Posted on 02/17/2003 1:06:49 AM PST by PeaceBeWithYou
A storm of particles and radiation from the Sun, a kind of disturbance that has disabled or destroyed satellites on dozens of occasions, crossed the path of the space shuttle Columbia just as it was making its descent to Earth, scientists said yesterday.The disturbance was detected by at least two NASA space probes as it passed from deep space toward Earth on Feb. 1, said Dr. Devrie S. Intriligator, director of the space plasma laboratory at the Carmel Research Center, a private laboratory in Santa Monica, Calif., who discovered the event by examining data from the probes.
Experts in this complex area of space science, often referred to as "space weather," said the possibility that the disturbance contributed to the loss of the Columbia could not be dismissed. But they cautioned that the Feb. 1 storm was milder than the powerful outbursts that have previously damaged equipment in space.
Dr. Intriligator and other scientists who have seen the data describe the phenomenon as a sort of gigantic wave of electrically charged particles, magnetic fields and radiation that was moving toward Earth at roughly 400 miles a second.
"It is a disturbance, a discontinuity, and it did deliver a punch," Dr. Intriligator said.
So far, a NASA spokesman said, nothing in the abnormal readings sent to the ground from the wounded craft suggested that its catastrophic loss began with an electrical jolt. But he would not rule it out.
"I'm not saying their theory is implausible," said James Hartsfield, a spokesman at the Johnson Space Center in Houston. "We are still in the process of evaluating everything."
Another space weather expert, Dr. Daniel Baker, director of the laboratory for atmospheric and space physics at the University of Colorado, said the phenomenon should be examined further. "With such an extraordinary event," Dr. Baker said, referring to the loss of the Columbia, "you want to look at every possible contributing factor."
But Dr. Baker said he would be more confident that the shuttle disaster was related to the disturbance if it had been more intense. Dr. Intriligator agreed that the disturbance was modest but said the lack of knowledge about the region of space where it was detected suggested scientists should study the possibility. Space physicists often refer to the region as the "ignorosphere" because they know so little about its complexities.
Satellites are especially vulnerable to these storms because they are in orbit for years at a time. By contrast, the storms have never caused a problem for the shuttle, NASA officials say, though they track the solar eruptions that give rise to them and avoid spacewalks when a storm is in progress.
NASA scientists have warned of the dangers that storms in space pose for spacecraft under some circumstances. An August 1996 technical report by scientists at NASA's Marshall Space Flight Center in Huntsville, Ala., noted that on Jan. 20, 1994, two Canadian communications satellites suddenly began to "spin out of control" because "the gyroscopic guidance system on both satellites had mysteriously failed" during a space storm.
The problem was traced back to an electrical charge picked up by the spacecraft from the electrically charged gas of space itself, the report said.
Dr. Intriligator said this kind of "charging" was one of at least three possible ways the Columbia could theoretically have been damaged by the storm. Other spacecraft have been damaged by fast-moving particles, which can strike delicate electronics like microscopic bullets, or by changes in Earth's upper atmosphere that occur when the Sun generates this kind of disturbance.
Earth's relatively dense atmosphere can warm and expand under the assault of a solar storm, several scientists said, increasing its grip on satellites and pulling them down. A Japanese science satellite suddenly tumbled back to Earth on July 14, 2000, Dr. Baker said, when the drag increased in a storm and ground controllers did not compensate adequately.In particularly intense solar storms, problems in space can occur by the dozens, Dr. Baker said. Eighteen operational failures were documented in one such period in May 1998. "There have been quite a large number of episodes in the past," he said.
Space storms like the one that moved across Earth on Feb. 1 usually start when powerful magnetic fields near sunspots suddenly pour their energy into the solar wind, the stream of particles that continuously speeds away from the Sun into space.
The particles and their associated magnetic fields move relatively smoothly until they reach the magnetosphere, a kind of magnetic field that surrounds Earth like a cocoon. At that point, the collision generates the powerful radiation and energetic particles that propagate like a wave toward Earth.
The two NASA space probes, positioned about a million miles from Earth, picked up such a disturbance at about 8 a.m., Eastern time, on Feb. 1. Using data from the two satellites, scientists could estimate the speed of the wave. Dr. Intriligator said she believed it enveloped the shuttle about an hour later, just about the time NASA began noticing abnormal sensor readings on the Columbia.
Data from other satellites in the general area could hold further clues to the potential effects of the storm on the Columbia, Dr. Intriligator said. She added that if the shuttle had suffered even small external damage from another source — like space debris or the piece of insulating foam that was seen to strike the orbiter on liftoff — it would be more likely that dangerous electrical effects could have come into play.
Such damage could create jagged areas that would act like lightning rods, increasing the danger of any electrical disturbance in surrounding space.
Spiros Antiochos, an astrophysicist at the Naval Research Laboratory, said there was a "very low probability" that a storm in space played a role in the Columbia's demise. But it would be "premature, a mistake, to make a claim that it's not viable," Dr. Antiochos said, urging that the possibility be studied.
Just an Act of God sort of occurence. That's what lawyers used to call pregnancies in Hollywood actresses, you know.
The picture with the bolt was dismissed as possibly being an anomaly of the camera lens, but the other theory was that the shuttle someohow passed through an electrical field that caused particles oppositely charged from the plasma around the shuttle to discharge.
A bolt of this type could explain the sudden loss of numerous electrical sensors and the subsequent breach of the hull.
Or it could have blown the emergency explosive release on the left side landing gear, causing a chain reaction of events that eventually brought Columbia down.
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