NASA needs more funding for commercial spaceflight, technology development and robotic missions. So said a group of Nobel laureates, former astronauts and former space agency officials in a recent letter to Congress.

The Aug. 31 letter took aim at the House Science Committee's NASA authorization bill currently making its way through the U.S. House of Representatives. The letter's 30 signatories argue that the House bill strays too much from President Barack Obama's proposal for NASA, which they support.

"President Obama?s new strategy revitalizes and expands our investments in technology, commercial spaceflight, student research, and robotic exploration precursors," the letter states. "These are the key elements of the President?s new plan for NASA that must be retained in any consensus solution reached by Congress and the White House."

The House bill would siphon funds from some of those efforts in order to resurrect NASA's existing Constellation program, an effort ?that began under former President George W. Bush to return astronauts to the moon.

Obama's ?space plan calls for the cancellation of the Constellation program to make way for an ambitious manned mission to an asteroid by 2025. He has also directed NASA to fund commercial spaceships to carry astronauts to low-Earth orbit after the space shuttles retire next year.

In the letter to House members, seven former astronauts and 14 Nobel prize winners spoke out in favor of Obama's space plan.

One of them is Scott Hubbard, a Stanford University professor and former director of NASA's Ames Research Center in California. He said the NASA authorization bill that recently passed the Senate is much closer to the plan put forth by Obama, and would offer a better direction for NASA.

Both the House and Senate bills, as well as the President's proposal, allocate about $19 billion for NASA in 2011, though each plan directs the money to be spent somewhat differently, Hubbard told SPACE.com.

"This group of people was deeply concerned about the House bill and that?s why we wrote the letter," Hubbard said. "It's up to the legislatures to figure out what they do. The reason we wrote the letter was that we think there is still time for discussions."

Hubbard and others who signed the House letter agree with the strategy to fund commercial crew transportation. They contend that it will free up NASA to focus on exploration beyond Earth.

"Without commercial crew, America will be forced to rely for astronaut access to space on the Russian Soyuz for years to come," the letter states. "NASA should invest far more in America?s launch industry than it invests in Russia?s launch industry, but the current House Science Committee authorization bill fails this test, sending over $900 million to Russia to buy seats on Soyuz over the next three years but only putting $450 million into commercial crew during the same period, and only allocating $14 million for the Commercial Cargo Program."

The group also objects to the House bill's cutting funding for developing new space exploration technology, funding space research by university students, and money for robotic precursor missions to precede human exploration trips.

"To ensure the highest scientific return on human exploration missions and to maximize the safety of human explorers traveling to new destinations, it is critical that NASA send robotic precursor missions to characterize hazards and scout out locations of future exploration interest," the letter states.