It took a court case, tens of millions of dollars and some heated words, but Elon Musk's quest to be able to launch satellites for the Pentagon finally concluded Tuesday.

The Air Force announced that SpaceX, Musk's California-based companywon its long-awaited certification from the Pentagon.

And now Musk, the billionaire entrepreneur, has earned the right to do what's he's angling to do for years: take on the United Launch Alliance, the behemoth space company that's a joint venture between Boeing and Lockheed Martin, which has had a virtual monopoly on the lucrative work of flying Pentagon satellites into space for years.

Last year, Musk, of PayPal and Tesla fame, sued the Air Force saying that his company should be able to compete against ULA. Musk and the Pentagon eventually settled the suit, and the Air Force pledged to work closely with SpaceX to get it certified so that it could compete for the contracts to send military satellites and other national security payloads into space.

The right to compete is the latest in a series of victories for SpaceX, which became the first commercial space company to resupply the International Space Station for NASA, and last year won a contract to fly astronauts there by 2017.

Now, with the Pentagon as a potential customer, the company could continue to see steady growth while also compiling important experience, as it attempts to develop space craft that would eventually take humans to Mars.

In a statement, Musk called it an "important step," thanked the Air Force and said the company looked "forward to serving it well."

"SpaceX's emergence as a viable commercial launch provider provides the opportunity to compete launch services for the first time in almost a decade," said Air Force Secretary Deborah Lee James. "Ultimately, leveraging of the commercial space market drives down cost to the American taxpayer and improves our military's resiliency."

SpaceX's first opportunity to compete against ULA could come as early as June, when the Air Force is expected to released a request for proposals to launch a GPS satellite.

ULA, though, has been preparing for this moment, knowing that the hard-charging SpaceX would eventually get certified. It hired a new CEO, Tory Bruno, who has said he is working “to literally transform the company,” in order to compete against SpaceX.  Last month, ULA unveiled a "next generation launch system," a new rocket called Vulcan that it said would make space travel more affordable.

“We welcome today’s announcement and look forward to competing with SpaceX and other new entrants," ULA said in a statement. "The fact is, we could not be more passionate and proud of our work, our people and our record of success."

In order to certify SpaceX, the Air Force said it invested more than $60 million, which included three flight demonstrations and reams of technical data to ensure that SpaceX's Falcon 9 rocket could be trusted with such crucial--and expensive--payloads.

And it seems an end to the rancor between SpaceX and the Pentagon. In an audio interview with Bloomberg Business Week earlier this year, Musk accused military procurement officials of holding up the certification to curry favor with the ULA.

“Essentially we’re asking them to award a contract to a company where they are probably not going to get a job, against a company where their friends are,” he said. “So they’ve got to go against their friends, and their future retirement program. This is a difficult thing to expect.”