Dream Chaser

Dream Chaser is an American reusable lifting-body spaceplane developed by Sierra Space. Conceived as a crewed vehicle, it is being developed in a cargo configuration known as the Dream Chaser Cargo System for missions to the International Space Station (ISS) under NASA's Commercial Resupply Services program.

Development of Dream Chaser began in 2004 as a project of SpaceDev, which was acquired by Sierra Nevada Corporation (SNC) in 2008. In 2021, the program was transferred to Sierra Space, a subsidiary spun off from SNC as an independent company.

Dream Chaser is designed for vertical takeoff and horizontal landing, launching atop a Vulcan Centaur rocket and landing on conventional runways. It is capable of carrying both pressurized and unpressurized cargo. A proposed variant for the European Space Agency would launch aboard an Ariane 6 rocket. The first flight of Dream Chaser was originally scheduled for the second flight of Vulcan Centaur but was not ready in time. As of September 2025, the spacecraft's propulsion system and software had not yet been certified by NASA, and the spacecraft's initial mission in late 2026 will no longer dock at the ISS as originally planned.

The Dream Chaser’s design is derived from NASA's HL-20 Personnel Launch System, a lifting-body concept studied in the 1980s and 1990s.

The Dream Chaser spaceplane is designed to be launched on the top of a typical rocket and land like an airplane on a runway. The design has heritage going back decades. Currently, the Dream Chaser will resupply the ISS with cargo. Per the company's website, a crew version is planned for a later date.

Sierra Space was contracted under CRS-2 to perform resupply missions to the ISS, but in a September 2025 contract change Sierra Space only needs to perform a free flight demonstration, with NASA optionally booking resupply missions.

On-orbit propulsion of the Dream Chaser was originally proposed to be provided by twin hybrid rocket engines capable of repeated starts and throttling. At the time, the SSC's predecessor, the SNC was also developing a similar hybrid rocket for Virgin Galactic's SpaceShipTwo. In May 2014, SNC involvement in the SpaceShipTwo program ended.

After the acquisition of Orbitec LLC in July 2014, Sierra Nevada Corporation announced a major change to the propulsion system. The hybrid rocket engine design was dropped in favor of a cluster of Orbitec's Vortex engines. The new unit would be a pressure-fed three-mode engine. At low- and mid-power regimes it uses monopropellant fuel – hydrogen peroxide – and in high-power demand, the engine adds injection of RP-1 fuel. This increased thrust will be useful to shorten the de-orbit burn duration of the Dream Chaser.