Stoke Space subjects its “three-pack” of thrust chambers to a hot fire test. (Stoke Space Photo)
In just six months, Kent, Washington-based Stoke Space Technologies turned empty ground in Moses Lake, Washington, into a bridgehead for the construction of a fully reusable rocket optimized for satellite launches.
“As recently as April, it was a barren desert,” Co-Founder and CEO Andy Lapsa told GeekWire, “and we were able to get all the facilities up and running to do long-term liquid hydrogen and liquid oxygen rocket engine tests out there.”
Measures have already been taken in the 2.3-hectare test facility at Moses Lake Airport: Last month, Stoke Space completed a full-size, second-stage production demonstration for its yet-to-be-named rocket. The two-year-old startup has also performed full-power test ignitions of components for its second stage rocket engine, a triplet of thrust chambers that Lapsa calls a “triple pack”.
“We did it on time and under budget, which I’m very proud of,” said Lapsa, a veteran of Jeff Bezos’ Blue Origin space company. “You don’t hear that too often in our industry.”
Like Bezos and his multi-billion dollar rival at SpaceX, Elon Musk, Lapsa and his teammates at Stoke Space pursue the dream of complete rocket reusability. Their goal is to lower the cost of access to orbit and open a new wave of space applications.
SpaceX’s Falcon 9 and Falcon Heavy rockets have shown the way with first stage reusability, but even these launch systems discard the second stage after a single use. Reducing these costs is the goal of SpaceX’s Starship development program. Blue Origin is also tracking second stage reusability as it works on its New Glenn orbital-class rocket with a program codenamed Project Jarvis.
Lapsa commends these larger carrier companies for their commitment to full reusability, but says their company is taking a different approach.
“The first place is with the second stage,” he said. “The entire system is designed to be 100% reusable at high frequency, and I think the industry is still looking for that solution.”
When Lapsa speaks of a high cadence, he means that he can launch the same inexpensive rocket every day without having to carry out detailed inspections or component replacement – just refuel and take off, modeled on commercial aviation.
It’s still getting started: Lapsa said the full-load thrust chamber fires hadn’t lasted more than 10 seconds so far, and he’s hesitant to provide details about the thrust levels.
“We start with these thrust chambers,” he said. “We have turbo machines that will be tested soon. We’re going to get into the full engine tests, which will be amazing. We still have to build some systems for this. And at the same time we work on the full stage. “
According to Lapsa, the workforce at Stoke Space has grown to 18 and more new hires are imminent. The team, which includes people with experience at Blue Origin, SpaceX, and Spaceflight Inc., has to hurry to meet the schedule.
“We’ll be flying this thing by the end of next year,” said Lapsa.
Lapsa isn’t ready to say where the flight tests will take place yet, but he has left some clues about the flight profile. Like Starship, there will be experiments with vertical take-off and vertical landing. In contrast to Starship, the descents do not require stomach flaps or other exotic maneuvers. “Our entire profile will have the acceleration vector along the centerline axis,” said Lapsa.
One of the key technologies has to do with the second stage heat shield: instead of using ceramic tiles, Stoke Space plans to build a ductile metallic heat shield from everyday materials.
Stoke Space built a manufacturing demonstrator for its second stage booster. (Stoke Space Photo)
Ultimately, Stoke Space aims to deploy a fully reusable rocket with a fast turnaround time that is well suited for satellite launches.
“The Starship-class vehicle is good for certain things, like colonizing Mars,” said Lapsa. “But I think if you only look at the satellite market, there are very few customers who want to fly so many things at once. And there are very few customers who want to share a lift with it. We already see this as a pretty big headwind in the industry. “
Will Stoke Space have what it takes to achieve its goal of 100 percent missile reusability? SpaceX is believed to be spending billions of dollars on Starship, while Jeff Bezos said he rakes in $ 1 billion worth of Amazon stock every year to fund Blue Origin. In contrast, Stoke Space has raised $ 9.1 million in seed capital and development grants from NASA, the National Science Foundation, and the US Space Force to date.
Lapsa said Stoke Space is considering various ways to raise additional capital, but for now, reaching the next phase of development of the second phase is a top priority.
“Our approach to grants is that if there are opportunities to attack things that we are already doing, we will pursue them,” he said. “But otherwise we’re head down – trying to move forward as quickly as possible.”