Curiosity and the No-Good, Very-Awkward Week

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Space is many things. Inspiring. Awesome. Humbling. But it’s rarely funny. Physics as it is written on the grandest scale across the breadth of the universe doesn’t tend to be amusing. Usually if something is going to be funny, it’s going to require some sort of biological creatures getting involved in some way, and we’ve notoriously not found any beyond our own planet (so far).

But we humans have sent our robotic explorers around the universe, and once humans are involved in some fashion the possibility of merriment is there. And recently our oldest still-functioning Mars rover, Curiosity, encountered a situation which I personally found hilarious.

If you’ve seen the gif of the rover getting its drill stuck in a rock, then you already know what I’m talking about, but this seems like a good chance to go into just what the heck happened and how it could have wound up being a major issue rather than an amusing footnote.

Off to Mars then, and the sticky rocks of Gale Crater! 

Quick Background

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Some quick background on the Curiosity mission. This rover, officially designated the Mars Science Laboratory but known by almost everyone simply as Curiosity, has been perusing the massive Gale Crater and its central peak, Mount Sharp, since 2012. When it left Earth in 2011 it was, at nearly 2,000 lbs (900 kgs) in Earth gravity, by far the largest thing we’d ever sent to the surface of Red Planet (Perseverance has since surpassed it in that regard).

This car-sized rover, in addition to many other attributes, is in possession of a triple-jointed arm on its front that can stretch nearly seven feet (2 m) in front of the rover. The end of this arm houses five devices: two science instruments (an x-ray spectrometer and a camera), and three attachments associated with taking samples—a brush, a scoop, and a drill.

The drill is capable of making holes up to 2 inches (5 cm) deep in a rock to get samples of the insides which can then be delivered into other science instruments housed in the rover’s body. The rover doesn’t drill frequently—shortly after its 12^th birthday on Mars it drilled its 42^nd hole, for an average of 5-6 holes drilled a year—but it’s Curiosity’s most effective way at looking below the surface of an interesting rock. And it’s this drill that got the rover in trouble recently.

The Sticky Rock

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On April 25^th, 2026, Curiosity went to drill a whole in a rock called “Atacama” (side note: we nickname everything on Mars. Like, not just the rocks, but the holes we drill in the rocks. We just love naming things on Mars).

Atacama, named for the Chilean desert that houses a number of premiere Earth-based observatories, is estimated to be 1.5 feet (0.5 m) across, 6 inches (15 cm) thick, and to weigh 28.6 lbs (13 kg). Full disclosure, I couldn’t find whether this estimated weight was in Martian or Earth gravity, but if it’s Martian gravity that would mean the same rock would weigh over 70 lbs (about 32 kgs) on Earth. The point is, this rock is no pebble.

I have yet to find anything that outlines why Atacama was deemed a drill-worthy rock, but it’s got some lovely weathering on its surface revealing sedimentary layers. That can be an indicator of the presence of water in the past (and one of the reasons Gale Crater was selected as Curiosity’s landing site is the suspicion, largely proven at this point, that it was once a lake). And one of Curiosity's key tasks on Mars is determine how habitable Mars was in the past. In that light, Atacama may have seemed like a solid drill target. 

If only the rock wasn’t so determined to stick.

Curiosity’s Annoying Week

When Curiosity had finished drilling into Atacama on April 25^th, it pulled its arm back in an attempt to withdraw the drill. Only…Atacama came with it. The sleeve that surrounds the rotating drill bit on the arm had lodged in the rock, somehow, and when the arm pulled back it lifted the entire rock off of the ground.

I wish I could have been amongst the rover controllers at that time to experience the reactions. I can only gleefully imagine a satisfying series of dumbfounded expressions and possibly some choice creative language. We’ve never seen this happen on Mars (or in testing sessions on Earth).

Obviously the rock had to go. With it stuck on the end of the arm none of the sampling devices and neither of the science instruments on it could be used. Coupled with the fact that the arm had something at least approaching half its own weight dangling from its end and was not designed to be a weightlifting arm, and this rock could have posed a potential risk to the rover itself. Certainly the rover couldn’t safely move with that thing there. It had to go.

The thing is, Atacama didn’t want to go.

Rover Dancing

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The first thing the team tried was to vibrate the drill and shimmy Atacama off the end. It didn’t work. A few days later, the team tried rotating the robotic arm somewhat into a new orientation and vibrating the drill again. No joy. Atacama remained firmly stuck.

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And remember that during all of this Curiosity couldn’t do much else. It could operate its other science instruments as long as it was worth the power usage, but apart from that it was as stuck as the rock apparently was. Not to mention the rover team had to make sure that if/when the rock did come off the arm, it came off in a way that posed no risks to any other part of Curiosity, which limited what they could do. After several days of this, I have to imagine the rover team was start to feel a little exasperated, if not slightly desperate.

Finally, on May 1, six days after Atacama stuck itself to the rover, the team went a little more all out. They twisted the arm so that Atacama was rotated a full 90 degrees from where it had been hanging from the drill bit, then both rotated and vibrated the drill bit. Having watched the gif of the full series of pictures captured by the rover’s front hazard camerasmultiple times at this point, because it hasn’t stopped bringing me joy, I noticed that you can see the rock shift a little before it’s suddenly in pieces on the ground. Curiosity was free!

Mmmm, Science!

Having dropped a few feet off the rover arm at an odd angle, Atacama broke into several shards once it hit the ground. And do you know what a broken rock means to someone operating a Mars rover? SCIENCE!

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I couldn’t find anything that said whether or not Curiosity was ever actually able to analyze the sample that the drill was originally trying to get out of this rock, but it shattering the way it did exposed all its inside layers, and the ground upon which Atacama had previously been resting was also exposed. Curiosity has aimed its ChemCam both at the rock and the rock’s former resting place, and examined the newly uncovered sand up close with its MAHLI and APXS instruments (after first carefully inspecting its poor drill for damage).

So never let it be said that Curiosity’s Great Rock Battle of 2026 did not, in the end, yield results. That said, the rover might want to be a little more careful the next time it goes to drill a hole. In the meantime I’ll be over here in the corner cackling ridiculously over the gif of the rover’s arm contortions as it tried to free itself, like a perfectly normal human thank you very much.