WASHINGTON, June 13 (Reuters) - The U.S. Department of

Defense picked Jeff Bezos' Blue Origin, Elon Musk's SpaceX and

Boeing-Lockheed joint venture United Launch Alliance (ULA) to

compete for national security space missions, making initial

selections under a $5.6 billion award program.

The Pentagon did not say which of the companies' rockets it

selected, but noted seven companies bid for entry into the

program, which seeks upcoming rockets that must be ready to fly

their first missions to space by December.

The three companies are the first to be selected under the

Pentagon's lucrative National Security Space Launch Phase 3

procurement program, a multibillion dollar competition among

U.S. rocket companies vying to launch some of the country's most

sensitive military and intelligence satellites into space for

roughly the next decade.

SpaceX and ULA, two titans in the launch industry, have

since 2020 been the Pentagon's primary rocket launch providers

under a predecessor program, called Phase 2. That program gave

ULA a 60% share of all Pentagon missions through 2027, with

SpaceX getting the rest.

But in the program's third phase, the Pentagon has sought a

wider variety of companies for its space missions into the next

decade, mainly to stimulate more competition in the U.S. launch

sector.

The announcement on Thursday brings Bezos' rocket launch and

human spaceflight company Blue Origin into a competitive arena

it has long wanted to enter as it tries to bring its giant New

Glenn rocket to market and ramp up its competitive footing with

SpaceX.

SpaceX's partially reusable Falcon 9 rocket has dominated

the launch industry while the company test launches its

next-generation Starship rocket, a massive, fully reusable

launch system that Musk sees as crucial to flying humans into

space and launching large batches of satellites into orbit.

While ULA's workhorse Atlas 5 rocket nears retirement, its

next-generation Vulcan rocket is poised to become the company's

centerpiece launcher. Vulcan first launched this year, and its

second mission - a crucial step to receive certification for

Pentagon missions - has been delayed but is expected to fly

later this year.

The three companies did not immediately reply to requests

for comment about their rockets' role in the Pentagon program.

The Pentagon's Phase 3 program is divided into two

categories, Lane 1 and Lane 2. Lane 1, the category of

Thursday's announcement, allows more novel or specialized

rockets to fly national security missions that have

less-stringent requirements. More companies, such as Rocket Lab

, are expected to be added to Lane 1 in the coming

years.

The U.S. Space Force, which manages the launch

procurement program, said Blue Origin received $5 million to

provide an assessment of how it will meet the Pentagon's launch

requirements. SpaceX and ULA - companies Space Force is more

familiar with - each got $1.5 million.

Lane 2, whose awards are expected in autumn, will tap three

companies whose rockets are capable of meeting a wider variety

of national security mission requirements, indicating the most

experienced players such as SpaceX and ULA will be most fit for

awards.