Thread: 2 days to get to the space station??

I heard it takes about 2 days for a rocket(soyus/shuttle?) to rendez-vous with the space station, but considering the fast rate of ascention what the heck are they doing all that time? Couldnt they reach the iss in a few hours??

what the heck are they doing all that time?

Calculus. Undoubtedly.

You cannot take the direct path to the ISS. Each spacecraft must climb slowly by increasing its orbit. The altitude depends on the orbital velocity (Kepler laws). Stable circular orbits can only be achieved in this way. So, it is not enough to leave the Earth. The velocity of the spacecraft must slowly converge with the one of the ISS to reach its altitude and also to avoid crashing into it.

Originally Posted by icewendigo

I heard it takes about 2 days for a rocket(soyus/shuttle?) to rendez-vous with the space station, but considering the fast rate of ascention what the heck are they doing all that time? Couldnt they reach the iss in a few hours??

They probably could if they had more fuel capacity.

They have to accelerate and decelerate slowly and in a very controlled manner. To do so faster requires more fuel. They would have to decelerate longer, for a faster orbital change, the accelerate longer to slow them down more.

At least it works something like that. The details might be different, but the effect is the same. The relative travel is slow to burn less fuel.