination will naturally be required before any decisions can be made about using the hardware on a future flight.

Faster isn’t Always Cheaper

It’s worth noting that Rocket Lab’s rationale for attempting to reuse their Electron rockets isn’t quite in line with that of SpaceX. Being a far smaller and cheaper rocket than the Falcon 9, the cost of recovery, especially this early in the program, likely exceeds the value of the hardware itself. But that’s not the point. The unique construction of the Electron, with its carbon composite fuselage and 3D printed engines, means it currently takes a month to produce each rocket. When your competitors are flying every two weeks, that’s simply not good enough.

Electron and Falcon 9 to Scale

As Peter Beck explained when he first announced the company’s plan to make Electron reusable in 2019, the hope is that a recovered rocket can be refurbished in less time than it takes to construct a new one. Even if the recovery and refurbishment ends up being more expensive, in the long-term, the increased launch cadence will be better for Rocket Lab’s bottom line. By reusing each rocket just once, they will double the number of missions they can fly in a year.

While SpaceX has used reusability to slash their operating costs, Rocket Lab sees it as an alternative to setting up a second Electron production line. Whether it will be as successful for them as it has been for SpaceX is yet to be seen, but one thing is clear: single-use rockets are becoming an increasingly quaint concept among this new breed of aerospace companies.

34 thoughts on “With Rocket Lab’s Daring Midair Catch, Reusable Rockets Go Mainstream

  1. First thought after seeing main art picture – someone figured out to launch missile between helicopter blades. As in WWI machine gun between aircraft propellers ;D

    1. RP-1 is basically kerosene, right? Why does dumping a very small amount of it in the upper atmosphere matter compared to the insane amounts we constantly dump into the lower atmosphere?

  2. If they were to vent the fuel and oxidizer into the atmosphere, wouldn’t that pose a pretty significant environmental impact? I guess mainly if it was a kerosene-type fuel.

    1. It uses RP-1 (basically kerosene) and liquid oxygen. The oxygen is fine, but the RP-1 would be problematic for the environment. Dumping it at high altitude so that it can disperse is probably a better alternative than the rocket not being recoverable and going in the ocean, fuel and all. Long term, we probably should transition away from fossil fuels for rocket propulsion, but I was under the impression that space flight is so infrequent that the environmental impact is relatively small compared to things like commercial air travel.

      1. Millions and perhaps billions of barrels of crude oil leak from the ocean floor into the ocean in the Gulf of Mexico every year, not to mention the geothermal vents spewing lots of toxic chemical so no a little RP-1 is not an issue. What fuel do you propose to use for rockets that is not a fossil fuel ?

        Also, recovery costs should not be high once perfected since it is essentially the cost of a helicopter flight. Don’t see any way that it would exceed the cost of the rocket. The main problem with the recovery method used here is that it won’t scale to larger rockets since you are limited by the capacity of the aircraft used. You can”t make helicopters arbitrarily large because the mass of the blades gets out of hand quickly

        1. ” What fuel do you propose to use for rockets that is not a fossil fuel ?”
          Not my fuel, but SpaceX seems to be having success with methane, which can be synthesized from CO2 and H20.

        2. But he likes the oil, he likes plane trips and vacations. He’s never even been on a rocket.

          ” So let’s blame the rockets.” isn’t exactly a surprising attitude. It’s actually the most common.

          You’re looking for a technical solution to an ethical problem. Some people would greatly prefer not to see the scale or scope of, or their own part in this mess we’ve made

  3. SpaceX recently turned around one of their Falcon 9’s in 9 days. All the other launch providers must be quaking in their boots. There is no way they can compete until they figure out reusability.

      1. Not that turn around time matters as long as you have enough inventory to support the launch schedule. SpaceX is looking to improve turn-around time greatly with Starship with much larger payloads and Elon Musk is talking about fleet sizes of 1000+ Starships.

  4. SpaceX uses reusability for both cost and capacity reasons. Capacity because they are also trying to develop Starship/Superheavy and they need the staff working on that rather than new Falcon rockets.
    The intent is to phase out Falcon once the new rockets are running, which should reduce turn-around time (less coking with methane as your propellant rather than RP1) and increase reusability as the upper stage becomes a reusable component also.

  5. Not knowing how long the helo held onto the booster, I’m guessing it allowed to engines to cool down a bit more before hitting the salt water (less thermal stress?).

  6. It sounds like so many things can go wrong. Would you want a rocket hitting the helicopter and going through its blades?
    Do you want a helicopter racing towards a moving object, miscalculate and hit the rocket? Do you want the inertia of both vehicles to pull each other off course and be dangerous? What would a little bit of wind do to the parachute? Would the wind gusts make the helicopter unstable?

    Space X has a working solution. Try to be like them or else you will be practicing a moon lander computer simulation except this isn’t a personal computer program. I already have an idea how Space X does it and if not, its how I would do it.

    1. 1. Rocket should be on parachute before helicopter approaches so not much chance of the rocket hitting the copter. US has used mid air capture on return spacecraft since before manned flight (see reconnaissance satellite payloads).

      2. SpaceX Falcon 9 and Electron are completely different things. Total size of Electron means it is too small to use propulsive landing because it does not have the capacity to lift usable payload plus the fuel to land. SpaceX Falcon 9 is far too heavy for a mid air capture but has the lift capacity for propulsive landing. Falcon 9 is geared to normal orbital launch capacities and Electron is geared to small (think Cubesat or LEOsat) payloads and extremely low costs. Not sure of the commercial viability of Electron given its limitations but maybe has a niche for small LEO satellites.

      1. “US has used mid air capture on return spacecraft since before manned flight”

        Ah yes, the secret 1891-1902 Space program headed up by James West and Artemus Gordon, along with a panoply of Wold Newton notables, like Phineas Fogg, Professor Challenger and a contingent of LXGers led by Captain Nemo … of course in response to the Martian attack on UK fictionalised by HG Wells.

        ;-)

  7. > helicopter successfully caught

    just like that time I successfully dated Jessica Alba by deciding to ask her out … if I ever see her in person

    What really happened:

    >for a few brief moments. However, the helicopter pilot noticed “different load characteristics” that Rocket Lab had not experienced during previous testing. “At his discretion, the pilot offloaded the stage

    I get that they need funding or good headlines to catch a contract (hopefully for longer than their helicopter), but cmon, lets not embellish the truth guys.

    1. Rocketlab have been launching successfully for several years and have quite a backlog of launches (hence the desire to recover and reuse boosters in the first place). They have no need to ‘catch contracts’.
      The core successfully reentered (without a deceleration burn or deployed TPS, which is a unique capability of Electron), targeted the catch area, deployed its parachute, and descended stably. The helicopter successfully rendezvoused with the descending core, manoeuvred to catch the trailing tether, and caught the trailing tether. That loading criteria were set conservatively (in favour of safety) does nothing to besmirch all the successes leading up to that.

      1. Not bad for an early attempt. SpaceX was not shy either about crashing a lot of rockets before stringing together lots of successes. The only negative I see to the Rocketlab solution is that it does not scale larger so if they look to move up in weight class they are going to have to perfect another (probably propulsive) landing method that puts them into square competition with SpaceX. I don’t think anyone really wants to be in direct competition with SpaceX at this point. Seems like ULA and Blue Origin are certainly losing that battle.

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