Nuclear fusion — which releases four times the energy of fission — could theoretically happen sooner in space than on earth, reports CNN.
“And it could help spacecraft achieve speeds of up to 500,000 miles (805,000 kilometers) per hour — more than the fastest object ever built…”
With funding from the UK Space Agency, British startup Pulsar Fusion has unveiled Sunbird, a space rocket concept designed to meet spacecraft in orbit, attach to them, and carry them to their destination at breakneck speed using nuclear fusion… For now, Sunbird is in the very early stages of construction and it has exceptional engineering challenges to overcome, but Pulsar says it hopes to achieve fusion in orbit for the first time in 2027. [Pulsar’s founder/CEO says the first functional Sunbird would be ready four to five years later.]
If the rocket ever becomes operational, it could one day cut the journey time of a potential mission to Mars in half.
CNN says the proposed Sunbird process would use helium-3 — which may be abundant on the Moon — to generate protons which “can be used as a ‘nuclear exhaust’ to provide propulsion”. (And without generating any dangerous radioactive material.)
“It’s very unnatural to do fusion on Earth,” says Richard Dinan, founder and CEO of Pulsar. “Fusion doesn’t want to work in an atmosphere. Space is a far more logical, sensible place to do fusion, because that’s where it wants to happen anyway….”
Sunbirds would operate similarly to city bikes at docking stations, according to Dinan: “We launch them into space, and we would have a charging station where they could sit and then meet your ship,” he says. “You turn off your inefficient combustion engines, and use nuclear fusion for the greater part of your journey. Ideally, you’d have a station somewhere near Mars, and you’d have a station on low Earth orbit, and the (Sunbirds) would just go back and forth….” Initially, the Sunbirds will be offered for shuttling satellites in orbit, but their true potential would come into play with interplanetary missions. The company illustrates a few examples of the missions that Sunbird could unlock, such as delivering up to 2,000 kilograms (4,400 pounds) of cargo to Mars in under six months, deploying probes to Jupiter or Saturn in two to four years (NASA’s Europa Clipper, launched in 2024 towards one of Jupiter’s moons, will arrive after 5.5 years), and an asteroid mining mission that would complete a round trip to a near-Earth asteroid in one to two years instead of three.
Other companies are working on nuclear fusion engines for space propulsion, including Pasadena-based Helicity Space, which received investment from aerospace giant Lockheed Martin in 2024. San Diego-based General Atomics and NASA are working on another type of nuclear reactor — based on fission rather than fusion — which they plan to test in space in 2027.
