Amid the cost growth, political division, and management missteps roiling NASA and ESA’s Mars Sample Return program, it is not unreasonable to ask if there are more affordable alternatives to return these samples to Earth, namely SpaceX’s own Mars project, Starship.
The answer is almost certainly “no.” At least, not anytime soon.
This is due to the unique needs of a scientifically relevant Mars sample return campaign, the uncertain capabilities of Starship, and the one-of-a-kind nature of the samples themselves.
Mars Sample Return, as envisioned by NASA and ESA, is a multi-mission campaign. The samples are collected and stored by the Perseverance rover. Years later, a Mars Ascent Vehicle (MAV) lands nearby, into which the samples are loaded. The MAV launches the samples into Mars orbit, where they are collected by an orbiting spacecraft provided by the European Space Agency. That orbiter returns to Earth and drops the protected samples into Earth’s atmosphere, where they land in a deserted area to be collected and analyzed.
SpaceX’s Starship and Super Heavy rocket, now making tremendous progress in Boca Chica, could, theoretically, complete a sample return project in a single mission, with far more mass, for less money. It is designed to be reliable and rapidly reusable, and it can also be fueled using natural resources processed on Mars. NASA has already committed nearly $3 billion to Starship to serve as its lunar lander for Artemis, a smart move since it nets the agency a two-for-one long-term investment in Moon and Mars hardware.
But once specifics start coming into play, the uncertainties of Starship in active development become more pronounced, and a number of critical questions are revealed as unanswerable, making any reformulation of Mars Sample Return via Starship functionally impossible in a near-term timeline.
These are some of the questions that need to be answered with confidence before Starship can be considered in a NASA-directed sample return campaign: