In war, one should seek to take and hold the high ground. From there, the enemy's movements are clearly visible, and he will struggle just to reach you, let alone fight you. High orbit is the highest ground there is.
— variably attributed to Codex Astartes and Star Wars Expanded Universe.
With their old Cold War-era networks obsolete or non-existent, the three superpowers look to upgrade their hardware.
Space warfare is utterly different from other mediums. Firstly, everyone is literally as predictable as the sunrise. All sides' electronic strategic maps can display orbits of all satellites, which are easily tracked by commercially available telescopes and some math; there is no element of surprise.
Secondly, even worse, one shot, one kill. "Kill-sats" are usually Kinetic Energy Kill Vehicles, which require a lot more armour - like, a lot more - than can be deployed in space. The lack of proper countermeasures means that as long as the weapon used hits, the satellite is permanently out of commission. And they generally hit.
Finally, space combat systems are ridiculously expensive and have short shelf life. While each superpower has near-endless supplies of conventional ordnance, any space launch carries Requisition expenses.
By type, we have:
A.k.a. "kill-sat". Unlike most other satellites, it is mostly a weapon; a large missile with terminal-stage guidance and a disproportionately heavy terminal stage. Limited on-board power means that such systems cannot remain orbiting dormant a la space mines, but they are designed using ballistic missile technology with a high shelf life, so it's very easy to stockpile them just under their launch sites. With improving mass allowances, additional weapons may be added to improve chance of intercept.
Much more importantly, the limited power of boosters involved and the capabilities of on-board sensors make intercept beyond low orbit extremely unlikely.
A good example are Soviet IS-series field-tested interceptor satellites.
Each of the superpowers maintains their own networks of satellites using secure radio and line-of-sight laser communication systems. They guarantee some degree of communication with every unit anywhere on the planet.
Located in high orbits, they are invulnerable to intercept.
POR-1 through 6
See Main Article
UN-operated satellites that track any ground-to-space and space-to-ground movements.
Too high-flying to shoot down.
Global Positioning Systems
Although the acronym is mostly associated with the US, each of the superpowers operates their completely independent but fundamentally same system: GPS-NAVSTAR (US), Galileo (EF), GLONASS (RF).
Cannot be shot down.
Well, it's good when you have friends round the globe who are willing to provide you their ground-space communication arrays, because when you don't have antennae with LOS on the satellite, you don't have a connection. It's not too bad if you install a memory bank and only get the photos half an hour late. But what if you can't trigger your weapons because they are above enemy territory but you need them NOW?
Well, you can send up heavy-duty communication satellites into very high orbits. You'll need large four-stage rockets, though.
Otherwise, all Space Operations Bases have their own communications arrays (and do you notice how each superpower has two sites, one of which is to the West and one of each is to the East?) and the United States Navy Command Ships can be retrofitted with their own orbital comm suites.
Some of the more conventional units can get near the edge of the atmosphere, but they never have enough thrust to stay in orbit - that is, fly forward so quickly that, despite constantly in free fall, never hit the ground. Examples include the Russian AShBM and their single-use guidance satellite, or the EFAF Scimitar bombers.
Use StAA, not A-Sat, to deal with them.
Such a risky environment had caused the military to actually reduce the involvement of manned systems. Aside from flights to and from the Industrial Stations, the only manned craft are operated by the 27th AF doing a RAID; neither should hang around long enough for an intercept.
Satellites with cameras. And thermal imaging. Fly low, which makes them vulnerable. Also have a much narrower field of view and harder-to-interpret data. Which is why they are used in locations where enemy units are already believed to be, and take single pictures with low zoom anyway. Upgrades include high-zoom video cameras that can have their imagery uplinked directly to upgraded units and can be used for precision beyond visual range fire.
These satellites are more vulnerable than you might think. Schedules of their overflights can be found on the walls of any self-respecting barracks and conspiracy theorist hideouts, and there are plenty of photographs of groups of off-duty soldiers flipping off the Eye in the Sky. Bad weather stops them dead in their tracks. And they can't be used to quickly search broad expanses.
Sharing the same orbit altitude and predictability, these have large power sources and RADARs mounted; often they are nuclear-powered and can scan continuously. They often have poor resolution, and hence can't be used to track land units and can rarely pick up aircraft. Their element is searching for ships. Supplementary capability includes direct downlink for missile targeting.
They are only slightly impacted by lighting-ridden large storms and space weather, which still makes them the most reliable of satellite types.
Space-to-Ground Weapon Units
If you drop it from high enough altitude, anything can be a weapon. A nut (the kind that is screwed onto a bolt) can penetrate a 1 cm-thick piece of plywood if dropped from Ostankino tower (540 m); imagine what a 1 t slug of carbon-carbon-coated rocket-propelled tungsten, steel and concrete coming down from a 450 km orbit can do. Even better, this unit is attached to a detachable support module with solar panels, so it can act as a “space mine” and be placed beforehand.
However, no-one appreciates this crap flying overhead. It significantly tenses the pre-war situation. It can be shot down before it’s used, less so when descending. Also, it’s inertially and GPS-guided, so it’s not too much better than JDAMs and artillery as it needs a spotter. It’s heavy, so it’s only sent into low orbit.
Best used against ships and immobile high-value installations. Everything else is a waste of Requisition; buy yourself some tanks instead.
Orbital Weapon Platforms
Now this satellite doesn’t fall out of the sky to kill you. Even better – it has a weapon with a fixed supply of shots that can be replenished. This allows better power for lower long-term costs. It also mounts its own sensors and hence acts as a self-sufficient orbital artillery unit.
However, the platform itself plus the heavy booster plus regular ordnance resupplies rack up a fortune of Requisition cost. And, aside from the slightly higher orbit making intercept slightly less likely to succeed, it’s just as easy to take out.
A semi-decent example would have been the 80-ton 17F19 Skif/”Polyus” and its sister system Kaskad, with the latter carrying missiles and he fromer mounting a 1MWt laser. Except for the whole “booster worked backwards and deorbited the whole thing” story.
Alright, enough killing! How else can space be useful for us? Well, after the ISS-2 was decommissioned in 2024, a whole slew of much more utilitarian projects for space exploration emerged. The US wants to send up a plant that would manufacture solid-state antennae and adaptive optics in microgravity; the Russians are really interesting in regular Earth-Moon-Earth runs with some drilling involved.
Most of these designs are only optionally manned, but need regular supply runs via re-entry-capable craft.
Also, some assembly is often required.
As mentioned before… Generally there are two variants of these: one is equipped with a proper docking sleeve and optional crew, the other is an ordnance carrier with some light docking umbilicals and robotic arms to attach its vacuum-proof cargo.
In order to reduce costs, these craft use increasingly elaborate designs, such as airborne launch.
Upgrading satellites is… well, difficult. Most upgrades are built as modular packages that can be bolted onto the highly versatile basic platforms by robotic arms.
Generally, the same basic model of shuttle is used for all three.