Main Engine Cut Off

Relativity Space’s Terran 1

Jeff Foust of SpaceNews had a great article about Relativity Space in the November issue of SpaceNews Magazine, and it’s now online. It contains some great photos of Relativity’s hardware, including one shot of their engine, which I had never seen.

Most interesting to me is the payload capacity they’re targeting with Terran 1, their first vehicle:

While the company has been developing technologies to 3D print launch vehicles, it has also been working on an engine for it. The Aeon 1 engine, powered by methane and liquid oxygen and producing more than 15,000 pounds-force of thrust, has undergone tests at NASA’s Stennis Space Center in Mississippi. The Space Act Agreement between NASA and Relativity for those tests was one of the few hints of the company’s activities while the company was in stealth.

“It simplifies a lot of the vehicle architecture,” Ellis said of the choice of propellants. That combination allows for what’s known as “autogenous” pressurization, where the propellants in effect self-pressurize, eliminating the need for helium bottles and plumbing to pressurize the tanks.

The company plans to initially put those technologies together into a rocket called Terran 1. The two-stage rocket will have nine Aeon 1 engines in its first stage and one in its second. It will be capable of placing up to 1,250 kilograms into low Earth orbit.

In recent weeks, I’ve been talking about the fact that the new batch of small launch vehicles—Electron, LauncerOne, and the like—are all a bit too small for some payloads—especially Department of Defense payloads.

If Virgin Orbit delivers on their stated cost and performance goals for LauncherOne, they’ll put Minotaur I out of work in a hurry. But the market is still without any vehicles that put the heavier Minotaurs—Minotaur IV and Minotaur-C specifically—in any danger.

Terran 1 could be the first truly commercial launch vehicle to take on those heavier Minotaurs.

Not to mention Relativity’s focus on a quick timeline from production to launch, which would also be quite interesting to the Department of Defense, I’m sure.