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Suborital intercontinental travel
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Spaceflight Enthusiast ![]() ![]()
Joined: Fri Sep 18, 2009 3:39 pm
Posts: 1 ![]() |
ahmmm...why can't wings change during flight? stub wings in orbit, extended for landing. flaps are basically trying to change wing shape, too, but this could be done in a much more sophisticated fashion for higher-cost aircraft.
/iaw |
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Spaceflight Trainee ![]() ![]()
Joined: Mon Sep 14, 2009 12:59 am
Posts: 44 ![]() |
iaw4 wrote: ahmmm...why can't wings change during flight? stub wings in orbit, extended for landing. flaps are basically trying to change wing shape, too, but this could be done in a much more sophisticated fashion for higher-cost aircraft. /iaw What would be the advantage of having any wings at all in orbit? |
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Spaceflight Enthusiast ![]() ![]()
Joined: Thu Dec 10, 2009 12:52 pm
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i wish there be space home exchange as well somewhere in near future
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Space Station Member ![]() ![]()
Joined: Thu Mar 06, 2008 9:22 pm
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If you do an analysis of the trades, rather than just arguing from a thought experiment, long distance suborbital point to point is actually harder than just orbital flight. idiom's points are correct.
Once you've developed a reusable SSTO, then intercontinental point to point will be a small market you can exploit. |
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Joined: Wed Jul 30, 2008 9:39 pm
Posts: 266 Location: Denmark ![]() |
new york to LA is about 4000km. NY to paris is about 6000km. that's about 36 adn 54 degrees around the planet respectively.
assuming a simplified model of having to bounce 4000km in a uniform gravity field (not a ball) which should be a halfway decent approximation. in reality it takes a bit less energy because the higher the less gravity connection to earth. I also ignore the earth rotation which helps/hurts a bit depending on direction. the optimal ballistic angle is 45% (longest for a given speed) if I did the math right the needed initial speed is V < sqrt(Dg) where D is the distance in meters and g is gravity accel 9.8m/ss for NY-LA of about 4Mm that's 6260m/s or about 22500km/h. about 83% of orbital speed. ballistic flight time of 15 minutes. peak altitude about 2000km above earth. should be quite a sight. that does however present a rather significant problem. it travels through satellite space. which means worst case scenario govs just say no. best case then each trip has to be timed carefully. might not be a real problem but certainly a possibility. NY-Paris is about 6000km needing < 7500m/s which is orbital speed which tells me that the longer the jump the more incorrect the formula although the correct math model eludes me at the moment. it would stand to reason that orbital speed is required only when going 180degrees or more. and short bounces fit v=sqrt(Dg) a rough guess is that NY-LA requires about 70% orbital speed and NY-paris about 80%. so the lifter vehicle would be designed for the route. 70% speed should mean a much smaller vehicle than orbital. |
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Spaceflight Enthusiast ![]() ![]()
Joined: Fri Sep 23, 2011 2:43 am
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iaw4 wrote: ahmmm...why can't wings change during flight? stub wings in orbit, extended for landing. flaps are basically trying to change wing shape, too, but this could be done in a much more sophisticated fashion for higher-cost aircraft. /iaw I dont think there's any reason to believe wings can't change. Many supersonic aircraft have flaps that change the angle of attack for a plane. Depending on the action, the plane can increase its speed drastically. |
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