Space shuttles and rockets

Shrykull · Post by **Shrykull** » 2002-12-30 01:03am

I thought for a while that space shuttles had made rockets obselete and that they could make it to the moon, I also remember Mike Wong's statement on it would take us ten years or something to prepare for a build another rocket so we could go to the moon (you can buy property on the moon you know, and you can buy pluto) Just how fast does a rocket need to go to get it so it will get to the moon in a few days, I would think that fuel gets better use out of it in space since you don't constantly need fuel like in a car or plane to go against the wind and gravity, that it would just take one burst to send you there- and one use your retro rockets, turn around and then another burst to get you home? And how do you go to the bathroom in space?

jaeger115 · Post by **jaeger115** » 2002-12-30 01:10am

I went to the US Space Academy in Huntsville, Alabama 2 years ago. Astronauts use a vacuum tube built in the toilet to suck up their pee, and for shit, the astronauts has to place his ass in exactly the right position (think of it as trying to line up your shit with the target).

As for orbital mechanics, there's also the moon's motion to cope with.

Slartibartfast · Post by **Slartibartfast** » 2002-12-30 01:18am

Ok, the average distance to the moon is about 384,000 km I think, so you divide that by the amount of days you want your trip to take, and you get an average speed (in km/day), further divide that by 24 to get km/h

In space, due to lack of gravity, you can't simply sit on a toilet and wait for the TURD to fall down (not to mention that there can't be water inside the bowl, because it would float too). Space Toilets are kinda like suction devices that you plug to your ass.

Yes, I think you accelerate to get your desired speed, then make corrections and decelerate on arrival. Of course if you go too slow, you end up eating more and using up more oxygen instead of using more fuel, so you need to find a balance. And of course you use a LOT of fuel to escape Earth gravity.

jaeger115 · Post by **jaeger115** » 2002-12-30 01:25am

Actually, the shuttle is less efficient than a Single-Use Launch Vehicle (SULV). A design that is reusable and even more efficient than the SULV is like a cone, with the edges blunted for aerobraking and reentry. I don't know why NASA is not using this design though...

Enlightenment · Post by **Enlightenment** » 2002-12-30 01:45am

Slartibartfast wrote:Yes, I think you accelerate to get your desired speed, then make corrections and decelerate on arrival.

Much more complex than that.

http://www.qrg.northwestern.edu/project ... lanet.html
http://www.usd.edu/phys/courses/phys451 ... rbits.html
http://spacecraft.ssl.umd.edu/academics ... 02_prt.pdf
http://cdeagle0.tripod.com/hohmann.pdf

For more sites, look up "Hohmann transfer oribts" on Google.

PeZook · Post by **PeZook** » 2002-12-30 06:34am

...and for a more practical understanding: http://www.orbitersim.com

There are several addons that will help you understand the various processes that space navigation involves, and why Space Shuttles did NOT make "normal" rockets obsolete. Yes, there are complete modules that allow you to perform a moon mission, from launch to splashdown. Yes, the are nearly impossible to complete on manual, at least for me. And last but not least, the whole sim is FUN

P.S. Post count +1

jaeger115 · Post by **jaeger115** » 2002-12-30 06:46am

I downloaded that program. Tried to play it. Crashed on me every time.

PeZook · Post by **PeZook** » 2002-12-30 07:14am

It worked fine for me...except for the Dragonfly

There's a great forum attached to the site full of tutorials and (mostly) newbie-friendly users. You might try to post your problems there.

kheegster · Post by **kheegster** » 2002-12-30 08:02am

Enlightenment wrote:
Slartibartfast wrote:Yes, I think you accelerate to get your desired speed, then make corrections and decelerate on arrival.
Much more complex than that.

http://www.qrg.northwestern.edu/project ... lanet.html
http://www.usd.edu/phys/courses/phys451 ... rbits.html
http://spacecraft.ssl.umd.edu/academics ... 02_prt.pdf
http://cdeagle0.tripod.com/hohmann.pdf

For more sites, look up "Hohmann transfer oribts" on Google.

The basic idea of Hohmann transfers is that from your initial orbit (e.g. around Earth) you boost your velocity so that you are put on an elliptical orbit which will eventually put you into a second, desired, orbit (i.e. the radius of the initial orbit is your perigee, and the final orbit is your apogee). When you reach apogee, you decelerate so as to put yourself into a velocity to allow you to orbit in the new, desired orbit. In practise, it's a bit more complicated because you want to insert yourself into orbit around the moon as well, instead of just orbiting the Earth at the moon's distance.

If anyone wants, I can calculate the energies and velocities necessary for this.

KG