A few weeks, NASA pulled off the impressive feat of landing a rover on Mars, the Mars Science Laboratory, as known as the Curiosity Rover. Its mission? To trundle about, collect soil, analyze rocks and discover whether or not Mars once supported life, or perhaps, still does. The MSL was by far the biggest object anyone had tried to land on the surface - so big that a whole new landing system had to be devised: the Skycrane. GrabCAD has a few contacts with NASA, and lucky for you we managed to get in contact with one of their Lead Engineers at the Jet Propulsion Lab in Southern California, Mr. Steven Sell.
Over nearly an hour, we talked about the Skycrane, its genesis, the next phase for their mission, his team and human exploration of Mars. Steve dispelled a few myths about the Skycrane. In a lot of ways, it wasn't as a revolutionary technique as it had been hailed. None of the components were particularly new - the Hydrazine rockets were taken from the Viking probes. The onboard computer, using a radiation harden RAD750 clocks in at 200 MHz, but can withstand powerful cosmic rays and temperatures of -25 to 125 Celsius. "It guides itself, but it's all mathematics in the end." Steve explained.
One thing I wanted to know the most was how they managed to test the Skycrane before launching it. "Prepare to have your mind blown. The first time we ever tested the rockets on the Skycrane was on Mars.". Testing the entire Skycrane under the correct conditions is an expensive task, Steve explained. Testing each component and simulating the conditions on computer provided enough data to perfect the final design. "Before we cut, mill or measure anything, we ask ourselves, 'Can we test it?' The exception to the rule was the end result - but every single design decision had to answer that question clearly.
Working with tried and tested ideas meant some design decisions were easier to make. The fiery re-entry into the Martian atmosphere, figuring out how to slow MSL down by parachute from hypersonic speeds and developing the guidance systems was pulled from Apollo, from Viking, from almost every single NASA mission. Good engineering comes from minimizing risks of failure by learning from the feats of engineering before you, and testing everything as much as possible. Still, getting approval for the Skycrane must have been difficult. Not so according to Sell, "We had a panel made of former Apollo astronauts, Senior engineers and a few former pilots who flew the big Sikorsky Skycranes, one of the biggest helicopters in the World." They advised NASA and agreed that using a rocket-propelled skycrane was the only feasible way of safety landing a payload of this size.
And they did it. Congratulations to Sell, his team, JPL and NASA for nearly a decade of hard work. But what's next? "We're not sure of that. JPL just signed a contract for another probe to Mars to measure seismic activity. We'll probably begin working on a project that comes after that." Manned Mission to Mars might be in the cards - but there are so many obstacles, mostly stemming from the fact that 'Humans are very fragile things'. Annoyingly so. Feeding and watering people over the estimated 3 years in space to get there, land and return, not to mention scientific gear and fuel, its a far-off proposition. The Moon? Probably far more likely. Anyone of the younger Engineers on GrabCAD could be one of the leads on that project.
Heck it might be a great idea if we just run a design competition to make a nice spaceship. Maybe something like this.
