Lunar Reconnaissance Orbiter Camera

Almost there!

 

LROC temperature plot

 

Once again the Goddard LRO Ops Team guided the spacecraft through a flawless orbit adjustment burn - we are now in a nearly circular 200 km (124 mile) orbit about the Moon.

Tomorrow morning, there will be one more burn that will place us into our 35x216 km commissioning phase orbit. Now that we are in low orbit and the plane of our orbit is drifting further onto the farside, we are experiencing "Loss of Signal" (LOS) as the Moon occults the LRO transmitter. The temperature plot clearly shows this outage. We are closely monitoring LROC temperatures as a normal precaution and to track progress dessicating the NAC telescopes. The red and green lines in the middle of the plot show the temperatures of the NAC CCDs. They are both unusually warm (21 and 23 degrees C) now because of the telescope heaters. During normal imaging periods we expect the CCDs to be in the range 0 to 20 degrees C (32 degrees F to 68 degrees F). Both NACs are powered off right now, if they were on the CCD temperature would rise even higher. Image quality degrades as temperature increases in a non-linear manner. For example the background may only rise a few DNs (pixel value) from 0 to 5 degrees C, but may rise tens of DN as temperature increases from 20 to 25 degrees C. We will have the heaters turned off when we begin the commissioning phase imaging in earnest, perhaps as early as July 3rd.


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