Shanahan joined the administration in April 2017 after a 30-year career at Boeing.

WASHINGTON — Since Congress in late 2017 put him in charge of restructuring the military’s space organizations, Acting Defense Secretary Patrick Shanahan has led the charge to make President Trump’s Space Force a reality.

Trump informed Shanahan on Thursday that he wants him to continue running the Pentagon and will nominate him to be defense secretary. Shanahan has been acting secretary since January following the resignation of Jim Mattis.

Shanahan joined the administration in April 2017 after a 30-year career at Boeing. In November 2017, he was suddenly thrust into the role of principal space adviser to then Secretary Mattis after Congress in the 2018 National Defense Authorization Act stripped that job from Air Force Secretary Heather Wilson, reassigned it to Shanahan and directed him to study ways to reorganize the DoD space enterprise. After Trump in June 2018 directed DoD to stand up a Space Force as a separate military service, Shanahan led the push to write a legislative proposal and persuade lawmakers to authorize the new branch.

Shanahan told reporters at the Pentagon on Thursday he is “very excited” about the nomination. He said carrying out the National Defense Strategy will be his top priority “but as you can tell there are real world events that happen every day, and so you have to spin a lot of plates.”

His nomination seemed in doubt after the Pentagon Inspector General in March launched an investigation into allegations that Shanahan took actions to promote his former employer, Boeing, and disparage its competitors. The IG on April 25 cleared Shanahan of any ethics violations.

For the past 18 months, the space reorganization has featured prominently on Shanahan’s agenda. After becoming acting secretary he delegated some responsibilities but still kept a constant eye on the Space Force legislative proposal and well as efforts to establish a U.S. Space Command and a Space Development Agency. Shanahan has been especially steadfast about the SDA, which he stood up in March and placed under the portfolio of Undersecretary of Defense for Research and Engineering Mike Griffin. When Griffin joined the administration, Shanahan found a like-minded partner who believed a shake up was needed in the DoD space business.

The space reorganization caused a growing rift between Shanahan and Air Force Secretary Wilson. Although she supported the Space Force proposal, Wilson was fervently opposed to the SDA which she saw as duplicating what the Air Force is already doing in space technology development.

Shanahan in recent weeks has run into congressional skepticism about his Space Force proposal and acknowledged that DoD needs to better communicate its vision. The most unconvinced of the congressional defense committees appears to be the Senate Armed Services Committee, the same committee he will have to face in his confirmation hearing.

In a statement, Shanahan said: “I am honored by today’s announcement of President Trump’s intent to nominate. If confirmed by the Senate, I will continue the aggressive implementation of our National Defense Strategy. I remain committed to modernizing the force so our remarkable Soldiers, Sailors, Airmen, and Marines have everything hey need to keep our military lethal and our country safe.”