Columbia discovery prompts structural failure fears and risks hampering Hubble and ISS mission schedules

Elongated bolt holes found in one of 12 attachment points that connect the two Orbital Manoeuvring System (OMS) pods to the Space Shuttle orbiter Columbia could delay its Hubble Space Telescope servicing mission in January.

If the problem proves to be generic, affecting the 14 bolt holes on each of the Space Shuttle's 12 connection joints, the 29 November Endeavour mission to the International Space Station (ISS) will also be threatened, leaving the third ISS expedition crew in orbit longer than planned.

Inspections could be limited to the OMS pods on the Shuttle fleet, delaying the Endeavour flight for a few weeks, but repairs to connection points across the fleet will hit other missions, including those planned for Atlantis and Discovery.

The fear is that the holes could weaken the area where the pod is attached by bolts to the orbiter's aft fuselage and cause a structural failure, particularly during a structurally stressful aborted launch.

Meanwhile, NASA and the United Space Alliance (USA), the joint Boeing and Lockheed Martin company which operates the Shuttle fleet, have signed a $62 million modification to the USA Space Flight Operations Contract to refurbish the orbiters over five years.

The work involves the complete refurbishment of the 11 actuators on the Columbia, Discovery, Atlantis and Endeavour orbiters, which operate the vehicle's rudder, speed brake and main engine gimballing during flight. These will be modified with a new one-piece spool-stop to correct a problem identified during maintenance. Endeavour will be the first to be modified.

The Russian Pirs docking and airlock module on the ISS detached its propulsion unit in early October, clearing the way for the first spacewalk from the craft, set for 8 October. It will be used to connect power and data cables between the ISS and the Zvezda service module.

Source: Flight International