The Taurus 2 rocket could be launched on a standalone test flight next summer if NASA provides supplemental funding for commercial cargo services, Orbital Sciences Corp. officials told investment analysts Thursday.

Artist's concept of a Taurus 2 rocket. Credit: Orbital Sciences

Orbital is designing the Taurus 2 rocket and Cygnus cargo freighter to deliver supplies to the International Space Station through 2015. The commercial resupply system is scheduled for its first test flight in the second quarter of next year, according to David Thompson, Orbital's chairman and CEO.

The company currently plans to launch the Taurus 2 and Cygnus on a demonstration mission to berth with the space station.

The White House's budget request for fiscal year 2011 includes a $312 million boost for the Commercial Orbital Transportation Services demonstration program. Congress is taking up their budget bills this month.

"If Congress approves NASA's request for COTS augmentation funds, as now appears reasonably likely, our plan would be to conduct a Taurus 2 test flight with the first production Taurus 2 rocket vehicle next June without the Cygnus spacecraft," Thompson said in a conference call.

The Senate's version of next year's NASA spending bill approves the extra COTS funding, but House legislation so far provides no additional funding.

Orbital and SpaceX are splitting a $3.5 billion Commercial Resupply Services contract for unpiloted cargo flights to the space station. Orbital's portion of the deal is worth $1.9 billion and calls for eight operational Taurus and Cygnus flights.

Artist's concept of the Cygnus spacecraft. Credit: Orbital Sciences

Neither company requested the extra funding, but Orbital says it could use the money to ensure schedule and technical margin.

"This would permit us to substantially reduce the risk to follow-on CRS cargo missions, which are due to begin less than 18 months from now," Thompson said.

Orbital executives fielded questions from investment analysts in a conference call announcing the company's second quarter financial results.

At the end of June, Orbital had spent about 84 percent of the planned research and development capital expenditures on the Taurus 2 rocket. Development costs of the Cygnus spacecraft for the COTS demo mission rose $15 million between April and June, Thompson said.

Including the higher cost estimate, Orbital spent 64 percent of its Cygnus development budget through the end of June, according to Thompson.

J.R. Thompson, Orbital's president and chief operating officer, said the Taurus 2's first stage engines will begin testing at NASA's Stennis Space Center in Mississippi next week.

Chilled liquid oxygen propellant will flow through the engine during the chilldown tests to check how parts respond to the cold temperatures.

The first Aerojet AJ26 engine arrived at Stennis on July 15 to start checks at the space center's modified E-1 test stand, according to NASA. The AJ26 is a modified Russian NK-33 engine built in the 1960s and 1970s for the Soviet Union's N1 moon rocket.

An AJ26 engine is installed in the E-1 test stand at Stennis Space Center. Credit: NASA

Each Taurus 2 first stage is powered by two AJ 26 engines.

J.R. Thompson said more AJ26 engines will begin arriving at Stennis next month, and the first test firing is scheduled for early September.

"Acceptance testing of these engines should be complete in early October," Thompson said. "At this point, we plan to complete the acceptance testing of the first two engine flight sets by the end of this year."

A first stage tank test article will be shipped by early October from Ukraine to the Taurus 2 launch site at Wallops Island, Va.

Officials also updated the Taurus launch pad's construction. Builders erected a 250-foot-tall water tower in June and continue working on the pad's ramp, concrete foundation and flame trench.

"By the end of the summer, the Horizontal Integration Facility, launch pad and propellant and gas facilities will be nearing completion and beginning the test and certification activity," J.R. Thompson said.