The U.S. Space Force is just 75 days old, but it has already narrowed down a tight list of 16 military job specialties that it will own, the director of Space Force Planning said Tuesday.

Maj. Gen. Clinton Crosier said Space Force now has built a staff of about 110 in its headquarters element, of about 200 that it needs. Space Force will build to a strength of roughly 15,000, he said, working to stay focused by avoiding duplication of infrastructure and support functions already provided by other services.

Rather, he said, the members of the nation's newest military branch will focus on five key technical areas: space operations, space engineering, space intelligence, space acquisition and science, and space cyber.

His remarks, to the Defense Advisory Committee on Women in the Services, offered vital insights to the function of a fledgling service that has been largely shrouded in mystery. Still unknown is what the rank and command structure will be; how new recruits can join the Space Force; and even what members of the service will call themselves.

Space Force, which is under the purview of the Department of the Air Force, just as the Marine Corps is within the Department of the Navy, will adopt 16 different specialty codes from the Air Force that all fall within the five main functions.

According to Crosier's presentation, they include the following:

13S Space Ops

1C6 Space Systems Ops

14N Intel

17C Cyber Ops Officer

17D Cyber Ops

1N0 All Source Intel

1N1 Geospatial Intel

1N2 Signals Intel

3D1N4 Fusion Analysis

3D0 Cyber Ops

3D1 Cyber Support

62E Development Engineer

62S Materiel Leader

63A Acquisition Manager

63G Senior Materiel Ldr-Upper Ech

63S Materiel Leader

"Eighty percent of the common support the space force needs ... is going to come from the Air Force. So we can really focus on the things we were told to do. If it's a Space Force-specific function, Space Force will execute," Crosier said.

That said, the service will draw specialists from all services to make up its ranks, he added. The headquarters element already includes 14 sailors, 26 soldiers and two Marines, as well as airmen, he said.

At least initially, infrastructure borrowed from the services will include initial training for enlisted members and officers.

"You'll enlist directly in the Space Force. You will go to Air Force basic training. If you want to commission as an officer, [you'll go to] the Air Force Academy, [along with the other service academies, ROTC and officer training school]," Crosier said. "We will commission people from any service and put them directly in the Space Force pipeline."

He noted that the service will have to overcome the challenge, then, of how to bring the new Space Force members together and "meld them into a common culture."

Crosier emphasized that the service will adopt new 21st century manning and personnel policies, noting that the specialists it requires may come from industry and academia and need nontraditional career paths. All that is being assessed right now, he said, with input from other services, foreign militaries and outside experts.

"It's going to be sized differently; it's going to have to run differently. We're going to have to tailor different policies and issues to the Space Force," he said.

-- Hope Hodge Seck can be reached at hope.seck@military.com. Follow her on Twitter at @HopeSeck.