see 6th image of http://www.microlaunchers.com/7816/L3/sa09/sa09.html for how Microlauncheers plans to do it.
We plan for the 1st stage to be flown by ground based video guidance from launch to 30 km, then after staging, an optical
horizon seeker and use of polar coordinates for the 2 vacuum stages. We think precision might be on order of 10-20 m/sec.