Lunar Case 8a: NRHO - True Anomaly 180
Scenario 8a tests Keplerian propagation of the Apollo LM model in a low-fidelity 8x8 GRAIL gravity field with Sun and Earth perturbations. This case uses a Near-rectilinear Halo Orbit (NRHO) and tests the sensitivity of Scenario 8 to changes in initial conditions.
Constants and models
The gravitational constant is defined from the GRAIL model specified in the table below. The ephemerides are: DE440. Time is expressed in UTC. Although test case initial conditions may be in the future, the following constants are used: TAI − UTC = 37 sec; DUT1 = 0.0 sec Low-Fidelity GRAIL uses the GRAIL gravity model of degree and order 8 (i.e. 8x8 GRAIL).
Initial Conditions
| Scenario | Lunar Case 8a: NRHO - True Anomaly 180 | |||
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| Body | Apollo Model | |||
| Orientation | Major axis is approximately along the velocity vector quaternionWrtMi = [0.930023544773565 0.319852453640438 -0.0390525111437773 0.176707428933728] Where the components are ordered [W X Y Z]' |
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| Rotation | [0.001, 0, 0] deg/s To be specified in inertial frame. Body angular rate w.r.t. MI expressed in body |
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| Gravitation | Low-Fidelity GRAIL | Gravity Gradient Effects | Off | |
| Sun/Earth Perturbations | On | Duration | 604,800 s | |
| Output Interval | 60 s | Output Format | CSV | |
| Initial states | ||||
| Time | 2026-1-31 9:42:03.51 UTC corresponds to output j2000UtcTime_s J2000 epoch of January 1.5, 2000 = -2451545.0 days Using 37 leap seconds j2000TtTime_s = j2000UtcTime + 32.184 + 37 = j2000UtcTime + 69.184 (s) Note that delta UT1/UTC is not relevant for checkcase and is thus not specified |
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| Frame | Planet-Centered Inertial | |||
| Position (m) |
miPosition_m_X miPosition_m_Y miPosition_m_Z |
-2845919.11896933 42880801.2794537 -55813619.8570753 |
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| Velocity (m/s) |
miVelocity_m_s_X miVelocity_m_s_Y miVelocity_m_s_Z |
66.3176950654487 21.5521352604019 13.1774942999742 |
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Latest Results
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| Sim | Raw Data Link |
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Interactive Plots
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Note: pp_euler variables are Euler angles automatically calculated from sim provided quaternions.
A link to the conversion used can be accessed from the References menu in the navigation bar.
Note: All quaternions are modified to be scalar positive.
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