After watching ep 19, I have come up the following wild speculation about what had happened to the 117th Research Fleet :
1. The landscape in Ranka’s dream is very similar to the terrain on Galia 4. If her dream turns out to be true, then the 117th Research Fleet was successfully landed there to study Vajra found there.
2. The initial objective of the 117th Research Fleet may be the cure of V-type infection, which though to be originated from Vajra.
3. Because Ozuma is a friend of Ranka’s family, so they were residents of Macross Frontier. Grace is known from Macross Galaxy. This tells that 117th Research Fleet was the joint research project from both Macross.
4. LAI (own by Bilrer?) probably was the main sponsor of the research at Frontier side, because Frontier government did not want to mess with Vajra (probably the insistence from Howard Glass). But not every one in government agreed with Howard. Leoh probably is the leader of this group. Without the government support, Bilrer starts SMS to provide protection for the research team, and Ozuma jointed it.
5. The potentials of Vajra are so great, the research team was pressed to find everything they can. Ranse Mei was so busy working she left her children along. Feeling lonely, Ranka somehow befriended with Vajra (very similar to her relationship with Ai-kun later?).
6. There was infighting between Frontier and Galaxy about the goal of Vajra research. Frontier camp wants to make peace with them, but Galaxy camp wants to know every thing about Vajra at all cost. Sensing the danger, Frontier camp decided to abandon the research.
7. During the pull out from Galia 4, something went very wrong that triggered the attack from Vajra (sabotage by Grace? Vajra though Ranka was in danger being taking away?) Only Ranka was saved by Vajra because they though she is their friend.