By Trevor Bach
By Francisco Alvarado
By Trevor Bach
By Michael E. Miller
By Allie Conti
By David Villano
By Jose D. Duran
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Shortly before Christmas AbuTaha presented L. Michael Weeks, deputy associate administrator for NASA, with visual evidence suggesting an alternate version of the Challenger accident. Both the Wall Street Journal and Aviation Week & Space Technology carried short reports about AbuTaha's campaign in December. AbuTaha was tight-lipped to the Journal, saying, "This is a jigsaw puzzle...I have to give NASA the pieces first." But NASA officials dismissed AbuTaha's analysis (see "Obviously a major malfunction...." sidebar).
Then, in 1987, as the shards of Challenger were being entombed in an abandoned missile silo, key NASA personnel began to express doubts about the thoroughness of the Rogers Commission investigation. On February 13, 1987, a memo written by John Young, head of NASA's astronaut office, was leaked to Washington Post reporter Kathy Sawyer. Young's memo inquired whether the shuttle was strong enough to stand up to the dynamic forces encountered during a launch, and whether NASA was capable of duplicating these forces during tests. The Post article revealed that in a November 1986 test, the aft skirt of a solid-fuel booster cracked under less stress than the Seventies predictions would have indicated. The aft skirt in question had flown three shuttle missions.
Astronaut Robert "Hoot" Gibson told the Post that damage to bolts on the solid-fuel boosters - which NASA had previously attributed to impact with the ocean - was actually taking place on the launch pad, during motor ignition.
This was exactly what AbuTaha had been trying to tell NASA for months. In a March 23, 1987, letter to NASA administrator James Rose, he complains, "A trend has set in. My findings are rejected out of hand in official letters. Then, months later, I find from the media or official sources that the same findings are discovered by NASA and the contractors."
Following the aft-skirt revelation, NASA increased stress standards for shuttle hardware by fifteen to twenty percent. The redesign of shuttle parts and construction of new test equipment delayed the first post-Challenger flight by an extra year.
By 1988 AbuTaha's funds were drying up, but he maintains he stuck with his investigation out of "duty to [his] adopted country."
"It had also become a matter of personal and professional credibility," he says. "When you know you're right, you can't walk away. You can't let NASA say you're an imbecile, that you don't know what you're doing."
In October of 1988 he applied to NASA's Inventions and Contributions Board for a monetary award. The board is authorized to reward researchers who have made significant contributions to NASA's space efforts. His claim was that NASA had used his data in redesigning the shuttle. After initially dismissing AbuTaha's application, the board scheduled an oral hearing for October 17, 1989.
As evidence AbuTaha cited the June 20, 1988, issue of Aviation Week & Space Technology, which reported that a new, $22 million hydraulic simulator was being used to apply forces of up to 330,000 pounds to test the strength of the solid-fuel booster where the struts (metal attachments) connect it to the liquid hydrogen/liquid oxygen fuel tank.
This figure of 330,000 pounds is significant. In his December 19, 1986, presentation of findings to NASA, AbuTaha had identified what he called a Rogers Commission error. Both solid-fuel boosters are connected to the fuel tank at the aft end by three struts each. The commission reported the total force exerted on the strut nearest the failed O-ring at 140,000 pounds. In Congress's independent investigation of the disaster (House Report 99-1016, October 29, 1986), the force on the struts is reported as 190,000 pounds. AbuTaha believes that the two figures refer to entirely separate forces. The 140,000 pounds represents the dynamic forces at liftoff. The 190,000-pound figure refers to "cryoloads" - shrinking stress induced on metal when supercold fuel is pumped into the fuel tank. Add the two forces together and you get 330,000 pounds, the amount NASA's new, improved hydraulic simulator was designed to deliver. AbuTaha claims he made his calculations abundantly clear to NASA in his December 1986 report.
NASA's Inventions and Contributions Board rejected AbuTaha's claims in writing, both before and after the appeal. Space agency officials asserted that the struts had been designed from the very beginning to withstand forces greater than 330,000 pounds and said, "Quoted media reports are secondary sources which are unreliable to establish facts."
As AbuTaha became convinced that NASA had neither understood his theories nor redesigned the shuttle to withstand the forces that he claimed were acting on it, he sought a greater audience. He gave two continuing education courses about the shuttle accident at George Washington University, and composed a shuttle expose, which was recently published in abbreviated form in the British journal, Professional Engineering.
This past April, shortly before the shuttle Discovery lofted the Hubble Space Telescope into orbit, AbuTaha wrote the team in charge of the mission, warning that excessive liftoff forces might damage the delicate instrument. Bob Crippen, former astronaut and current director of the space shuttle, curtly ended NASA's communication with AbuTaha with a written reply.
"In your most recent letter to NASA, you raise the same issues that previously have been analyzed and rejected. In light of this, I cannot justify any further expenditure of program resources to review what already has been done several times," Crippen writes. "[T]here comes a time when repetitive review becomes counterproductive. We have reached that point and...I have no choice but to consider the matter closed."