Stoke Space performs reusable Hopper prototype test flight

"The test successfully demonstrated our novel hydrogen/oxygen engine, regeneratively cooled heat shield, and differential throttle thrust vector control system, as well as our avionics, software, and ground systems," the statement reads.

🐇 pic.twitter.com/2EXvwX1IH0

— Stoke Space (@stoke_space) September 18, 2023

Stoke Space believes it is now one crucial step closer to achieving its goal of developing fully-reusable rockets. If it does, it will become the only company after SpaceX to launch a system designed with no expendable rocket stages.

"We've also proven that our novel approach to robust and rapidly reusable space vehicles is technically sound, and we've obtained an incredible amount of data that will enable us to confidently evolve the vehicle design from a technology demonstrator to a reliable reusable space vehicle," the company explained in its statement.

The future of reusable spacecraft

During Hopper 2, Stoke Space tested some unusual techniques not typically used in the modern rocket industry.

Hopper, for example, features a differential throttle system designed for attitude control. The regenerative cooling heat shield, meanwhile, pumps pressurized coolant through metal pores on the rocket's exterior to cool it down during reentry.

As Space.com points out, Elon Musk originally wanted to use regenerative cooling for SpaceX's Starship, though the company eventually opted for a more traditional design. Regenerative cooling is currently unproven as a viable reentry method, so Stoke Space may be the first to test it under the extreme heat conditions of reentry.

In its statement, Stoke Space said, "Although this vehicle didn't directly experience the heat from hypersonic atmospheric re-entry, it has successfully operated at 100% of the expected heat load in a simulated environment."

Now that work on the second-stage demonstration is complete, Stoke Space will work on the development of a reusable first-stage rocket.

Back in 2019, SpaceX performed a number of hop tests with a very early Starship prototype dubbed Starhopper that had a similar appearance to Stoke Space's Hopper 2. Both companies still have some way to go before they are in possession of a fully reusable, operational spacecraft.

SpaceX is awaiting Federal Aviation Authority approval for its second Starship test flight, while Stoke Space is still in the early testing stage of its own system.

"With our innovative second stage design, our team at Stoke is attempting to do something that has never been done before: design and build a rocket that is 100 percent reusable with a 24-hour turnaround," Stoke Space said in its statement. "To reach that goal, we will now continue moving through our development program by increasing focus on our reusable first stage."