In the wake of Shanahan’s resignation, speculation has swirled in the Pentagon about how the transition might affect efforts to stand up a Space Force and modernize the military’s satellites.

WASHINGTON — President Trump made a “good choice” naming Army Secretary Mark Esper acting defense secretary following the resignation of Patrick Shanahan, said former Air Force Secretary Heather Wilson.

Wilson, who stepped down on May 31 and whose name had been floated as a candidate for defense secretary, praised Esper in a statement to SpaceNews. “He is calm, honest and experienced,” she said. “I enjoyed working with him. His understanding of, and respect for the role of the services and the Joint Staff will make him a better secretary of defense.”

Esper will become acting defense secretary on June 24.

In the wake of Shanahan’s resignation, speculation has swirled in the Pentagon about how the transition might affect efforts to stand up a Space Force and modernize military satellites and other systems. Shanahan was a staunch space advocate and personally oversaw DoD’s legislative proposal to stand up a Space Force. He also was the driving force behind the establishment of the Space Development Agency.

Acting Air Force Secretary Matt Donovan told Military.com at the Paris Air Show on Wednesday that he does not expect the transition to affect the Space Force reorganization and that Esper supports the administration’s proposal.

During a news conference in October at the Association of the U.S. Army’s annual symposium, Esper said the Army would be a “team player” in the space reorganization,

DoD sources told SpaceNews that Esper is likely to continue to advocate for space investments.

A graduate of the U.S. Military Academy, Esper served in the regular Army as an infantry officer for over a decade, including service in the 1990-1991 Gulf War with the 101st Airborne Division. He later commanded an airborne rifle company in Europe. Following active duty, he served in both the Virginia and District of Columbia National Guard, and Army Reserve before retiring in 2007. Before being tapped as Army secretary, Esper was Raytheon’s vice president of government affairs.

About 2,220 active-duty soldiers, reservists and civilians work in space-related jobs under the Army Space and Missile Defense Command. “The Army is a big user of space,” Esper said at AUSA. “We’re heavily reliant on it.”

Army space forces perform intelligence, surveillance and reconnaissance; missile warning; environmental monitoring; satellite communications; and positioning, navigation and timing, or PNT. More than 70 percent of the Army’s major weapons and equipment need satellites to function. Each Army brigade requires at least 2,500 PNT devices and 250 satellite communications terminals. The Army also deploys its own remote sensing satellites.

Space Development Agency

Shanahan approved the establishment of the SDA on March 12 and placed it in the office of Undersecretary of Defense for Research and Engineering Mike Griffin. In the months leading up to the standup of the new agency, Shanahan offered multiple explanations for why the SDA was needed. He said the traditional DoD procurement system was too slow and only a new organization could speed things up. He also said the SDA would help consolidate disjointed programs.

Shanahan told reporters in October that his determination to create the SDA was partly shaped by conversations with Army Futures Command’s Lt. Gen. John Murray. Ground forces have huge demands space services like communications, timing, navigation and early warning of missile launches. Shanahan said the Army should have some say in the “space architecture,” such as how future constellations are designed and constructed. “If the Army is first in developing a component of our space architecture, how do we get everybody to hold hands and say the Air Force is going to adopt the same thing?” Shanahan asked. The SDA also would help address equipment problems on the ground, such as the compatibility between satellites and radios.

Esper has not publicly weighed in on the SDA. DoD sources said the agency might not get the same level of support it got from Shanahan and that there are still factions in the Pentagon that don’t see a real purpose for the SDA and view it as duplicative of what other organizations do in the Air Force.

“Most people kept their heads down in the building because Shanahan wanted this but now the question is, ‘does it fall apart?’” a defense official told SpaceNews.

The SDA has an ambitious agenda to design a large constellation of small satellites in low Earth orbit using commercial products. To get started, it needs Congress to approve a $149 million request for fiscal year 2020 but the SDA also was counting on Shanahan to approve reprogramming of funds from other accounts. In the March 12 memo that created the SDA, Shanahan said the undersecretary of defense for R&E would work with the DoD comptroller to reprogram funds during fiscal year 2019.

“I don’t see anyone pulling the levers to shift money on this in the wake of Shanahan’s departure,” the official said.

If the SDA is successful at developing an internet in space for military communications, the Army would be a major beneficiary. “Army leaders have been supportive of DARPA’s Blackjack program, but are starting to grow more cautious about the SDA’s enthusiasm for a new more complicated architecture,” an Army official told SpaceNews. In the Blackjack program, the Defense Advanced Research Projects Agency is developing a LEO constellation to test the concept. There is talk in the Army, the official said, that they will seek to block SDA projects “if they get too far off track or don’t provide real capability to the warfighter.”