A LOOK AT . . . Spy Satellites & Hollywood
By Dwayne A. Day
Sunday, July 2, 2000; B03
The Washington Post
Originally posted at: http://www.washingtonpost.com/wp-dyn/articles/A33942-2000Jul1.html
In this summer's blockbuster movie " Mission Impossible 2," the good guys command a spy satellite to locate a bad guy on the ground. Peering over a computer screen, they watch a terrorist and his ex-girlfriend kiss on a boat dock in Sydney while the satellite hovers overhead like the Goodyear blimp.
The people who build and operate America's spy satellites would love to be able to do that. But they can't. Such satellites exist only in the movies, where the laws of physics do not apply and satellite technology owes more to " Star Trek" than to Silicon Valley. Spy satellites have leading roles in a handful of recent flicks, but only rarely has Hollywood gotten close to showing how their new stars actually work and how the intelligence community really uses them.
A vivid example of satellite fiction is the 1998 paranoid thriller "Enemy of the State." Evil National Security Agency agents (played by unshaven twentysomething techno-nerds) "re-task" satellites to follow virtually every move being made by hero Will Smith and ex-spook Gene Hackman. The satellites whoosh into position over the nation's capital, where they float in space while beaming live images of our heroes directly into the NSA command center. Exciting? Yes. Accurate? Not even close.
First, satellites do not hover. Reconnaissance satellites, such as the KH-11 KENNAN that entered service in 1976, travel in low Earth orbits of varying heights. These orbits bring them closest to the things they need to see. This means that they are traveling so fast that they can "track" an object on the ground for only a brief time before moving out of view. An observer standing in an open, flat field would see the satellite appear above the horizon in one direction and watch it disappear in the opposite direction in less than 15 minutes.
But speed isn't the only limitation to keeping tabs on someone on the ground. When a satellite first appears above the horizon, it has to look through a lot of atmosphere that can block its view. In fact, haze would probably completely obscure the view for five to 10 degrees above the horizon (this haze is why the sun appears red when it sets).
Furthermore, as the distance from the satellite to the ground target increases, the resolution of the image decreases. The best resolution is when the satellite is at its zenith (directly overhead). If we generously assume that a modern spy satellite can take decent images within 45 degrees of its zenith, its window for taking good pictures is about three minutes. But the reality is that satellites deliver their best images at the low point in their orbit, the perigee. If we assume that the satellite is only taking images when the low point is also the zenith, this reduces the observing time to a little more than a minute before the target is too distorted by atmosphere. That means a lot of grainy photos--followed by hours of blank screens--in that fictional NSA command center. So much for the Goodyear blimp.
"MI2" and "Enemy of the State" play off a Hollywood myth: that satellites are just cruising in space, available at a moment's notice--or at least a few minutes' wait. In reality, satellites are almost never where they need to be during a crisis. In May 1998, for example, India made its preparations to test a nuclear bomb when U.S. reconnaissance satellites were not overhead. Often, photo interpreters have to wait a day or more for a satellite to fly over a trouble spot. If the target is obscured by clouds or smoke, the delay can be even longer. Just like movie stars, the satellites are on a schedule all their own.
Spy satellites have shown up in other movies, including a pair of 1997 releases--"The Peacemaker," a George Clooney dud, and "Shadow Conspiracy," starring Charlie Sheen. In these films, the satellites are cheats--a way for lazy writers to overcome holes in their stories or a cheap way of adding excitement. In the ridiculous " Shadow Conspiracy," the evil NSA guys find White House adviser Sheen by reading the license plate of his car. But remember: Satellites take their best images while directly overhead. Therefore, they would have a hard time seeing license plates from above. Think about it: If you stood on a very tall ladder on the roof of your car, could you read its license plate?
Even if a satellite had the right angle on the license plate, it wouldn't be able to make out the letters and numbers. The best resolution of an American spy satellite, achieved by an older series no longer in use, was reputed to be about 2 1/2 inches. This means that the smallest visible object would be the size of a baseball, not the thin letters and numbers on a license plate. And smoke, haze, smog or clouds would all reduce the quality of the resolution, as would the distance required to see the license plate from an angle. Memo to future filmmakers: License plates cannot be read from satellites.
The satellite in " MI2" does not even look right, although the filmmakers get some credit for trying. Reconnaissance satellites look a lot like the Hubble Space Telescope, with a large opening at one end that points toward the Earth. They have big mirrors with a charge coupled device (CCD) array at the focal point. CCDs have migrated from spy satellites to a more everyday use: They can now be found in personal digital cameras and home video cameras. The CCD arrays in satellites, however, work more like the ones in digital cameras than in video cameras. They take still pictures, not moving images. And they have severe limitations.
One factor is the time that it takes to "read out" the array's data into the on-board computer. When the CCD array is exposed, all of the information from the millions of individual picture elements has to be transmitted from the chip to the processor. This can't be done fast enough to produce the kind of TV-like images that movie audiences saw in "MI2." The array on the powerful $1.5 billion Chandra X-ray telescope, launched last July, takes about three seconds to read out each image. A spy satellite is probably no better.
There are other limitations as well. The big one is bandwidth, which determines how fast an image can be relayed either directly to the ground or through another satellite. An average high-resolution reconnaissance image might be on the order of 30-100 megabytes compressed and encrypted. How fast the satellites can actually transmit images is classified, but it is not hard to take a guess. A typical satellite channel that relays satellite images to ground troops is capable of transmitting 1.544 megabytes per second. That is fast compared with a high-speed telephone modem, but it still means that a 30-megabyte image will take roughly 20 seconds to relay. So, while one image is being relayed to the ground, four more have been taken, stacking up in memory or on a tape recorder. These will eventually be relayed to the ground when the satellite is no longer imaging (for instance, during its long passes over the oceans).
Unlike a digital camera's, reconnaissance satellite pictures are not in color. At most, they have one or two colors, undoubtedly in the infrared spectrum. The primary reason is that monotone images are easier to take, smaller in size and have higher resolution than color images. They also are easier to store, transmit and manipulate.
Almost as laughable in these movies is the notion that a couple of young, sloppily dressed NSA technicians are controlling the satellites. The NSA is the popular bad guy in spy movies these days, often depicted as all-seeing and all-knowing. But in reality, the NSA's job is listening to foreign signals, not looking at images. The agency does not even control its own satellites--it merely receives data from satellites owned and operated by others.
The designer, owner and operator of America's spy satellites is the National Reconnaissance Office (NRO), located near Washington Dulles International Airport. Its satellites are expensive and always in demand. The idea that a couple of poorly groomed technicians--or even Tom Cruise--could gain control of these billion-dollar pieces of machinery and use them for a special project is absurd. In the intelligence community, nobody lets the kids play with the expensive toys.
So does Hollywood ever get it right? The answer is yes, almost. The film that has come closest is " Patriot Games," a 1992 thriller based on a Tom Clancy novel.
Harrison Ford plays Jack Ryan, an ex-CIA analyst helping track down a rogue group of Irish Republican Army terrorists. The terrorists are believed to be training in a camp in the Libyan desert, but there are many such camps and the correct one must be identified before an attack can be launched.
Using satellite imagery, Ryan and a photo interpreter (known as a "squint" in intelligence community slang) try to determine exactly who is in the camp. But the few images that they view are grainy and full of mystery. They can see people, but cannot see their faces. In a number of scenes, Ryan and the photo interpreter compare film images using a microscope. They identify a woman by her cleavage and a man by his bald head.
All of this is reasonably accurate (with the exception that the images Ryan is examining are in color rather than in black and white). Indeed, the filmmakers demonstrate their knowledge of the cat-and-mouse game of reconnaissance: The IRA terrorists know exactly when American satellites will be flying overhead and hide in their tents to escape detection.
To counter this move, Ryan asks that the satellites be reprogrammed so they can look sideways, off their orbital track. "Do you have any idea how big a deal it is to retask the satellites?" a senior CIA official asks him. "Yes," Ryan answers bluntly.
This was a great example of the screenwriter getting something right and wrong at the same time. Satellites rarely fly directly over their targets, so they normally take images at least slightly off of their orbital track. If Ryan had asked that the satellite orbit be altered so that it appeared overhead at an unexpected time, the film would have been more accurate. Moving a satellite's orbit is indeed a big deal.
Later in the film, unfortunately, " Patriot Games" truly enters the world of science fiction: A satellite provides live images of a nighttime attack on the terrorist camp. Nonetheless, the filmmakers deserve credit for at least showing some obeisance to the laws of physics and the limits of technology. Their counterparts on the sets of "MI2" and "Enemy of the State," however, are to be commended only for their imaginations.
Dwayne Day is a space policy analyst and historian who lives in Northern Virginia. He is the editor of "Eye in the Sky" (Smithsonian Institution Press), a book about early spy satellites.
When Science and Fiction Collide
Since we are living in an age of enlightenment, you ought to know just what those eyes in the sky can and can't do--even if Hollywood shows you something different. A guide to some modern films featuring satellites:
How satellites figure in the plot.
What it got right.
What it got wrong.
ICE STATION ZEBRA (1968)
A capsule of 16mm film from a satellite falls in the Arctic and superpowers race to find it (based on a true story)
Early satellites did drop their film to Earth
Resolution of images about right
The resolution of 16mm film isn't good enough to see anything
Film capsule could have fallen anywhere, not just in the Arctic
THE HUNT FOR RED OCTOBER (1990)
Satellites image Soviet warships leaving port
Still images of the ships
Nothing (Tom Clancy did his homework)
PATRIOT GAMES (1992)
CIA tracks IRA terrorists in Libya
Still images of the ground
Waiting for images
Inability to see small detail
The art of photo interpretation
Satellites don't take color images
Live nighttime images of commando raid are impossible
THE PEACEMAKER (1997)
American satellite just happens to photograph a train hijacking in Siberia
Takes pictures before, after and during a nuclear blast
Still images of the ground
Incredible luck at photographing the right place at the right time
Nuclear explosion would have burned out camera
SHADOW CONSPIRACY (1997)
Satellites track Charlie Sheen through Georgetown
Satellites do exist
See list for "Enemy of the State" at right
ENEMY OF THE STATE (1998)
Evil, unshaven NSA nerds command satellites to follow good guys through Georgetown
NSA is a real agency
Satellites don't hover or take TV-quality images
Satellites don't look like antennas
NSA doesn't own the satellites
THE WORLD IS NOT ENOUGH (1999)
British spy satellite photographs James Bond in the sack with beautiful scientist
When did the British get a spy satellite?
Last updated 4.9.2003