Ice giants are among the most attractive targets in the solar system, and Uranus has recently risen to the top of the list. The National Academies’ 2022 Decadal Study identified it as a top priority destination for future exploration. However, despite its strong support, there is still no fully developed mission ready for launch opportunities expected in the 2030s.
This delay may not be completely negative. Powerful new launch systems are emerging that have the potential to significantly change the way such missions are designed. SpaceX’s Starship continues to show progress through recent successful tests. In a paper presented at the IEEE Aerospace Conference, MIT researchers investigated its potential impact, focusing on how it could support the proposed Uranus Orbiter and Probe (UOP).
Why Uranus still matters
Uranus remains one of the least studied planets. The only spacecraft to visit was Voyager 2, which passed by the planet about 40 years ago. Neither Uranus nor Neptune have ever had orbiters or long-duration missions, making them the only planets in the solar system that have not been studied in detail for many years.
There is a reason why there is so much interest in Uranus. This planet has some unusual features that scientists are still struggling to explain. It rotates sideways, has an irregular magnetic field, and is surrounded by moons that may contain an underground ocean beneath its icy crust. Studying Uranus could help scientists better understand similar planets outside our solar system, as ice giants appear to be common throughout the Milky Way galaxy.
Challenging the distance
Reaching Uranus is difficult mainly because of its great distance. It orbits about 19 times further away from the Sun than Earth. Voyager 2 took more than nine and a half years just to pass the planet without attempting to enter orbit.
Recent mission concepts estimate even longer travel times. Plans based on the Falcon Heavy and multiple gravity assists would take more than 13 years to come to fruition. Sustaining a mission for such a long period of time increases costs and introduces risks such as staffing changes and possible funding interruptions. Reducing travel time makes missions more realistic and sustainable.
How starships can change missions
Starship may offer a way to overcome these challenges. Despite setbacks in previous tests, the system recently completed a successful test flight and is making steady progress. If development continues as expected, it could be operational by the end of this decade, making it a strong candidate for launching a Uranus mission.
The benefits go beyond just lifting power. One important feature is the ability to refuel in orbit. Starship is designed to store and transport fuel during its stay in space, potentially allowing the spacecraft to travel faster than a system that requires carrying all the fuel from launch. Although this capability has not yet been demonstrated, future tests could explore it and open new possibilities for deep space travel.
Use your starship as a giant heat shield
Another idea considered in the MIT study involves using Starship itself as part of the mission upon arrival. Rather than separating after launch, Starship could travel with the probe all the way to Uranus. Its heat-resistant design was originally intended for re-entry to Earth and Mars, and could be used to cope with the intense heating caused by aerobraking in Uranus’ atmosphere.
In this scenario, the starship acts as a protective shield, slowing down the spacecraft as it enters the planet’s atmosphere. This would allow the spacecraft to slow down enough to stay in orbit, rather than just passing by.
Cut travel time in half
The study calculated that this aerobraking approach, combined with refueling in space, could reduce the travel time to Uranus to about six and a half years. This is approximately half the duration of previous mission plans. It would also eliminate the need for gravitational support from other planets.
Although carrying a Starship on a journey increases complexity and cost, shortening mission schedules could significantly reduce overall operating costs. Faster travel also reduces long-term risks related to funding and staffing.
Uncertain future of Uranus mission
Despite their promise, Uranus orbiters and probes are still far from reality. Starship has not yet demonstrated aerobraking capabilities for such a mission, and the mission itself has not received funding approval. The schedule remains uncertain given the challenges currently facing NASA.
If we miss the launch opportunity in the 2030s, the next favorable window may not arrive until the mid-2040s. That means nearly 70 years will pass between missions to Uranus. The hope for scientists and space exploration activists is that support will gather in time to make a return to this fascinating world possible, whether Starship plays a role or not.
