1. LRO Mission Baseline Ephemeris v10.0
Released July 1, 2009
Mark Beckman

2. Baseline Ephemeris
LRO Mission Baseline Ephemeris is the baseline reference trajectory for the LRO mission
What’s in v10.0?
Same format as previous versions
Consistent with actual launch date of June 18, 2009 (p30 case)
Ephemeris starts at beginning of Commissioning Orbit
No transfer orbit ephems
M. Beckman/595

3. File 1 Description
File 1 (LRO_Mission_Baseline_Ephemeris_v9_file1.txt)
Time (Julian Date)
Line every 5 minutes
LRO Osculating Cartesian Position and Velocity
(km) and (km/sec)
Moon Centered Fixed coordinate frame
Defined by DE421 Principal Axis frame
LRO Right Ascension (deg) and Declination (deg)
Moon Centered Mean J2000 coordinate frame
Declination positive to Mean J2000 +Z axis
Lunar Altitude (km)
From mean lunar sphere
Lunar Latitude (deg) & Longitude (deg)
DE421 Principal Axis frame
Lunar Ground Track Velocity (km/sec)
Local Solar Time (deg)
Angle between Moon-Sun vector and Moon-LRO vector measured about north ecliptic
Solar Zenith Time (deg)
Angle between Moon-Sun vector and Moon-LRO vector
Lunar Pole Right Ascension (deg) and Declination (deg)
Sun-Moon Distance (km)
Subsolar Latitude (deg) & Longitude (deg)
M. Beckman/595

4. File 2 Description
File 2 (LRO_Mission_Baseline_Ephemeris_v9_file2.txt)
Time (Julian Date) of Lunar Equator Ascending Node
Line each ascending node
Starts at first lunar ascending node after LOI-1
Osculating Semi-Major Axis (km)
Osculating Eccentricity
Osculating Inclination (deg)
Osculating Argument of Periapsis (deg)
Lunar Ground Track Velocity (km/sec)
Local Solar Time (deg)
Solar Zenith Time (deg)
Orbit Beta Angle (deg)
Angle between orbit plane and Sun
M. Beckman/595

5. SPK Files Nominal Mission SPK file
LRO_Mission_Baseline_Ephemeris_v9.bsp
Moon centered
Type 13
Interpolation order 11
LRO SPICE ID of -85
M. Beckman/595