why does the Space Shuttle turn during the climb so the cabin is upside down?

Question

must be really uncomfortable for the crew, why do they make them go upside down like that instead of turning the other way with the cabin facing upwards?

is it something to do with avoid negative g?

Answer 1

There are two overriding reasons for the shuttle stack to adopt the 'orbiter down' orientation during the climb, and neither of them have anything to do with astronaut comfort or having the thrust in the right direction. The first is that the stack is more aerodynamically stable that way up. The second, more practically, is that the telemetry and voice communication antennas on the shuttle orbiter then have a clear line of sight to the receiving stations on the ground.

Answer 2

At one time I worked in aviation. During that time I came to know a NASA engineer. I asked him the same question and he only gave me one reason. He told me that programmed roll was to remove the mass of all the hardware from the path of the radio antennas. It rolls the shuttle onto its back aiding in all the communication that is taking place between the vehicle and all the ground stations responsible for those communications.

He was not a practical joker in anyway and I never caught him giving me bad information either for our professional or personal discussions. I.E. I trust the man.

I know from personal experience that a climb out in a high performance fighter is the same even if the aircraft is inverted. I doubt the roll has anything at all to do with g-forces.

Answer 3

The effect of gravity is totally insignificant to the power of those huge rocket engines. It doesn't matter in terms of crew comfort if the top of the orbiter's up or down -- remember, they're going into ORBIT, that's why it's called an ORBITER.

The main reason for keeping the orbiter upside-down at that point is the engines can more easily point up than down, so they can better control the craft in an inverted attitude.

Answer 4

It has much to do with the amount of g force the astronauts must endure while reaching escape velocity. Blood circulation becomes impaired as the heart must work harder to pump blood through the body. This impaired circulation can lead to a dimming of consciousness as the heart can no longer pump blood to the brain. You will start to experience tunnel vision, then colors will fade away and everything will appear white, then fade to black. You have just experienced a gravity induced loss of consciousness, or blackout. In general, anything more than 4 or 5 G’s will cause the average person who has not been trained to deal with these effects to black out. Extremely high G-levels can lead to more serious complications such as compacted bladders, bursting red blood cells, subdural hematomas, the inability to breathe and the cessation of circulation. So, hanging upside down, for one, can help blood to the brain.
Shuttle astronauts are exposed to a very tolerable 3-G’s. Effects are mitigated by a variety of means, including the arrangement of seating relative to direction of acceleration and de-acceleration. Seats are arranged such that the entire body faces the direction of acceleration or de-acceleration, so forces are spread across the body rather than concentrated in one area. In addition, the seats are constructed of special composite materials designed to lessen the stresses on the body, and are contoured such that they provide extra support to areas of the body that are more susceptible to injury, such as the neck and the lower back. Astronauts are strapped in to these specially designed chairs so they remain seated correctly

Answer 5

The weight of the fuel tank needs to be on top for the engine thrust vector to push the shuttle the way they want. If the tank was on the bottom, the engines would tend to push the nose down.

Answer 6

3 main reasons....
1) Having the crews head down stops pressure loading
2) So the shuttle is at the correct angle
3) So the cargo bay faces earth

Answer 7

If the engines are still firing, it makes very little difference how the shuttle is rotated---"down" will be "toward the engines", no matter what the orientation of the shuttle with respect to the Earth.

If the engines are not firing, it means they're in freefall (hopefully, in orbit), in which case there is no "down".

Answer 8

Less chance of micrometeorite/debris impact on the cockpit.
Less stress on the tiles.
Because the heatshield is taking first hit.

Answer 9

They have to aim it so it can enter its orbit in the right direction.

Answer 10

To freak out the astronauts.