Budget constraints are forcing NASA to postpone the launch of a next-generation spacecraft Lockheed Martin is building to take astronauts to the moon.

The Orion spacecraft, which Lockheed engineers are designing at the company's metro-area facilities, won’t blast off until 2015, or six months later than planned, NASA chief Michael Griffin told lawmakers in Washington.

"We simply do not have the money available" to fly in 2014 as originally planned, Griffin told the Senate Commerce Committee’s space subcommittee, according to the Associated Press.

The delay stems from a $545 million gap between President Bush's funding request for NASA this year and the money Congress stipulated in a spending bill the president signed recently. Lawmakers gave NASA the same amount of money it received in 2006.

"The net result of the decrease will be a four- to six-month delay of the Orion crew vehicle," the AP quoted Griffin as saying.

Lockheed Martin Space Systems in Jefferson County — which landed the $8.2 billion Orion contract last year — currently has 350 employees in the Denver area working on Orion. The company ultimately expects to have 600 employees here on the job.

Lockheed spokeswoman Joan Underwood said Griffin's announcement would have "no impact or jobs or schedules at this time."

In a separate e-mailed statement, she added: "The Orion team at Lockheed Martin is working closely with NASA to have Orion ready to fly no later than 2014 based on the current program requirements."