Fusion-Powered Spacecraft Could Be Just a Decade Away

[Elderberry]

Space.com by Mike Wall 6/12/2019

The tech could allow a probe to make it to Saturn in just two years.

Fusion-powered spacecraft may not be just a sci-fi dream for much longer.

The Direct Fusion Drive (DFD) engine could take flight for the first time in 2028 or so, if all goes according to plan, the concept's developers said.

That would be big news for space fans; the minivan-size DFD could get a 22,000-lb. (10,000 kilograms) robotic spacecraft to Saturn in just two years, or all the way out to Pluto within five years of launch, project team members said. (For perspective: NASA's Cassini mission made it to Saturn in 6.75 years, and it took the agency's New Horizons probe 9.5 years to get to Pluto.)

And the engine doubles as a potent power source, meaning the technology could have a broad range of off-Earth applications.

For example, the DFD could help power NASA's planned moon-orbiting space station, known as the Gateway, as well as bases on the moon and Mars, project team member Stephanie Thomas, vice president of Princeton Satellite Systems in Plainsboro, New Jersey, said late last month during a presentation with NASA's Future In-Space Operations working group.

More: https://www.space.com/fusion-powered-spacecraft-could-launch-2028.html

[The_Reader_David]

Fusion powered anything (leaving aside weaponry) has been "just a decade away" for the past half-century plus, and I expect it to remain so for at least the next half-century.

[Elderberry]

Testing ion thrusters for space exploration

https://www.aerospacetestinginternational.com/features/testing-ion-thrusters-for-space-exploration.html

The reactor Swanson is developing for use in ion thrusters is much smaller – just 1.5m (5ft) across by 4-8m (13-26ft) long.

But although building a small-scale fusion reactor to fit on spacecraft sounds daunting, it is not the hardest part of the work.

“Generating fusion power isn’t the puzzle,” Swanson says. “Significant amounts of fusion power were generated in the 1990s. The puzzle is converting the energy output from the reactor into thrust.”

Princeton Satellite Systems plans to solve the conundrum with an engine design composed of two layers of plasma – a super-heated core and a cooler outer layer. As hot ions from the core heat up the cooler plasma, an energy transfer will cause this outer layer to expand into a magnetic nozzle at the rear, resulting in thrust.

Swanson says, “It turns a hot, slow-moving plasma into a cold, fast-moving plasma. It’s like the constriction in a conventional rocket nozzle – except it’s all mediated by a magnetic field.”

“If you can create the conditions for fusion, then the same device that is used to generate power would be capable of very fast exhaust speeds if reconfigured as a rocket,” says Richard Dinan, CEO of Applied Fusion Systems. “I think we’ll be deploying these devices in space before we’re powering homes with them.”

Despite all their hard work, Swanson and Dinan acknowledge that nuclear fusion space rockets are still in the very early stages of development. Swanson’s team at Princeton Satellite Systems expects each of its test engine upgrades to take three years, meaning it will be at least 2028 before there is a working prototype.

But those involved in the development of fusion power are used to long research projects. Construction of ITER in the South of France started in 2007 and the experiment isn’t scheduled for completion until 2025. ITER aims to prove fusion power is technically feasible. Engineers believe it won’t be until 2050 that a power plant capable of producing electricity from fusion will be built.

Cassibry also believes that fusion is the future of space travel. He says, “To go into deep space we’ll need nuclear power of some sort. Deep space manned missions require a lot of energy and the smallest mass of reactor you can get.

“Solar won’t work because when you get past Mars there’s not enough sunlight – the power falls right off. Going to Saturn right now takes 10 years. If you want to get there in a year, you’re going to need fusion.”