President George W. Bush's proposed 2006 budget would give NASA a modest funding increase, but would cancel a proposed robotic servicing mission to the Hubble Space Telescope as well as a nuclear-powered spacecraft to explore the moons of Jupiter.

NASA is scrubbing plans for a final servicing flight to the Hubble Space Telescope. Credit: NASA

The budget proposal, released by the Bush Administration February 7, would give NASA $16.45 billion in fiscal year 2006, which starts on October 1 of this year. That is about 2.4 percent more than the agency received for 2005, and also makes the agency one of the few in the federal government outside of the military to get a budget increase. That increase, however, falls short of the $17 billion NASA was expecting for 2006 based on the original plans for the Vision for Space Exploration, the agency's new exploration initiative announced last year.

"The fiscal 2006 NASA budget reaffirms the President's commitment to the Vision for Space Exploration and provides us the next step in implementing it," outgoing NASA administrator Sean O'Keefe said in a statement accompanying the budget. "We are transforming NASA and making great progress."

While the proposed budget contains sufficient funding for the space shuttle, International Space Station, and other key programs that are part of the exploration initiative, most of the attention on the budget is on what it does not contain: funding for a repair mission to the Hubble Space Telescope. Instead, the budget includes $75 million to work on a deorbit module to safely dispose of the telescope once it shuts down, and about $20 million more to extend the life of critical components, like its batteries and telescopes, without mounting a repair mission.

NASA officials said they decided not to include money for a robotic repair mission for the telescope because of growing concerns, including a recent report by the National Academy of Sciences, that such a mission would not be ready before the telescopes irretrievably fails.

"While I remain convinced that this is not necessarily an accurate view, it is nonetheless a position that has made it incredibly difficult to demonstrate to the contrary," O'Keefe said

Also missing from the budget is funding for the Jupiter Icy Moons Orbiter (JIMO), a large nuclear-powered spacecraft that would have explored Jupiter's moons Callisto, Europa, and Ganymede.

An artist's concept shows the JIMO spacecraft at Callisto. Credit: Boeing

JIMO, whose launch had already been pushed back from around 2012 to 2015, faced what NASA called "concerns over costs and technical complexity," leading the agency to effectively cancel the mission. JIMO was intended to be the cornerstone of Project Prometheus, a nuclear power and propulsion program; NASA will instead seek a less-complex alternative mission to demonstrate those technologies.

Initial reaction from Congress about the budget was lukewarm.

"I would love to save the Hubble, but the decision needs to be made in the context of the overall NASA budget," said Congressman Sherwood Boehlert, chairman of the House Science Committee. "Congress will have to make a decision about Hubble very soon‹probably no later than the end of March‹if a servicing mission of any kind is to have a realistic chance of moving forward."