The Gryphon Technologies engineering firm has been awarded a US$14-million contract by DARPA to fund the development and demonstration of a nuclear rocket engine for the agency’s DRACO (Demonstration Rocket for Agile Cislunar Operations) program. The US military will be able to carry out missions in cislunar space once the High-Assay Low Enriched Uranium (HALEU) Nuclear Thermal Propulsion (NTP) system is complete.
One of the most significant limitations when it comes to space travel is the propulsion system. Here on Earth, it’s possible to build motors that have an ultra-high payload ratio, but getting into space is another story. It requires such high velocities and energies to travel into space that engineers are forced to use enormous engines and massive amounts of fuel to bring tiny payloads into orbit.
Once a spacecraft is in space, there are essentially two options for thrust. One is to use eclectic propulsion systems that produce minimal thrust for very long periods of time. The other is to use chemical rockets, but these have reached their theoretical limits when it comes to thrusting.
Since 1945, it has been recognized that a third option exists, which is to harness the atom’s power to produce a rocket that’s more powerful than options one and two. The only issue has been to make a practical design that produces enough thrust to warrant the investment.
The DRACO program will involve DARPA looking at NTP to power spacecraft outside the Earth’s atmosphere, out to just beyond the Moon’s orbit. A nuclear reactor would heat a propellant, like hydrogen, to extreme temperatures, resulting in a thrust that would be five times the efficiency of a chemical rocket and 10,000 times of an electric engine.
Dr. Tabitha Dodson, Gryphon’s Chief Engineer and NTP systems expert said:
A successfully demonstrated NTP system would provide a leap-ahead in-space propulsion capability, allowing agile and rapid transit over vast distances as compared to present propulsion approaches.
The DRACO program moves forward on two tracks – track A is to create the baseline NTP reactor design, and track B is to develop an operational system. Gryphon will develop a HALEU propulsion system that uses nuclear fuel made of recycled civilian reactor fuel that’s reprocessed and enriched to between 5 and 20% – less than that of naval reactors and greater than civilian reactors.
The results will see a small reactor core that has excellent efficiency, produces less waste, and has a longer core life, making it more appropriate for use in space travel than previous designs.
