NASA’s space shuttle programme manager Wayne Hale put the May launch of Space Shuttle Discovery for mission STS-121 in doubt last week when he said that “it may take us until the fall to complete work” on solving the external tank foam problem. NASA engineers found nine hairline cracks along a protective foam ramp on NASA’s external tank 120 (ET-120), which could be used for STS-121. Its the same area where foam came off during Discovery’s return to flight July launch. Engineers think thermal and pressurisation changes caused by fuelling are the cause.
Source: Flight International