OBJECT = COLUMN NAME = STEP_NUMBER COLUMN_NUMBER = 1 BYTES = 2 DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 1 DESCRIPTION = "Step in the observation. PER STEP column." END_OBJECT = COLUMN /* SPICE DERIVED GEOMETRY VALUES */ OBJECT = COLUMN NAME = PLANET_SUN_VECTOR_TG COLUMN_NUMBER = 2 BYTES = 24 DATA_TYPE = IEEE_REAL START_BYTE = 3 ITEMS = 3 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived (x,y,z) vector giving center-to-center planet- sun position in target body-fixed coordinate system. Unit = kilometers. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = PLANET_SC_VECTOR_TG COLUMN_NUMBER = 3 BYTES = 24 DATA_TYPE = IEEE_REAL START_BYTE = 27 ITEMS = 3 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived (x,y,z) vector giving center-to-center planet- spacecraft position in target body-fixed coordinate system. Unit = kilometers. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BORESIGHT_UNIT_VECTOR_CENTER_TG COLUMN_NUMBER = 4 BYTES = 24 DATA_TYPE = IEEE_REAL START_BYTE = 51 ITEMS = 3 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived (x,y,z) vector giving look direction of MASCS UVVS center in target body-fixed coordinate system. Unit = N/A. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BORESIGHT_UNIT_VECTOR_C1_TG COLUMN_NUMBER = 5 BYTES = 24 DATA_TYPE = IEEE_REAL START_BYTE = 75 ITEMS = 3 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived (x,y,z) vector giving look direction of MASCS UVVS corner 1 in target body-fixed coordinate system. Unit = N/A. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BORESIGHT_UNIT_VECTOR_C2_TG COLUMN_NUMBER = 6 BYTES = 24 DATA_TYPE = IEEE_REAL START_BYTE = 99 ITEMS = 3 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived (x,y,z) vector giving look direction of MASCS UVVS corner 2 in target body-fixed coordinate system. Unit = N/A. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BORESIGHT_UNIT_VECTOR_C3_TG COLUMN_NUMBER = 7 BYTES = 24 DATA_TYPE = IEEE_REAL START_BYTE = 123 ITEMS = 3 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived (x,y,z) vector giving look direction of MASCS UVVS corner 3 in target body-fixed coordinate system. Unit = N/A. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BORESIGHT_UNIT_VECTOR_C4_TG COLUMN_NUMBER = 8 BYTES = 24 DATA_TYPE = IEEE_REAL START_BYTE = 147 ITEMS = 3 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived (x,y,z) vector giving look direction of MASCS UVVS corner 4 in target body-fixed coordinate system. Unit = N/A. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SURFACE_TANGENT_VECTOR_CENTER COLUMN_NUMBER = 9 BYTES = 24 DATA_TYPE = IEEE_REAL START_BYTE = 171 ITEMS = 3 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Vector from center of target planet through tangent line (a radial line which intersects the boresight look direction at a 90 deg. angle) to the planet surface, with a magnitude equal to the planet radius, UVVS Center. In target body-fixed coordinate system. Unit = kilometers. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SURFACE_TANGENT_VECTOR_C1 COLUMN_NUMBER = 10 BYTES = 24 DATA_TYPE = IEEE_REAL START_BYTE = 195 ITEMS = 3 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Vector from center of target planet through tangent line (a radial line which intersects the boresight look direction at a 90 deg. angle) to the planet surface, with a magnitude equal to the planet radius, UVVS Corner 1. In target body-fixed coordinate system. Unit = kilometers. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SURFACE_TANGENT_VECTOR_C2 COLUMN_NUMBER = 11 BYTES = 24 DATA_TYPE = IEEE_REAL START_BYTE = 219 ITEMS = 3 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Vector from center of target planet through tangent line (a radial line which intersects the boresight look direction at a 90 deg. angle) to the planet surface, with a magnitude equal to the planet radius, UVVS Corner 2. In target body-fixed coordinate system. Unit = kilometers. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SURFACE_TANGENT_VECTOR_C3 COLUMN_NUMBER = 12 BYTES = 24 DATA_TYPE = IEEE_REAL START_BYTE = 243 ITEMS = 3 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Vector from center of target planet through tangent line (a radial line which intersects the boresight look direction at a 90 deg. angle) to the planet surface, with a magnitude equal to the planet radius, UVVS Corner 3. In target body-fixed coordinate system. Unit = kilometers. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SURFACE_TANGENT_VECTOR_C4 COLUMN_NUMBER = 13 BYTES = 24 DATA_TYPE = IEEE_REAL START_BYTE = 267 ITEMS = 3 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Vector from center of target planet through tangent line (a radial line which intersects the boresight look direction at a 90 deg. angle) to the planet surface, with a magnitude equal to the planet radius, UVVS Corner 4. In target body-fixed coordinate system. Unit = kilometers. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = RA_SET COLUMN_NUMBER = 14 BYTES = 40 DATA_TYPE = IEEE_REAL START_BYTE = 291 ITEMS = 5 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Right ascension of UVVS footprint center, and 4 corners - 5 total values. Format: (center, corner 1, corner 2, corner 3, corner 4). Unit = degrees. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = DEC_SET COLUMN_NUMBER = 15 BYTES = 40 DATA_TYPE = IEEE_REAL START_BYTE = 331 ITEMS = 5 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Declination of UVVS footprint center, and 4 corners - 5 total values. Format: (center, corner 1, corner 2, corner 3, corner 4). Unit = degrees. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TARGET_LATITUDE_SET COLUMN_NUMBER = 16 BYTES = 40 DATA_TYPE = IEEE_REAL START_BYTE = 371 ITEMS = 5 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "For exosphere observations, this indicates the latitudes below the tangent points of the UVVS field-of-view center and corners. For surface observations, this indicates the latitudes at the locations where the field-of-view center and corners intersect the planet surface. Format: (center, corner 1, corner 2, corner 3, corner 4). Unit = degrees. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TARGET_LONGITUDE_SET COLUMN_NUMBER = 17 BYTES = 40 DATA_TYPE = IEEE_REAL START_BYTE = 411 ITEMS = 5 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "For exosphere observations, this indicates the longitudes below the tangent points of the UVVS field-of-view center and corners. For surface observations, this indicates the longitudes at the locations where the field-of-view center and corners intersect the planet surface. Format: (center, corner 1, corner 2, corner 3, corner 4). Unit = degrees. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TARGET_ALTITUDE_SET COLUMN_NUMBER = 18 BYTES = 40 DATA_TYPE = IEEE_REAL START_BYTE = 451 ITEMS = 5 ITEM_BYTES = 8 MISSING_CONSTANT = -1.E32 DESCRIPTION = "For exosphere observations, this indicates the altitudes of the actual field-of-view center and corner tangent points above the surface along a radial line. For surface observations, these altitudes have a value of 0. Format: (center, corner 1, corner 2, corner 3, corner 4). Unit = kilometers. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SLIT_ROTATION_ANGLE COLUMN_NUMBER = 19 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 491 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Angle of long dimension of the slit with the surface tangent line. Unit = degrees. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ALONG_TRACK_FOOTPRINT_SIZE COLUMN_NUMBER = 20 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 499 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived length of UVVS footprint along track, accounting for smear across surface. Unit = meters. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ACROSS_TRACK_FOOTPRINT_SIZE COLUMN_NUMBER = 21 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 507 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived width of UVVS footprint across track, accounting for jitter across surface. Unit = meters. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = FOOTPRINT_AZIMUTH COLUMN_NUMBER = 22 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 515 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived angle of footprint smear relative to a N-S line. 0 is North, plus/minus 180 is South, sign denotes east (clockwise) or west rotation of azimuth from North. Unit = degrees. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = INCIDENCE_ANGLE COLUMN_NUMBER = 23 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 523 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived solar incidence angle of footprint center. Unit = degrees. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = EMISSION_ANGLE COLUMN_NUMBER = 24 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 531 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived emission angle of footprint center. Unit = degrees. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = PHASE_ANGLE COLUMN_NUMBER = 25 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 539 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived phase angle of footprint center. Unit = degrees. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SLANT_RANGE_TO_CENTER COLUMN_NUMBER = 26 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 547 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived slant range from s/c to footprint center (equal to s/c NADIR_ALTITUDE in nadir pointing case). Unit = kilometers. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SUBSPACECRAFT_LATITUDE COLUMN_NUMBER = 27 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 555 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived subspacecraft latitude on planet surface. Unit = degrees. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SUBSPACECRAFT_LONGITUDE COLUMN_NUMBER = 28 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 563 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived subspacecraft longitude on planet surface. Unit = degrees. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = NADIR_ALTITUDE COLUMN_NUMBER = 29 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 571 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived spacecraft altitude above nadir point. Unit = kilometers. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SUBSOLAR_LATITUDE COLUMN_NUMBER = 30 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 579 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived subsolar latitude on planet surface. Unit = degrees. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SUBSOLAR_LONGITUDE COLUMN_NUMBER = 31 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 587 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived subsolar longitude on planet surface. Unit = degrees. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SOLAR_DISTANCE COLUMN_NUMBER = 32 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 595 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived subsolar distance to footprint center on planet surface. Unit = kilometers. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = PLANET_TRUE_ANOMALY COLUMN_NUMBER = 33 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 603 MISSING_CONSTANT = -1.E32 DESCRIPTION = "Derived true anomaly of planet. Unit = degrees. PER STEP column." END_OBJECT = COLUMN /* CALIBRATED ITEMS AND ADDITIONAL METADATA */ OBJECT = COLUMN NAME = MIDSTEP_TIME COLUMN_NUMBER = 34 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 611 DESCRIPTION = "A calculated value indicating the mission elapsed time since launch at the middle of an individual UVVS step. Unit = seconds. This is a double precision value. The formula used is: MIDSTEP_TIME = (N-1)*(INT_TIME+STEP_TIME)/3000 + SC_TIME + PACKET_SUBSECONDS*5/1000 + (INT_TIME/3000)/2 where N is the Nth step in an observation sequence, and the other values are contained in the UVVS Science Header CDR. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = STEP_UTC_TIME COLUMN_NUMBER = 35 BYTES = 17 DATA_TYPE = CHARACTER START_BYTE = 619 DESCRIPTION = "UTC time in YYDOYTHH:MM:SS.00 format derived from the MIDSTEP_TIME using SPICE kernels. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = GRATING_OFFSET COLUMN_NUMBER = 36 BYTES = 4 DATA_TYPE = IEEE_REAL START_BYTE = 636 DESCRIPTION = "From lookup table; however, currently, the grating offset table is not implemented correctly. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = STEP_POSITION COLUMN_NUMBER = 37 BYTES = 4 DATA_TYPE = MSB_INTEGER START_BYTE = 640 DESCRIPTION = "Actual grating position calculated by start position + (step number * step size) + offset. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = STEP_WAVELENGTH COLUMN_NUMBER = 38 BYTES = 4 DATA_TYPE = IEEE_REAL START_BYTE = 644 DESCRIPTION = "From wavelength equation. Unit = nanometers. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = RAW_STEP_DATA COLUMN_NUMBER = 39 BYTES = 2 DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 648 DESCRIPTION = "Column of uncompressed raw data. Unit = counts. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = COUNT_RATE COLUMN_NUMBER = 40 BYTES = 4 DATA_TYPE = IEEE_REAL START_BYTE = 650 DESCRIPTION = "Count rate of step. Unit = counts/second. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = DEAD_CORRECTED_COUNT_RATE COLUMN_NUMBER = 41 BYTES = 4 DATA_TYPE = IEEE_REAL START_BYTE = 654 DESCRIPTION = "Count rate corrected for nonlinearity due to dead-time. Unit = counts/second. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = DARK_RATE COLUMN_NUMBER = 42 BYTES = 4 DATA_TYPE = IEEE_REAL START_BYTE = 658 DESCRIPTION = "Dark count rate at step from model/module. Unit = counts/second. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SCATTERED_LIGHT_RATE COLUMN_NUMBER = 43 BYTES = 4 DATA_TYPE = IEEE_REAL START_BYTE = 662 DESCRIPTION = "Scattered light at step from model/module. Unit = counts/second. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = FULLY_CORRECTED_COUNT_RATE COLUMN_NUMBER = 44 BYTES = 4 DATA_TYPE = IEEE_REAL START_BYTE = 666 DESCRIPTION = "Count rate corrected for dark, scattered light, dead time, etc. Unit = counts/second. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = FULLY_CORRECTED_COUNT_RATE_UNCERTAINTY COLUMN_NUMBER = 45 BYTES = 4 DATA_TYPE = IEEE_REAL START_BYTE = 670 DESCRIPTION = "Uncertainty for count rate, equivalent to instrument shot noise. Unit = counts/second. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = STEP_RADIANCE_KR COLUMN_NUMBER = 46 BYTES = 4 DATA_TYPE = IEEE_REAL START_BYTE = 674 DESCRIPTION = "Calibrated radiance value at step. Unit = kiloRayleighs/nanometer. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = STEP_RADIANCE_W COLUMN_NUMBER = 47 BYTES = 4 DATA_TYPE = IEEE_REAL START_BYTE = 678 DESCRIPTION = "Calibrated radiance value at step. Unit = W/(m^2 steradian micron). PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = STEP_RADIANCE_SIGNAL_TO_NOISE COLUMN_NUMBER = 48 BYTES = 4 DATA_TYPE = IEEE_REAL START_BYTE = 682 DESCRIPTION = "Signal to noise ratio for the step radiance values." END_OBJECT = COLUMN OBJECT = COLUMN NAME = PMT_TEMPERATURE COLUMN_NUMBER = 49 BYTES = 4 DATA_TYPE = IEEE_REAL START_BYTE = 686 DESCRIPTION = "PMT temperature in degrees C." END_OBJECT = COLUMN OBJECT = COLUMN NAME = DATA_QUALITY_INDEX COLUMN_NUMBER = 50 BYTES = 21 DATA_TYPE = CHARACTER START_BYTE = 690 DESCRIPTION = "21 character index of data quality. Each digit signifies quality factor of measurements. PER STEP column. Format: A-BCDEF-GHIJ-KLM-NOPQ A: SBOS trip 0 = no trip 1 = trip 9 = Unknown. No information found from MASCS HK EDR for the time period START_TIME to STOP TIME. B: Footprint center on planet 0 = not on planet 1 = on planet C: Footprint C1 on planet 0 = not on planet 1 = on planet D: Footprint C2 on planet 0 = not on planet 1 = on planet E: Footprint C3 on planet 0 = not on planet 1 = on planet F: Footprint C4 on planet 0 = not on planet 1 = on planet G: Partial scan (macro cutoff) 0 = No partial scan. 1 = Partial scan. H: Temperature 1 flag for this UVVS detector 0 = Temperature does not exceed 25 deg C threshold. 1 = Temperature exceeds 25 deg C threshold but less than 45 deg C threshold. 2 = Temperature exceeds 45 deg C threshold. 9 = Unknown. No information found from MASCS HK EDR for the time period START_TIME to STOP TIME. I: UVVS noise spike flag 0 = No noise spike detected. 1 = Noise spike detected. J: VIRS operating flag 0 = VIRS is not scanning during readout. 1 = VIRS is scanning during readout. 9 = Unknown. No information found from MASCS HK EDR for the time period START_TIME to STOP TIME. K: Buffer overflow flag 0 = No buffer overflow. 1 = Buffer overflow. L: Background subtraction method # = Method used M: Background quality flag (not yet implemented) 0 = Not yet implemented. 1 = Inside TBD threshold. N: SPICE Version Epoch. Indicates what SPICE is used to determine pointing fields in CDR. 'Predict' SPICE may change one or more times before settling on 'Final' pointing solutions about 2 weeks from data acquisition. 0 = No SPICE 1 = Predict 2 = Actual O: Bad data identifier for UVVS. Bad data encompass when a Solar Energetic Particle event interacts with the instrument causing noisy data that should not be used. There are also times when the instrument wavelength fiducial mis registeres. The data is compromised when these events happen and should not be used. 0 = Good Data 1 = Bad Data P-Q: Spares" END_OBJECT = COLUMN OBJECT = COLUMN NAME = SC_TIME COLUMN_NUMBER = 51 BYTES = 4 DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 711 DESCRIPTION = "Spacecraft time in integer seconds that is transmitted to the MESSENGER subsystems by the Integrated Electronics Module. This is assigned as the start time of the UVVS observation. A UVVS observation is defined as all the scan data contained within one UVVS science packet. This is due to the highly configurable nature of the instrument, i.e. it can be commanded to take multiple scans over multiple wavelengths. Unit is in mission elapsed time which is the number of seconds since launch. PER OBSERVATION column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = OBSERVATION_TYPE COLUMN_NUMBER = 52 BYTES = 30 DATA_TYPE = CHARACTER START_BYTE = 715 DESCRIPTION = "Describes the type of observation being executed at this MIDSTEP time. PER STEP column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ORBIT_NUMBER COLUMN_NUMBER = 53 BYTES = 8 DATA_TYPE = IEEE_REAL START_BYTE = 745 DESCRIPTION = "Orbit number is a unique identifier for a given orbit of the MESSENGER spacecraft around Mercury. Orbit number is defined as starting at apoherm and is calculated using the MIDSTEP_TIME value and appropriate SPICE kernels. Orbit numbering does not start until MESSENGER performs the Mercury orbit insertion. Until that time the value for orbit number is 0." END_OBJECT = COLUMN