SpaceX’s Dragon cargo spacecraft executed an initial reboost test of the International Space Station (ISS) on Sept. 3, 2025, using newly added trunk-mounted thrusters to raise the station’s orbit. The demonstration introduces a new option for ISS altitude maintenance alongside existing capabilities. Details were published in a NASA update (source).
The five-minute, three-second maneuver employed two trunk-mounted Draco engines fed by an independent propellant system. The burn increased the station’s perigee by about one mile, placing the ISS in a 260.9 x 256.3 mile orbit, according to NASA.
Key details
- Spacecraft and mission: Cargo Dragon supporting CRS-33.
- Burn duration: Five minutes, three seconds.
- Thruster configuration: Two Draco engines integrated in the Dragon trunk with an independent propellant supply.
- Orbit change: Perigee raised by ~1 mile; post-burn orbit of 260.9 x 256.3 miles.
- Planned operations: A series of longer reboost burns through fall 2025 to help sustain ISS altitude.
- Timeline: Dragon arrived Aug. 25, 2025; departure planned for late December or early January, returning research and cargo with splashdown off California.
Why it matters
ISS altitude steadily decays due to atmospheric drag, requiring periodic reboosts to maintain operational altitudes. Adding Dragon’s trunk-based propulsion as a reboost option expands the station’s toolkit for station-keeping, potentially improving scheduling flexibility, building redundancy, and distributing propellant demand across multiple vehicles. The capability can support altitude maintenance planning and may offer additional responsiveness for operational needs.
What’s next
NASA plans a cadence of longer Dragon reboosts throughout fall 2025 to help sustain the ISS orbit. Mission planners will tailor burn profiles to flight dynamics, traffic, and research schedules. The CRS-33 Dragon remains at the station until late December or early January, after which it will undock and return downmass, including research samples and hardware, to a splashdown zone off the California coast.
Context for station operations
Reboosts have historically been conducted by onboard propulsion systems and visiting vehicles. Dragon’s new trunk thrusters add another pathway for station-keeping, enhancing operational resilience as the ISS continues routine logistics, science, and crewed activities.
