Reditus Space Finishes Building Its Reentry Vehicle, Promises to Bring Stuff Back From Space

WASHINGTON - Reditus Space, a startup that wants to make spacecraft as reusable as a good Tupperware container, has completed its first vehicle. The company announced July 13 that it has finished assembling ENOS, a 200-kilogram reentry vehicle scheduled to launch later this year on a SpaceX rideshare mission. ENOS will spend two months in orbit before reentering and splashing down off the coast of Florida, presumably to the delight of any nearby boaters.

Reditus Space is one of several companies working on reentry vehicles that can return microgravity research and manufacturing payloads from orbit. But unlike the more traditional approach - where you have a big satellite with a tiny capsule attached that makes the dramatic reentry while the big satellite burns up like a forgotten pizza - Reditus is taking a different tack. “In contrast to a more traditional reentry mission where you would have a big satellite and a small capsule attached to it that makes its reentry, this is a singular system where more than 80% of the mass of the actual system makes its way back down to Earth to have the ability to be launched again in the future,” said Stef Crum, the company’s chief executive, in an interview.

That approach creates what he calls a “step change” in capabilities. One is the ability to recover and reuse the spacecraft. The second is that returning the entire spacecraft increases the payload that can be returned. He estimated that the 200-kilogram ENOS can carry about 60 kilograms of payload - roughly the weight of a small adult, if that adult were made of scientific instruments.

Crum said it is unlikely the company would refly much of the hardware from ENOS as it revises the designs of future vehicles based on the experience of building and operating ENOS. “The biggest driver for us is going to be focused on frequency: building more systems out, building them to have more capabilities,” he said. That includes vehicles specialized for specific applications, such as hosting biological payloads - because nothing says “advanced science” like space-faring petri dishes.

This first mission is primarily a technology demonstration, but it is carrying some customer payloads. He said the company is seeing interest in its vehicles from the pharmaceutical industry as well as companies developing advanced materials for semiconductors. The company is also seeing interest in using its vehicles to advance hypersonic technologies by testing them during reentry - because if you can’t test your hypersonic tech on a vehicle screaming through the atmosphere at Mach 20, where can you?

The technology demonstration portion of ENOS will validate the design of the spacecraft. One challenge, Crum said, was thermal management: The spacecraft is designed to prevent heat from getting into it during reentry, but that also makes it difficult for the spacecraft to expel heat while in orbit. “It was an engineering challenge that was simultaneously very fun and frustrating,” he recalled. The spacecraft uses a proprietary material called RHEA for its thermal protection system that the company developed with support from NASA - because nothing says “fun” like inventing a new material to keep your spaceship from melting.

Some systems on the spacecraft, including solar panels, radiators and some sensors, are in a “backpack” that will be jettisoned before reentry and thus not recovered. “As we continue to iterate, that backpack will continue to grow smaller and, at some point, cease to exist altogether,” he said. The backpack, presumably, will go to that great lost-and-found in the sky.

Reditus Space raised $7.1 million in seed funding last December that funded development of ENOS. Crum said the company expects to use a combination of additional investment and customer revenue to fund future missions but did not disclose specifics. That limited funding was sufficient because the company developed ENOS from a clean sheet in 15 months with only about a dozen employees. “From our side, we just wanted to bring the group together that we knew could do this as quickly as possible,” he said, but he expects a “pretty drastic” increase in staffing as the company works on new vehicles - because apparently, small teams can still build spaceships.

Reditus Space is one of several companies working on reentry vehicles that are facing new competition from industry powerhouse SpaceX. The company performed the first test flight in June of Starfall, a large reentry vehicle that some believe could disrupt the market for smaller vehicles in much the same way SpaceX rideshare missions altered the market for small launch vehicles. Crum said he saw Starfall as a validation of the market for reentry vehicles. “Starfall’s introduction is going to play a big role in providing an infrastructure on which we all can benefit,” he said. “Having an entity the size of SpaceX underwrite the tremendous potential of this is a good thing for everyone in the reentry world.”