Prestwick spaceport?

Prestwick spaceport?

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Discussion

RizzoTheRat

Original Poster:

26,018 posts

199 months

Monday 20th February 2017
quotequote all
http://www.bbc.co.uk/news/video_and_audio/headline...

So it is this likely?

Orbital Access's proposed small satellite launch system looks perfectly feasible being a similar system to Pegasus, and are tied in with Reaction Engines for their second generation launcher, who seem to have been rumbling on for years. Is it all just another paper exercise to soak up government grants or will it ever make it to orbit?


AshVX220

5,933 posts

197 months

Monday 20th February 2017
quotequote all
RizzoTheRat said:
http://www.bbc.co.uk/news/video_and_audio/headline...

So it is this likely?

Orbital Access's proposed small satellite launch system looks perfectly feasible being a similar system to Pegasus, and are tied in with Reaction Engines for their second generation launcher, who seem to have been rumbling on for years. Is it all just another paper exercise to soak up government grants or will it ever make it to orbit?
I would have thought that places like Prestwick wouldn't have had the weather reliability needed for a space launch site.

Eric Mc

122,858 posts

272 months

Monday 20th February 2017
quotequote all
It's not an ideal site for land based launch pads. Launches are best aimed west to east in order to capitalise on the earth's rotation. However, that would be precluded because any such launch from Prestwick would take the booster over built up areas.

Also, the further south you are the better to take advantage of the earth's spin.

The best site for a British spaceport is Ascension island. It even has an appropriate name smile

ninja-lewis

4,571 posts

197 months

Monday 20th February 2017
quotequote all
AshVX220 said:
RizzoTheRat said:
http://www.bbc.co.uk/news/video_and_audio/headline...

So it is this likely?

Orbital Access's proposed small satellite launch system looks perfectly feasible being a similar system to Pegasus, and are tied in with Reaction Engines for their second generation launcher, who seem to have been rumbling on for years. Is it all just another paper exercise to soak up government grants or will it ever make it to orbit?
I would have thought that places like Prestwick wouldn't have had the weather reliability needed for a space launch site.
Prestwick was a key transatlantic stopping point in the early days as it generally enjoyed good weather and was often fog free when other UK airports were shut by fog.

Einion Yrth

19,575 posts

251 months

Monday 20th February 2017
quotequote all
Prestwick's "natural", for want of a better term, orbital inclination is about 55.5 degrees. Not completely useless, but far from ideal for most missions. Plane changes are incredibly expensive in terms of delta v, so no. Not likely IMO.

RizzoTheRat

Original Poster:

26,018 posts

199 months

Tuesday 21st February 2017
quotequote all
Earth rotation speeds:
462 m/s in Guiana
407 m/s at Kennedy space centre
262 m/s in Prestwick

So they'd need 200m/s (nearly 450mph) more dV than an ESA launch. I assume they'd fly a bit further south to launch but it's still not ideal is it.

Plus as said you then end up in a fairly inclined plane.

Eric Mc

122,858 posts

272 months

Tuesday 21st February 2017
quotequote all
It might be useful for polar orbits - if the rockets are launched in a northwards direction. Plesetsk Cosmodrome in Russia is 62 degrees north (more northerly than Prestwick) and is used by Russia for its polar orbit launches.

Most polar orbit missions are military in nature although some are civilian. So, on that basis, Prestwick might make some sense. Ideally, you need two launch sites to cater for various mission requirements - one where you can launch high inclination missions (polar usually) and one where you can launch low inclination missions(closer to the equator).

The US has Cape Canaveral and Vandenberg Air Force Base (plus Wallops Island and White Sands if needed) and Russia has Baikanour (actually in Kazakhstan) and Plesetsk.

towser44

3,667 posts

122 months

Tuesday 21st February 2017
quotequote all
Watching the video, the 'rockets or space craft' go up underneath a normal plane and are then released at 40,000 feet, so location doesn't matter does it?

Eric Mc

122,858 posts

272 months

Tuesday 21st February 2017
quotequote all
That type of launch, although it does confer some advantages, means that you are limited to very small payloads.

As a percentage of total launches each year, air launches make up a tiny percentage. Indeed, you can go for years without one.

RizzoTheRat

Original Poster:

26,018 posts

199 months

Tuesday 21st February 2017
quotequote all
towser44 said:
Watching the video, the 'rockets or space craft' go up underneath a normal plane and are then released at 40,000 feet, so location doesn't matter does it?
Potentially not as they could fly to the equator and launch from there, but that's a long flight, and presumably they need some sort of permission from whoever's airspace they're in to launch the rocket.


Eric Mc said:
That type of launch, although it does confer some advantages, means that you are limited to very small payloads.

As a percentage of total launches each year, air launches make up a tiny percentage. Indeed, you can go for years without one.
43 Pegasus launches in 17 years, with a maximum payload of a bit under half a tonne, so under 19 tonnes total....or slightly more than 2 Arianne 5 payloads. $55M launch cost for Pegasus vs $200M for Ariane, so Ariane does around 20 times the payload for 4 times the cost? I'm really shocked at how expensive Pegasus is in that case.

Are there any other air launched systems similar to Pegasus?


Edited by RizzoTheRat on Tuesday 21st February 12:07

Eric Mc

122,858 posts

272 months

Tuesday 21st February 2017
quotequote all
Not all air space is owned by a country. There is what is known as international air space.

An air launcher can launch from international air space, although it would be normal procedure to obtain air traffic permission and obtain clearances from any countries over which the launch vehicle would pass over in its climb to orbit.

In theory, Prestwick could support air launches only with the air launchers (whatever they turned out to be - usually older large airliners such as the Tristar used by Orbital ATK).

However, building a spaceport and all its range facilities (including range safety, telemetry, radar, communications etc) would not be viable if it could only be used for air launched missions.

A true spaceport also has to support land launches too - because that is where most of your business will come from.