A dream that, right now, looks all too literally fantastic.
Highs and Lows
The Jet Propulsion Laboratory is not a laboratory at all, but something more like a high-tech college campus, parked against the scrubby brown hills of a sun-washed valley at the base of Mount Wilson. A visitor will want to stop by the Space Flight Operations Facility, also known as Mission Control, which is the closest thing here to something resembling the bridge on "Star Trek."
A few employees in the darkened room are stationed at computer monitors while, overhead, a screen flashes graphics of Saturn and the solar system. This is partly for show, for the entertainment of tour groups. Real science is rather uncinematic these days. The rover teams are in a different building, and Cooper works on a desktop computer, manipulating graphics, looking like any other office drone in the Information Age -- just one who happens to drive a rover on Mars.
"We see lots of slip," he says. His rover's wheels spin in the Martian soil. As he manipulates a mouse, the rover on his screen pivots, looking around that crater. Cooper can interpret features that, to an untrained eye, appear indistinct, a bunch of shadowy shapes. One of his colleagues, who drives the other Mars rover, named Spirit, has a sign on his office door that reads: "My other cars are on Mars."
When a voice comes over a loudspeaker and announces a cross-agency discussion on the reorganization of NASA, the engineers don't seem to hear it. A subsequent glimpse into the auditorium reveals only five people watching the video feed from NASA headquarters in Washington. Here, people have more exciting things to do -- like exploring Mars and Saturn.
JPL has had its own traumas. Five years ago, two robotic probes, the Mars Climate Orbiter and the Mars Polar Lander, vanished when they reached the Red Planet. When things go wrong with robotic probes, they don't tend to say goodbye. They just disappear. There's no video feed of a crash scene. There's not so much as a poof. The expensive, cherished spacecraft is just no longer there.
The fate of the Mars Climate Orbiter in particular proved not only heartbreaking but embarrassing. Any spacecraft can have bad luck with storms on Mars or mechanical failure. But an investigation showed that the spacecraft fell victim to a navigational mistake by an outside contractor in converting English units to metric. No one at JPL caught the error. It's hard to imagine that the JPL of the 1970s, which flew the fabled Viking and Voyager planetary probes, would have made such a blunder.
So now imagine that you are Bob Mitchell, project manager for Cassini, a $3 billion spacecraft, the cost shared with the European Space Agency. Cassini is a blast from the past, the last of the "Battlestar Galacticas," the huge robotic probes dreamed up in the 1970s and 1980s, before NASA adopted its famous and controversial "faster, better, cheaper" philosophy. Conceived in the early 1980s, Cassini is a dramatic reminder of how long it takes to design, build and fly a spaceship to the outer reaches of the solar system.
Mitchell couldn't sleep well for months as he waited for Cassini to arrive at Saturn on July 1. His team had to brake the spacecraft in a precise manner, enabling it to go into orbit around the planet.
Many things could have gone wrong. One of the biggest challenges was simply knowing where Saturn was, precisely. Sure, you can see it in the sky, but it's a billion miles away (and that's not just hyperbole). The distance makes it impossible to control Cassini in real time, because it takes more than an hour for a message to travel at the speed of light from Earth to the spaceship.
"It had to be just absolutely perfect," said Mitchell, who speaks with a quiet, square-jawed earnestness. "Any flaw had the potential, if not the high probability, of being mission-catastrophic."
You'd want to remember to convert your miles to kilometers in such a situation.
Complicating matters were those rings around Saturn. To take advantage of Saturn's gravity as an aid in braking the spacecraft, the engineers wanted to fly relatively close to Saturn's surface. But that would mean flying through the rings. They decided to aim for a gap between the F and G rings.
They had to thread the needle, shoot the moon -- or perhaps the new saying should be "shoot the rings." And they did just that, a perfect entry that allowed Cassini to become a Saturn satellite.
