stalk space
On Sunday, small launch company Stoke Space flew its upper stage for the first time at an airfield in eastern Washington.
Admittedly, the flight was quite low-key. The second stage rocket only rose to an altitude of about 30 feet (9 meters) and had a range of only a few feet. The entire flight took 15 seconds.
But it was an important step for Stoke Space, which is less than four years old and has about 90 employees. The test successfully demonstrated the performance of the company’s oxy-hydrogen engine, which is based on a ring of 30 thrusters. The ability to throttle this engine and its thrust vector control system. The same goes for vehicle avionics, software, and ground systems.
“It was a tiny little bunny hop,” Stoke Space co-founder Andy Rapsa said in an interview with Ars. “But that was the icing on the cake. It was great to get a notch in our belt.”
A novel second stage
This hopper vehicle lacked a payload fairing but was otherwise similar to the Stokes rocket’s planned upper stage, measuring 13 feet (4 meters) in diameter and 20 feet (6 meters) tall. This was his second prototype hopper manufactured by Stoke. The first one was lost during spring testing.
Stoke Space plans for the second stage to return to Earth after liftoff and land vertically. Therefore, the upper stage has a novel engine design: a ring of 30 thrusters instead of a single engine with a nozzle, making it safe for both the vacuum of space and the thick atmosphere near the surface. Now you can fly. Earth. This stage was the more complex and novel element of the rocket design, so Lapsa and the small team at Stoke began their work there.
Lapsa said that after achieving all the technical milestones with the upper stage, the company will now shift its focus to developing the rocket’s as-yet-unnamed first stage. Lapsa said Stoke engineers have already developed a full-flow, multi-stage combustion rocket engine for the first stage. Seven of them will power the booster. Testing of the components of these engines is already underway.
Lapsa said the company is working towards a 2025 debut for the Stoke rocket, but added: “There are some interesting opportunities to get it flying sooner than that.”
From here to orbit
Stoke Space is assigned the use of Launch Complex 14 at Cape Canaveral Space Force Station, Florida. This historic airfield is where John Glenn launched in his 1962, becoming the first American to reach orbit. The most recent opening was in 1966, so the site requires a significant amount of work to renovate.
It’s an interesting company to keep an eye on, as the company consisted solely of Rapsa and his co-founder Tom Feldman until the end of 2020. They were both propulsion engineers at Blue Origin and believed the company wasn’t moving fast enough. Over the past three years, they and their team have really moved quickly to get to the second stage of operations where short-haul flights are possible.
“I love Jeff’s vision for space,” Rapsa said in an interview with Ars magazine last year. “I’ve been working closely with him for a while on various projects, and I’m basically 100 percent onboard with that vision.” Beyond that, I think it’s just a matter of letting them tell the history of their executions. I thought I could move faster. ”
Small rockets designed to carry just over 1.5 metric tons into low Earth orbit still have a long way to go from this hop to orbit. But assuming SpaceX is able to operate the Starship rocket, Stoke Space appears to have a chance of becoming the second company to build a fully reusable rocket. And no company started out with such a singular goal for their first rocket.
