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Author Topic: Itís not exactly rocket science, or is it?  (Read 921 times)

sevenlayermuddle

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Itís not exactly rocket science, or is it?
« on: July 16, 2018, 12:04:32 AM »

I used to understand a certain amount of physics as, without it, youíd not get a degree in electronics.  But that was nearly half a century ago.

Even so, with my very limited recollections, I basically thought that the best place to launch a rocket into space was as close as possible to the equator, as you get maximum assistance from the planetís rotation.  That is borne out empirically, the US launches rockets from southern states, such as Florida.

It seems Scotlandís Highlands and Islands Enterprise sees the physics differently, as does the BBC in reporting it...

https://www.bbc.co.uk/news/science-environment-44841123

So, genuine question or few...

Can a launch from northern UK, in these days of striving for conservation of fossil fuel and reduction of greenhouse emissions, ever really be efficient and socially justifiable use of resources? 

Can it really be commercially viable?

And wouldnít the Scandinavians have something to say about it from safety perspective,  assuming they launch in that direction?

 
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boost

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Re: Itís not exactly rocket science, or is it?
« Reply #1 on: July 16, 2018, 06:39:30 AM »

It's just another post brexit potential pop up shop.

We'll be seeing lots of stuff like this now. Anything which can increase GDP will be entertained, I imagine?
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Black Sheep

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Re: Itís not exactly rocket science, or is it?
« Reply #2 on: July 16, 2018, 02:07:01 PM »

I read Tim Peake's, 'Ask an Astronaut' the moment it was released and he touches ever so slightly on the topic 7LM.

He concurs with you, if memory serves.  ;) :)
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chenks

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Re: Itís not exactly rocket science, or is it?
« Reply #3 on: July 16, 2018, 02:50:57 PM »

Can a launch from northern UK, in these days of striving for conservation of fossil fuel and reduction of greenhouse emissions, ever really be efficient and socially justifiable use of resources? 

Can it really be commercially viable?

And wouldnít the Scandinavians have something to say about it from safety perspective,  assuming they launch in that direction?

the russians don't seem to think it's a problem, and they aren't exactly near the equator.

what safety issues would there be for the scandinavians to be concerned about?
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chenks

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Re: Itís not exactly rocket science, or is it?
« Reply #4 on: July 16, 2018, 02:53:16 PM »

I read Tim Peake's, 'Ask an Astronaut' the moment it was released and he touches ever so slightly on the topic 7LM.

He concurs with you, if memory serves.  ;) :)

i met him during one of his talk tours.
i hope he doesn't become like Buzz where he'll turn up to the opening of an envelope.
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sevenlayermuddle

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Re: Itís not exactly rocket science, or is it?
« Reply #5 on: July 16, 2018, 05:49:59 PM »

the russians don't seem to think it's a problem, and they aren't exactly near the equator.

what safety issues would there be for the scandinavians to be concerned about?

Pretty sure Baikonur Cosmodrome is a lot further south than any part of the UK.   We tend to forget just how far North we are, just because our climate is a slight oddity compared to other similar locations.

That said, on closer reading of the BBC article, despite saying the satellites would be ďeverything you can imagineĒ  it goes on to explain that the site would be launching a particular category of so called polar-type orbit satellites, that are launched Northwards rather Eastwards, and destined for an orbit taking in Arctic and Antarctic.

That does makes more sense, I was really questioning whether such a launch site could ever be viable for geostationary satellites, or for spacecraft destined to leave Earth orbit altogether.   I remain of the mind that for these purposes, you want to be near the equator, and launch towards the   East.   But I am certainly no expert.  I wish I was, I find it rather interesting. :)
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chenks

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Re: Itís not exactly rocket science, or is it?
« Reply #6 on: July 16, 2018, 06:07:59 PM »

the distance difference isn't that big.

Distance between Baikonur, Kazakhstan and the Equator
5078 km = 3155 miles

Distance between Aberdeen, United Kingdom and the Equator
6361 km = 3953 miles

i used aberdeen as i couldn't get a match on anything closer to A'Mhoine Peninsula
« Last Edit: July 16, 2018, 06:23:50 PM by chenks »
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Ronski

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Re: Itís not exactly rocket science, or is it?
« Reply #7 on: July 16, 2018, 07:14:22 PM »

It's not just Scotland, on the news tonight they mentioned Newquay Council has signed a deal and potentially one in Wales as well eventually.
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sevenlayermuddle

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Re: Itís not exactly rocket science, or is it?
« Reply #8 on: July 16, 2018, 07:25:21 PM »

It's not just Scotland, on the news tonight they mentioned Newquay Council has signed a deal and potentially one in Wales as well eventually.

These seem to be horizontal launches, piggie backed to an aircraft that flies off somewhere else before the actual launch, as I understand it.   The Scottish site claims to be for "proper" vertical launch, direct to orbit.
« Last Edit: July 16, 2018, 07:48:24 PM by sevenlayermuddle »
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Black Sheep

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Re: Itís not exactly rocket science, or is it?
« Reply #9 on: July 16, 2018, 08:15:12 PM »

the distance difference isn't that big.

Distance between Baikonur, Kazakhstan and the Equator
5078 km = 3155 miles

Distance between Aberdeen, United Kingdom and the Equator
6361 km = 3953 miles

i used aberdeen as i couldn't get a match on anything closer to A'Mhoine Peninsula

The distance difference may not be that big when posted in that format ..... but it equates (pardon the pun) to circa 200mph difference in sling-shot on launch .... that's mph .... not km/h.  :)
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sevenlayermuddle

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Re: Itís not exactly rocket science, or is it?
« Reply #10 on: July 16, 2018, 09:50:37 PM »

A bit more from the BBC.  Acknowledges that Baikonur and othersí proximity to the equator can indeed be a help, so I wasnít entirely wrong.  Phew.  But for certain satellites & orbits, Launching from northern Scotland does make sense.

https://www.bbc.co.uk/news/uk-scotland-highlands-islands-44841963

Quote
This might seem counter intuitive. The hitherto famous launch sites - Cape Canaveral, Baikonur, Kouru - are near the equator because the spin of the Earth at those latitudes gives rockets an extra 'throw' into high orbits.
But northern Scotland allows smaller satellites to be placed into polar or sun-synchronous orbits. As the name suggests, polar flights go over the top and bottom of the world and can see in better detail things which satellites over the equator cannot.
A sun-synchronous orbit places a probe where it is over the same spot on the Earth's surface when the Sun is in the same position in the sky each day. That means images can be accurately compared to detect erosion, subsidence or crop changes.
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Weaver

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Re: Itís not exactly rocket science, or is it?
« Reply #11 on: July 17, 2018, 01:28:49 AM »

Shocking to see the mangling of the Gaelic language by the BBC. There are so many mistakes there all packed into two words that I don't know where to begin. Missing space, and missing an accent too. It should of course be "Aí MhÚine" (the peat), but possibly it is a mangled part of a noun phrase. [North Sutherland Gaelic takes some getting used to for me, it sounds rather different to Skye Gaelic. I imagine there are very very few living speakers now. I have only once had the privilege of hearing one, the school teacher from Eilean nan RÚn, a small island just off the north coast somewhere near Tongue, iirc.]
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Weaver

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Re: Itís not exactly rocket science, or is it?
« Reply #12 on: July 17, 2018, 01:48:59 AM »

According to my calculator the loss of speed by using Scotland as opposed to the equator is only about 500 mph, which is not much really, compared to 20000 mph for low earth orbit. [ Using (1 - cos (58.6 * pi / 180)) * ( 24900 mi / 24 hr ). Actually, that is 4 min per day out too. Not very accurate because the earth is not spherical so the actual figure ought to be slightly more than that I would think. ]
« Last Edit: July 17, 2018, 01:58:14 AM by Weaver »
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Black Sheep

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Re: Itís not exactly rocket science, or is it?
« Reply #13 on: July 17, 2018, 07:25:49 AM »

According to my calculator the loss of speed by using Scotland as opposed to the equator is only about 500 mph, which is not much really, compared to 20000 mph for low earth orbit. [ Using (1 - cos (58.6 * pi / 180)) * ( 24900 mi / 24 hr ). Actually, that is 4 min per day out too. Not very accurate because the earth is not spherical so the actual figure ought to be slightly more than that I would think. ]

It's not the orbiting of the Earth that costs fuel, it's the getting up there, Weaver.  :)

As with all things 'flight orientated' .... weight is the enemy. If you can get more bang for yer buck with regard to fuel consumption, then they will take it every day.

Looking at the graph I saw yesterday (which I haven't time to go looking for again), shows an approx. 200mph rotational spin difference, between the Aberdeen and the Baikonur latitudes. 
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sevenlayermuddle

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Re: Itís not exactly rocket science, or is it?
« Reply #14 on: July 17, 2018, 08:45:34 AM »

A quick search has revealed a calculator that provides rotational speed on surface vs latitude.   I donít trust my own maths enough to try and verify it, but I see no reason to doubt that it has been written by somebody with better maths than me, and that it is accurate.

https://www.vcalc.com/wiki/MichaelBartmess/Rotational+Speed+at+Latitude

So, Baikonur has latitude 45, velocity 735mph
John oíGroats has latitude 59, velocity 535mph

This does indicate a difference of 200mph. 

GPS satellites orbit at about 8700mph.

Way out of my depth here, but I would have imagined the earliest part of the flight, while still travelling through dense atmosphere, would be the hardest to sustain acceleration.   That might explain why the benefit of equatorial launch is more significant than meets they eye in pure percentage terms?

Iíd have thought the other benefit of equatorial launch would be for geo-stationary satellites, which must always be above the equator.    By launching at the equator in the first place, youíd avoid having to modify the orbit so much once your satellite is up there.  Still just guessing, though; Iím sure thereíll be  better informed forums, with properly qualified contributors, if it we wanted the real facts.

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