"One prime piece of unreal estate for human exploration, Durda said, is
asteroid 1991 VG. It passed about 1.2 lunar distances of Earth in December
of 1991. The orbit of this tiny world is very Earth-like.

Outbound and return trek times involving asteroid 1991 VG would each be in
the neighborhood of 15 days. Once at the body, a crew could study the space
rock for 30 days. The entire mission would take about two months, "well
within our experience base when you consider the stay times that we become
accustomed to for International Space Station (ISS) expeditions," Durda
said. "
http://abob.libs.uga.edu/bobk/ccc/cc060702.html
FIRST STRIKE OR ASTEROID IMPACT?

1991 VG
First launch summer 2016
Best launch summmer of 2017
And window closes by around summer of 2018
Check out it's orbit:
http://neo.jpl.nasa.gov/cgi-bin/db?name=1991+VG&group=all&search=Search