The Jet Propulsion Laboratory (JPL) confirmed that the rover Curiosity -- after a 36 week space flight -- landed successfully on Mars at 10:32 PM PDT on August 5 (0532 UTC August 6). Built by JPL and launched by NASA on November 26, 2011, the 2000 pound machine features something that radio amateurs are sure to appreciate: Morse code.

If you look carefully at Curiosity’s wheels, you might notice that along with treads, there are square and rectangular holes. According to JPL Rover Mechanical Engineering Team Manager Richard Rainen, these holes actually have a purpose: odometer markers. “We will be looking at the visual odometer markers that we have on the wheels,” he explained in a video. “There are asymmetric patterns, actually holes, inside the wheels of the rover that will leave an imprint on the surface of Mars. We’re going to be looking at these imprints and verifying that it has traversed the distance it expects to traverse. If it looks like it’s not traversing, even though the wheels are going, that is an indication that the vehicle is getting stuck and it will stop and call back home.”

But in 2007 -- when the Curiosity team at JPL 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. “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.”

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 . - . .

“Today, the wheels of Curiosity have begun to blaze the trail for human footprints on Mars,” said NASA Administrator Charles Bolden in a press release. “Curiosity, the most sophisticated rover ever built, is now on the surface of the Red Planet, where it will seek to answer age-old questions about whether life ever existed on Mars -- or if the planet can sustain life in the future. “This is an amazing achievement, made possible by a team of scientists and engineers from around the world and led by the extraordinary men and women of NASA and our Jet Propulsion Laboratory. President Obama has laid out a bold vision for sending humans to Mars in the mid-2030s, and today’s landing marks a significant step toward achieving this goal.”

“Touchdown Confirmed”

Two minutes after JPL Laboratory Engineer Al Chen exclaimed “touchdown confirmed” (near the foot of a mountain three miles tall and 96 miles in diameter inside the Gale Crater), the first image popped onto video screens -- a grainy black-and-white image that showed one of the rover’s wheels and the Martian horizon. A few minutes later, a clearer version appeared, and then came another image from the other side of the rover. “That’s the shadow of the Curiosity rover on the surface of Mars,” explained Robert Manning, the project’s chief engineer.

Even more photos were beamed back a couple of hours later. “Curiosity’s landing site is beginning to come into focus,” said NASA’s Mars Science Laboratory Mission Project Manager John Grotzinger in a NASA news release. In one photograph, the rim of the crater is seen in the distance. “In the image, we are looking to the northwest. What you see on the horizon is the rim of Gale Crater. In the foreground, you can see a gravel field. The question is, where does this gravel come from? It is the first of what will be many scientific questions to come from our new home on Mars.”

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. Curiosity carries 10 science instruments with a total mass 15 times as large as the science payloads on the Mars rovers Spirit and Opportunity. Some of the tools are the first of their kind on Mars, such as a laser-firing instrument for checking elemental composition of rocks from a distance. The rover will use a drill and scoop at the end of its robotic arm to gather soil and powdered samples of rock interiors, then sieve and parcel out these samples into analytical laboratory instruments inside the rover. Curiosity will search areas of Mars for past or present conditions favorable for life and for conditions capable of preserving a record of life.

Over the first week, Curiosity is to deploy its main antenna, raise a mast containing cameras, a rock-vaporizing laser and other instruments, and take its first panoramic shot of its surroundings. NASA will spend the first weeks checking out Curiosity before embarking on the first drive. The rover will not scoop its first sample of Martian soil until mid-September at the earliest, and the first drilling into rock is not expected until October or November.

You can follow Curiosity on Twitter and on Facebook.   -- Thanks to NASA and JPL for the information