Orbital Sciences Corp. could reevaluate moving some of its Taurus 2 rocket missions from Virginia to Florida if the company wins a contract to launch astronauts or stacks its backlog with satellites, a senior company official said Tuesday.

Artist's concept of a Taurus 2 rocket on the launch pad at Wallops Island, Va. Credit: Orbital Sciences

The firm is contending for rights to launch future NASA astronaut crews to the International Space Station, but it faces stiff competition from SpaceX, Boeing Co., and other companies.

NASA wants to transition human transportation to low Earth orbit to private industry after the shuttle's retirement, but it will be several years before any company can demonstrate crew flights.

Orbital is already operating under a NASA contract to develop the unmanned Cygnus cargo freighter and the Taurus 2 rocket. The vehicles are scheduled for their first test flight next summer, according to Frank Culbertson, senior vice president and deputy general manager of Orbital's advanced programs group.

Culbertson's division oversees Orbital's human space progams.

In addition to the test flight, NASA has ordered eight operational Cygnus and Taurus 2 missions to deliver cargo and supplies to the space station through 2015. SpaceX was awarded 12 logistics flights using its Falcon 9 rocket and Dragon capsule.

The resupply flights will blast off from a launch pad now under construction at Wallops Island, Va. Orbital chose Wallops due to strong political support from the state of Virginia and its proximity to the company's headquarters near Washington, D.C.

"At the time, it looked like Florida was going to be really busy," Culbertson said.

In a speech Tuesday at a luncheon of the the National Space Club Florida Committee, Culbertson said Orbital could reconsider launching Taurus 2 rockets from Cape Canaveral if the company receives a contract to fly astronauts.

Artist's concept of a Cygnus spacecraft approaching the International Space Station. Credit: Orbital Sciences

Culbertson said it would take Orbital three or four years to field human-rated rocket and spacecraft from the point of a firm contract award.

More Taurus 2 launch sites, including Florida, could also be required if Orbital signs deals to launch a large number of satellite payloads on the Taurus 2, according to Culbertson. Other locations under review include Vandenberg Air Force Base, Calif., and Kodiak Island, Alaska, for polar orbit launches.

Culbertson, a former astronaut, said Orbital is still discussing opportunities to launch the Taurus 2 from several facilities at Cape Canaveral.

One vacant launch pad is Complex 36, the former home of Atlas rockets. Complex 36 is managed by Space Florida, a state government's aerospace economic development agency.

A Space Florida spokesperson did not respond to questions Tuesday, but Orbital considered Complex 36 in its first search for a suitable Taurus 2 launch site.

Meanwhile, construction of the primary Wallops launch site is on track for completion by the end of 2010.

The launch pad base and horizontal integration facility are both under construction, and workers have erected a 30-story water tower to dampen liftoff acoustics, Culbertson said.