A rocket launched from earth with a rest mass of 150,000Kg moves at 2.8x10^8 m/s during a voyage that takes 1.3 years, according to a clock on board the rocket.

a) Using relativity, calculate how long the voyage would take, from earth's reference frame.
b) Find the length of the rocket in earth's frame of reference when it is moving, given that the rest is 150m. Assume you are a stationary observer viewing the rocket from the side.