Courtesy Wired, March 2014 issue, page 57, in an article by Matt Jacer.
Edited by David Barth, 14 May 2014.
The Lockheed U-2 first flew in 1955 and was used to spy on Soviet bomber bases and rocket launching
sites. One of the early missions was to determine the "bomber gap." There had been
reports that the Soviet Union had many more bombers than the U.S., but U2 photography showed that
the Soviet Union had far fewer bombers than the reports suggested.
In the early days, flying at 70,000 feet, the plane was difficult to handle. Computer-controlled
autopilots weren't available and the plane had to be hand-flown near the "coffin corner" where a
slight increase in speed could cause the plane to go supersonic and be destroyed in the shock wave
or go too slow and stall the wings, resulting in a possible unrecoverable spin. The speed range between these
disastrous limits were only a few knots.
Although satellites have taken over much of the spying, the U2 continues to be useful because it
can be launched relatively quickly and photograph an area that a satellite in polar orbit might not
cross over for many revolutions of the planet.
Although satellites can be maneuvered into a
different orbit, that takes precious fuel and is only used in dire emergencies, primarily to correct drift from the prescribed orbit to remain on station and to dodge space debris. Once a satellite
has expended its onboard fuel supply, until a satellite tanker becomes available someday, it is doomed to stay aloft until it either falls to earth due to molecular friction in space that slows it below the speed required to maintain orbit or is unable to be moved out of the way of debris and is blown apart.
By 2014 the U2 had been made more capable through improvements:
- The airframe was 40 percent larger than the 1955 original.
- A more efficient engine was used.
- A Computerized instrument panel was introduced.
- Wet-film cameras were replaced by digital models.
- Digital camera data was transmitted to analysts in real-time, via ground station repeaters or satellites.
- It was thought that for extremely high resolution, there continued to be a use for a wet-film camera for certain applications.
- Cockpit pressurization in the original was weak. It could only bring the cockpit pressure to 29,000 feet when the plane flew at 70,000. By 2012, a new system brought pressurization to 14,000 feet, still a much lower pressure than the 8,000 feet in most commercial aircraft, or 6,000 feet for the Boeing 787 Dreamliner.
- Because of the very long nose, the old U2s had an optical sight to see how far above the ground the plane was when landing. Looking through an optical sight during landing increased the pilot's workload during the critical landing phase. In the early 2000s, the sight was replaced by a chase car that radioed the pilot his altitude above the ground.
- Pilots were given pure oxygen to breathe before flight which reduced the nitrogen in the blood that could cause nitrogen narcosis (decompression sickness) as the plane ascended from the surface to the cockpit pressure altitude of 14,000 feet. Nitrogen bubbles can form in blood vessels, disrupting oxygen transfer to the brain and other organs, which can result in death, or at the very least, extreme pain. Removing most of the nitrogen in the blood reduced this danger.
- In addition to the cameras, sensors that pick up electronic emissions were added, called electronic intelligence (Elint). Elint is important for determining the types of radar being used in the target area.
- A typical U2 flight was usually long because the plane had to get from its base to the target area, and pilots need nourishment during those long flights. Food used to be mush in a tube, but new, flavored and textured foods that tasted better were developed.