Orbital ATK, a Dulles-based aerospace manufacturer, is suing the Defense Advanced Research Projects Agency over plans to award a Canadian firm a $15 million contract to build a fleet of space-faring robots capable of repairing government and commercial satellites.

Orbital argues that the federal program, called the Robotic Servicing of Geosynchronous Satellites, would unfairly compete with its own privately funded effort, a system called the Mission Extension Vehicle 1, backed by at least $200 million from investors. The company has set up at a production facility in Northern Virginia, with a launch planned for next year.

DARPA wants to build out a government-funded program of its own, and is close to awarding a contract to a company that Orbital views as a competitor. In a contract announcement briefly posted on the agency’s website, DARPA said it is awarding a $15 million contract to Space Systems/Loral (SSL), a U.S. subsidiary of Canadian aerospace firm MacDonald, Dettwiler and Associates. DARPA spokesman Jared B. Adams said the contract award was posted in error and elements of the deal are still being worked on.

In its lawsuit, Orbital alleges that the contract violates federal policy against creating government space programs that compete with existing commercial ones.

“The U.S. National Space Policy explicitly directs government agencies to avoid funding activities that are already in development in the commercial marketplace,” the company said in a statement. “Orbital ATK will continue to pursue all available options to oppose DARPA from moving forward with this illegal and wasteful use of U.S. taxpayer dollars.”

A DARPA spokesperson declined to comment on pending legal action.

Opposition to the contract first stirred last month when Rep. Duncan D. Hunter (R-Calif.) wrote to DARPA acting director Steven Walker expressing concern that the contract could “dramatically disrupt normal market conditions” in the commercial spaceflight industry by creating a government-funded competitor. Last week, several lawmakers asked DARPA to halt its program entirely, including Rep. Barbara Comstock (R-Va.), whose district includes Orbital ATK’s headquarters.

The robotic repair program “seems to duplicate efforts of other government agencies and commercial industry,” the representatives wrote, according to a copy of the letter obtained by The Washington Post. “Without considering a pause in the program for appropriate review and justification to Congress, your agency is demonstrating intransigence and is acting in bad faith.”

The agency contends the contract calls for certain capabilities that are not covered by any existing government or commercial efforts. In a response to the lawmakers, the agency said a NASA satellite repair program called Restore-L does not have the same degree of autonomous control as what DARPA is planning. The NASA program — also awarded to Space Systems/Loral — is set to launch by 2020. DARPA argued that commercial solutions have a more narrow range of capabilities.

“No existing or planned commercial servicing systems address this full set of capabilities,” the agency said in a response letter that did not mention Orbital ATK.