MISSION PLAN - PDS Small Bodies Node

6.2 Science Operations
6.2.1 Aerogel Collection of Cometary Dust
Although the collection of cometary dust samples is the primary goal of the mission, it is
totally passive. Occurring mostly during the Closest Encounter sub-subphase of the
mission, it is enabled by deployment of the aerogel collector and the setting of the
spacecraft / collector attitude perpendicular to the dust stream. Collector deployment is
currently planned approximately 9 days prior to encounter, and the encounter spacecraft
attitude will be established after the last nominal pre-encounter TCM performed at E-18
hours. The collector is planned to stay deployed until E+5 hours which is approximately
when the spacecraft exits the comet coma.
6.2.2 Comet Coma and Nucleus Imaging
All images (and other data for that matter) taken before E-4 minutes will be sent to Earth
in real-time as the tracking schedule permits. All images taken within E±4 minutes will
be stored on-board for delayed transmission. The data rate and storage capabilities of the
spacecraft are such that a substantial number of images should be possible.
Imaging plans are heavily related to the comet image profile. This profile is defined as a
function of image resolution and size (number of pixels) of the coma and nucleus in the
camera field-of-view. Figures 6.2-1.a-c define these parameters as a function of time and
Wild-2 encounter subphase.
1E+4
Image Resolution (km/pixel)
2910 2188 1552 934 312 31
No of pixels (1-D)
Assume ~ 100,000 km radius coma
1E+3
coma
1E+2
1E+1
-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0
Time From Encounter (days)
a. Far Encounter
Figure 6.2-1 Wild-2 Encounter Comet Profile
6.2.2.1 Coma Images
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