More than six years ago, NASA investigated extensive thermal tile damage on the space shuttle Columbia as a result of the shedding of external tank insulation on launch – now a prime suspect in the Columbia’s disastrous disintegration upon re-entry yesterday.
The problems began when the space agency switched to materials and parts that were considered more “environmentally friendly,” according to a NASA report obtained by WorldNetDaily.
Did concerns for environment cause shuttle disaster?
NASA investigators have quickly focused on the possibility that Columbia’s thermal tiles were damaged far more seriously than the space agency realized during liftoff. Just a little over a minute into Columbia’s launch Jan. 16, a chunk of insulating foam peeled away from the external fuel tank and smashed into the left wing, which like the rest of the shuttle is covered with tiles to protect the ship from the extreme heat of re-entry into the atmosphere. Yesterday, that same wing started exhibiting sensor failures and other problems 23 minutes before Columbia was scheduled to touch down. With just 16 minutes to go before landing, the shuttle disintegrated over Texas killing all seven in the crew.
In 1997, during the 87th space shuttle mission, similar tile damage was done during launch when the external tank foam crashed into them during the stress of takeoff. NASA knows that problem occurred again on this Columbia launch. However, the agency is not certain this was the cause of the disintegration of the craft upon re-entry.
“Immediately after the Columbia rolled to a stop, the inspection crews began the process of the post-flight inspection,” wrote NASA’s Greg Katnik in a review of the problems of that 1997 flight. “As soon as the orbiter was approached, light spots in the tiles were observed indicating that there had been significant damage to the tiles. The tiles do a fantastic job of repelling heat, however they are very fragile and susceptible to impact damage. Damage numbering up to forty tiles is considered normal on each mission due to ice dropping off of the external tank (ET) and plume re-circulation causing this debris to impact with the tiles. But the extent of damage at the conclusion of this mission was not ‘normal.'”
The alarming report continued: “The pattern of hits did not follow aerodynamic expectations, and the number, size and severity of hits were abnormal. Three hundred and eight hits were counted during the inspection, one-hundred and thirty two (132) were greater than one inch. Some of the hits measured fifteen (15) inches long with depths measuring up to one and one-half (1 1/2) inches. Considering that the depth of the tile is two (2) inches, a 75% penetration depth had been reached. Over one hundred (100) tiles have been removed from the Columbia because they were irreparable. The inspection revealed the damage, now the ‘detective process’ began.”
NASA investigators seven years ago noted that the damage followed changes in the methods of “foaming” the external tank – changes mandated by concerns about being “environmentally friendly.”
“During the STS-87 mission, there was a change made on the external tank,” said the report. “Because of NASA’s goal to use environmentally friendly products, a new method of ‘foaming’ the external tank had been used for this mission and the STS-86 mission. It is suspected that large amounts of foam separated from the external tank and impacted the orbiter. This caused significant damage to the protective tiles of the orbiter.”
NASA’s report on that earlier Columbia flight concluded on a positive note, suggesting changes would be made in procedures to avoid such problems at launches in the future.
“As this investigation continues, I am very comfortable that the questions will be answered and the solutions applied,” wrote Katnik. “In fact, some of the solutions are already in progress. At present the foam on the sides of the tank is being sanded down to the nominal minimum thickness. This removes the outer surface, which is tougher than the foam core, and lessens the amount of foam that can separate and hit the orbiter.”
This 6-year-old problem is sure to raise new concerns about NASA’s safety procedures. Already, new public concern is focusing on a former NASA engineer who pleaded last summer for a presidential order to halt all further shuttle flights until safety issues had been addressed.
In a letter to the White House, Don Nelson, who served with NASA for 36 years until he retired in 1999, wrote to President George W. Bush warning that his “intervention” was necessary to “prevent another catastrophic space shuttle accident.”
During his last 11 years at NASA, Nelson served as a mission operations evaluator for proposed advanced space transportation projects. He was on the initial design team for the space shuttle. He participated in every shuttle upgrade until his retirement.
Listing a series of mishaps with shuttle missions since 1999, Nelson warned in his letter that NASA management and the Aerospace Safety Advisory Panel have failed to respond to the growing warning signs of another shuttle accident, reported the London Observer. Since 1999 the vehicle had experienced a number of potentially disastrous problems:
- 1999 – Columbia’s launch was delayed by a hydrogen leak and Discovery was grounded with damaged wiring, contaminated engine and dented fuel line;
- January 2000 – Endeavor was delayed because of wiring and computer failures;
- August 2000 – inspection of Columbia revealed 3,500 defects in wiring;
- October 2000 – the 100th flight of the shuttle was delayed because of a misplaced safety pin and concerns with the external tank;
- April 2002 – a hydrogen leak forced the cancellation of the Atlantis flight;
- July 2002 – the inspector general reported that the shuttle safety programme was not properly managed;
- August 2002 – the shuttle launch system was grounded after fuel line cracks were discovered.
Yesterday, Nelson told the London Observer that he feared the Columbia disaster was the culmination of “disastrous mismanagement” by NASA’s most senior officials and would inevitably lead to a moratorium on future flights.
“I became concerned about safety issues in NASA after Challenger,” he said. “I think what happened is that very slowly over the years NASA’s culture of safety became eroded. But when I tried to raise my concerns with NASA’s new administrator, I received two reprimands for not going through the proper channels, which discouraged other people from coming forward with their concerns. When it came to an argument between a middle-ranking engineer and the astronauts and administration, guess who won.”