You are, the total energy required for a transfer varies considerably depending on the phasing of the planets. This is mars->Earth, but you get the idea. http:

You are, the total energy required for a transfer varies considerably depending on the phasing of the planets. This is mars->Earth, but you get the idea. http://www.projectrho.com/public_html/rocket/images/mission/Mars2103PorkChop.png http://www.projectrho.com/public_html/rocket/images/mission/...