Extreme programming controls Mars Lander robot

Scooping up soil samples and searching for elements that could support life on Mars isn't just an adventure for the Mars Lander and the robotic arm doing the scooping.

It's also an adventure for the approximately 30 engineers and programmers at NASA who are tasked with writing and testing 1,000 to 1,500 lines of software code and then beaming it about 170 million miles away — every day.

Matthew Robinson, the robotic arm flight software engineer at the Jet Propulsion Laboratory, said the team has to write the code sequences to run different parts of the Phoenix spacecraft, including the robotic arm, the cameras and analysis equipment. One mistake and the Lander sits idle for a day, wasting precious time that could be used to discover if the planet can support life.

So far, all the code they've beamed up to Mars in the past week has worked.

"It's a challenge because we have a two- to three-day strategic plan, and then each day that plan is refined," Robinson told Computerworld. "They decide on the final plan that day. You have to build 20 to 30 sequences, and each can have 50 lines of code in it. And they have a lot of interplay between different instruments, so you have to make sure the sequences are not just working, but working together.