A former Toronto aerospace engineer with ties to London is playing a key role in NASA's latest Mars expedition. Janis Chodas is the flight software manager for the Mars Exploration Rover Project, including Spirit, which landed on Mars last weekend, and its counter-part Opportunity, due to land later this month. The software controls all aspects of the mission, from the entry into Mars' atmosphere to the descent, landing and exploration.
Chodas, whose husband was born and raised in London and still has siblings here, said when the first images of Mars started to appear, it was a defining moment for her.
"I think I'll always remember that, that ecstasy of the tangible proof that it worked," she said, of the landing last weekend.
"It was pandemonium. People were just ecstatic. For me, that was the defining moment of 'Wow, it's working, our software is working, the hardware is working, we're getting the images back, this is fantastic. We're on Mars.'"
She said the "textbook perfect" landing was almost surreal.
Before the rover landed, Chodas was in charge of developing and implementing the flight software. Now that the rover is on the red planet, she's in charge of tweaking and improving the software to optimize the vehicle's performance during its 90-day lifespan. In December, her team uploaded new software to the two rovers while they were on their way to Mars.
Chodas met her husband, Paul Chodas, at the University of Toronto, where they both studied. Now they both work at NASA's Jet Propulsion Lab (JPL) in Pasadena, Calif.
One of the biggest unknowns was the terrain on Mars, but now that they have images of the terrain -- with rocks smaller than expected -- they can alter the software to improve how the rover drives around the planet.
"Part of my job is to co-ordinate all of that, to find out what the operations team think they need and make it happen," she said.
The operations team also has a list of so-called "first-time activities" they want the rover to do, but Chodas and her staff must first analyse and test those activities to make sure they won't hurt the rover.
"If we find a problem, that something is not working quite right, we can modify it on the ground, test it in the test bed, and then send up a change to that part of the software," she said. "You can't change the hardware, the hardware is on Mars, but you can change the software."
Chodas has been at JPL since 1980, when she was first hired to work on the Galileo spacecraft mission to Jupiter, launched in 1989. The Rover mission is her first involving Mars and the first that has involved a landing.
Chodas said when she was first hired she never imagined it could lead her to be a key member of a Mars mission team.
"I don't even think I dared to dream that big," she said. "It's very far out, literally."
Work on the Mars mission has been intense for the last 3 1/2 years and with the successful landing, routines have changed -- including some of the staff having to work the Martian day, which starts in our afternoon and is 24 hours and 37 minutes long.
"All of a sudden you try to work an issue with someone and they're not here, because they're coming in later," she said, of the schedule that's worked out with battleship-like precision.
Chodas said the most challenging part of software development was figuring out what the rover has to be able to do, under all circumstance. Not only does the vehicle have to conduct scientific analysis, but it also has to monitor its own health.
The rovers are designed to last 90 days, but Spirit is now expected to go more than 120 days, depending on how much power its batteries can get from the sun. When its batteries start to fade, it won't keep itself warm enough at night and things will start to break -- an event Chodas expects will be a sad one at the office.
The $820-million unmanned project is NASA's first visit to the surface of Mars since Pathfinder in 1997.
