Sunbird
A planned fusion-powered space tug that would wait in low Earth orbit, dock with spacecraft and push them toward Mars or the outer planets far faster than today's engines.
Why it matters
Fusion exhaust can be much faster than chemical rocket exhaust, which could cut trip times sharply. Pulsar projects cargo to Mars in under six months, though none of this has flown and fusion propulsion remains unproven.
How the technology works
Sunbird would use Pulsar's Dual Direct Fusion Drive, a set of compact linear fusion reactors meant to supply both thrust and about 2 MW of power. The company quotes a specific impulse of 10,000 to 15,000 seconds.
Spacecraft would launch to low Earth orbit, dock with a Sunbird, and get 3 to 5 km/s for Mars. Static tests were scheduled from 2025, with an in-orbit demonstration of core components planned for 2027.
Sources
Updated Oct 22, 2026 · How we source facts · Suggest a correction