NASA Mars Mission Gets An Assist From Delta-Grown Engineer

Sep 15, 2017

Originally from Bethel, Christopher Liu is the engineer behind the Muktuk Plot - a strategy that will help NASA pilot its next orbiter mission to Mars.
Credit Courtesy of Christopher Liu.

Thousands of miles to the south of us, engineers at NASA are hard at work on the NeMO Mission, the next orbiter mission to Mars. This summer they got a little help from an engineering intern from Bethel, and something called the Muktuk Plot.

Growing up in Bethel, Christopher Liu says that he was a quiet kid with a perfectionist streak who was always passionate about math.

"I think I just continued to maintain this sense of curiosity," Liu said. "About the world, how it works."

Today, after years of hard work, he’s studying electrical engineering as a graduate student at Stanford University in California. You might remember Chris from our story back in July, when we interviewed him about his efforts to build a Yup’ik "Siri" voice recognition system. This summer, Liu landed an internship with NASA's Jet Propulsion Lab (JPL) in Pasadena, California. Or, more specifically, a desk at Division 39, Section 392, where Liu crunched numbers for the next Mars mission.

Liu describes NASA as a heady experience. His colleagues casually talked about things like the office party they’re planning to throw for the Cassini Grand Finale today at the moment when the Cassini spacecraft orbiting Saturn is scheduled to plunge into the planet’s atmosphere and burn itself up. JPL was full of bright, collaborative scientists, though Liu said that working there wasn't quite as glamorous as it is in movies like Hidden Figures or The Right Stuff.

"I had an ugly cubicle in the basement of the building," he said with a laugh. He insists that it was actually one of the nicer ones in his department.

The shop that Liu found himself in was surprisingly diverse, but to his knowledge he was the only Alaska Native on staff. Liu says that there aren’t many Native American people in his field and that he did what he could to introduce his colleagues to Yup’ik ways.

"I shared some pikes, uquq, seal, and dried fish with some of the other JPL employees," Liu said. "And akutaq as well. And they were pretty happy to try it."

As he snacked on akutaq in NASA's basement, Liu chose to zero in on an issue that he calls “the missed thrust problem.” When NASA launches its next orbiter it will be preprogrammed with the most efficient route to Mars, but it's trip will be treacherous as it hurtles through space. The unpredictable can occur: a volley of cosmic rays, a missed thruster boost, and it's not something that a NASA engineer can go out there and fix. If an unexpected event occurs, the spacecraft will be programmed to go into “safe mode.” Its thrusters will turn off, and its software will wait for further instructions as NASA tries to plot a new course from Earth.

The problem is that as the orbiter waits for help, it’s going to drift off course. So when the spacecraft slingshots through space, Liu says that it needs to have enough fuel on board to correct its trajectory and plot a new course if or when things go wrong.

"And that's basically where the Muktuk Plot comes in," he said.

That’s right, the Muktuk Plot. As an intern, Liu charted out a new strategy that will help the Mars orbiter save fuel, even if it has to course-correct after several things go awry. Liu said he didn’t think it was even a new discovery at first, but his strategy could have implications for the way that NASA both plans out and executes the NeMO mission. He took his work to his mentor, who said, "present it." 

The presentation was crowded. Liu’s group supervisor was there, as were a fair number of other curious employees. Liu plotted his findings on a large, colorful graph - a chart that reminded him of something.

"You know the whales that you see in Fantasia?" Liu asked.

Liu said it’s something of a tradition for the NeMO team to name these discoveries after food; there’s a Bacon Plot and a Pork Chop Plot. So he named his discovery the Muktuk Plot because the chart reminded him of the humpback whales in the Disney film Fantasia 2000. Liu said that he was honored to bring a piece of Alaska Native culture with him into the Space Age.

"I think it was fulfilling for me personally," he said. "I was able to connect it to where I'm from."

Liu will return to Stanford this fall to finish the final year of his master’s program, and he encourages Yukon-Kuskokwim Delta teenagers to follow him into technical and scientific fields.

"It shouldn't be a barrier," he said, referring to living in the Delta. "A lot of people, they can't even visualize themselves working for NASA or being an astronaut, but it's definitely possible. And it's something that should excite students who are currently in school."

He added that any Delta teenagers interested in working for NASA, or just looking for college application advice, should feel free to contact him.