DARPA awards contracts for orbital nuclear propulsion demonstrator Artist's concept of a nuclear-propelled spacecraft DARPA DARPA DARPA's nuclear space rocket project is progressing, with contracts awarded to General Atomics, Blue Origin, and Lockheed Martin for the first phase of the agency's Demonstration Rocket for Agile Cislunar Operations (DRACO) program. The goal is to place a Nuclear Thermal Propulsion (NTP) demonstrator into low Earth orbit by 2025. Humanity is just dipping its toes into the solar system, but it's surprising to many to find out that we are already near the theoretical limits of what chemical rockets can do. In fact, that limit emerged almost as soon as Werner Von Braun produced the first practical rockets in the 1940s.