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wd40
2014-Jan-30, 09:12 PM
States (http://en.wikipedia.org/wiki/Baikonur_Cosmodrome):
"it is an advantage to place a space launch site closer to the equator, as the surface of the earth has higher rotational speed there."

How much % of an advantage and in what way, e.g. between a launch on the equator and a launch from 45 degrees N?

If e.g. Canada or Sweden had become rocket nations, would launching from 75 degrees N be ballistically and economically viable?

Is there any difference at all in launching in to space from 45 degrees N or 45 degrees S?

NEOWatcher
2014-Jan-30, 09:16 PM
How much % of an advantage and in what way, e.g. between a launch on the equator and a launch from 45 degrees N?
If e.g. Canada or Sweden had become rocket nations, would launching from 75 degrees N be ballistically and economically viable?
about: 1000mph * COS(latitude)


Is there any difference at all in launching in to space from 45 degrees N or 45 degrees S?
no.


ETA:
of course the speed advantage depends on what direction you want to go.

wd40
2014-Jan-30, 09:20 PM
Would a Shuttle, as was, launched from the North Pole even make it in to orbit, or would it require more boosters?

NEOWatcher
2014-Jan-30, 09:23 PM
Would a Shuttle, as was, launched from the North Pole even make it in to orbit, or would it require more boosters?
Yes; but it would entail carrying only half the weight in cargo.
Wiki states (http://en.wikipedia.org/wiki/Space_Shuttle) polar orbit in the shuttle specs, but it's fairly close to polar launch.

swampyankee
2014-Jan-31, 12:00 AM
As an aside, Israeli satellite launches are opposite Earth's rotation for geopolitical reasons.

Trebuchet
2014-Jan-31, 01:20 AM
Would a Shuttle, as was, launched from the North Pole even make it in to orbit, or would it require more boosters?

Polar orbit launches of the shuttle were planned from Vandenberg AFB but cancelled after the Challenger disaster. If you're launching to a polar orbit, I don't think the latitude makes much, if any, difference. Getting the shuttle to the pole, however, is difficult!

Boeing's Sea Launch (http://en.wikipedia.org/wiki/Sea_launch) project was launching Russian Zenit Rockets from the ocean near the equator, using a converted oil platform. It wasn't particularly successful, partly due to the time it took to get to the launch site and complications from being at sea, and partly due to one of the rockets blowing up. Although now that I've been to the Wiki page to get the link, it looks like they've launched more since the big failure than I thought.

cjameshuff
2014-Jan-31, 01:47 AM
If you're launching to a polar orbit, the closer to the pole the better. The boost due to Earth's rotation is in the wrong direction, you have to cancel it out.
However, I don't think the severity of the loss and demand for polar satellites have made it worthwhile for anyone to put a launch site at high latitudes specifically for the purpose of launching polar satellites.

skysurfer5cva
2014-Jan-31, 08:52 PM
There is a small rocket launch facility on Kodiak Island in Alaska. It's latitude is 57.4°N. http://www.akaerospace.com/klc_overview.html

A quick Google search turned up this Wiki page, which lists several sites more northerly sites in Russia, Norway, Iceland, etc: http://en.wikipedia.org/wiki/List_of_rocket_launch_sites

However, I don't know how often these sites are used for polar orbits as opposed to simply high inclination orbits.

Local Fluff
2014-Feb-04, 03:53 PM
0.46 km/s difference between the pole an the equator. That's small compared to the escape velocity of 11.2 km/s and for interplanetary travel small to the orbital speed of Earth of about 30 km/s. But the relationship to fuel mass needed is exponential so it is more important than it looks from those comparisions.

The new Russian cosmodrome in Vostochny (near China) and the old (and new again?) at Plesetsk are at 51 and 62 degrees north. At 60 degrees you have half the rotational speed as at the equator.

I think that more important than the rotational speed of the surface of Earth, is the relationship to the orbits you want to reach .The ISS has been pushed to a more inclined orbit in order to fascilitate launches from Baikonour, since now only Russian rockets can bring crews to the ISS. And they recently reached the ISS at a record short time of only 6 hours after launch.
http://www.nasaspaceflight.com/2013/03/soyuz-tma-08m-crew-iss-record-time/

I think that if you want a weather or surface resource satellite in LEO in order to get good data about Russia, then it is even better to launch it from Russia than from the equator. But to reach geostationary orbit, the equator should be optimal.

NEOWatcher
2014-Feb-04, 04:05 PM
I think that more important than the rotational speed of the surface of Earth, is the relationship to the orbits you want to reach
They go hand in hand. You want a low inclination prograde orbit, you use the equator, for a retrograde orbit, you use a higher latitude. Plus, it depends on how much cross-range ability you have with the launch vehicle.


The ISS has been pushed to a more inclined orbit in order to fascilitate launches from Baikonour, since now only Russian rockets can bring crews to the ISS.
ISS always was in that orbit. The first module was Zarya which was launched from Baikonour, and there were russian missions all along.


And they recently reached the ISS at a record short time of only 6 hours after launch.
Which has nothing to do with the advantages of latitude. It has to do with timing and the orbit of the craft as it approaches. They are more accurate on the initial launch, so it doesn't require a lot of orbits to sync up.


I think that if you want a weather or surface resource satellite in LEO in order to get good data about Russia, then it is even better to launch it from Russia than from the equator. But to reach geostationary orbit, the equator should be optimal.
Any prograde orbit has the advantage of an equatorial launch. It may be miniscule at higher inclinations, but it's still an advantage.

glappkaeft
2014-Feb-04, 07:22 PM
If [snip] Sweden had become rocket nations, would launching from 75 degrees N be ballistically and economically viable?

The Esrange Space Center (http://en.wikipedia.org/wiki/Esrange) (200 km north of the polar circle) has been operating since 1964...

cjameshuff
2014-Feb-04, 10:46 PM
There is a small rocket launch facility on Kodiak Island in Alaska. It's latitude is 57.4°N. http://www.akaerospace.com/klc_overview.html

A quick Google search turned up this Wiki page, which lists several sites more northerly sites in Russia, Norway, Iceland, etc: http://en.wikipedia.org/wiki/List_of_rocket_launch_sites

However, I don't know how often these sites are used for polar orbits as opposed to simply high inclination orbits.

"KLC is the nation’s only high latitude full service spaceport. It features all indoor, all weather, processing and was designed specifically to provide optimal support for space launches to polar orbit..."

Good find.

Amber Robot
2014-Feb-05, 12:17 AM
A quick Google search turned up this Wiki page, which lists several sites more northerly sites in Russia, Norway, Iceland, etc: http://en.wikipedia.org/wiki/List_of_rocket_launch_sites

However, I don't know how often these sites are used for polar orbits as opposed to simply high inclination orbits.

I believe these are for sub-orbital rocket launches. I know they launch rockets studying the aurora from Norway.