Illustration of a conceptual spacecraft enabled by nuclear thermal propulsion. Credits: NASA

“We explore space not because it’s there, but because of the potentials it has to offer.” —Krafft Ehricke

President Trump pushed hard for nuclear rocketry which is the key to rapid and repeated travel to the Moon as it is colonized and developed.  It is also mission critical for humans reaching Mars without major damage to their bodies from exposure to radiation.  Now, we are seeing major breakthroughs in the development of nuclear rockets.

It has long been understood that human development of space requires a full commitment to the development of low-earth orbit and cislunar space, as well as the industrialization of the Moon and utilization of the resources of the lunar regolith to transform the physical economic conditions of humanity—both in space and here on earth. The breakthroughs in science and technology and popular sense of mission accompanying this journey are, in turn, critical in making the United States a manufacturing superpower once again.  To cite but one example, Helium 3, abundant and capable of being mined on the Moon can radically advance the development and commercialization of fusion power here on earth. 

In his first administration. President Trump set forth a renewed mission to pave the way to accomplishing that goal.  His commitment to return American astronauts to the Moon for the first time in over 50 years through what became named the Artemis program, can once again, “serve to organize and measure the best of our  energies and skills,” which was the mission orientation President Kennedy declared for the successful Apollo program. 

In this brief report, we will outline the advances in the use of nuclear power for space exploration.  The successful completion of Artemis will require many more.  So, if you are a young person, you’ll find we have plenty of work to do, but it’s exactly the kind of work which brings with it the joy of human discovery.  

When President Trump signed Space Policy Directive 6 on space nuclear power and propulsion, he laid out a national strategy for development and effective use of Space Nuclear Power and Propulsion (SNPP) systems.

Although the Nuclear Engine for Rocket Vehicle Applications (NERVA) nuclear thermal rocket (NTR) program began in the 1960s, it was shut down in the early ’70s as human deep space exploration and development were abandoned.  The Artemis program created an immediate high demand for nuclear surface and propulsion systems for space exploration, and industrialization of the Moon and Mars. We must demand that funding for these new nuclear rocket concepts and research not be cut, but that these advancements in nuclear technologies (unlike the NERVA project) be given ample funding and the highest priority.

An Update On Nuclear Thermal Propulsion for Cislunar Space Applications and Missions to Mars

Research and development of nuclear power and propulsion systems for space exploration is now rapidly advancing. It will be used both for electrical power and propulsion. Nuclear propulsion that could send spacecraft, robotics, and eventually humans to Mars in less than 45 days—and that’s only the beginning. 

In April 2021, in an article titled “DARPA  Announces Nuclear Rocket By 2025!” Ben Deniston reported on a project to demonstrate a nuclear thermal propulsion (NTP) system above low Earth orbit in 2025.  According to a Defense Advanced Research Project (DARPA) release, contracts were awarded for the first phase of the Demonstration Rocket for Agile Cislunar Operations, the DRACO Program. The companies awarded contracts were General Atomics, Blue Origin, and Lockheed Martin.

In May 2022, DARPA sought proposals for phase 2 and 3 of the DRACO program for the design, development, fabrication, and assembly of a nuclear thermal rocket engine to execute an in-space flight demonstration in fiscal year 2026. 

In November 2022, General Atomics completed a DRACO nuclear thermal propulsion system design and test milestone. General Atomics Electromagnetic Systems (GA-EMS) announced that it had completed major milestones for the track A phase 1 DRACO program. GA-EMS delivered a baseline design of a DRACO NTP reactor and engine and successfully tested key components of the nuclear reactor.

The work by GA-EMS performed under a Track A, Phase 2 contract for the DRACO program could culminate in a demonstration of a nuclear-propelled spacecraft in cislunar space during fiscal year FY 2026 as reported in (Nuclear Newswire).

NASA has been stepping up its own programs for Nuclear Thermal Rockets and for nuclear space power applications for the lunar surface and missions to Mars. NASA’s Marshall Space Flight Center is heading up NASA’s Game Changer Development Program which aims to develop bimodal nuclear propulsion—a system combining both Nuclear Thermal Propulsion (NTP) and Nuclear Electric Propulsion (NEP), that could enable transit to Mars in 100 days. 

Conventional chemical rockets and nuclear thermal rockets operate by heating gasses to high temperatures and pressures, and then expelling them out a nozzle to provide thrust. This short video by NASA demonstrates this. Electric propulsion systems, by contrast, magnetically accelerate small particles up to significant fractions of the speed of light. The hot gasses from the two thermal propulsion types (chemical or nuclear) produce ample thrust, but at a relatively low efficiency when measured in Specific Impulse (ISP). Electric propulsion, by contrast, produces little thrust but at super high efficiencies. Electric propulsion has the highest ISP numbers of anything–with ISP ratings for nuclear electric propulsion going above 10,000 as opposed ISP ratings of around 450 for the most efficient chemical rockets, and double that for nuclear thermal rockets. But electric propulsion systems are not capable of providing adequate thrust for maneuvers such as those required by entering or leaving an orbit.

So the idea behind bimodal systems (NTR and Nuclear Electric) is to be able to produce the most efficient use of propulsion mass in whatever flight regime the vehicle is in. That means NTR for exit from and entry to orbit, and electric propulsion for the long journey. 

This week NASA and DARPA announced their collaboration in rocket propulsion during this year’s 2023 American  Institute of Aeronautics and Astronautics (AIAA) Sci-Tech forum. The NASA/DARPA agreement outlines collaboration between NASA’s Space Technology Mission Directorate (STMD) and DARPA in advancing and successfully demonstrating Nuclear Thermal Propulsion. The agreement states that, “NASA shall lead  management of the overall NTP engine  development and fabrication and shall retain final authority over all aspects of the successful execution  of the NTR engine.” The only exceptions are those areas explicitly listed as DARPA responsibilities. According to the release, “The Parties agree that all NASA-managed activities, and all systems developed and data created thereunder, shall be unclassified at any level.” DARPA shall retain authority over and be solely responsible for the experimental Nuclear Thermal Reactor Vehicle, (X-NTRV) and for “launch vehicle integration…”

These developments reflect the growing realization that meeting NASA’s Moon-Mars objectives require breakthroughs in the efficiency and speed of space transportation technology. The plan calls for demonstrating NTP as soon as 2027. 

Advanced Propulsion Systems and More Powerful Rockets Mean That Travel TIme to Mars Will Be Greatly Cut

Shortly before this week’s AIAA forum, NASA selected a bimodal nuclear rocket concept for phase 1 development through its NASA Innovative Advanced Concepts (NAIC) program for 2023. The proposal was put forth by Professor Ryan Gosse, the Hypersonic Program Area Lead at the University of Florida and member of the Florida Applied  Research in Engineering, (FLARE) team. Gosse’s proposal is titled “Bimodal NTP/NEP with a Wave Rotor Topping Cycle” This bimodal nuclear propulsion concept would use a topping cycle to radically further improve the efficiency of the Nuclear Thermal Rocket aspect of the bimodal system up to the 1,400-2,000 range and raise the ISP of the overall system (including both the thermal and electric components) up to the 1,800 to 4,000 range.

Professor Gosse expects that such a system could reduce travel time to Mars to just 45 days. That would be quite a reduction in travel time as compared to the six month times now typical for chemical rockets. Further, this system could also mean that you wouldn’t have to wait 2 years for planet alignment to launch either to or from Mars. While the development of NTP/NEP systems will bring about a much greater ISP, it is far from that which would be accomplished with the development of fusion rockets which could potentially generate a specific impulse of around 130,000 sec. Now that is some rocket power!

As developed in LaRouchePAC’s Moon-Mars Mission report, “compact, advanced nuclear fission systems can power the first lunar mining and manufacturing  capabilities, while more advanced capabilities will come with the development of fusion technologies.” As we prepare for missions to Mars, the achievements we make in using the resources of the Moon and other elements for rocket fuel, drinking water, and living and working on the Moon, for bases and settlements, will have dramatic consequences on developments on earth – like greening and inhabiting the deserts and adapting to all modes of weather.  Training a new skilled workforce here on earth to meet these challenges on the frontiers of science and technology will herald a human renaissance both in the United States and in the world as a whole. 

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