Perseverance's Empty Drill Hole and the Long Road to Mars Sample Return
After Perseverance's first coring attempt came up empty, here's where the Mars Sample Return campaign goes from here.
Perseverance’s first attempt at drilling a rock core, back on August 6, didn’t go the way anyone hoped. The rover executed the maneuver correctly, but when the sample tube came back up, it was empty. The rock it bored into turned out to be too crumbly to hold together as a core, and the material likely just disintegrated. NASA has been pretty matter-of-fact about it: this is a new procedure on an alien planet, and not every rock is going to cooperate.
The good news is that nothing about this setback threatens the broader campaign. NASA and ESA are still planning to send the rover after a new target rock, hopefully one with better structural integrity, and try coring again. Perseverance has a whole toolkit of instruments to scout candidate rocks before committing the drill, so expect more caution and more scouting before the next attempt.
Why this matters more than a single drill hole
It’s worth stepping back and remembering what Perseverance is actually doing here. It’s not just a geology rover — it’s the first phase of a multi-mission relay race that could take a decade to finish. The current plan calls for Perseverance to collect and seal a set of sample tubes and cache them on the Martian surface. Later missions would then land a fetch rover (or use Perseverance itself, if it’s still operational), a small rocket capable of launching off Mars’s surface, and an orbiter to catch that rocket’s payload and carry it back to Earth. If all goes to plan, the samples wouldn’t actually arrive on Earth until sometime in the early 2030s.
That’s an enormous amount of choreography, and it’s easy to lose sight of it in the day-to-day rover updates. Every core attempt, successful or not, is a small step in a project that spans multiple spacecraft, multiple space agencies, and roughly a decade of mission planning.
The reason anyone is doing this at all comes down to one basic limitation of robotic exploration: you can pack a lot of instruments onto a rover, but you can’t pack a full planetary science lab. The analytical techniques available in Earth-based labs — the kind of high-precision isotopic dating and microscopy that can actually make a definitive case for ancient biosignatures — just aren’t things you can miniaturize and fly to Mars. Rovers can flag interesting chemistry and interesting textures, but distinguishing “this looks like it could be biological” from “this is definitely evidence of ancient microbial life” is a much higher bar, and it’s the kind of claim scientists want to be able to defend with every tool available, not just what fits on a spacecraft.
So the empty tube from August 6 is really just noise in a much longer signal. The mission timeline was never going to be a straight line, and if this ambitious relay of landers, rockets, and orbiters actually pulls off returning sealed Martian rock to Earth, it’ll be one of the more remarkable feats of robotic engineering to date. Worth watching closely as Perseverance rolls toward its next target.