# Homework Help: Hohmann Transfer Problem

1. Dec 19, 2011

### yz250fcaptain

1. The problem statement, all variables and given/known data
Hello all in the physics forum!
During the DAWN mission NASA planned to visit Vesta (2.36 AU) and Ceres (2.77AU). Assuming both asteroids are in the eliptic plane, how much time in years would it take by hohmann transfer orbit to travel from earth to vesta?
I dont expect anyone to solve this but i need some type or direction

2. Relevant equations

Was giving no further information that what is in the question

3. The attempt at a solution

Dont know where to begin

2. Dec 19, 2011

### Staff: Mentor

A Hohmann transfer orbit is an ellipse joining two other (usually circular) obits. In this case one orbit is that of the Earth and the other is that of Vesta. The major axis of the ellipse has ends on each orbit, and thus the travel time from one end of the ellipse to the other end is half the period of the whole elliptical orbit with that major axis.

Your job is to determine the length of the semimajor axis of the transfer ellipse, and then using appropriate formulas the period of the ellipse that it describes.

Last edited: Dec 19, 2011