The Washington Post February 14, 2003
Satellite Views of Shuttle Unsought; Columbia Orbited In Camera Range
By Rick Weiss, Washington Post Staff Writer
At least one U.S. spy satellite had several opportunities to take pictures of the space shuttle Columbia while NASA engineers blindly tried to determine how much damage it had sustained, according to an analysis by a Canadian expert who tracks the satellites.
During three of those passes, the shuttle was within 100 miles of the top-secret satellite -- close enough, perhaps, to detect areas of damage as small as two inches in diameter.
But while the agency has asked for and received images from the military when other spacecraft were in trouble, no such assistance was sought for Columbia, NASA officials have said.
No one knows whether satellite pictures would have provided information helpful to NASA or could have changed the crew's fate. The astronauts had no way to make repairs. But with revelations that some NASA engineers remained concerned about Columbia's fate even after mission managers concluded there was no threat to its "safe return," some experts are now asking whether the agency erred by not at least trying to get a better look at the shuttle while it was still in orbit. "It could be argued that obtaining imagery would have been futile," said Ted Molczan, a Toronto energy and engineering consultant who is one of about half a dozen hobbyists around the world who meticulously track America's spy satellites in space, and who did the orbital analysis and provided it to The Washington Post. "But it could also be argued that an image of the defect that caused the break-up would have been invaluable diagnostically, even if vehicle and crew could not have been saved."
For a scientific agency not to have sought all the hard data it could is surprising, others said, and may indicate overconfidence in the ground-based simulations and analyses that predicted no threat to the craft's return.
"They saw the tile problem as a maintenance issue as opposed to a safety issue, and then there's no need to look in orbit because you're going to get a look at them on the ground," said John Pike, director of GlobalSecurity.org, a nonprofit defense and space policy group based in Alexandria. "In a resource-constrained organization, you cannot afford a lot of goose-chasing," Pike said, acknowledging that it would be no small matter to ask for spy satellite assistance -- especially given current world events.
Nonetheless, he said, "you wonder what they might have seen."
Molczan cross-referenced the shuttle's orbit with the orbit of a KeyHole satellite known as USA 129 -- one of several spy satellites whose orbits are secret but which he and his colleagues precisely track with telescopes and binoculars. The nameless, loose-knit group is widely respected in astronomy, space and aviation circles but has long been a thorn in the side of the National Reconnaissance Office (NRO), which oversees spy satellites for the Department of Defense and the Central Intelligence Agency.
Starting on Day Two of Columbia's mission, by which time it was clear that NASA had concerns about possible damage to the shuttle's heat shielding tiles during launch, there were six opportunities for USA 129 to see the shuttle, Molczan said. (Either or both of the other two KeyHoles may also have had opportunities, but on Jan. 16 both entered orbits that make them invisible to the group's members.) USA 129's closest passes were on Jan. 20, when it flew within 88 miles of the shuttle, on Jan. 25 (70 miles) and on Jan. 29 (99 miles), with all three offering a probable resolution of two inches, Molczan said.
After the shuttle disintegrated during reentry on Feb. 1, program manager Ronald D. Dittemore was asked at a news briefing whether the agency had tried to take pictures in orbit.
"We certainly had that discussion," Dittemore said, "because we know there is a capability available to us to take a look at the orbiter and, perhaps, get us some pictures that are quite a bit -- a close-up view."
But past satellite images "did not reveal a lot of granularity that would help us," Dittemore said, in partial explanation of why the effort was not repeated with Columbia.
Dittemore's suggestion that the images would not have been sharp or detailed enough to help Columbia is difficult to assess, several experts said, because details of the nation's spy satellite network have never been made public.
"The capabilities and operations of our satellites are classified," said National Reconnaissance Office spokesman Art Haubold.
Yet some experts who specialize in knowing what they're not supposed to know about U.S. spy satellites say they believe NASA might well have learned something had it asked for some pictures.
The three KeyHole satellites take optical images (unlike their three sisters, the radar-imaging Lacrosse satellites) and are widely reputed to be able to discern objects as small as four inches on the ground, said Greg Roberts, a retired astronomer living in Cape Town, South Africa, and a member of the tracking network.
But distance is not the only variable affecting the quality of a satellite image. Also important is the relative speed between the object being shot and the camera, which uses a light-sensitive charge-coupled device. Earth-viewing satellites orbiting at 17,000 mph are designed to handle that relative motion, but the challenge can be greater if the object being photographed is itself moving fast. That's where the tracking group's data come in.
USA 129 was launched on Dec 20, 1996, and during Columbia's flight it was in a roughly north-to-south orbit that stretched between 172 miles and 612 miles above the Earth, circling the globe once every 97 minutes, Molczan said. Columbia began its mission in an orbit between 176 miles and 186 miles above the Earth, which decayed to as low as 170 miles by the end of its mission. It was traveling roughly west to east, circling the globe every 90 minutes.
The relative speed, known as angular velocity, of those crossings could cause pictures to be a little blurrier than those taken of Earth. But for several of the Columbia photo opportunities, angular velocity was in the range of 1.0 to 2.6 degrees, close to the 1.6 degrees that USA 129 typically handles when photographing the Earth, Molczan calculated.
Image quality is also affected by the angle of the light. Sidelighting offers the best contrast and, for spying, allows the use of shadow lengths to calculate the height of buildings and silos.
The two closest passes occurred when the shuttle wing was in shadow, Molczan calculated, but other opportunities offered better lighting. And as Dittemore said, the shuttle can be moved a little to get in range of a camera.
Not everyone agrees that spy satellite photos, which are beamed to higher-altitude satellites before being instantaneously streamed down to Earth, would have revealed anything useful.
Although the loss of black tiles might reveal a white underbelly easily discernable to a space-based camera, it's not clear whether a satellite could make out cracks, divots or even missing tiles if a skin of dark adhesive were left attached to the craft.
"You've got smear, you've got lighting, you have to get a reasonably sized divot before you can get something good," said a satellite industry source familiar with U.S. reconnaissance abilities.
Also unknown is whether the nation's intelligence satellites were already overworked tracking crises in Iraq, North Korea and the Middle East, and perhaps unavailable during the shuttle flight.
"If you're asking, 'Can you do this instead of seeing what crops are being grown in Nigeria?' then that's one thing," said the industry source, who spoke on condition of anonymity. "But if you want to interrupt a key 20 minutes of Iraqi army inspection, that may be something else."
NASA has not expressed any second thoughts about its decision to forgo satellite assistance, but the agency recently put out a request for any images that might shed light on what happened to Columbia.
NRO spokesman Haubold would not say whether his agency might have caught a few shots "by accident." "Anything we have that might be useful," he said, "we will provide to NASA."
Staff writer Vernon Loeb and staff researcher Margot Williams contributed to this report.
Copyright © 2003, The Washington Post
