Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Astronomy - Hohmann Transfer Orbit

  1. Mar 13, 2012 #1
    The most efficient way to reach Mars from Earth is following the Hohmann Transfer Orbit
    (Wolfgang Hohmann, 1925). A spaceship must first get free of Earth (it still orbits the Sun
    together with Earth, at 30 km/s, at a distance of 1 AU), then it adds speed so that its aphelion
    (in its orbit around the Sun) just grazes the orbit of Mars, A = 1.524 AU (ignoring ellipticity).

    (a) Draw the orbits of Earth and Mars, together with the Hohmann Transfer Orbit.

    (b) What are the minimum and maximum separation from the Sun? What is the semi-major
    axis of this orbit?

    (c) Using the Newtonian derivation of Kepler's 3rd law once again, determine the orbital
    period, and hence the time taken to reach Mars from Earth. Express your answer in
  2. jcsd
  3. Mar 13, 2012 #2


    User Avatar

    Staff: Mentor

    The posting template is there for a reason. You must show your own thoughts and efforts on the problem so we'll know how to help; no help can be given if you don't show effort.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook