connecting a cable to the moon
- Thread starter Gordon Gekko
- Start date
archangel is right about the space elevator, it can't be done with today's technology. Of course the space shuttle program is on its last legs and we need something new or else end the manned space program.
the practical alternative is..................THE SPACE PLANE. The space shuttle has reusability, and lands like a plane, but still takes off like a rocket. Make it take of like a jet using aerodynamics and then you have something. Research has been done on this for decades and its mostly a matter of cost at this point. The cost couldn't be justified because we had all these shuttles flying all the time. Now maybe attitudes will be different.
the practical alternative is..................THE SPACE PLANE. The space shuttle has reusability, and lands like a plane, but still takes off like a rocket. Make it take of like a jet using aerodynamics and then you have something. Research has been done on this for decades and its mostly a matter of cost at this point. The cost couldn't be justified because we had all these shuttles flying all the time. Now maybe attitudes will be different.
can someone explain how the space shuttle slows down when coming back to earth? for example, i heard that the space shuttle at some point re-enters at about 12,500 mph. when it is about to land, how does it slow down? i suppose you could have some type of reverse thrusters, but i don't see them on the space shuttle.
also, when re-entering the earth's atmosphere, do spaceships have to enter at such a high speed? if possible, why wouldn't nasa bring the speed down a little to make it a little less strenuous on the aircraft?
EDIT: i found somewhat of an answer...
"When it is time to come back to earth the Space Shuttle must slow down in order to be less susceptable to Earth's gravity pull and to lesson the friction on it as it enters Earth's atmosphere. The astronauts maneuver the Shuttle into a tail first position and fire its OMS rockets for a few minutes to counteract orbital motion and slow it down. Next, they turn it forward and upward; the Shuttle glides in bellyfirst. As the Shuttle nears earth it goes through a series of S turns to further slow down. The pilot uses the Orbiter's rudder and the wings (much like a Jet pilot uses the wing flaps on a jet) to continue to slow down the descent. The Orbiter touches down on the runway at about 215 mph."
"If too shallow an angle at descent, the spacecraft could be "bounced" back into space. If the angle is too steep, the craft would plunge through the atmosphere and burn."
http://www.uaf.edu/asgp/space/shuttle.html
also, when re-entering the earth's atmosphere, do spaceships have to enter at such a high speed? if possible, why wouldn't nasa bring the speed down a little to make it a little less strenuous on the aircraft?
EDIT: i found somewhat of an answer...
"When it is time to come back to earth the Space Shuttle must slow down in order to be less susceptable to Earth's gravity pull and to lesson the friction on it as it enters Earth's atmosphere. The astronauts maneuver the Shuttle into a tail first position and fire its OMS rockets for a few minutes to counteract orbital motion and slow it down. Next, they turn it forward and upward; the Shuttle glides in bellyfirst. As the Shuttle nears earth it goes through a series of S turns to further slow down. The pilot uses the Orbiter's rudder and the wings (much like a Jet pilot uses the wing flaps on a jet) to continue to slow down the descent. The Orbiter touches down on the runway at about 215 mph."
"If too shallow an angle at descent, the spacecraft could be "bounced" back into space. If the angle is too steep, the craft would plunge through the atmosphere and burn."
http://www.uaf.edu/asgp/space/shuttle.html
When it is time to come back to earth the Space Shuttle must slow down in order to be less susceptable to Earth's gravity pull and to lesson the friction on it as it enters Earth's atmosphere. The astronauts maneuver the Shuttle into a tail first position and fire its OMS rockets for a few minutes to counteract orbital motion and slow it down.
This is called a de-orbit burn. Basically they're slowing down the shuttle enough so that it falls out of its orbit.
Next, they turn it forward and upward; the Shuttle glides in bellyfirst.
It's not exactly "gliding" - more like FALLING at over 12,000 MPH. It has to fall into the atmosphere belly first because that where the primary heat shield (all those stupid tiles) is located. Note that they were forced to go the tile route rather than the preferred unitized heat shield due to budget cuts.
Also note that the primary reason it undergoes such stress is that the descent into the atmosphere is NOT under power. It's falling like a meteor and like a meteor it's on fire due to air friction. If it was under power and could fly into the atmosphere in a more controlled manner (the reverse of flying out of the atmosphere in a multi-propulsive lifting body (sometimes called a space plane), the degree of heating could be controlled.
As the Shuttle nears earth it goes through a series of S turns to further slow down. The pilot uses the Orbiter's rudder and the wings (much like a Jet pilot uses the wing flaps on a jet) to continue to slow down the descent. The Orbiter touches down on the runway at about 215 mph
After it's fallen into the lower atmosphere they can get some degree of control - now it's a gliding brick. They have to blow off momentum by executing a number of turns in order to get the speed low enough to land.
when re-entering the earth's atmosphere, do spaceships have to enter at such a high speed?
The do if they're not under power and have little or no flight control - reentry isn't much different than it was in the 60s, you basically just fall like a stone.
if possible, why wouldn't nasa bring the speed down a little to make it a little less strenuous on the aircraft?
It is possible, but the vehicle has to be designed to fly in and out of the atmosphere - but the shuttle is essentially the same technology used 40 years ago, you blast them into space on the back of a big firework and they fall back to the ground preying that the heat shield holds together.
This is called a de-orbit burn. Basically they're slowing down the shuttle enough so that it falls out of its orbit.
Next, they turn it forward and upward; the Shuttle glides in bellyfirst.
It's not exactly "gliding" - more like FALLING at over 12,000 MPH. It has to fall into the atmosphere belly first because that where the primary heat shield (all those stupid tiles) is located. Note that they were forced to go the tile route rather than the preferred unitized heat shield due to budget cuts.
Also note that the primary reason it undergoes such stress is that the descent into the atmosphere is NOT under power. It's falling like a meteor and like a meteor it's on fire due to air friction. If it was under power and could fly into the atmosphere in a more controlled manner (the reverse of flying out of the atmosphere in a multi-propulsive lifting body (sometimes called a space plane), the degree of heating could be controlled.
As the Shuttle nears earth it goes through a series of S turns to further slow down. The pilot uses the Orbiter's rudder and the wings (much like a Jet pilot uses the wing flaps on a jet) to continue to slow down the descent. The Orbiter touches down on the runway at about 215 mph
After it's fallen into the lower atmosphere they can get some degree of control - now it's a gliding brick. They have to blow off momentum by executing a number of turns in order to get the speed low enough to land.
when re-entering the earth's atmosphere, do spaceships have to enter at such a high speed?
The do if they're not under power and have little or no flight control - reentry isn't much different than it was in the 60s, you basically just fall like a stone.
if possible, why wouldn't nasa bring the speed down a little to make it a little less strenuous on the aircraft?
It is possible, but the vehicle has to be designed to fly in and out of the atmosphere - but the shuttle is essentially the same technology used 40 years ago, you blast them into space on the back of a big firework and they fall back to the ground preying that the heat shield holds together.
thanks, ArchAngel. 