The simplest constellation that could use Liaison Navigation would consist of two spacecraft, one in a halo orbit and one in a lunar orbit. The halo orbit shown provides about 8 days of continuous south pole coverage with a 5-day coverage gap. The lunar orbiter passes over the south pole once every two hours. This type of constellation would be a good choice as an initial technology demonstration mission. The two spacecraft could be small satellites and could prove the feasibility of the BLT's and Liaison Navigation for very little cost. Besides demonstrating the technology, this mission could provide data relay and tracking for the Robotic Lunar Exploration Program missions that will be investigating the lunar south pole. This mission design was described in detail in an
AIAA conference paper.