Spaceport maximum and minimum inclination?

[xpell]

(I'm not sure if this would be a 'school-type' question... it's definitively not for any kind of homework, so I'm posting it here, please relocate if appropiate)

I've recently learned that spaceports have a maximum and minimum launch inclination, and that minimum inclination corresponds to the spaceport geographical latitude. But I'm not really grasping the concept, and after I've searched a lot in the Internet and wherever, I haven't found any explanation. So I'm asking it here.

1. Why do spaceports have a maximum or minimum inclination?
2. I assume that certain launchs' target orbit is way lower than the minimum inclination (for example, equatorial launches from Baikonur). How do they do this? Extra thrust or what?
3. If so, could you launch a spacecraft from Baikonur, another one from Plesetsk (let's say both at 62º), rendezvous them in orbit, then move them to a low-inclination interplanetary injection orbit?

And how is this calculated?

Thank you in advance! (I know I'm asking a lot of questions here, but I'd love to know how this works!)

 

[Valerie Park]

The reason that spaceports have a maximum and minimum launch inclination is because the launch vehicle needs to generate enough thrust to overcome the force of gravity and reach a certain altitude and velocity in order to achieve orbit. At lower inclinations, the launch vehicle needs to generate more thrust to compensate for the lower altitude, while at higher inclinations, it needs less thrust to reach the same altitude and velocity. The minimum launch inclination is determined by the geographical latitude of the spaceport; the location of the spaceport affects the minimum launch inclination because the Earth's atmosphere is thicker at lower latitudes, resulting in more drag on the launch vehicle and thus requiring more thrust to reach orbit. In order to launch a spacecraft from Baikonur to an equatorial orbit, extra thrust would need to be applied in order to ‘push’ the spacecraft into a higher inclination. This can be done by using a combination of gravity assists (using the gravity of other celestial bodies) and/or additional propulsion such as onboard thrusters. In terms of calculating the required thrust, it depends on the type of launch vehicle and its specific design parameters. Generally speaking, the required thrust can be calculated using basic physics equations (e.g. Newton’s second law of motion).