MISSION PLAN - PDS Small Bodies Node

the installation of the HGA. The sun is 17° off the +z-axis near the encounter which
results in a slight cosine power loss.
Independent of launch date, the comet closest approach time has been established to be
02 January 2004, 19:20 ET, under near-identical sun, Earth, comet and spacecraft
geometries. This time was chosen to allow for scheduling of the comet flyby during the
Goldstone-Canberra DSN viewperiod overlap. The elevation angles for this period of the
mission are illustrated in Figure 6.1-2. An encounter phase overview is provided in
Figure 6.1-3.
50
40
5000
4000
S
30
20
-50
10-day
Tics
3000
2000
S,T (Mkm)
10
00
-10
T
To
Sun
E -100 d
W2
S,T (km)
1000
0
-1000
T
To
Sun
To
Earth
150 km Sunside @
Closest Approach
W2
0.5-hr Tic
-20
-30
-40
S
W2 Centered
RS plane = W2 orbit plane
R = Radial direction (W2 to Sun)
S = Circumferential (Orthogonal to R
along W2 velocity direction)
T = Out-of-Plane component
E+50 d
-2000
-3000
-4000
-50
-90
-80
-70
-60
-50
-40 -30
R (Mkm)
-20
-10
00
10
-5000
-5000 -4000 -3000 -2000 -1000 0 1000 2000 3000 4000 5000
R (km)
Figure 6.1-1 Encounter Phase Spacecraft Trajectory
90
Elevation Angle (deg)
80
70
60
50
40
30
20
10
0
GLD = DSS15
CAN = DSS45
MAD = DSS65
MAD
GLD
-12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12
Time From Wild-2 C/A (hours)
CAN
Figure 6.1-2 Encounter Elevation Angle Profile
A trajectory data set containing the following parameters can be found in Appendix 9.4:
70