Proposals/Satellites

While PHALANX doesn't have the resources to launch satellites themselves, they could engineer the satellites and have them launched by civilians. Satellites would be used for monitoring alien activities and, later in the game (ironically, when civilians are on the brink of destruction and can barely afford to carry on their space program) as weapons. Nowhere close to "ultimate" weapons, since the aliens ships can shoot them out of the sky in a heartbeat if they prove too much of a nuisance.

(I'm aware that none of this is going to be implemented soon, but still, there you go.)

Satellite engineering

The most basic surveillance sat may be available without research at the beginning of the game, and could even be bought instead of produced. Still, it would be very expensive, and sats would be a risky investment in UFO:AI since the aliens are out there in outer space with their particle beam weapons.

Research would improve range, then allow to see through some alien stealth technologies. Particle beams sound like a good candidate for putting on late-game sats with additional research and maybe the addition of antimatter power to these sats.

Producing a satellite should be appropriately long and expensive, between 2 and 4 weeks. And then you'd have to get them up there...

Launching

Each month, nations that are happy with PHALANX may offer to launch one satellite for them in addition to providing cash and personnel. The player should be able to decide which satellites to send first, if there are not enough launchers available to take care of every satellite waiting in his or her bases.

Also, it might be nice to offer a choice between geostationary or low orbit. Low orbit would mean more chance to spot small and stealthy UFOs, but in a smaller area. Low orbit may be required for particle beam (or another weapon) sats to keep their beam focused enough.

Surveillance satellite operation

On the geospace, you'd see base-like radar circles (maybe in a semi-transparent green or another color altogether) and get a chance to spot alien ships and ground operations within. Maybe some advanced satellites would have gamma-ray cameras (since antimatter engines produce a lot of those, as reported in UFO engine research).

During tactical missions, having an advanced hi-res satellite currently orbiting over the area would provide line-of-sight outdoors and maybe even a bit indoors with infrared imaging. Would that be too powerful ? That feature could be weakened by making the satellite LoS randomly blocked by cloud cover or fooled into reporting fake aliens (would be identified as fake by soldier's LoS but meanwhile you could waste a lot of time and grenades) by alien technology (that last idea sounds like a lot of work to implement, though).

Weapon satellite operation

On the geospace, you'd see a red (or some other threatening color depending on the type of weapon) circle representing the area covered by the satellite weapon. Weapon satellites would show up in the list of interceptors and SAM bases, and whenever a UFO is within one's red circle that satellite could attempt to shoot it down. Any such attempt would, naturally, have a chance to attract alien attention. A satellite's movement being pretty much predictable (even for 17th century Earth science), it's very easy to shoot down from far away with a good targeting computer and the aliens have these. PHALANX satellites' only hope lie in stealth technologies.

If ground bombing is ever implemented (as in bombing a crash site to reduce or cleanse aliens, reducing or eliminating the need to send in soldiers), you could use satellites to the same purpose.

I can't think of a way to use weapon sats during tactical missions. If they were accurate enough to hit only a few squares of the map (which would require technology even the aliens don't seem to possess), well, that wouldn't be much fun. They could possibly blast only half the map but there would always be some civilian trapped there, whose nation wouldn't be as likely to send off your next $1M orbiting monstrosity.

In the same vein, there is something in development with modern weaponry, which might be something to consider. The 'kinetic bombardment'. One such theoretical project is the 'Rods from God', discussed since the 80s, and Project Thor, in discussion as far back as the 50s. A rod of metal, varying in size from that of a somewhat large dowel rod, for anti-vehicle or small facility work, up to a telephone pole for bunker busting, dropped on a target, varying sizes between for various targets. The destructive potential is figured to be quite great, if the optimal positioning of the satellite is found (too high, the weapon vaporizes before hitting, too low, won't build up the maximum concussive force). The largest size could be seen as a potential use, in the storyline, for penetrating an earthbound alien base with a massive concussive hit. Though, like with any other large satellite weapon, it would cause a truly massive amount of destruction, though this would be far less than that of a large laser, or rockets/missiles (such as have also been planned in history). If this plan were used, various satellite weapons of great destructive power could maybe be used, with some being more potent, or just cheaper, but with a more major hit to one's reputation with the nation in which it is employed.