Mars Lander Runs into Tough Digging

NASA's Phoenix Mars Lander has hit a roadblock while trying to scoop a sample of dirt into one of its ovens.

For the past day, Phoenix has been using its robotic arm to scrape away at a hard icy surface on the red planet, trying to claw enough dirt out to pour into its onboard instrument. So far, it has only accumulated small piles of shavings, which it has not been able to scoop into the oven.

Phoenix robotic arm co-investigator Ray Arvidson of Washington University in St. Louis compared the probe's task to trying to scrape away at a sidewalk.

"We have three tools on the scoop to help access ice and icy soil," Arvidson said. "We can scoop material with the backhoe using the front titanium blade; we can scrape the surface with the tungsten carbide secondary blade on the bottom of the scoop; and we can use a high-speed rasp that comes out of a slot at the back of the scoop."

He said the team hoped to make some progress with a motorized rasp tool on Phoenix's robotic arm to help dig into the hard icy soil and ice deposits.

Though the probe managed to scrape away a bit of material from the surface, the small piles it accumulated were smaller than on previous digs, and it wasn't able to get any of the dirt into its scoop.

"It's like trying to pick up dust with a dustpan, but without a broom," said Richard Volpe, an engineer on Phoenix's robotic arm team from NASA's Jet Propulsion Laboratory in Pasadena, Calif.

On Monday Phoenix performed 50 scrapes in a trench called "Snow White" it had previously dug. The material is intended to be analyzed in Phoenix's onboard oven instrument, the Thermal and Evolved Gas Analyzer (TEGA), to determine its chemical properties.

The $420 million Phoenix probe landed May 25 in the northern polar region of Mars in search of signs the environment could be habitable to life.

• Video: Digging on Mars
• Video: Phoenix, Rising to the Red Planet
• Images: Phoenix on Mars