The news came in around 1:30am (did you stay up for it?).
America’s latest Mars rover, the aptly named Curiosity, made a successful landing on the surface of a planet that is, at this moment, almost 155 million miles away. At that distance, it takes roughly fourteen minutes for the signals relaying this information to reach us.
If you’re not astonished by that … well, honestly, I don’t think you quite comprehend the totality of what just happened.
The problem, as it usually is when it comes to space, is one of scale. While they’re great entertainment, decades of Star Wars and Star Trek and the like have greatly warped (ha!) our vision and understanding of interplanetary travel (much less interstellar or — sigh — intergalactic). Most of us lack a notion of the difficulties and the dimensions.
The rover Curiosity is about the size of the average American car. It weighs about a ton. It is packed to the brim with delicate and sophisticated instruments. The United States put that car atop a rocket and launched it into space without blowing it up.
Frankly, that’s another gold medal right there, folks. And it’s just leg one. Because NASA’s engineers then sent this car to Mars.
Okay, stop. Seriously. Take a peek outside. Look at the nearest car. Now try to imagine what you would need to pick it up and throw it. Start easy. What would it take to throw it, say, twenty feet? Okay, now what about a city block? A mile? What would it take, do you imagine, to throw that car to grandma’s house, over the river and through the woods?
It becomes preposterous, right? Who would dream of such a thing? Now imagine looking at that car and then deciding to throw it off the planet. Better than that, try to imagine not just deciding to do it, but actually pulling it off. You pick up the car, you throw it into space, and then — just for good measure — you throw the car to Mars. To motherf—ing Mars.
God, I love me some science.
For eight months this car, this testament to human endeavor, hurtled through space, each second bringing the potential of some micro-meteorite crashing through its shielding and destroying it. By the time it arrived at the red planet, Curiosity had already traveled about 350 million miles.
As it happens, that wasn’t even the hard part.
After arriving at the red planet, Curiosity had to get down through the atmosphere and onto the ground. NASA took to terming that dangerous descent “Seven Minutes of Terror.” Any miscalculation, any malfunction, and the craft would be blown into tatters above or upon the Martian landscape. Here’s an awesome video from the NASA Jet Propulsion Laboratory that explains the plan and the perils better than I ever could.
Incredible, right? And this morning, at around 1:30, some fourteen minutes after it was done, the signals came in from Curiosity, loud and clear.
To keep the sports metaphor going a bit, NASA Administrator Charlie Bolden summed it up (from an excellent article today) thusly:
It’s like us launching something from Kennedy Space Center and having it land in the Rose Bowl, on the 50-yard-line, on a frisbee.
Shooting something from Florida to land on a frisbee in California sounds pretty badass, no? It certainly gives a decent scale to the enterprise, I think.
That said, Bolden’s analogy actually falls short of the complexity of the problem, because unlike Florida and California, which are stable in relation to one another, Curiosity’s launching and landing points are very much not. To the contrary, they are both on the surface of planets that are spinning like tops. What’s more, those two planets are themselves orbiting the sun at different speeds and levels.
To see one part of this problem happening in real-time, give a look at this terrific little webpage from Emory’s Physics department, which gives current calculations on the relative distance from the Earth to Mars. At the moment I am writing this (just to add to the engineering fun, these relative numbers change over the course of the year), Mars is moving away from the Earth about seven miles every second, spinning all the while.
That’s one tough target to hit.