Nuclear Thermal Propulsion


Non-nuclear testing of fuel element materials is an affordable approach to nuclear thermal propulsion engine development. This image captures the compact fuel element environmental test underway.

Nuclear Thermal Propulsion (NTP) is an attractive option for in-space propulsion for exploration missions to Mars and beyond. NTP offers virtually unlimited energy density and specific impulse roughly double that of the highest performing traditional chemical systems.
As missions aim for targets farther out into the solar system, nuclear propulsion may offer the only viable technological option for extending the reach of exploration missions beyond Mars, where solar panels can no longer provide sufficient energy and chemical propulsion would require a prohibitively high mass of propellant and/or prohibitively long trip times.

NTP is directly relevant to the Agency’s vision, mission, and long-term goal of expanding human presence into the solar system and to the surface of Mars because it provides the fastest trip time of all currently obtainable advanced propulsion systems. Fast trip times will safeguard astronaut health by reducing exposure to zero gravity and cosmic radiation and reduce risks associated with reliability uncertainties inherent in complex systems as well as those associated with life-limited, mission critical systems.
The overall goal of this Game Changing Development Program project is to determine the feasibility and affordability of a low enriched uranium (LEU)-based NTP engine with solid cost and schedule confidence.

The project will be considered a success if these objectives are met:
1. Demonstrate the ability to purify tungsten to 90 percent purity (or higher if possible) and determine the cost to produce a kilogram at that level of purity.
2. Determine, to a conceptual level of fidelity, the technical and programmatic feasibility of an NTP engine in the thrust range of interest for a human Mars mission. The thrust range of interest will be agreed to by the Space Technology Mission Directorate and the project as soon as feasible after the start of the project.
3. Determine the program cost of an LEU NTP system and the confidence level of each major cost element.

Principal Technologist Project Manager
Ron Litchford ( Doyce “Sonny” P. Mitchell Jr. (

NASA Contracts with BWXT Nuclear Energy to Advance Nuclear Thermal Propulsion Technology

As NASA pursues innovative, cost-effective alternatives to conventional propulsion technologies to forge new paths into the solar system, researchers at NASA’s Marshall Space Flight Center in Huntsville, Alabama, say nuclear thermal propulsion technologies are more promising than ever, and have contracted with BWXT Nuclear Energy, Inc. of Lynchburg, Virginia, to further advance and refine those […]