Shuttle Safety Plans Detailed

One of the highest-ranking officials in the space shuttle program to have survived the management housecleaning after the Columbia accident acknowledged Monday that the agency made serious errors.

William F. Readdy, associate administrator for spaceflight, outlined plans NASA is making to improve the safety of the shuttle fleet and resume flights, including fixing the problem of foam debris during launches and developing a way to repair a damaged shuttle in space.

The two problems are among the most difficult technical challenges that the agency must meet before it can get the grounded shuttle fleet back into space and complete assembly of the international space station, Readdy and other senior NASA officials said Monday.

Readdy is one of the few top NASA officials directly involved in the shuttle program whose career survived the accident. In October, he chaired the Columbia mission’s flight readiness review, a detailed examination of the flight hardware and crew training that occurs before each shuttle flight. At that review, the risk of foam debris was discounted as a safety problem.

Readdy also signed the “certificate of flight readiness,” the official document that approves the shuttle for launch. Since the accident, NASA has replaced shuttle director Ron Dittemore and the chiefs of its centers in Texas, Alabama and Florida. It also reassigned Linda Ham, who headed the flight team that ran the Columbia mission, and retired the manager for the external tank project at the Marshall Space Flight Center.

The Columbia Accident Investigation Board faulted the culture within NASA for failing to prevent the accident and cited errors made during the flight readiness review. Readdy, a former astronaut and engineer, said he accepted that finding Monday.

“Quite frankly, we missed something,” he said of the agency’s failure to recognize since the first shuttle mission that foam debris was a looming threat. “We screwed up.”

NASA released a 158-page report Monday indicating that flights could resume as early as March 11, although officials stressed that the space agency will not attempt a mission until it has met all the recommendations made last month by the accident board.

“Whether that turns out to be March or April or May or June or July, so be it,” Readdy said.

He added that NASA engineers are still trying to fully understand why insulating foam falls off the shuttle’s external tank during launch. A 1.67-pound piece fell off during Columbia’s launch Jan. 16, punching a hole in the delicate thermal protection system on the orbiter’s wing. During reentry, the hole allowed superheated gases to destroy the shuttle, killing the seven-member crew.

By the late 1990s, NASA had thought it understood why foam was falling off and had come to regard it as a maintenance nuisance and not a risk to flight safety. But the accident board debunked much of NASA’s conventional wisdom about the foam and ordered an aggressive effort to reduce as much foam debris as possible, although it did not call for the agency to completely eliminate the problem.

NASA must also develop methods to repair the heat resistant tiles and the leading edges on the wings in space. The tile repair procedures are further along because NASA researched the problem in the early days of the program. But Readdy said that devising methods to repair the leading edges, which are made of reinforced carbon carbon, will be more difficult.

The accident board also called on NASA to develop the capability to fully inspect the shuttle in orbit, which would require a boom-mounted camera attached to the spacecraft’s robotic arm.

The next shuttle mission will involve a great deal of research work to test new inspection and repair procedures, indicating that NASA may not make much progress in assembling the space station and may not take up a fresh crew for the station, Readdy said. The content of the mission will be decided in the next several weeks, he added.

NASA is continuing to analyze what it must do to reduce the risk to the public of falling wreckage if another shuttle were to break up. One option is to land the orbiter at Edwards Air Force Base in the Mojave Desert.