Stoke Completes Static Fire for its Reusable Second Stage Rocket, Looks to Hop

Image: Stoke Space

While all eyes remain on Starship, another rocket startup is quietly ticking off milestones in its pursuit of full reusability.

Stoke Space completed a static fire of its fully reusable second-stage rocket earlier this week. The prototype—which looks more like a fiery Tin Man than a final product—also underwent avionics, power systems, navigation, heat shield, and tank pressurization testing. 

The company announced a hop flight is up next.

Stoke Space 101: Founded in 2019, and armed with ~$75M of funding, Stoke has set out to build a fully reusable 30-meter-tall two-stage rocket. Instead of pursuing an incremental strategy in rocket building, the Kent, WA-based company has embedded full reusability into its design from the onset.

Its primary focus has been on developing the elusive fully reusable second stage rocket.

The second stage problem: Given the shielding and fuel requirements needed for a second stage vehicle to execute a controlled landing, a rapid and fully reusable upper stage rocket has proven difficult to achieve with legacy architectures—necessitating novel and inventive solutions.

  • The shuttle achieved the feat, but refurb between flights was far from fast. 
  • SpaceX is attempting to solve the problem by maneuvering Starship into a belly flop to break its fall, before rightsizing for a controlled landing.

Like the shuttle and SpaceX’s Falcon, Stoke has also chosen a radical approach for its second stage rocket. 

How it works: The spacecraft resembles a traditional reentry capsule, with a large circular heat shield. To power the vehicle, 30 small thrusters are arranged in a circle around the perimeter of the heat shield. 

  • Hyrdolox fuel is channeled into the 30 combustion chambers, creating thrust.
  • The exhaust pushes against the heat shield, improving efficiency by creating what is known as an aerospike effect.
  • Instead of an ablative heat shield—as in Dragon and Orion capsules—in which protective material burns off, Stoke employs a liquid-cooled shield designed for reusability.

For the test firing, only 15 thrusters were used. 

The unique design—which looks like a showerhead with jets solely around its edges—allows Stoke to incorporate a sturdy heat shield for reentry, thrusters for in-space maneuvering, and legs for a controlled landing.   

If successful, the company will look to pair the second stage with a first stage booster to create a fully reusable rocket. 

With the company nailing its final static fire, the only question now is wen hop?!