posted 01-24-2023 09:37 AM               

NASA, DARPA Will Test Nuclear Engine for Future Mars Missions

NASA and the Defense Advanced Research Projects Agency (DARPA) announced Tuesday (Jan. 24) a collaboration to demonstrate a nuclear thermal rocket engine in space, an enabling capability for NASA crewed missions to Mars.

Above: Artist concept of Demonstration for Rocket to Agile Cislunar Operations (DRACO) spacecraft, which will demonstrate a nuclear thermal rocket engine. Nuclear thermal propulsion technology could be used for future NASA crewed missions to Mars. (DARPA)

NASA and DARPA will partner on the Demonstration Rocket for Agile Cislunar Operations, or DRACO, program. The non-reimbursable agreement designed to benefit both agencies, outlines roles, responsibilities, and processes aimed at speeding up development efforts.

"NASA will work with our long-term partner, DARPA, to develop and demonstrate advanced nuclear thermal propulsion technology as soon as 2027. With the help of this new technology, astronauts could journey to and from deep space faster than ever – a major capability to prepare for crewed missions to Mars," said NASA Administrator Bill Nelson. "Congratulations to both NASA and DARPA on this exciting investment, as we ignite the future, together."

Using a nuclear thermal rocket allows for faster transit time, reducing risk for astronauts. Reducing transit time is a key component human missions to Mars, as longer trips require more supplies and more robust systems. Maturing faster, more efficient transportation technology will help NASA meet its Moon to Mars Objectives.

Other benefits to space travel include increased science payload capacity and higher power for instrumentation and communication. In a nuclear thermal rocket engine, a fission reactor is used to generate extremely high temperatures. The engine transfers the heat produced by the reactor to a liquid propellant, which is expanded and exhausted through a nozzle to propel the spacecraft. Nuclear thermal rockets can be three or more times more efficient than conventional chemical propulsion.

"NASA has a long history of collaborating with DARPA on projects that enable our respective missions, such as in-space servicing," said NASA Deputy Administrator Pam Melroy. "Expanding our partnership to nuclear propulsion will help drive forward NASA's goal to send humans to Mars."

Under the agreement, NASA's Space Technology Mission Directorate (STMD) will lead technical development of the nuclear thermal engine to be integrated with DARPA's experimental spacecraft. DARPA is acting as the contracting authority for the development of the entire stage and the engine, which includes the reactor. DARPA will lead the overall program including rocket systems integration and procurement, approvals, scheduling, and security, cover safety and liability, and ensure overall assembly and integration of the engine with the spacecraft. Over the course of the development, NASA and DARPA will collaborate on assembly of the engine before the in-space demonstration as early as 2027.

"DARPA and NASA have a long history of fruitful collaboration in advancing technologies for our respective goals, from the Saturn V rocket that took humans to the Moon for the first time to robotic servicing and refueling of satellites," said Dr. Stefanie Tompkins, director, DARPA. "The space domain is critical to modern commerce, scientific discovery, and national security. The ability to accomplish leap-ahead advances in space technology through the DRACO nuclear thermal rocket program will be essential for more efficiently and quickly transporting material to the Moon and eventually, people to Mars."

The last nuclear thermal rocket engine tests conducted by the United States occurred more than 50 years ago under NASA's Nuclear Engine for Rocket Vehicle Application and Rover projects.

"With this collaboration, we will leverage our expertise gained from many previous space nuclear power and propulsion projects," said Jim Reuter, associate administrator for STMD. "Recent aerospace materials and engineering advancements are enabling a new era for space nuclear technology, and this flight demonstration will be a major achievement toward establishing a space transportation capability for an Earth-Moon economy."

NASA, the Department of Energy (DOE), and industry are also developing advanced space nuclear technologies for multiple initiatives to harness power for space exploration. Through NASA's Fission Surface Power project, DOE awarded three commercial design efforts to develop nuclear power plant concepts that could be used on the surface of the Moon and, later, Mars.

NASA and DOE are working another commercial design effort to advance higher temperature fission fuels and reactor designs as part of a nuclear thermal propulsion engine. These design efforts are still under development to support a longer-range goal for increased engine performance and will not be used for the DRACO engine.

posted 07-26-2023 10:31 AM               

Lockheed Martin Selected to Develop Nuclear-Powered Spacecraft

DARPA and NASA's Joint DRACO Project Technology Will Help Enable Humans to Travel to Mars

Lockheed Martin has won a contract from the Defense Advanced Research Projects Agency (DARPA) to develop and demonstrate a nuclear-powered spacecraft under a project called Demonstration Rocket for Agile Cislunar Operations (DRACO). The project will represent a rapid advancement in propulsion technology to benefit exploration and national defense.

Above: Illustration of a the DRACO spacecraft being developed by Lockheed Martin for DARPA that will demonstrate thermal nuclear engine technology. (Lockheed Martin)

DARPA partnered with NASA's Space Technology Mission Directorate on the DRACO project, as both agencies will benefit from this leading edge technology. The in-space flight demonstration of a nuclear thermal rocket engine vehicle will take place no later than 2027.

Faster, Farther, More Agile

Chemical propulsion engines have long been the standard for spaceflight, but for humans to travel to Mars, they will need much more powerful and efficient propulsion. Nuclear thermal propulsion (NTP) engines offer thrust as high as conventional chemical propulsion with two-to-five times higher efficiency, which means the spacecraft can travel faster and farther and can significantly reduce propellant needs. They also enable abort scenarios on journeys to Mars that are not possible with chemical propulsion systems.

"These more powerful and efficient nuclear thermal propulsion systems can provide faster transit times between destinations. Reducing transit time is vital for human missions to Mars to limit a crew's exposure to radiation," said Kirk Shireman, vice president of Lunar Exploration Campaigns at Lockheed Martin Space. "This is a prime technology that can be used to transport humans and materials to the Moon. A safe, reusable nuclear tug spacecraft would revolutionize cislunar operations. With more speed, agility and maneuverability, nuclear thermal propulsion also has many national security applications for cislunar space."

Safe and Efficient Nuclear Tech

An NTP system uses a nuclear reactor to quickly heat hydrogen propellant to very high temperatures and then funnels that gas through the engine nozzle to create powerful thrust. The fission-based reactor will use a special high-assay low-enriched uranium, or HALEU, to convert the cryogenic hydrogen into an extremely hot pressurized gas. The reactor will not be turned on until the spacecraft has reached a nuclear safe orbit, making the NTP system very safe.

Above: Illustration of a the DRACO spacecraft being developed by Lockheed Martin for DARPA that will demonstrate thermal nuclear engine technology. (Lockheed Martin)

Lockheed Martin has partnered with BWX Technologies to develop the nuclear reactor and produce the HALEU fuel.

"In the past several years, BWXT has been maturing its nuclear thermal propulsion fuel and design, and we are excited to further expand into space with our ability to deliver nuclear products and capabilities to the U.S. Government, " said Joe Miller, BWXT Advanced Technologies LLC president. "We look forward to building the reactor and manufacturing the fuel at our Lynchburg, Virginia, facilities."

While nuclear systems are an emerging field, Lockheed Martin has a long history and expertise in nuclear controls and has built many of NASA's radioisotope thermoelectric generators for NASA's planetary missions. Lockheed Martin has also invested heavily in cryogenic hydrogen storage and transfer. This key technology will be needed in deep space exploration not only for NTP, but for conventional propulsion systems.