The US Defense Advanced Research Projects Agency (Darpa) said on 12 April that it had awarded contracts for the first phase of the Demonstration Rocket for Agile Cislunar Operations (Draco) programme. The three prime contractors are General Atomics, Blue Origin, and Lockheed Martin. Darpa previously announced an award of $22 million to General Atomics to design a small nuclear reactor for space propulsion under the Draco) project.
“Cislunar” refers to space between the Earth and the moon. Draco, set up in 2020, aims to demonstrate nuclear thermal propulsion, namely, using a nuclear reactor to heat rocket fuel in order to generate thrust. In May 2020, Darpa’s Tactical Technology Office issued a “broad agency announcement” asking for proposals to test a nuclear thermal propulsion (NTP) system in orbit by 2025.
Rapid maneuver is a core tenet of modern Department of Defense (DoD) operations on land, at sea, and in the air. However, rapid maneuver in the space domain has traditionally been challenging because current electric and chemical space propulsion systems have drawbacks in thrust-to-weight and propellent efficiency, respectively, Darpa said. Draco’s NTP system has the potential to achieve high thrust-to-weight ratios similar to in-space chemical propulsion and approach the high propellent efficiency of electric systems. This would give a spacecraft greater agility.
“The performer teams have demonstrated capabilities to develop and deploy advanced reactor, propulsion, and spacecraft systems,” said Major Nathan Greiner, USAF, programme manager for Draco. “The NTP technology we seek to develop and demonstrate under the Draco programme aims to be foundational to future operations in space.”
Phase 1 of the programme will last 18 months and consist of two tracks. Track A will entail the preliminary design of an NTP reactor and propulsion subsystem concept. Track B will produce an Operational System (OS) spacecraft concept to meet mission objectives and design a Demonstration System (DS) spacecraft concept. The DS will be traceable to the OS concept, but specifically focus on demonstrating an NTP propulsion subsystem. “This first phase of the DRACO programme is a risk reduction effort that will enable us to sprint toward an on-orbit demonstration in later phases,” added Greiner.
General Atomics will perform the Track A reactor development work. Blue Origin and Lockheed Martin will independently perform the Track B work to develop OS and DS spacecraft concept designs. Draco’s Phase 1 is expected to inform follow-on phases for detailed design, fabrication, and on-orbit demonstration. Any follow-on phases will be solicited by Darpa in a future announcement.