| A portion of Columbia’s exterior skin with the tiles lies where it fell in Nacogdoches, Texas. (AFP)
Johnson Space Center (Texas), Feb. 3 (Reuters): Crews combed suburban gardens and remote Texas woodlands for the remains of space shuttle Columbia today as experts focused on a heat surge on the left side of the doomed spacecraft in the early investigation of why it disintegrated.
For a third day, hundreds of police and soldiers fanned out across east Texas and Louisiana in a search for debris and the remains of the seven astronauts who perished on Saturday when Nasa’s oldest shuttle broke apart high over Texas.
Body parts, fragments and pieces of the shuttle were strewn across an area more than 160 km long and 16 km wide, much of it in the thick Texas forests known as the Piney Woods.
Nasa scientists pored over reams of data for clues, focusing initially on a sharp heat spike along Columbia’s left side and an unusually sharp corrective manoeuvre recorded just before the vehicle disintegrated.
An independent inquiry board appointed by Nasa also was to meet for the first time, led by retired navy Adm. Harold Gehman, who co-chaired an independent commission that investigated the attack on the destroyer USS Cole in Yemen.
That review will run parallel to Nasa’s internal review.
Bill Readdy, Nasa associate administrator for space flight, a former shuttle commander who flew three times, said Nasa was keenly aware of the need for safety upgrades.
“This is far from something being ignored, it is a constant part of what we do. We have made tremendous upgrades to the shuttle over the past 10 years. Even though it looks the same on the launch pad, from the tip of the external tank to the hold-down posts of the solid rocket boosters, the entire vehicle has been continually upgraded,” he told reporters via a video hookup.
Columbia blew apart just 16 minutes before it was due to land in Florida, ending a 16-day science mission, and almost 17 years to the day after the shuttle Challenger exploded during liftoff.
Data beamed down from Columbia — which first flew 22 years ago — showed the temperature on part of the left fuselage spiked 32° Celsius in five minutes as the spacecraft was reentering the atmosphere.
Four minutes later, “we had an increase in drag on the left side of the vehicle,” shuttle programme manager Ron Dittemore told a news conference yesterday .“The flight control system was countering that drag by trying to command the vehicle to roll to the right-hand side. ... Soon after, we had loss of signal.”
Dittemore said the flight control surfaces moved to a degree “outside our family of experience.”
There was no “smoking gun” to focus on, but Dittemore added: “We are gaining some confidence that it was a thermal problem, rather than ... a structural indicator.” A shuttle endures 1,650° Celsius temperatures when it re-enters the earth’s atmosphere, but is protected by tiles that shield it from heat.
Dittemore said Columbia’s left wing was banged 80 seconds after launch by insulation from its fuel tanks, but engineers believed it caused no serious damage to the heat shield.
Debris from Columbia will be sent to Barksdale Air Force Base near Shreveport, Louisiana, where the independent board appointed by Nasa to investigate the disaster was to meet for the first time today.
Nasa issued a statement yesterday saying that human remains were found, and that it could not confirm that remains of all seven astronauts had been recovered.
At the entrance of the Johnson Space Center in Houston, dozens of signs, flowers and balloons were placed in tribute to the fallen astronauts.
The crew was mourned across the US at church services and visits to space centers to pay respects.
The US was not alone in its sorrow. The crew of Columbia — five men and two women — included Kalpana Chawla and Israeli air force Col. Ilan Ramon, the first Israeli astronaut.
Nasa has grounded the three remaining shuttles until the disaster’s cause is found and corrected.
The Challenger disaster grounded the fleet for almost three years until the faulty O-ring seals in rocket boosters that caused it were found and fixed.
Keeping the shuttles grounded will delay the resupply and construction of the International Space Station, since the shuttle is the main transport vehicle for the $95 billion space outpost.
Russia’s Soyuz passenger craft and Progress cargo ship will handle ferrying of space station supplies and crew while the shuttles are grounded.
US President George W. Bush met Nasa’s chief for a private briefing on the Columbia disaster today, as the White House said the US space programme would continue with a bigger budget.