PARIS — Orbital Sciences Corp. on Oct. 18 said its new Antares rocket will not launch its Cygnus cargo freighter on a demonstration flight to the international space station until around March or April, assuming that two preceding rocket tests occur without a hitch.

In a conference call with investors, Orbital officials did not attribute the fresh delay of the NASA-funded program, of three or four months compared with its last quarterly update, to any particular event.

In recent months the company has restructured its relationship with the Mid-Atlantic Regional Spaceport at Wallops Island, Va., becoming a supplier to the spaceport rather than a partner in the new facility’s development. Antares will launch from that facility.

As part of that transaction, Orbital booked $25.6 million in cash from the sale of infrastructure at the Wallops facility. Orbital Chief Financial Officer Garrett E. Pierce said during the call that the transaction, which resulted in no losses for Orbital, was good for the spaceport and good for Orbital as well.

Orbital Chief Executive David W. Thompson said propellant-loading tests of the Antares rocket’s first stage on the Wallops Island launch pad will start the week of Oct. 21. Assuming no hiccups in this procedure, the first stage will be test-fired for 30 seconds on the pad in early November.

A successful engine-firing test will lead to the preparation of a full Antares rocket for a test flight, without the Cygnus cargo vehicle, in December.

Thompson said the demonstration flight to the international space station, this time with Cygnus, would then occur late in the first quarter of 2013 or early in the second quarter, depending on the station’s traffic schedule and on Antares’ status.

Orbital added the Antares test flight to its manifest in 2011, with NASA’s accession, as part of the Commercial Orbital Transportation Services (COTS) contract with NASA to demonstrate the abilities of Antares/Cygnus. This contract is cost-shared with NASA, with Orbital booking zero profit.

Once the Antares/Cygnus configuration has demonstrated its ability to deliver cargo, Orbital will begin station deliveries under its Commercial Resupply Services contract with NASA. This contract is valued at $1.9 billion and calls for Orbital to make eight flights, delivering 20,000 kilograms of payload to the station.

Thompson said that while the delays in the program will not have any direct financial impact on the company, they are causing Orbital to make COTS-related research-and-development expenditures for a longer period than had been expected.

Despite the delays, the company’s launch vehicles division delivered the best performance among Orbital’s three divisions for the three months ending Sept. 30. Launch vehicle revenue, including NASA money for the future commercial cargo-transport flights and Orbital’s work on target vehicles for the U.S. Defense Department, jumped 21 percent compared with the same period a year ago, to about $141 million.

Thompson said Orbital expects to book just under $375 million in revenue from the NASA commercial resupply contract in 2012, and $400 million in 2013.

The launcher division’s operating profit margin was 6.6 percent, up from 4.5 percent a year ago, Orbital said.

Orbital has booked one order for a commercial telecommunications satellite in 2012 and expects at least one more before the end of the year, Thompson said. The company specializes in smaller spacecraft, and in early October placed into service its first all-Ka-band telecommunications satellite, the Hylas 2 spacecraft for British operator Avanti.

Thompson said he expects the global market for geostationary-orbiting telecommunications satellites to total 17 to 20 orders in 2012, with about the same volume in 2013. He said there is reason to hope that around 2014, the cyclical market will turn upward as the major fleet operators replace existing satellites.

Meanwhile, unlike many U.S. Defense Department contractors, Orbital does not look at the current impasse hanging over the U.S. government budget as necessarily a bad thing for its business.

Thompson said a budget agreement that freezes spending at 2012 levels — a scenario he said is more likely than wholesale budget cuts as part of a sequestration procedure — might be good news for Orbital.

Of biggest concern to Orbital is that 12-13 percent of its annual revenue comes from work on NASA science satellites. NASA’s science division looks to be among the hardest hit from the current budget situation.

Orbital’s total revenue for the three months ending Sept. 30 was $372.9 million, a record for the company and a 9 percent increase from the same period a year ago. Operating income, at $31.3 million, was up 27 percent from last year.

Peter B. de Selding was the Paris Bureau Chief for SpaceNews.