The Lasagna Was Good That Night

About a week ago I moved some boxes from the Waste Water Treatment Plant to a warehouse up the hill. It turns out much of what we moved may have been exposed to partially treated sewage. One of the treatment tanks overflowed around Christmas. Consequently, it was my job today to wipe down these potentially contaminated boxes and objects with a bleach cocktail. At least I got to wear a white Tyvek suit, big green polyvinyl chloride gloves, blue booties, gray goggles, and a black respirator.

But that's not what I came to tell you. NASA is working on replacing the processors and basic software in its lunar and Mars rovers. When they run tests, often they run tests down here in the Dry Valleys, as the landscape is quite similar, and the harshness of climate somewhat similar, to martian landscapes. Before dinner, right outside the dining hall, the Ice Cube Team, as it's called, was displaying a prototypical rover. They were explaining the basics of the navigational software and demonstrating its ladar unit - essentially sonar with a laser. Behind the dark black plastic in the image to the right is where the laser is housed. Ladar works like this: the laser starts pointing more or less straight down. A mirror spins around the laser; the black plastic in front offers a 180-degree field of vision. (So if the robot is looking directly north it can capture a 180-degree sweep, from due west on the left to dues east on the right, with all points in-between.) The laser shoots out, bounces off a surface, and returns to the unit where it is detected by a sensor. Because the speed of light is known, this sensor can calulate the distance to whatever object the laser returns from. Information is received in an almost continuous arc across the 180-degree field of vision, giving a very thin line of information. Next, the laser shifts up a degree, repeats the scan, shifts up a degree, repeats the scan, etc. Eventually, the robot has scanned from the ground at its base to an angle about thirty degrees above straight forward. These data are then fed into an interpreter which produces an image delineating a groundlevel view of topography with horizontal distances keyed by color. (That is, different colors correspond to different distances from the sensor. I was told each pixel is registered as a distance, and that the rover could quite precisely tell you the distance of your lip from your teeth.) What's amazing is that this bot can scan the same area from different angles and extrapolate an incredibly accurate overhead topographical map, like the hiking maps you might find in a store. Based on this information, the bot then decides whether or not it is safe to proceed.

Ridonculous.

With the shameless excitement of a tourist, I asked the NASA computer engineer if his ladar bot could take my picture. And it did. I'm on the stairs, Streaks are people passing through the image on their ways to or from dinner.

The lasagna was good that night, but it didn't satisfy me like Ladar.