Ralph doesn’t look like much; the best visual reference point would probably be a gold foil-wrapped Amazon box big enough for a few pairs of shoes, topped with a short stack of dinner plates. But a lot of map-making power is wrapped up in that funky package. In the past few weeks, Ralph’s been hard at work adding color to the increasingly detailed images you’ve seen of Pluto. And its real work will come in deciphering Pluto’s geology, geography, and geomorphology. Using bands of electromagnetic energy in color, infrared, and black and white ranges, the camera can gain insight into the type and texture of Pluto’s rocks, as well as the temperature and measurements of the dwarf planet’s atmosphere.
The camera can do all that because, really, Ralph is more than just a camera—anything you send up into space to take photos of a freezing-cold, never-before-seen space rock will have to raise the engineering and design bar a bit. Though it takes light through a single hole, Ralph is essentially two cameras. A beam splitter sends half the incoming photons to an infrared imager called LEISA, and the other rest to a seven-band imager called MVIC. The two are an odd couple: LEISA long and narrow; MVIC short and wide. LEISA collects a single band of infrared energy, and primarily looks for temperature variations, though it also helps MVIC gather data on the Plutonian ground and air.
MVIC is what Ralph’s makers call a ‘pushbroom detector,’ meaning it gathers up a wide swath of data. It cobbles together color pictures from multiple light bands: Red and blue, a near-infrared for detecting methane, and black-and-white. By splicing different layers together, analysts can get more detail and more information out of the images than they could get from individual detectors. MVIC also has what’s called a panchromatic band that it uses for backup navigation. “It’s visual, so we can pick out points in space and measure where we are relative to them and relative to Pluto, and adjust course from there,” says Lisa Hardaway, an engineer at Ball Aerospace and systems manager for Ralph.
Yes, Ball Aerospace is part of the same Ball that makes mason jars, and it built a state of the art camera that is on a probe that is currently spitting distance from the edge of the solar system. And though it’s a decade old, it’s one of the most sophisticated cameras in existence. (Or at least until we find out for certain that ETs are shutterbugs.)
Consider that the camera had to travel nearly ten years and 2.9 billion miles through harsh space. Time and distance alone put huge stress on electronics, so Ralph had to be built to last. Hardaway and her team had to use ultralight, ultratough components that don’t use a lot of energy or generate a lot of heat. Altogether, Ralph runs on about the same amount of energy as a small desk lamp. “This is why aerospace missions are so expensive, because the components are so much better,” she says.
Consider also that space is incredibly cold. Some of Ralph’s parts could work in absolute zero, while others needed room temperature warmth—in particular the electronics, which Hardaway and Co. wrapped in insulating aluminum blankets so they could act as their own heat source. And while space is cold, it’s not uniformly so, and objects traveling through it shrink and expand as the temperature fluctuates. In a camera, this is a particularly vexing problem, because parts that shrink or expand at different rates can mess up the ability to take pictures. Ralph’s cameras are all made from aluminum, so they change shape at the same rate—and the focal length never really changes.
Finally, consider that high noon on Pluto is about as bright as dusk on earth. “We had to design a telescope lens to work in that kind of condition,” says Hardaway. But a camera meant for Earth dusk would burn out in Earth noon. Which led to Ralph’s only moving part: A hinged lens cover. Out of everything, the only improvement Hardaway would make if she were building Ralph today would be a smaller, lighter solid state drive—it’s just that the best high-capacity versions weren’t available when New Horizons launched in 2006.
Now, Ralph is only one of New Horizon’s three cameras. Alice is Ralph’s companion (The Honeymooners, get it?), and will measure Pluto’s atmosphere (whatever it may be) with ultraviolet rays. And LORRI uses a telescope lens to take the long distance images that we ooh and ahh over on Earth and that NASA scientists use to fine tune New Horizon’s flight path. Besides those, the Prius-sized probe has a pair of particle detectors, a sensor for space dust, and a chip for radio emissions.