[Canadian Army]

The US Space Shuttle programme produced the Columbia (Destroyed in 2003), Challenger (Destroyed in 1986), Discovery, Atlantis and Endeavour, as well as the never flown Enterprise. I've always been partial to the USAF taking control of the Enterprise and rebuilding it for military flights into orbit.

The Enterprise (OV-101) was constructed without engines or a functional heat shield, and was therefore not capable of spaceflight. Originally, Enterprise had been intended to be refitted for orbital flight, however, during the construction of Columbia (OV-102), details of the final design changed. Refitting Enterprise for spaceflight would have involved dismantling the orbiter and returning the sections to subcontractors across the country. As this was an expensive proposition, it was determined to be less costly to build the Challenger (OV-099). Similarly, Enterprise was considered for refit to replace Challenger after the latter was destroyed, but Endeavour (OV-105) was built from structural spare parts that had been ordered by NASA as part of the construction contracts for Discovery (OV-103) and Atlantis (OV‑104).

The rival Soviet Space Shuttle produced the Buran which was flown unmanned in 1988. If the USSR hadn't broken up I'm sure the Soviets would have used it for manned flights, and the Ptichka was over 95% complete when the Soviet shuttle programme was cancelled. The Soviets/Russians maintained a rocket launched manned spacecraft programme throughout the period but who knows what might have been? The US DoD and NASA were working on a number of Space Shuttle replacements at the time and the European Space Agency (France) was also tinkering with the Hermes Spaceplane project, and the British were (and still are) working on air-breathing spaceplanes.

I agree the Soviet shuttle program would not have been cancelled and US DoD and NASA were working on a number of Space Shuttle replacements, and the European Space Agency could build the Hermes Spaceplane. But who would fly them? Most pilot astronauts come from military background, which means as soon as the war starts, the military is not going to release any pilots for astronaut training and some point they are going recall all military personnel serving as astronauts. What you would see is switch to unmanned rockets or the Shuttle-C (https://en.wikipedia.org/wiki/Shuttle-C)

Someone brought up the USAF ASM-135 ASAT programme a few years ago stating that there was a real possibility it may have continued after its official cancellation as a Black Project.

You would see Anti-satellite weapons, most missles used during the Twilight War. Remember GPS and GLONASS use a constellation of 24 satellites and numerous military reconnaissance, weather, and communications are prime targets.

Also here is a link to The ASM-135 ASAT: https://en.wikipedia.org/wiki/ASM-135_ASAT

Here is a list of US Unmanned Rockets and Military Launch in use during Twilight.

US Rockets:

Delta II
Atlas I
Atlas II
Taurus
Pegasus
Titan II (deactivated Titan II ICBM)
Titan IV

US Military Launch Bases:

Vandenberg Air Force Base

Space Launch Complex 1
Space Launch Complex 2
Space Launch Complex 3
Space Launch Complex 6
Space Launch Complex 8
Space Launch Complex 10

Cape Canaveral Air Force Station

Space Launch Complex 40
Space Launch Complex 41
Space Launch Complex 37