Contracts to demo novel space propulsion technologies

18 May 2022

The US Defense Innovation Unit (DIU) has awarded contracts to Ultra Safe Nuclear Technologies and Avalanche Energy to demonstrate the next generation of nuclear propulsion and power capability for small spacecraft.

A rendering of a spacecraft powered by Ultra Safe Nuclear's EmberCore (Image: USNC)

The two companies will be testing solutions that give small spacecraft the ability to manoeuver at-will in cislunar space and enable high-power payloads that will support the expansion of Department of Defense (DoD) space missions, said the DIU, which aims to accelerate the adoption of commercial technology throughout the US military.

The companies are advancing two different approaches to accelerate ground and flight testing for nuclear-powered prototypes: compact fusion and next-gen radioisotope concepts. The DIU said the ultimate objective of the new contracts - the value of which was not disclosed - is to launch a successful orbital prototype demonstration in 2027 of each approach.

Under its contract, Ultra Safe Nuclear will demonstrate a chargeable, encapsulated nuclear radioisotope battery - called EmberCore - for propulsion and power applications in space. This next-generation radioisotope system will be able to scale to ten times higher power levels, compared with plutonium systems, and provide more than 1 million kilowatt hours (kWh) of energy with just a few kilograms of fuel.

Avalanche Energy has developed a device called an Orbitron, which utilises electrostatic fields to trap fusion ions in conjunction with a magnetron electron confinement scheme to overcome charge density limits. The resulting fusion burn then produces the energetic particles that generate either heat or electricity, which can power a high-efficiency propulsion system. DIU said compared with other fusion concepts, Orbitron devices are promising for space applications as they may be scaled down in size and enable their use as both a propulsion and power source.

Future missions will demand more manoeuverability and electrical power to expand the capabilities of spacecraft, the DIU said. The DIU's Nuclear Advanced Propulsion and Power (NAPP) programme is expected to "have a direct impact on how the USA employs space power, ushering in an era where spacecraft can manoeuver tactically in cislunar space."

"Bottom line, chemical and solar-based systems won't provide the power needed for future DoD missions," said US Air Force Major Ryan Weed, manager for the NAPP programme at DIU. "Advanced nuclear technologies will provide the speed, power, and responsiveness to maintain an operational advantage in space. Nuclear tech has traditionally been government-developed and operated, but we have discovered a thriving ecosystem of commercial companies, including start-ups, innovating in space nuclear."

Weed noted that the US Defense Advanced Research Projects Agency (DARPA) and the US National Aeronautics and Space Administration (NASA) are pursuing nuclear fission approaches for larger spacecraft. DIU's programme is targeted at highly manoeuverable, small spacecraft using fusion and radioisotopes.

Researched and written by World Nuclear News