Spaceflight

Space Shuttle Discovery is expected to launch in July with the external tank (ET) protuberance air load (PAL) ramp removed, but no further changes, despite NASA acknowledging a need for further ET modifications. Discovery will use ET 119 for its mission, STS 121, to the International Space Station, the launch window for which is from 1-19 July.

NASA administrator Michael Griffin and the agency’s Space Shuttle programme manager Wayne Hale made the ET announcement on 28 April.

Testing for further modifications will continue while Discovery and its ET 119 are prepared for flight. The decision follows alleged failures of the newly designed ET acreage foam that insulates the tank (Flight International, 28 February–6 March).

With the PAL ramp removed, foam further down the ET experiences different aerodynamic loading, causing potentially dangerous foam loss during launch.