As the Jet Propulsion Laboratory (JPL) builds the next Mars rover -- this one is named Curiosity -- to deploy to the red planet in the fall of 2011, they’re having a little fun with it. Back in 2007 when the Curiosity team was putting together the rover, its wheel cleats had a raised pattern with the letters “JPL,” leaving a little stamp of the rover’s birthplace everywhere it rolled. “At the time, I asked whether the real rover would have those wheels, and they said, no, they weren’t going to get to advertise JPL with each turn of each of the rover’s six wheels; the real rover would have some other pattern,” said Emily Lakdawalla of The Planetary Society in her blog. Lakdawalla is the organization’s Science and Technology Coordinator.

Lakdawalla said that there is nothing special about the shapes of the markers in Opportunity’s wheels; they are just square holes through the wheels through which the wheels were bolted to the lander during cruise and landing.” Opportunity is the name of the rover that went to Mars back in 2003. “But Curiosity didn’t need holes in its wheels for attaching to any lander -- there isn’t one. So the engineers got to make the markers in any shape they wanted to.”

But in March 2011, she saw a video of the rover as it is today: “I had to chuckle at those ‘visual odometry markers’ [on its tires]. Before I explain why, I’ll point out that they really are useful things to have in rover wheels. The repeating pattern of the ‘visual odometry markers’...makes it fairly easy for both the rover and human operators to determine visually how far the rover has roved using rear-view imagery.”

So what pattern did JPL choose to put on Curiosity’s wheels? One that Lakdawalla called “very amusing. The holes are in a pattern of short squares and longer rectangles -- almost like dots and dashes. Morse code.” And what does it spell out in Morse code? JPL.

J . - - -
P . - - .
L . - . .

According to JPL, Curiosity is about the size of a small SUV -- 10 feet long (not including the arm), 9 feet wide and 7 feet tall -- or about the height of a basketball player -- and weighs 2000 pounds. It features a geology lab, rocker-bogie suspension, a rock-vaporizing laser and lots of cameras. Curiosity will search areas of Mars for past or present conditions favorable for life and for conditions capable of preserving a record of life. It is set to launch between November 25-December 18, 2011 from Cape Canaveral, Florida and will arrive on Mars between August 6-20, 2012. The prime mission will last one Mars year, or about 23 Earth months.