Cape Kennedy, Florida -- Technicians at NASA's Kennedy Space Center in Florida began modifications to 34 support beams, called stringers, on space shuttle Discovery's external fuel tank today (Tues 4 Jan 2011).
In a 3 Jan announcement, NASA, the US space agency, said that crews will fit pieces of metal, called radius blocks, over the tops of the stringers located at the external tank's thrust-panel area. The aim is to increase the structural support of the stringers.
The thrust-panel areas are at the attachment points between the tank and the solid rocket boosters, and these points experience the most stress during the flight into orbit. The work is expected to take about one week, said NASA.
Teams are also performing scans on all of the tank's stringers using a backscatter device, which bounces radiation off the tank allowing engineers to see below the foam insulation.
NASA also noted that, "Engineers at various NASA centres continue to analyse testing and imaging data."
Managers for the shuttle programme will meet again 6 Jan to decide if radius block modifications are needed on the remaining stringers.
According to the agency announcement, repairs to stringer cracks on the opposite side of the tank from Discovery, discovered on 20 Dec, began 3 Jan and are expected to be completed mid-week.
The repairs are similar to repairs made on cracks found on two stringers after Discovery's 5 Nov launch attempt, said NASA.
The next available launch window for Discovery's STS-133 mission to the International Space Station remains 3 Feb through to 10 Feb.
PIC: A NASA technician taking a computed radiography (CR) scan of the tank. The red machine in the foreground is the CR device. (Photo NASA/Frankie Martin).