Sierra Space's New Engine Is All About In-Space Propulsion

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Sierra Space, the company behind projects like the Dream Chaser spaceplane and inflatable LIFE habitat, has developed a new engine specifically for in-space propulsion.

The company said it recently completed a hot-fire test for the Vortex VRM1500-H at its ​​200-acre propulsion test facility near Baraboo, Wisconsin. The engine was able to efficiently produce 1,500 pounds of thrust, which Sierra said makes it especially suitable for maneuvering spacecraft and powering extraterrestrial landers.

The rocket engine gets its name from Sierra’s vortex injector, which uses a swirling propellant flow to keep the combustion chamber cool. By using additive manufacturing, Sierra said it’s been able to keep the part count low and simplify manufacturing for the new Vortex.

Sierra’s latest engine relies on hypergolic propellants, which it said are easier to store in space for long periods of time. They also help to boost reliability and reduce complexity compared to other ignition systems since they spontaneously ignite upon mixing. The company said hypergolic propellants make it easier to continually ignite the engine as many times as necessary.

Sierra Space said the next testing cycle for the new Vortex, which began development in 2021, will focus on even further simplification of the manufacturing process.

In addition to its work developing space propulsion systems, Sierra Space is also developing the Dream Chaser and LIFE habitat, which are expected to be core pieces of the Orbital Reef commercial space station being developed by Blue Origin. The Dream Chaser is being called the first-ever winged commercial spaceplane built for high reusability. The LIFE is an inflatable habitat that reduces cargo space but maximizes usable space once in orbit.

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