BK: â€œSo, if you were to arm wrestle this, youâ€™d lose, but for anything that involves throwing something, youâ€™re definitely the winner.â€
JM: NASAâ€™s latest Mars Rover probably wonâ€™t be arm wrestling on the Red Planet, but it does have a strongalbeit slow-movingrobot arm, designed for other things. Iâ€™m Jim Metzner, and this is the Pulse of the Planet. Brett Kennedy is an engineer at NASAâ€™s Jet Propulsion Laboratory, and heâ€™s in charge of constructing and testing a giant arm for the Mars Science Laboratory, launching in 2011.
BK: â€œIt actually acts very much like your own arm, although much, much larger. Right in this area is equivalent to a human shoulder. So, we actually have two big motors here that run that shoulder, and then it runs up to an elbow, and then it runs up to a wrist.â€
JM: The roverâ€™s arm will drill into Martian rocks, collecting dust samples, and scooping up that signature red soil. Engineers are testing components here on Earth, with an eye towards the unique conditions that the rover will eventually face.
BK: â€œThere are a lot of challenges to sending anything to Mars, and, in particular, when we do these robotic systems, we have to worry about things like the temperature on Mars, which is, most of the time, very, very cold, and we have to worry about the dust on Mars. We donâ€™t want to spend all of our time and energy sending this to Mars just to have it frozen up due to dust. On the plus side, however, only 38 percent of Earth gravity on Mars means that this really large arm that weighs a lot on Earth doesnâ€™t weigh nearly as much on Mars, which makes a lot of the things it does, particularly moving itself around, a lot easier. So, we test it here, and thatâ€™s actually the hardest itâ€™s going to have to work. When we send it to Mars, itâ€™s going to be a lot easier.â€
Brett Kennedy is a participant in our Kidsâ€™ Science Challenge, a competition for 3rd to 6th graders, made possible by the National Science Foundation. Check out kidsciencechallenge.com.