Rocket Lab unveils reusable medium-lift neutron rocket

To date, Rocket Lab has successfully launched the first dedicated small satellite launcher, Electron, which CEO Peter Beck said would never be reusable. Then the company managed to recover a first step. Now Beck says Rocket Lab is ready to do something else that he previously said he never would do: build a big rocket.

The Neutron Launcher is an eight-ton reusable low-earth orbit (LEO) rocket designed primarily to build constellations of satellites. But Neutron will also be designed from the start to be able to resupply space stations with LEO and even flight crew, another market Beck had previously moved away from.

Beck’s decision to ‘eat his hat’ metaphorically is based on feedback from Electron customers, including exploration missions for future constellations where the satellite operator has developed a relationship with Rocket Lab.

“Historically, the average lifting mass is four to five tons, so large launchers mostly fly empty,” Beck said in an interview with NASASpaceflight. “Most constellations are made up of 500-700 kilograms of spacecraft, with five to 11 satellites per plane.”

These figures relate to the capacity of an eight-ton launcher, but differ by particular constellation.

“Starlink is a unique case because they are in a very low earth orbit, so there are a lot more spaceships.”

Neutron will be a different size from the larger Falcon 9 vehicles that launch Starlink missions. Despite the Falcon 9’s greater payload capacity and the resulting lower cost per kilogram of payload, a partially filled payload shroud still forces the customer to pay the full cost of launching the vehicle.

“The cost per kilogram is a very easy measure to understand. But I don’t know of a single launcher purchased at cost per kilogram. “

Beck says Neutron is ideally sized to deploy satellites to specific orbital planes, and is capable of lifting 98% of all satellites slated for launch through 2029. This could even include bundles of Rocket Lab’s Photon satellites, playing on one of the strengths of the company. .

“Rocket Lab is very good at building complex systems on a large scale.”

Rocket Lab also says Neutron will be able to fly in human space. However, Beck says there is “no current” crew spacecraft in development.

“Developing a crew vehicle is different from developing a vehicle for satellites.” He says Neutron is about keeping crew certification in mind early on in development, in order to keep this market on the table for the future.

Likewise, Rocket Lab is not currently developing a freight replenishment vehicle.

“Cargo certification is a step down in crew certification. But there is no product in development. The priority is to get to the market to serve the constellations. “

That debut, according to Rocket Lab, could take place as early as 2024. But a lot of work remains to be done before a neutron rocket is ready for flight, including the development of a new rocket motor to power the vehicle.

The currently operational Electron rocket uses Rutherford engines powered by RP-1 kerosene and liquid oxygen, the same fuel mixture used for neutrons. These engines are both 3D printed and use electric turbopumps, the first two for an orbital launcher. However, only one of these achievements will impact Neutron’s propulsion.

“Definitely additive manufacturing. But more traditional pumps are needed at this scale. Beck says Neutron’s first stage will be powered by multiple motors, but not as much as Electron’s.

“Nine engines is good if you stop, but otherwise it’s a bit of a pain,” citing the build and testing required for each engine. “A small number of motors is optimal, but large motors have limited acceleration capacity.” Beck says Neutron will have “as few engines as possible”.

A key component of Neutron’s engine development program will be reuse. Beck says, “Reusability determines many engine design decisions.”

Unlike Electron, which uses a parachute recovery system, Neutron will look more like SpaceX’s Falcon 9 in that the first stage will propulsively land on an ocean platform. To do this, the engines must be able to be restarted in flight to perform the landing maneuver. Other aspects of the engine design will also take reflight into account.

Neutron’s announcement comes very early in development. “Our priority has been to analyze the market and raise capital.”

That said, there is the hardware and flying experience from Electron that Rocket Lab can harness for Neutron. “Electron’s avionics will be transferred directly to Neutron. Cryogenic valves are easily scaled. The hard part is developing a cryo valve that works in the first place. There is a lot of heritage. “

Neutron’s choice of launch site also speeds up flight time in 2024. Directly adjacent to their future Electron Launch Complex 2 (LC-2) at the Wallops Flight Facility in Virginia is Pad 0A. , which currently houses Northrop Grumman’s Antares rocket. . This is the launch pad where Neutron will debut, taking advantage of the already existing infrastructure.

“The Pad 0A was really designed as a multi-user pad. With Antares’ relatively low theft rate, we hope not to disturb any other user. “

Wallops is also just the first Neutron launch site. Much like with Electron, Rocket Lab plans to add additional neutron launch sites in the future.

Neutron manufacturing is expected to take place in the immediate vicinity of the Wallops launch site. “Many US launch vehicle diameters are based on the height of the lowest bridge between California and Florida,” says Beck, referring to SpaceX’s Falcon 9 rockets, built in Hawthorne, Calif., And shipped by road to Cape Town. Canaveral.

Designed specifically for reuse, Neutron will also have a different appearance than Electron, with a lack of carbon fiber in the main body. This is due to the poor qualities of carbon fiber when subjected to high heat flux, such as when re-entering.

“The electron can sit behind a shock wave to protect itself from the heat flow. It’s more difficult to do with a bigger vehicle. “

Regarding recovery for reuse, Beck does not anticipate a SpaceX-esque “hop” test program.

“Our priority is to put ourselves into service and deliver a customer satellite. Reuse can’t work, and the mission can still be successful, so we can take some risk there. “

The first phase of recovery should take place on an ocean platform stationed downstream. While the option to perform return to launch site (RTLS) landings is not out of place, it should not be useful for Neutron either.

“I learned never to say anything. Otherwise, it results in unpleasant dining experiences. But we established a flight profile with a downstream landing. “

“It’s a propellant trade between the RTLS and the downstream landing. RTLS begins to develop the vehicle. “

Asked about the potentially creative names of Rocket Lab’s downstream salvage vessel, Beck said. “Of all the problems that we are trying to solve at the moment, this has not arisen, but I am sure we will not disappoint.”

Beck envisions a reusable fleet of neutron boosters. “Our engineering has focused on reusability. We want Neutron to be not only usable, but truly reusable. “

“Electron’s focus is manufacturability. The goal of Neutron is reusability. “

Beck says more work is needed to determine the duty times needed between flights and how many flights a single booster could support.

Beck also says that Rocket Lab could offer a consumable version of Neutron, with a payload capacity of over eight tons at LEO, which is achievable with salvage. “We can spend the vehicle, but it would be a different price.”

In the short term, the priority is to bring Neutron to market to deploy customer constellations, with recovery for reuse using design improvements between flights. Beck says Neutron’s launch rate will be paced to enable these improvements, another difference from Electron where manufacturing has been scaled up to achieve a very high theft rate.

“There are areas in which we innovate and areas in which we are not. We’re not really about pushing the boundaries and innovating with rear-wheel drive.

By focusing on constellation building and reuse, Neutron has the potential to allow Rocket Lab to enter new markets, including human spaceflight. The Neutron vehicle, in its reusable configuration, can also deliver two tons to the moon, or 1.5 tons to Venus or Mars.