|WikiProject Spaceflight||(Rated Start-class, High-importance)|
u should have some more good answers, but i am also thanking you ur 'good' work
Energy At Altitude
This article said "much more energy is needed to orbit at higher altitudes", but actually the KE of any circular orbit is equal to the added energy needed for escape from that orbit, so only a maximum of twice the energy for a particular orbit is needed by the payload to reach any higher orbit. The reason much larger rockets are needed for higher orbits, such as going to the moon, is because of the exponential fuel use of rockets, caused by them having to lift their own fuel. To hit the moon with a slingshot, or even escape completely, (above the top of a mountain to avoid air resistance), would only require a slingshot twice as big as one that achieves low earth orbit. Therefore I removed the word "much".
I think this is an issue with this whole article. The article deals mostly with the physics of launch (air resistance, gravity drag, ...) without discussing the practical aspect that rockets, the only means that has ever been used for launch, are dominated by their exponential fuel use, especially for higher orbits or escapes. This is discussed much more extensively in the literature (I used to read) than it is here... If there had been a focus on developing a non-rocket launch vehicle for the last 40 years...
In any case, it would be cool if this article went into the mathematics of launch, in terms of payload size, air resistance versus altitude, various trajectories, and the fuel (energy) formulas for rockets and other generic launch systems. Then it would be cool if it applied this math to particular launch systems, such as the major historical ones, boosting to LEO/I.S.S. and then launching from there, and other systems described in Non-rocket spacelaunch such as the Space elevator, StarTram, Lofstrom Loop/Launch Loop, etc.
Perhaps this article should be merged with Non-rocket spacelaunch. However, it seems to me wikipedia has a certain redundancy, and this article has a place as an overview of space launch issues, especially if the mathematics of launch is developed here. When I was in high school I knew the current references and I could have easily written this, but sorry it has been a while. 126.96.36.199 (talk) 05:37, 11 July 2011 (UTC)