Sierra Space Expands VORTEX® Product Line with New 1,500 lbf Hypergolic Engine

Sierra Space VORTEX VRM-1500-H Engine

VORTEX® VRM1500-H is a new addition to the company’s family of engines that will power a new generation of critical spacecraft

LOUISVILLE, Colo. – April 5, 2023 Sierra Space, a leading, pureplay commercial space company building the first end-to-end business and technology platform in space, announced today it successfully completed a hot-fire test campaign of a new hypergolic engine.

The Sierra Space VORTEX® VRM1500-H produces 1,500 pounds of force (lbf) thrust and achieved high thrust efficiency during recent testing. VORTEX technology will serve a critical industry need for engines that can support in-space propulsion for spacecraft orbital maneuvering and extraterrestrial landers.

The VRM1500-H is rooted in Sierra Space’s patented VORTEX engine design technology, which promotes efficient, stable combustion. A vortex injector utilizes a unique swirling propellant flow to naturally cool the combustion chamber. Depending on mission requirements, both pressure-fed and electric pump-fed variants will be available. The new engine relies on additive manufacturing to reduce part count and simplify manufacturing. Coupled with the unique VORTEX technology, this results in a robust, lightweight and cost-efficient rocket engine system. A video of the recent testing can be found here.

Sierra Space, which is building the Dream Chaser® spaceplane and inflatable LIFE® habitat, is reimagining rocket fuels and their engines at a 200-acre propulsion test facility outside Baraboo, Wisconsin. The company is also developing a larger, 35,000 lbf thrust upper-stage engine, the VORTEX VR35K-A, in conjunction with the Air Force Research Laboratory. With VORTEX, robust design margins deliver extremely high durability, reliability and reusability in engines that are inexpensive to manufacture and maintain.

“Commercial companies and government entities sometimes require a high thrust, high efficiency propulsion solution that provides a large payload with the ability to move to a new orbit rapidly,” said Rusty Thomas, Senior Vice President and General Manager of Space Applications at Sierra Space. “Our VORTEX engine technology couples high performance with reliability in a small package. This recent successful hot-fire test program brings us one step closer to another dynamic addition to our family of engines to propel us in building and growing an accessible commercial space economy.”

The VORTEX VRM1500-H uses hypergolic propellants, which have long-term storability in space and spontaneously ignite upon mixing, thereby improving reliability and removing the complexity of a traditional ignition system. Use of hypergolic propellants allows the VRM1500-H to easily and reliably ignite and reignite multiple times, as needed.

Sierra Space began development and initial testing of the VRM1500-H in 2021. After optimizing the design, a second test campaign commenced in 2022, with the VRM1500-H ultimately achieving the high performance of 1,500 lbf thrust in vacuum. The next design and testing cycle of the VRM1500-H will address the industry’s need for cost-efficient solutions using design for manufacturing best practices.

About Sierra Space

Sierra Space ( is a leading, pureplay commercial space company at the forefront of innovation and the commercialization of space in the Orbital Age®, building an end-to-end business and technology platform in space to benefit life on Earth. With more than 30 years and 500 missions of space flight heritage, the company is enabling the future of space transportation with Dream Chaser®, the world’s only commercial spaceplane, and is bringing LIFE® (Large Integrated Flexible Environment) to low-Earth orbit with its modular, three-story commercial habitation and science platform. Both Dream Chaser and LIFE are central components to Orbital Reef, a mixed-use business park in LEO being developed by principal partners Sierra Space and Blue Origin, which is expected to be operational by the end of the decade. Sierra Space also builds and delivers a host of systems and subsystems across solar power, mechanics and motion control, environmental control, life support, propulsion and thermal control, offering myriad space-as-a-service solutions for the new space economy.



Alex Walker
Sierra Space
(303) 803-2297

Allison Gregg
Griffin Communications Group
(256) 520-3985

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