CAPE CANAVERAL, Florida (Reuters) - With more than 1,500 space shuttle workers facing layoffs this week, legislators say they will take a final shot at passing a blueprint for the U.S. human space program before adjourning ahead of the November 2 congressional elections.

Contrails are seen as workers leave the Launch Control Center after the launch of the space shuttle Discovery and the start of the STS-131 mission at NASA Kennedy Space Center in Cape Canaveral, Florida, April 5, 2010. REUTERS/Bill Ingalls-NASA/Handout

“We’re teetering right on the edge,” U.S. Senator Bill Nelson, a Florida Democrat, said on Monday at a space policy symposium at the University of Central Florida in Orlando.

With no time left to resolve conflicts between rival House and Senate spending plans for NASA for the fiscal year beginning October 1, the only option to break the gridlock is for the House to vote on the Senate bill, according to a key legislator who said that should happen on Wednesday.

“For the sake of providing certainty, stability and clarity to the NASA workforce and larger space community, I felt it was better to consider a flawed bill than no bill at all as the new fiscal year begins,” House Science and Technology Committee chairman Bart Gordon, a Tennessee Democrat, said in a statement.

The U.S. human space program was thrown into turmoil when President Barack Obama, acting on advice from an outside advisory panel, decided to end the agency’s follow-on moon program called Constellation, and embark on a more flexible approach to deep space exploration.

That plan, unveiled in February, also would make the government a customer, rather than provider, for crew transportation services to the International Space Station. The proposal has divided legislators and the space community.

The Senate plan reigns in Obama’s spending on commercial initiatives and directs NASA to begin work sooner on a heavy-lift rocket that would be needed for missions beyond the space station’s orbit.

Passage of the Senate bill this week would not avert the layoffs scheduled for Friday but would authorize programs that will need workers.

“This NASA bill will push development of this new heavy-lift rocket with the goal to fly by 2016. Right off the bat, that would hire 2,000 of the space workers that otherwise would be losing their jobs,” Nelson said.

He said another 2,000 workers would eventually be hired by firms developing space taxis and other commercial space services for NASA, under the proposal.

The space station, a $100 billion project of 16 nations, is due to be finished in February with the arrival of a $2 billion particle detector known as the Alpha Magnetic Spectrometer. NASA has one shuttle mission before then, a cargo delivery flight scheduled to launch on November 1.

The Senate bill adds another shuttle mission next summer in an attempt to lessen the gap until a new vehicle -- commercially developed or government owned -- is ready. In the meantime, astronauts will be ferried to and from the outpost aboard Russian spaceships.

“This legislation -- we’ll find out if it passes this week -- reduces the amount of time we have to depend on Russia,” Nelson said. “This week is bittersweet. We have hope for the future with a new space program with exciting new goals while a major job layoff accelerates.”

With the shuttle program winding down, prime shuttle contractor United Space Alliance reports 1,222 employees - 877 in Florida, 333 in Texas and 12 in Alabama -- will be laid off on Friday. Another 350 shuttle contractor jobs also are expected to end on Friday.

United Space Alliance is a joint venture between the Boeing Co and Lockheed Martin Corp.