Telescope could become uncontrollable without much-needed servicing, but price of robotic mission causes concern

NASA insiders are increasingly concerned about the rising cost of a robotic servicing mission to the Hubble Space Telescope in 2007. But the US space agency declines to comment on reports of a potential $2 billion pricetag on the mission to extend the Hubble's life and ensure safe deorbiting.

The reports surface as NASA administrator Sean O'Keefe warns that the agency faces significant budget challenges despite receiving almost all of $16.2 billion in funding requested for fiscal year 2005. The Space Shuttle return-to-flight (RTF) effort is already $760 million over budget and more than $300 million must be found next year to fund the Hubble repair mission.

Critics argue a manned servicing mission using the Space Shuttle could be accomplished more cheaply and easily - four having already been flown between 1993 and 2002. But O'Keefe has banned Shuttle missions to non-International Space Station (ISS) orbits, out of reach of a safe haven in the event of damage. The ISS orbits at 51.6¡ while the Hubble is in a 28.45¡-inclination orbit.

The 2007 deadline for a robotic mission is considered ambitious by industry observers, including former astronauts. Critics say a manned servicing mission might be as expensive, but could be flown earlier and with a greater chance of success. The Hubble's batteries, gyroscopes and sensors need replacing and, if they fail, the telescope could become uncontrollable.  

For the unmanned mission as planned, a robotic manipulator based on the Canadian Dextre two-armed robot for the ISS will be used to replace batteries and gyros and two instruments on the Hubble, while a propulsion unit will raise the spacecraft's orbit then remain attached to perform the deorbit burn after 2013.

The Hubble robotic mission is considered a NASA priority after the Shuttle RTF and cost increases on both could divert funds from completion of the ISS and the US space exploration initiative, which is set to get under way next year.


Source: Flight International