WASHINGTON — A principal in a venture capital fund whose investments include SpaceX has joined President-elect Donald Trump’s transition team for the Department of Defense.

The office of President-elect Trump announced Nov. 23 that it was adding Trae Stephens to the existing transition team for the Defense Department. He joins an original group of nine people assigned to the “landing team” covering the Pentagon on Nov. 18, with a tenth person added Nov. 21.

Stephens is a principal at Founders Fund, a San Francisco-based venture capital fund co-founded in 2005 by billionaire investor Peter Thiel and several others. Thiel supported Trump’s campaign, giving a speech backing him at the Republican National Convention in July, and was named Nov. 11 to the executive committee overseeing Trump’s transition.

Founders Fund was the first venture firm to invest in SpaceX, putting $20 million into the company in July 2008. The fund subsequently participated in a $50 million round in November 2010 and the $1 billion round in January 2015 led by Google and Fidelity. Founders Fund has not disclosed the size of its stake in SpaceX, but Luke Nosek, a partner and co-founder of the fund, is on SpaceX’s board of directors.

Stephens came to Founders Fund from Palantir Technologies, a data analytics company that is also part of the fund’s portfolio. Stephens “focuses on startups operating in the government space” at the fund, according to his biography on its website. Palantir’s initial customers were primarily in the U.S. intelligence community.

SpaceX has, in recent years, made it a priority to win business from the Defense Department in addition to customers from NASA and the private sector. After a protracted dispute with the U.S. Air Force that included a lawsuit, the company won certification in May 2015 for Falcon 9 missions under the Air Force’s Evolved Expendable Launch Vehicle program. It won its first EELV launch contract, for a GPS satellite, in April after United Launch Alliance declined to bid.

While Stephens came to Founders Fund from Palantir, he does follow the progress of SpaceX to some degree. “BOOM. Two in a row,” he tweeted May 6 after SpaceX successfully landed a Falcon 9 first stage on a ship in the Atlantic Ocean during the launch of the JCSAT-14 satellite.

BOOM. Two in a row. https://t.co/dnacId3K2w — Trae Stephens (@traestephens) May 6, 2016

That landing came four weeks after another Falcon 9 first stage landing during the launch of a Dragon cargo spacecraft. Stephens retweeted a note of congratulations about that landing April 8 from President Obama, adding the hashtag “#thanksobama.”

After a slow start, Trump’s transition efforts have ramped up in the last week, with landing teams assigned to most cabinet-level departments and many other agencies. However, as of Nov. 25 the transition team had yet to officially announce any landing team members for NASA.