Primarily for general aviation discussion, but other aviation topics are also welcome.
#1825689
To add to that, the equatorial advantage is 2-fold:
(i) proximity to the equator reduces the need for inclination adjustments to equatorial orbits (ie not relevant to SSO or most other LEO launches, which is where the smallsat/small launcher market is mostly perceived) and
(ii) being further away from the earth's axis of rotation gives a (not insignificant - 460 m/s at the equator) headstart as you are already travelling at some speed merely by being at the launch site. As long as your orbital plane has some component in that direction you will benefit from it. But again, the popular LEO orbits are at 80° inclination or above and in some cases even retrograde (i.e. 'backwards').
#1825697
The other part of that story is 'Unst [as opposed to Sutherland] selected as launch site for rockets'. I suppose this does not preclude use of Sutherland site by others. As others' postings have clarified, for small satellites heading for POlar LEOs, high latitude launch sites have advantages. It is for large ones heading for equatorial, geostationary or geosynchronous, orbits that sites nearer the equator such as Kourou have their different advantages.
#1825698
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:

Image

- 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! :D
kanga, Lockhaven, Paul_Sengupta and 2 others liked this
#1825699
The rocket launch site was chosen maybe for the same reason the UKAEA built test reactors in the far north in the early 50s - if it all went wrong it seems, the local population then were expendable. Indeed, some mad scientists wanted to set off a nuclear “device” close to Wick in the 50s too.
They are unlikely to build a launch site near Manchester. At Unst, the sea is near at hand for a ditching. I strongly suspect that the site on the north coast near Tongue was abandoned due to its close proximity to four nuclear test sites at Dounreay.
#1825701
Iceman wrote:I don’t think that anyone was suggesting that the rocket would come by air (the runway’s not long enough for that size of aircraft). I would hope, though, that the support staff and the workers required to build that infrastructure would require a convenient means of arrival and departure.

Iceman 8)

If I recall correctly, there's plenty of room at both ends to extend the runway.
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By kanga
#1825705
chevvron wrote:..
.. rhs of the scheduled Loganir Islander in Sep 1972.


I can recall when Loganair had a Skyvan, for cargo too bulky to get in their Islanders (or their Beech 18! This was late '60s), as well as for the occasional larger passenger numbers requirement. Tempting to wonder whether all the components of a CKD rocket would fit into one, and how many round trips would be required. :)

https://www.airliners.net/photo/Loganai ... n-3/754655
#1825743
The Israeli's launch the wrong way - presumably because they don't want to upset the Arabs to the east if it RUD's :mrgreen:

Saw a satellite going the wrong way and zapped it with an app. Said it didn't have a nose cone any more :pirat:
#1825747
Not just RUD, the first stage drops back to earth regardless. Note that one of the Scottish companies have recovered the first stage from the Prospero launch in Australia from the desert, surprisingly undamaged apart from a few squished rocket motors, and were exhibiting it at the last RIAT. Most launches are over the sea to drop the first stage into the sea. SpaceX land theirs. China launch over land and drop theirs anywhere!





Second stages normally are high enough to burn up.
#1825769
kanga wrote:
chevvron wrote:..
.. rhs of the scheduled Loganir Islander in Sep 1972.


I can recall when Loganair had a Skyvan, for cargo too bulky to get in their Islanders (or their Beech 18! This was late '60s), as well as for the occasional larger passenger numbers requirement. Tempting to wonder whether all the components of a CKD rocket would fit into one, and how many round trips would be required. :)

https://www.airliners.net/photo/Loganai ... n-3/754655

Visited Sumbirgh seversal times in my 4 weeks stint there mostly to/from Unst for a re-fuel but I recollect it as 'CS not 'YG.