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Not being a rocket scientist, I am unfamiliar with some details. Aren't there only a very small number of launch sites even viable for consideration in the US f

by loteck 12y ago

Not being a rocket scientist, I am unfamiliar with some details. Aren't there only a very small number of launch sites even viable for consideration in the US for this kind of activity? Something about being close to the equator, and not landing your rocket on a major city. So, South Texas and... ummm...

tedsanders 12y ago
Yes. To save fuel, many rockets are launched west to east (they get a headstart from the Earth's rotation). Launching close to the equator helps the most, because rockets get the biggest headstart. To minimize risk to people, launch sites are in locations that have low-population corridors for long distances to their east. Texas and Florida are both southern, with ocean to their east, so they make ideal launch sites for the United States. https://en.wikipedia.org/wiki/List_of_rocket_launch_sites https://en.wikipedia.org/wiki/List_of_rocket_launch_sites For polar orbits, there is a spaceport in Southern California that launches north to south (so that its flights also go over ocean). https://en.wikipedia.org/wiki/Vandenberg_Air_Force_Base https://en.wikipedia.org/wiki/Vandenberg_Air_Force_Base Interestingly, you might think that launching from high elevation helps (starting at Mr Everest would give you a headstart), but the benefit is small, a fraction of a percent.
- InclinedPlane 12y ago
  The velocity boost for launching from nearer the equator is only part of the advantage. Another major factor is that many of the most expensive commercial payloads (such as major geosynchronous comsats) need to end up in equatorial orbits. The latitude of the launch site is also the minimum inclination of the initial orbit the launch vehicle can provide. At the equator you can launch into any orbital inclination. At the North Pole you can only launch into polar orbits. At 45 deg. latitude you can only launch into orbital inclinations of 45 to 90 deg. The higher the initial orbital inclination the more work you'll have to do (the more delta V you'll have to apply) in a plane change burn in order to get into an equatorial orbit.
  - simonh 12y ago
    Bonus points if you didn't learn that from playing KSP.

by loteck 12y ago

tedsanders 12y ago

Yes. To save fuel, many rockets are launched west to east (they get a headstart from the Earth's rotation). Launching close to the equator helps the most, because rockets get the biggest headstart. To minimize risk to people, launch sites are in locations that have low-population corridors for long distances to their east. Texas and Florida are both southern, with ocean to their east, so they make ideal launch sites for the United States. https://en.wikipedia.org/wiki/List_of_rocket_launch_sites https://en.wikipedia.org/wiki/List_of_rocket_launch_sites For polar orbits, there is a spaceport in Southern California that launches north to south (so that its flights also go over ocean). https://en.wikipedia.org/wiki/Vandenberg_Air_Force_Base https://en.wikipedia.org/wiki/Vandenberg_Air_Force_Base Interestingly, you might think that launching from high elevation helps (starting at Mr Everest would give you a headstart), but the benefit is small, a fraction of a percent.

InclinedPlane 12y ago
The velocity boost for launching from nearer the equator is only part of the advantage. Another major factor is that many of the most expensive commercial payloads (such as major geosynchronous comsats) need to end up in equatorial orbits. The latitude of the launch site is also the minimum inclination of the initial orbit the launch vehicle can provide. At the equator you can launch into any orbital inclination. At the North Pole you can only launch into polar orbits. At 45 deg. latitude you can only launch into orbital inclinations of 45 to 90 deg. The higher the initial orbital inclination the more work you'll have to do (the more delta V you'll have to apply) in a plane change burn in order to get into an equatorial orbit.
- simonh 12y ago
  Bonus points if you didn't learn that from playing KSP.