Panel: Digital imaging key to mission safety

0 Comments | Oakland Tribune, Jul 31, 2003 | by Eric Pianin, Washington Post

Space shuttles should be equipped with digital cameras that can transmit high-resolution pictures of the orbiter and its propellant tank during critical moments in future missions, according to the latest recommendation of the board investigating the Columbia disaster, released Wednesday.

The board said NASA shuttle managers should be able to examine a shuttle's large external propellant tank as it separates from the orbiter minutes after launch. In addition, managers should be able to monitor in real time the underside of the leading edge of a shuttle's wings and the heat-resistant tiles and panels on the wings' forward sections.

After nearly six months of investigation and experimentation, the board recently concluded that a large chunk of foam that broke loose from the external tank and struck the left wing of the Columbia 81 seconds after liftoff created a large hole that allowed superheated gases to penetrate and destroy the shuttle during re-entry into the Earth's atmosphere on February 1.

The board and some lawmakers were dismayed that NASA managers ignored engineers' warnings that the foam strike posed a serious risk and denied repeated requests for spy satellite or ground-based imagery of the orbiting shuttle to determine the extent of the damage. Seven astronauts were killed when the shuttle broke up over Texas.

"Imaging the space shuttle system during launch and ascent provides necessary engineering data, including the ability to examine the space shuttle system for any unexpected debris or other anomalies during ascent," the board said in a statement.

The remaining shuttles have two 35-mm film cameras attached to their underbellies that can photograph the external tanks after separation, but images from those cameras are available only after the flight is completed. "Very little engineering-quality onboard imaging of the (external tank) was available" during Columbia's last flight, the report stated.

The board said Wednesday that NASA could solve that problem by converting one of the two cameras to a digital camera that could downlink high-resolution images almost immediately.

NASA has been working since late February on various schemes for providing close photographic surveillance of the underside of the orbiter's leading edges and the forward sections of the wings.

Agency engineers and officials are looking at a combination of mounted digital and video cameras and hand-held digital cameras used by the astronauts on board.

"All of this will be in place before we return to flight," NASA spokesman Allard Beutel said Wednesday. "We will have some system in place that would address all of these issues."

The recommendation was the fifth formally offered by the board to assist NASA officials in preparing for the resumption of shuttle operations, possibly as early as next March. NASA officials and engineers already are considering a number of steps to make it more likely that any damage to future flights will be spotted and fixed before it is too late.

Some of those ideas include eliminating night launches, adding spacewalks to hunt for structural problems and adding a repair kit that would permit attempts to patch damaged heat-shielding tiles and panels. In-orbit repairs to the shuttle present enormous technological and physical challenges, and the Columbia was not equipped with a repair kit on its final mission.

NASA officials have said that it may be easier to detect damage to a shuttle, such as a breached wing, because most of the flights scheduled for the forseeable future will be to the International Space Station. Using the space station as a platform, astronauts would be better positioned and equipped with a robotic arm to inspect their space vehicles for damage and make repairs, officvials say.

The board said Wednesday that it was aware "of the excellent preliminary work already in progress at NASA in this area."

The investigative board, headed by retired Adm. Harold W. Gehman Jr., is rushing to complete a final report and recommendations by late August.