A routine mission on Mars turned into an unusual problem for NASA after a large rock stuck to the Curiosity rover’s robotic arm — putting a key scientific instrument monitored by researchers at Ontario’s University of Guelph at risk.
The issue began on April 25, when Curiosity drilled into a 28-pound rock on the Martian surface to collect a sample.

But when the rover retracted its arm, the entire rock lifted from the ground and remained attached to the drill.
Fixing the problem wasn’t exactly simple, considering the rover is operating more than 200 million kilometres away from Earth.
“We saw that something is not working or not normal. Then you look at the pictures and it’s like, ‘Woah!’” said Ralf Gellert with the University of Guelph’s Department of Physics.

What is Curiosity doing?
Curiosity uses its drill to collect powdered rock samples that can then be analyzed by onboard instruments as part of the search for clues about Mars’ geology and whether the planet may once have supported life.
“We are looking at rocks. We are figuring out what they are made of, how they look,” Gellert explained. “And once in a while we drill into the rock to extract powder to be analyzed by big instruments looking for mineralogy and even organic material.”
One of those instruments is the Alpha Particle X-Ray Spectrometer (APXS), operated in part by researchers at the University of Guelph.
The APXS is mounted on the rover’s robotic arm, which is the same arm that was holding the stubborn Martian rock.
Orbax, a science communicator with the University of Guelph (U of G), said the situation quickly became a concern because of the communication delays involved with operating machinery on another planet.
“We’re talking about distances so far away that you can have seven to 10-minute-long lapses in communication,” Orbax said. “So, an entire strategy had to be come up with. To my knowledge, (NASA) has not yet had this problem.”
Saving Curiosity
NASA engineers first tried vibrating the drill in an attempt to shake the rock loose.
It didn’t work.
They then repositioned the robotic arm and tried again.
Still, the rock remained firmly attached.
Finally, after about a week and multiple attempts, the rover managed to free itself, sending the rock crashing back onto the Red Planet’s surface.
“Whew,” Gellert said with a nervous laugh.

Despite the unusual ordeal, Curiosity was not damaged and the APXS instrument is operating normally.
“I think people are nervous when you have an issue like this. Is this the end of the Curiosity rover?” Orbax said. “Well, in this case, it wasn’t. We were able to push through and continue to gather data from it for hopefully years to come.”
That seems to be a reality, considering the Canadian Space Agency gave Gellert and his team of U of G researchers an extension to do this work about a month ago. Gellert said NASA also recently extended the Curiosity rover by another three years.
So, Curiosity can now roll on with its Mars mission, making sure it leaves no stone unturned.
For more space stories, skywatching tips and updates from University of Guelph researchers, viewers can check out the University of Guelph Physics Star Gazing Guides on YouTube: University of Guelph Physics Star Gazing Guides

