Tag: Stoke Space

Stoke’s Nova rocket

The rocket startup Stoke Space, which is attempting to develop its own fully reusable two stage rocket, announced yesterday that it has successfully raised $260 million of private investment capital in its most recent funding round, more that doubling what it had raised previously and bringing the total raised by the company to $480 million.

The funding round involves new and existing investors including Breakthrough Energy Ventures, Glade Brook Capital Partners, Industrious Ventures, Leitmotif, Point72 Ventures, Seven Seven Six, the University of Michigan, Woven Capital, and Y Combinator, among others.

The company’s Nova rocket will use what has become the standard for first stage re-use, a vertical take-off and landing. Its second stage however will also be reusable, something no one has yet succeeded in doing, and Stoke intends to do it in a radical manner. Rather than use a single nozzle on its upper stage, it has instead gone with a new design whereby thrust is released through a string small nozzles placed in a ring on the bottom outside of the stage. The base of the stage can thus get a heat shield. The plan is to have the stage return much like many returnable capsules, with the small nozzles then used to provide control and thrust during landing.

This new influx of cash indicates renewed confidence in the company among the investor class. Its recent successful test of its Zenith first stage engines probably help fuel that confidence.

It had hoped to do its first test launch this year from Cape Canaveral, but has recently been burdened with new environmental red tape that might impact those plans.

The rocket startup Stoke Space has successfully completed the first static fire test of the methane-fueled rocket engine that will be used on the first stage of its entirely reusable Nova rocket.

The engine, designed to produce up to 100,000 pounds-force of thrust, went up to 50% of its rated thrust in the two-second test. The goal of the test was to see how the engine started up and shut down, Andy Lapsa, chief executive of Stoke, said in an interview. “All of the complexity and a lot of the risk is in that startup transient and shutdown transient,” he said. “The duration of the test was short because the goal was to demonstrate the transient and then back out.”

The engine uses a design called full-flow staged combustion, where both the engine’s fuel and oxidizer — liquified natural gas and liquid oxygen, respectively — go through separate preburners before going into the main combustion chamber. That approach offers greater efficiency and a longer engine life, but is more complex to develop. It is currently used only on SpaceX’s Raptor engines that power its Starship vehicle.

The rocket’s upper stage uses hydrogen as its fuel, as well as a radical nozzle design. Instead of a single large nozzle, the thrust is released from a ring of tiny outlets at the permeter of the stage. It is hoped this design will better protect the system during re-entry from orbit, while allowing for more precise control upon landing, and thus make it possible to reuse the upper stage.

The first test launch is presently scheduled for 2025. This new engine test makes that date more realistic.

Link here. This Nasaspaceflight.com article provides an excellent update on the status of the development of Stoke’s Nova rocket, which will have a radical new engine design in its upper stage, using a ring of small nozzles rather than one single central one. That design will allow the upper stage to return to Earth for reuse, something that no other rocket now in use at present can do.

Stoke Space recently carried out the first test of the full-size 30-thruster version of the innovative engine that the company is producing for its in-development second stage. This will be an integral part of its future Nova rocket, which aims to be a fully reusable medium lifter.

The engine test took place on Feb. 26 and follows the engine’s first test flight on its prototype vehicle, Hopper 2, in September 2023. Although fitted with only 15 chambers for that flight, Hopper 2 flew for 15 seconds, achieved a maximum altitude of 30 feet, traversed to a landing site, and touched down softly.

The article includes a lot of interesting technical details about this upper stage and what engineers are learning about this radical engine design. Worth reading. At present Stoke is the only company other than SpaceX attempting to make its upper stage fully reusable. If successful it will jump ahead of everyone else.

No launch schedule however for its new rocket was revealed in this report, so it might be awhile, if ever, before any of this bears fruit.