Why is Scotland a good location? Lots of reasons!
- Over half of the <300kg satellites that have been launched in the past 20 years are in sun synchronous orbits (SSO). This is the preferred orbit for an imaging satellite. They go almost, but not quite, over the poles.
- The ground track of a satellite in SSO is either around 352º or 188º depending on which side of its orbit it is on. (Required track varies with orbital altitude, but these numbers are right for the 500-600km altitudes which are most common.) This picture shows the ground tracks for one day's orbits for a satellite in SSO:
- So you need to be able to launch on a track of either 352º or 188º - or else burn a lot of fuel to make a turn after launch. You also need to launch over an unpopulated area so as not to drop bits of rocket on people, and you need to launch into an area which is within range of a ground station for telemetry.
- From Scotland you can launch straight into SSO, over the sea, and you can track the launch all the way to orbit from ground stations in the UK, Svalbard and Canada.
- Launch sites on the US East coast can't launch into SSO. Satellites needing this orbit are typically launched from California, French Guiana, Chennai in India (needs a dogleg manoeuvre to avoid Sri Lanka), China, Russia or Kazakhstan. If you're launching an observation satellite, or any kind of sensitive payload, your options shrink a lot. Scotland would be a good choice - assuming it doesn't align itself too closely with China after independence!