It could have gone horribly wrong.
Imagine pushing a car off the top of the Empire State Building -- and then driving it away from where it fell.
Even if using precautions to make sure it falls safely, like a parachute, it's still a challenging task.
But now imagine if it was more challenging still -- when the car lands, not only does it have to be drivable, it has to pretty much intact. No broken headlights or cracked mirrors. And instead of falling from the top of the Empire State Building, it's falling even farther.
Imagine dropping a car from a spaceship, and landing it without a dent fender.
It would sound impossible, if it hadn't just been done this week, with the landing of the Curiosity rover on Mars.
To accomplish it, NASA engineers devised an incredibly complicated system, involving an exterior shell that protected the rover as it entered the atmosphere, a parachute to slow its entry, and a rocket-powered hovercraft that lowered the rover to the ground on cables.
Curiosity is the largest rover ever sent to another world, and getting it on the surface of Mars safely took extreme measures. The mission used the largest heat shield and largest parachute ever used on a mission to another planet, but even those weren't enough to put the rover on the ground intact. Air bags, like those used by the last Mars rovers, Spirit and Opportunity, would have shredded under Curiosity's weight. And so the elaborate "sky crane" method was devised.
It was an elaborate system designed for a spectacular performance, which arguably meant there was just that much more that could go wrong.
Take, for example, the story of the Genesis spacecraft.
Genesis was NASA's first mission to return samples from space since the Apollo astronauts brought back moon rocks. The unmanned Genesis probe used delicate collectors to trap samples of solar wind particles. The samples were so delicate that it was feared that a normal parachute re-entry to Earth's surface after the mission would damage them, so NASA came up with a plan to recover the spacecraft before it ever hit the ground. The agency hired helicopter stunt pilots from Hollywood to come to the site where the spacecraft would arrive and, once its parachute deployed, catch it in mid-air before it landed.
The idea of catching the falling spacecraft was ambitious, and any number of things could have gone wrong. As it turned out, they never got to find out whether the plan would have worked or not, since the thing that did go wrong was that the parachute never opened in the first place. Genesis fell from space without anything besides Earth's atmosphere to slow it down, and hit the surface so fast and hard that it dug halfway into the ground.
Genesis' story has a happy ending -- although some of the sample collectors were damaged, enough survived that scientists were able to get the material they needed -- but it serves as an example of how even the best plans can go awry.
Either way, Curiosity's encounter with Mars was going to be dramatic, and the U.S. Space & Rocket Center provided an opportunity to get into the spirit of things in a unique way with its "Snoozeum" event, a sleepover at the museum that included watching the landing on a big screen in the Davidson Center for Space Exploration. Thankfully, the landing, like the event, was a success.
But, as exciting as the landing was, the best part is, now that Curiosity is safely on Mars, the real adventure is just beginning.
Contributing Author: David Hitt
