Over the past five months Mango has been drifting from the orbit achieved by the transfer start maneuver, and the result is now clearly visible when comparing TLE sets. The image below shows the three orbits of Tango (purple), Mango (yellow) and the target orbit (red) based on TLE’s as of Nov-06 2013.
The initial phase of the IRIDES experiment has successfully been completed – Mango is now in transfer orbit. For the last couple of weeks quite some dV (delta velocity) has been used for perturbing Mango’s orbit into a state where we have achieved a drift towards possible rendezvous objects. The drift is high enough for reaching the objects within a foreseeable time span, typically 12 to 18 months. The second phase, the drift campaign, is characterized by surveying the spacecraft’s progress; no firings of the thrusters are foreseen during this period.
During the starting campaign when performing orbit lowering maneuvers the scheduled PRISMA passages quickly became obsolete and had to be refreshed. This is the natural result when altering an object's altitude to also alter its orbit period, and in the case of PRISMA the orbit was lowered which resulted in shorter orbit period and the satellite came early to the following passages.
Mango’s initiated search and rendezvous with a new formation flying buddy was given attention in Swedish television previously this week. The autonomous PRISMA satellite system constituted by the Mango and Tango satellite pair has delivered results many times more than initially expected by the system. The system’s initial mission was planned to last 433 days, today the mission clock in the mission control center shows 1078 days since launch. 53 days ago the formation was deliberately separated by terminating Tango.