Since 1972, the has been beaming pictures of the Earth's surface down from outer space. Today, the eighth Landsat satellite was from , on California's Central Coast.

Hurtling through the air at 1,700 mph when it lifted off, Landsat 8 was several miles above the ground within a matter of seconds. Less than five minutes after liftoff, its booster rocket had burned so much fuel, it was at only 25 percent of its liftoff weight.

Now that it has jettisoned its booster rocket, the satellite cruises along nearly 200 miles above the Earth's surface at more than 13,000 mph, taking pictures of the land and sea below. The program is a joint venture between NASA — which provides the rockets — and the U.S. Geological Survey, which takes all of the images and turns them into something everyone can use.

Vandenberg Air Force Base has a little known history museum (it's rarely open and base security is tight) with some interesting relics of a bygone era of satellite imaging. Back in the '60s, satellites were equipped with actual cameras, each with a little battery-operated motor to advance the film. If recovery crews somehow missed the satellite when it finally splashed down, no pictures.

Of course today, NASA gets the images instantaneously from satellites circling the planet in a . The polar orbit is why they don't launch from Cape Kennedy, Fla., the place most people associate with rocket launches. That's because Vandenberg is, for all practical purposes, in the middle of nowhere. Rockets launched from its pads, which are perched on desolate, rocky points jutting out into the Pacific Ocean, go straight into polar orbit.

The folks at Vandenberg told me that rockets launched from Florida have to dogleg out over the Atlantic Ocean to avoid flying over populated areas, juuuust in case. That uses more fuel and costs more money. For a while, NASA had even considered launching space shuttles from Vandenberg. They never did, but some of the roads on base still have an odd cut along narrow roads — a little step dug out of the roadway walls to clear a shuttle's wings.

Images transmitted back to Earth from Landsat satellites are useful for all sorts of things, from imaging the wildfires that ravaged the American West last summer to educational applications. The data is also used by the government, and although they don't say explicitly what for, we can only guess that the Pentagon gets a peek.