Ever wonder how those crisp still photos of the Space Shuttle rising off the pad are made? It is harder than it looks.
No media person is allowed closer than 3 miles to the pad, and in Florida haze that makes a crisp photo impossible. In the early days of the Shuttle program (1982) media people were allowed to place tripods with cameras within about 1000 feet of the pad 24 hours in advance of the shot. The problem was how to set them off at the right time, and how to keep the inevitable rain showers during the 24 hours from soaking the gear?
Radio control was ruled out by NASA, and you could not run wires 3 miles back to the press center either. People tried all kinds of sensors, including light sensors, but the white Shuttle in bright sunlight was as bright as the exhaust flame so that wasn’t reliable. They tried seismic sensors, but they weren’t reliable either. They tried sound sensors, but 2 minutes before launch a security helicopter would circle the pad and set their cameras off before ignition. Another problem was that for the first 6 seconds of a launch the shuttle would sit bolted to the pad and rev up the main engines, and a motor-drive camera would run thru a roll of film in 6 seconds, and all you had was the Shuttle blowing smoke around. Very frustrating, after braving the mosquitoes and snakes setting up the gear!
What worked? First, we would wrap the cameras in plastic garbage bags to keep the rain out, with just a hole cut for the lens. Then, to keep raindrops off the lens front, some genius (who we all copied) used Tupperware lids secured on the lens opening with rubber bands, one of which was hooked to the rewind crank old film cameras had. With the first exposure the crank would whirl around, the rubber band would fly off, and the Tupperware lid would fall off and uncover the lens. Simple, cheap, and brilliant!
Which left the problem about how to trigger the cameras. Back in 1982 there were no portable computers (the very first desktop IBM PC was introduced in 1981) but HP had a programmable handheld calculator called the HP-41, and you could hook it to external stuff. I built a rig with two microphones (and amplifiers, and comparators, and analog-to-digital converters), one in a parabolic dish pointed at the pad, and one away from the pad, and programmed the calculator to wake the systems up 5 minutes before a planned launch, then compare the signals between the two microphones. If the one facing away from the pad was stronger, we would figure it was the helicopter or other false signal. If the one facing the pad was stronger, the calculator would wait 6 seconds and check again, and if it still was stronger, the calculator would figure it was a valid launch, and command the cameras to fire 18 frames (half a roll) with one frame shot every ¾ second, and then the whole system would reset and wait for a second try, just in case it was faked out the first time.
It worked like a charm, and on one launch preceded by heavy rains, it was the only media system among dozens that worked, giving AP a “scoop”!
Have you had to engineer a wacky solution? Whether it was getting that perfect shot or your own take on digital photo management, share the story!
Posted by David Tenenbaum
Photos by David Tenenbaum