U-2 Spy Plane Crash: Why 'Cold War' Aircraft Are Still Relevant Today

By Jesse Emspak, Live Science Contributor

**One of the U.S. Air Force's Lockheed U-2 Dragon Lady.**
**Credit: U.S. Air Force**

A U-2 spy plane that crashed in northern California earlier this week, killing one of the two pilots, focused attention on a normally clandestine aspect of the U.S. military. The U-2 plane has a long and storied history that stretches back to the late 1950s, but how is the reconnaissance aircraft used today?

U-2 planes have been flown by the United States and other nations for more than 60 years, as both a spy plane and an instrument of science. They key to the aircraft's longevity is its robust and efficient design, said Richard Aboulafia, vice president of analysis at Teal Group Corp., which conducts research and analysis on the aerospace and defense industry. He added that Clarence "Kelly" Johnson, the man who designed the U-2, "got it right."

"Those designers at the Lockheed Skunk Works deserve their legendary status," Aboulafia told Live Science. [Supersonic: The 11 Fastest Military Airplanes]

What sets the U-2 apart is its ability to fly higher than any other aircraft for long periods, which is what makes it a good spy plane, he said.

And spy planes are still relevant today, even in the age of satellites. "Satellites are an additional layer," Aboulafia said. "But they can't be retargeted quickly. They are in whatever orbit and they can't be moved, and they are easily blocked by bad weather." Spy planes, on the other hand, have a lot more flexibility. "They can be easily moved from one part of the Earth to another, at any time," Aboulafia said.

Spy in the sky

By the time the first U-2 flew in 1955, the problem of gathering intelligence was becoming more acute. Spy planes were in operation as far back as World War I, when aircraft were used to take photos of enemy positions. But during the Cold War, the U.S. government wanted a way to fly over what was then the Soviet Union without being detected or shot down.

In fact, the U.S. had been flying spy planes into the USSR as early as the 1940s, according to Gregory Pedlow and Donald Walzenbach, authors of "The Central Intelligence Agency and Overhead Reconnaissance: The U-2 and OXCART Programs, 1954-1974" (Military Bookshop, 2013).

Pedlow and Walzenbach said the USSR didn't have complete radar coverage of its borders or interior at that time, and modified B-47 bombers would fly in to take photos of sensitive targets, and then fly out. Moscow protested these flights but didn't shoot any down (though they fired warning shots). That changed in 1950, when the USSR shot down a U.S. plane over the Baltic Sea. Later that year, with the outbreak of the Korean War, Moscow adopted a policy of shooting down aircraft that violated its airspace. [Flying Saucers to Mind Control: 7 Declassified Military & CIA Secrets]

The U.S. Air Force asked aircraft companies to submit designs for a plane that could reach altitudes of 65,000 to 70,000 feet (20,000 to 21,300 meters), and just as important, be able to stay there for long periods. One of the changes to previous designs was that the plane didn't have to be equipped with the heavy armor or weaponry that were the hallmarks ofmilitary planes before, Pedlow and Walzenbach wrote. — Such specifications added weight, and made it more difficult to design a plane that could fly high enough.

It was Johnson's design that won out. To make the plane efficient at high altitudes, he adopted long and straight wings rather than a swept-back design, to improve lift at relatively low speeds (for a jet). The airframe also wasn't as strong or as heavy as the usual military-grade models, allowing for higher flight with less fuel. Johnson's design also dispensed with conventional landing gear and a pressurized cabin.

In operation

The U-2 was introduced into military service in 1957. Even after the USSR shot down one of the planes in 1960, the aircraft was still used in a number of conflicts such as the Vietnam War, providing intelligence to the U.S. and its allies. (The Christian Scence Monitor reported that a U-2 was even stationed in Cyprus in 2011, to monitor the no-fly zone established in Libya). In 1971, NASA started using U-2s as part of the agency's Earth Resources Aircraft program, flying the plane over the United States to gather scientific data. While NASA no longer uses the original U-2 model, a modified U-2, called the ER-2, still flies for the agency.

The first U-2s carried large-format cameras, but the sensors on board have grown much more sophisticated over the years, as have the controls. The engines, avionics and surveillance equipment have all been updated as technology has improved.

"You can fit a lot more [monitoring instruments] on them now than you could then," Aboulafia said. [7 Technologies That Transformed Warfare]

According to the U.S. Air Force, the U-2 carries an "electro-optical infrared camera, optical bar camera, advanced synthetic aperture radar, signals intelligence and network-centric communication" for reconnaissance flights.

But the U-2 is still a notoriously difficult aircraft to fly, Aboulafia said, even though the only remaining part from the 1950s version of the plane is the airframe.

The U-2 still conducts reconnaissance missions; there are two flying in the Middle East on any given day to monitor the Islamic State, reported the Los Angeles Times. The plane flies high enough to "peer in" to airspaces where they might not be allowed, as it's no longer a good assumption that radar can't detect the planes or that a surface-to-air missile can't hit them. (Although, the kind of missile that could reach a U-2 is more likely to be in the repertoire of a major military power than a small group of militants in a remote area, Aboulafia noted.)

In September 2015, 60 years after the U-2 was introduced, Lockheed Martin said it would unveil a replacement for the venerable spy plane, called the TR-X. According to a report from Defense News, the Air Force hasn't formally committed to it, though there is a plan to retire the U-2 in 2019. That may not happen, though, as the U-2 has already outlasted some of the planes that were supposedly more advanced, including theLockheed SR-71, which could reach similar altitudes and travel at 3.5 times the speed of sound. The SR-71 was retired in 1998 because it was too expensive to fly regularly.

Original article on Live Science.

How I Learned to Stop Worrying and Love the Big Bang — **This map of the cosmic microwave background, the light released just 380,000 years after the Big Bang, was created using observations by NASA's WMAP spacecraft.**
**Credit: NASA/WMAP Science Team**

Paul Sutter is an astrophysicist at The Ohio State University and the chief scientist at COSI Science Center. Sutter is also host of Ask a Spaceman,RealSpace, and COSI Science Now.

Unfortunately, the Big Bang theory can be a pretty contentious topic. You mention it in casual conversation (well, maybe you don't, but I drop it into as many inappropriate places as possible), and some folks get all up in arms and defensive.

When this happens, I take a long breath and recite my Big Bang Mantra: The Big Bang is not a theory of the creation of the universe, but a model of the history of the universe. Look, I'll even show you a baby picture!

And at this point I pull out my wallet. Instead of smiling kids or cozy family group shots, I've got the cosmic microwave background (CMB). It's about the right age: it's a photograph of the universe when it was only 380,000 years old, which is equivalent to a picture taken of a baby at the end of its first day. [Cosmic Microwave Background: Big Bang Relic Explained (Infographic)]

That image is solid evidence, a smoking microwave gun, in favor of the Big Bang theory. Scientists are some of the most critical people you'll ever meet, forever reluctant to accept a new idea. It took decades of developing theories and accumulating evidence before the Big Bang was even warmly thought of, but the detection of the cosmic microwave background forced even the most truculent astronomers to grudgingly accept it.

Free the light

The early universe was a hot and sweaty place, a seething mosh pit of electrons, protons and high-energy photons. The CMB was released when the universe cooled off juuuust enough that stable atoms could form, turning the entire universe transparent and letting that high-energy light go free. Over the eons that radiation has traveled the cosmos, stretching along with the expansion of the universe, shifting down from white-hot intensity to a feeble few Kelvin above absolute zero.

That leftover light is in the form of microwaves, and is incredibly, fantastically … boring. To one part in 10,000, it's exactly the same, from one end of the sky to the other.

But if you examine those minute differences, strange features appear. Some parts of the CMB sky are 0.0001 Kelvin hotter or cooler than others. There are big patches twice the width of the full moon, and many small bumps and wiggles overlying them. What's going on?

Seeing what the universe is saying

Those larger patches in the CMB are the early universe rocking out. In that hot dense plasma of the infant cosmos, gravitational pressures pulled gases in, and radiation pressure pushed those gases back out. This constant seesaw reverberated throughout the volume of the universe, echoing from one end to the other.

What we see in the CMB is a frozen moment in time, the drums in mid-beat, the cymbals in mid-crash, the guitar in mid-note. Once the radiation disconnected from the protons and electrons, the music couldn't go on, but an image of it remained. Caught in the act, some parts of the universe were slightly denser and hotter than others, and these patterns imprinted themselves on the radiation left behind.

So when we examine those 1-in-10,000 differences, we're really mapping out the state of the universe as it was just 380,000 years into the cosmic concert.

The beautiful technical term for this process is "baryon acoustic oscillations." Baryon = stuff. You and me are made of baryons. Acoustic: something to do with sound. Oscillations: something to do with waves. It's really a fancy way of saying "sound waves," but hey, what's the point of getting a Ph.D. if you can't say fancy things every once in a while?

[Watch this video to learn more about sound waves in the early universe.]

A lesson in flatness

Those bumps and wiggles in the CMB — those echoes of the crashing chaotic cosmic symphony — are a treasure trove of information. By studying the CMB, we are looking directly at the early universe, and we can use those glorious photons to deduce all sorts of juicy cosmological information.

For example, the global shape of the universe. The big patches in the CMB give us a very handy ruler for measuring shapes. It turns out it's really, really easy (well, OK, only sort-of easy) to figure out how big the patches ought to be. Sure, the universe back then was a crazy-hot plasma, but we're pretty good at figuring out how crazy-hot plasmas operate, especially when the universe was still young and hadn't developed complex structures yet.

We can compare how big those patches ought to be to how they look. If the universe was curved on a global scale (like, say, the surface of a sphere), light from the CMB would bend on its way to Earth, either converging or diverging — making the patches look bigger or smaller than they should.

The result: the scale of the largest patches is precisely what we would expect for a perfectly flat universe. Parallel light rays in our cosmos stay parallel. No hints of exotic geometry to report.

[Watch more about cosmic flatness in this video.]

The cosmic time capsule

That's not all. The CMB teaches us about the composition of the early universe. Neutrinos zooming around? Dark matter lurking mysteriously? Exotic relics of even earlier epochs wreaking havoc? All those things affect the statistics of the bumps and wiggles in the CMB: how large the largest patches are, how many large versus small patches, the maximum or minimum temperatures, etc. We can toss in any ingredient we want and see how it affects the detailed structure in that ancient light pattern.

The result from decades of analysis of the CMB: We live in a flat universe, dominated by dark energy, with a healthy dose of dark matter, and a few floating bits of normal everyday matter to lighten things up.

We're still not exactly sure what dark matter and dark energy are, but no matter what, the overall picture of the Big Bang remains unchanged: At one time, the universe was small, hot, and dense, and it left us a postcard.

Learn more by listening to the episode "What is the Cosmic Microwave Background? (Part 2)" on the Ask A Spaceman podcast, available on iTunesand on the Web at http://www.askaspaceman.com. Thanks to Arlington T., Jeffrey B., Edward J., Jason A., Ernie J., Rea N., Chris L., and Randy B. for the questions that led to this piece! Ask your own question on Twitter using #AskASpaceman or by following Paul@PaulMattSutter andfacebook.com/PaulMattSutter.

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