Though NASA has launched seven shuttle missions since the loss of seven astronauts aboard Columbia five years ago,

the disaster still resonates as the space program prepares for its most ambitious year since the accident.

Beginning with the Atlantis orbiter’s planned Feb. 7 launch to the International Space Station (ISS), NASA hopes to launch up to six shuttle flights this year – five of them dedicated to space station assembly missions.

The lessons from Columbia, however, are always close by, mission managers said.

“I think every day about Columbia and how that came about, and how we can prevent similar events,” said NASA

shuttle chief Wayne Hale,

who attributed the Columbia

accident to what Apollo astronaut Frank Borman called a “failure of imagination.”

Legacy of Columbia

Columbia broke apart while reentering the Earth’s atmosphere

early Saturday morning

Feb. 1, 2003, bringing to a tragic end what had until then been a successful 16-day science mission.

The shuttle’s destruction claimed the lives of mission commander Rick Husband, pilot Willie McCool and mission specialists Michael Anderson, KalpanaChawla, David Brown, Laurel Clark and Ilan Ramon – Israel’s first astronaut.

Months later, investigators would trace the physical cause of the accident to a suitcase-sized chunk of foam that popped free from Columbia’s external fuel tank during its Jan. 16, 2003, launch. The foam punched a hole in the orbiter’s heat shield along its left wing leading edge, leaving it vulnerable to the superheated atmospheric gases during landing.

But investigators also faulted NASA’s internal culture for contributing to the accident, a point the space agency has worked hard ever since to prevent from resurfacing. “I think we had a culture that was very adversarial in a lot of ways, where bad news was not particularly well received,” Hale said in an interview,

adding that the agency has since strived to foster more open communications. “I think that has allowed a lot of the workforce to feel much more comfortable in bringing things forward that they would have been more hesitant to in the old days.”

NASA held an official Day of Remembrance Jan. 31

to recall Columbia’s crew, as well as the seven astronauts killed in the 1986 Challenger accident,

the three astronauts who died in

the 1967 Apollo 1 launch pad fire and others who died in the pursuit of space exploration.

NASA returned its shuttle fleet to flight in July 2005 after spending more than two years and $1.4 billion to develop new heat shield inspection and safety tools. That year, the agency flew one shuttle flight and followed with three more 2006, and another three in 2007.

Former astronaut Eileen Collins, who commanded NASA’s first post-Columbia mission STS-114, said the accident taught her that spaceflight is more dangerous and complicated than she realized. But it did not dampen

her support for the endeavor.

“I believe that one of the most important things that we’re doing as a country, if not the most important thing, is leaving our planet and exploring space,” Collins said.

Astronauts now use a sensor-tipped extension of their shuttle’s robotic arm to scan for heat shield damage in orbit. Before a shuttle docks at the ISS, station astronauts make a complete photographic survey of its heat shield, then return the images to Earth for analysis. Meanwhile, engineers continue to develop new tools, some of which will be tested during shuttle flights this year, while tweaking orbiter fuel tanks to reduce the risk of foam debris like that which struck


“There seems to be a lean towards excessive caution,” said John Logsdon, director of the Space Policy Institute at George Washington University, in an interview. Logsdon said that, unlike its post-Challenger years, NASA has not slid back into a complacency or comfort zone during the last five years of shuttle flight.

The fact that the agency delayed Atlantis’ launch from early December to next week to identify and fix a recurring fuel gauge sensor glitch is an example of its reinvigorated approach to safety, Logsdon said. “They were tempted to say these sensors weren’t needed, but they didn’t,”

Logsdon said. The sensors

serve as a backup system to shut down an orbiter’s main engines before their fuel tank runs dry.

Logsdon said much of the shuttle’s success since Columbia lies with top NASA leaders like Griffin and Hale, who have demonstrated a scrupulous and strong commitment to safety.

Their successors, he hopes, will continue that track record as NASA retires its three remaining space shuttles to make way for their capsule-based successor – the Orion Crew Exploration Vehicle and its Ares rockets.