Toys, balloons, and serious science
In a lab that appears to mix serious R&D with the ambiance of Santa's festive workshop, Jones and his colleagues are surrounded by shiny Mylar balloons of various sizes, pink and yellow beach balls, heavy-duty nylon tumbleweed ball prototypes, tall tanks of compressed gas and worktables full of mechanical and electronic devices.
The team, which includes senior engineer Sam Kim and design engineer Jay Wu, is now preparing for desert tests later this month that will incorporate a radar into the ball's center to test the prototype's ability to find underground water. Such instrumentation could eventually be used to search for possible water hidden beneath Mars' surface.
The ball is weighted so that it has a preferred axis of rotation. It tends to roll with the heaviest part down, so two weights opposite each other send the ball along a straight path. The upcoming tests will also try out a center-of-mass control device that would allow the ball to be steered by pumping contained fluid to the left, right or center of the tire, which will be slightly oblong.
"Again, this is experimental, so we're trying different things," says Jones. "But I'm pretty confident it will work."
"With a 20 kilogram ball and 20 kilogram payload, the 6-meter diameter tumbleweed ball is light enough that it could be added on to another lander and deployed from the ground, or it could be in its own delivery vehicle," he added. The large, lightweight ball could possibly also serve as its own parachute and landing airbag able to withstand the bounce following a 30-meter per second terminal velocity descent to Mars. The ball shares the same heritage as the airbag used for the 1996
advertisement
