The Washington Post ran a story yesterday about a new spy satellite with commercially-available imagery. The full story is here. One paragraph in particular says:
Say what?! The film was dropped from the satellites to Earth?
How the heck would that work? Not only would that method be prohibitively heavy (the weight of enough film for years of pictures, the ablative protection for the canisters, the parachutes, etc.), but it would be nearly impossible to retrieve the film once it got here.
The world is a very big place, and as far as the U.S. government is concerned, I imagine about 99.99% of it is the wrong place for those canisters to land – i.e., oceans, volcanoes, Farmer Bob’s back forty, unfriendly nations, etc. What are the chances the canisters behaved themselves and conveniently dropped on the CIA’s front lawn in Langley???
It’s hard to believe we had the technology in the 60s to create and launch a spy satellite, but hadn’t yet figured out anything less primitive than chemical emulsions and parachute drops for the film!
So does anyone have the straight dope on this? Did we really do this, or was someone pulling the reporter’s leg? If we did, how did it work, given all the possible (and probable) complications?
Yes, they used “primitive” methods such as parachutes that would be snatched out of the air by planes towing cables. There were no CCDs in those days - vidcon tubes are fragile - and electronic image storage was still in its infancy.
Thanks for the responses, JonF & Padeye. I had no idea we ever had a spy satellite system that worked like this.
Does anyone have a clear understanding of exactly how the canisters were snagged by a passing plane? The websites JonF linked to are pretty vague on the actual mechanics of it.
Padeye, you say the planes towed a cable, but I just don’t see how a length of cable could catch a parachuting canister.
Also, any idea on the physical size of the canisters?
The process, as I understand it, involved a “V” shaped catcher mounted on the nose of a plane. The plane would simply fly into the reefing lines of the paracute and the “V” would funnel them together for capture.
I think Mistah Bond and his sweetie are picked up in much this way at the end of Thunderball. Not exactly a factual example, but it give a good visual depiction of the process (using a helium balloon instead of a parachute, I think).
Well, they obviously did have the technology to capture images electronically and send it by radio waves. It’s called a TV station. It’s just that film was far lighter and provided better images. Don’t underestimate the resolution and data capacity of film! Even today, it takes a $3000 digital camera to barely match the resolution of 35mm film. And it takes an inch of film to record an image; digitized, it may require many megabytes of storage.
Film is still used on some sounding rocket instruments - i.e. small rockets that go up a couple of hundred miles and fall back down after maybe 5 minutes. These instruments are usually recovered and reused anyway, so there’s often no point in putting a heavy and expensive digital imaging system. One I’m familiar with is the HRTS solar spectrograph, which used film till only a few years ago.
“The film-retrieval plan called for dispatching a squadron of six cargo planes, each equipped with a trapeze-like loop hanging beneath it, to the vicinity of the ejected capsule as it parachuted to earth. Detecting the capsule’s radio beacon and sighting its descending orange canopy, the pilots would fly the cargo planes across the top of the parachute and hook onto it while crew inside the plane’s bay yanked the capsule aboard with a winch. If the airborne feat failed, Corona’s recovery vehicle was designed to float long enough for recovery from the ocean by helicopter launched from a nearby ship.”
There’s a picture about halfway down the page here; the caption makes it clear that the capture is not actually a Corona capture but the plane and its rigging are correct. There’s another picture here, and a diagram of the recovery sequence and several other interesting Corona images.