During LRO's two-month commissioning phase, many special operations will take place to help prepare LROC and all of the instruments for their first year of operation.
LRO will remain in a 30 km by 199 km (19 mile by 124 mile) orbit with a periapsis above the South Pole during the commissioning phase. This orbit requires very little in the way of station-keeping, thus it saves fuel while the spacecraft and instruments are running through their checkout procedures. For LROC we have two types of checkout observations. First, there are sequences that require the spacecraft to maneuver to a special orientation to support our observations. For example, we will image stars and Jupiter to check the geometric and radiometric calibrations we performed on the ground. Second, there will be other calibration sequences that are taken while the spacecraft is in its nominal nadir (looking straight down at the Moon) position. There are seven instruments on LRO, and each has its own specific requirements for calibration and checkout. Some of the calibration sequences prevent other instruments from acquiring data at the same time, so there is a bit of planning that takes place so all of the instrument teams can get the observations they need within the commissioning phase. Of course, not everything goes exactly as planned, so each instrument team must remain flexible in terms of adjusting the timelines. We hope to have all of the LROC checkout and calibration sequences completed by mid-August so we can begin systematic data acquisition with the NACs and WAC. Of course, we will post images from the commissioning phase soon after receipt on the ground to allow everybody to follow our progress. Right now, the spacecraft is still performing a series of maneuvers to get LRO into the commissioning orbit by the end of this week.
Published by Mark Robinson on 24 June 2009