Working the Martian Night Shift

by John Thompson
Office of University Communications
  • The sun begins to set on another Martian day in this image from the Opportunity rover. The Mars 2020 mission, featuring the Perseverance rover, begins in earnest when the rover touches down on Mars on Thursday, Feb. 18.
    The sun begins to set on another Martian day in this image from the Opportunity rover. The Mars 2020 mission, featuring the Perseverance rover, begins in earnest when the rover touches down on Mars on Thursday, Feb. 18.
  • Perseverance is loaded with cameras and sensors in its search to answer the same question each rover before it was tasked to discover: Did life ever exist on Mars? (Image courtesy NASA)
    Perseverance is loaded with cameras and sensors in its search to answer the same question each rover before it was tasked to discover: Did life ever exist on Mars? (Image courtesy NASA)
  • Ingenuity will bring aerial support to a rover mission for the first time.
    Ingenuity will bring aerial support to a rover mission for the first time.
  • Orbiter image shows the “bullseye” landing ellipse for Perseverance on the edge of Jezero Crater, as well as the size of the landing ellipses for past missions; new navigation software allows for a much more precise idea of where the rover will set down.
    Orbiter image shows the “bullseye” landing ellipse for Perseverance on the edge of Jezero Crater, as well as the size of the landing ellipses for past missions; new navigation software allows for a much more precise idea of where the rover will set down.
  • Western students and Melissa Rice at Malin Space Science Systems for the testing and calibration of Mastcam-Z in May 2019. From left to right: Darian Dixon, Tina Seeger, Melissa Rice, Katherine Winchell, and Mason Starr.
    Western students and Melissa Rice at Malin Space Science Systems for the testing and calibration of Mastcam-Z in May 2019. From left to right: Darian Dixon, Tina Seeger, Melissa Rice, Katherine Winchell, and Mason Starr.

Western Washington University Associate Professor of Geology Melissa Rice is going to be working nights for the next three months.

Martian nights.

Rice, who is a science team member of NASA’s Mars 2020 rover mission that lands on the Red Planet on Thursday, Feb. 18, said she is prepping for “90 days of jet lag” once the rover sets down.

“We work Martian nights for a very important reason: We need to work while the rover sleeps, so that when it wakes up the next day, it can begin work on its new to-do list,” Rice said.

Of course, nights on Mars don’t sync up with nights on Earth, so Rice will have a very “fluid” sleep cycle during the first three months the rover is operating on Mars … and to make matters worse, Mars days are 40 minutes longer than ours, so each work day and subsequent sleep cycle gets advanced 40 minutes.

“Sleep scientists have studied people doing this kind of work, and it really starts to take its toll after a while, which is why we can only do it for 90 days,” she said. “When we go back to Earth time after that initial three months, we are less efficient but far more sane.”

So while she may not be excited about her upcoming adventures in sleep deprivation, Rice said she couldn’t be more thrilled with the work she and many of her students will be doing with Perseverance, the rover touching down on Feb. 18.

“This mission is going to be incredible,” she said. “The scope of what we can ask of Perseverance is just so much greater than what we could ask of previous rover missions like Curiosity or Opportunity.”

For one thing, Perseverance, nicknamed “Percy” by its Earthbound crew and support staff, is carrying its own air support in the form of a small drone named Ingenuity.

Like a mother kangaroo with its baby, Percy will carry Ingenuity around Mars for the first 30 days of the mission, then seek out a flat spot to designate as a helipad and drop it there, followed by about a month of flights and image gathering.

“The imagery from Ingenuity will fill in the gaps between the ground-based images that Perseverance will take, and the images from the orbiters circling the planet,” Rice said. “So that is very valuable. Plus it is a proof-of-concept, as we’ve never operated aircraft on Mars before.”

Where are we, anyway?

Rice said one of the first jobs for the mission will be to determine where, exactly, the rover has set down.

“We’ve got a target site, but the question will be how close the rover actually gets to the bullseye,” said Rice. Called the “landing ellipse,” the target sits near an old riverbed near the edge of the Jezero Crater, a massive bowl on the surface of Mars almost 30 miles across that is thought to have once been flooded by a now long-gone Martian river.

As the craft descends towards the bullseye, a set of software instructions called Terrain Relative Navigation, or TRN, takes over, and guides the craft down, avoiding deep sands, cliff walls, boulder fields and other potential hazards.

“TRN is pretty smart, it will find us a safe place to land. Then the big question is who wins the pool,” referring to an in-house wager by NASA scientists over where exactly the craft will land inside the ellipse.

Western alumna Tina Seeger, a former student of Rice’s who is now getting her doctorate at Cal Tech and working directly with NASA through the Jet Propulsion Laboratory, is just as excited about Perseverance’s mission in Jezero Crater as Rice.

“I can’t wait to see all the hard work we have all put into this mission in preparation be rewarded with the stunning geology we will get to explore on the ground. Jezero Crater has a rich geologic history, and I am floored to be a part of detangling the complex rock record from the observations that will be collected as we drive around,” she said. “It’s been really special to be a part of the Perseverance team during development — I came onto the Curiosity rover team several years after landing, so it was a well-oiled machine by then.”

Seeger is one of the many graduate and undergraduate students who — over the past 7 years — contributed directly to Perseverance’s mission during their time at Western. Student research projects have informed decisions about the design of the Mastcam-Z instrument (Mastcam-Z is the pair of zoom-enabled cameras that will be the “scientific eyes” of the rover). In 2016, Rice and her research students hosted the entire Mastcam-Z instrument team on campus for their annual in-person meeting. In 2019, more students came with Rice to Malin Space Science Systems to test and calibrate the Mastcam-Z cameras, and now four Western alumni have jobs there.

Western students also helped select Jezero crater as the rover’s landing site. Six students traveled to the final NASA landing site selection workshop, where they got to vote for their favorite of three candidate sites. And after Jezero was announced the winner, some of those same students helped create the geologic map that the Perseverance team will use to plan out the rover’s route.

Time to unpack and stretch our legs

Once on the surface, Percy’s first four days will consist of a lengthy and comprehensive self-diagnostic to make sure it has arrived in one piece, followed by an extensive software update sent from Earth.

“We basically sent Perseverance to Mars with software that is now already out of date,” Rice said. “So we need to update its OS, first thing.”

Next steps will depend on where Perseverance touches down. NASA has preplanned a number of paths and routes, and Percy will drive to reach one of these “trails” in its first month, then begin searching for the helipad site.

And like all the previous rover missions she has worked on, including Curiosity and Opportunity, Rice will get new fresh images from another planet delivered to her home desktop each morning.

“New images from the crater! I can’t wait,” she said.

Once it is out and about, Percy will be doing things no other rover has done.

“Where the previous rovers were solely about finding a rock and studying it, and sending us what data it could glean from that rock back to us, Perseverance isn’t just studying rocks, it’s collecting them,” she said.

And collecting, points out Rice, has little point if you don’t at some point bring those collections back.

Percy has room for 39 sample tubes, and eventually, it will leave those samples in a collection site on the surface. In 2027, the next Mars mission, featuring the as-yet-unnamed “fetch rover” is scheduled to go to Mars, land, and fetch the collection left by Percy. Fetch will be the first rover to land and then lift off again from Mars, but will only be able to get as far as Mars orbit. A third mission, no sooner than 2029 (the window to go to Mars from Earth opens every two years) will go to Mars, grab Percy’s collection from Fetch, and return it to Earth.

“This is the kind of planning that has to happen just to get a sample back from Mars,” said Rice. “And each new step is always something we’ve never done before. But it could be more than a decade before the samples that Perseverance starts collecting next month get back to Earth.”

But each mission, and each new hurdle cleared, builds the science for the next mission, with the goal of one day potentially sending humans to study there.

“Every time we send a rover to Mars, it’s obsolete by the time it gets there because of the advances made between building the rover and when it lands; most of Perseverance was designed in 2013,” she said. “But we get more and more efficient. So perhaps one day we can send a rover and have it return its cargo in one mission instead of three? Everything we learn now helps us plan and grow the possibilities for later.”

For example, Rice said one of the on-board experiments being run by Perseverance is called “MOXIE,” which turns carbon dioxide from the Martian atmosphere into either breathable oxygen potentially useful to human colonists or liquid oxygen that could be used as rocket fuel.

In the end, all the effort, all the planning, all the missions — they all come down to trying to answer one central question.

“Was there ever life on Mars? That’s what we are seeking to find out with every rover mission, every image, every experiment,” she said.

Setting down next to an ancient river bed in a crater that was once a giant lake gives them as good a chance to find that answer as possible.

“Now Perseverance just needs to put in the work,” Rice said.

And then bring on the Night Shift.

Want to know more about Rice’s research or the work of her students? Find out more here.

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Wednesday, February 17, 2021 - 10:57am

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