A dataset provided by the European Space Agency

Name HP-SSA-DISR-2-3-EDR-RDR
Mission CASSINI-HUYGENS
URL https://archives.esac.esa.int/psa/ftp//CASSINI-HUYGENS/DISR/HP-SSA-DISR-2-3-EDR-RDR-V1.3
DOI https://doi.org/10.5270/esa-oqsg7fa
Author European Space Agency
Abstract N/A
Description Data Set Overview = On January 14, 2005, the Huygens Probe, part of the joint NASA/ESA Cassini-Huygens mission to Saturn, entered the atmosphere of Titan, descended for 2.5 hours under a parachute and eventually landed softly on the surface of Titan [LEBRETONETAL2005]. Six experiments collected data during the descent and on ground. The data set, which this data set catalog belongs to, is the archive of the Huygens Descent Imager and Spectral Radiometer (DISR). The DISR consists of 14 instruments; Three imagers, four solar aureole cameras, two imagers covering the visible spectrum, two imagers in the near infrared, two violet photometers, and a sun sensor. The data were taken from an altitude of approximately 145km down to Titan's surface. The data taking was optimized by altitude and spin rate to meet the science objectives. The DISR data are presented in the PDS archive as described below. Data users are encouraged to also look at the DISR Data Users' Guide in: \DOCUMENT\DISR_SUPPORTING_DOCUMENTS\DISR_DATA_USERS_GUIDE DATA Directory The DATA directory contains all the data collected by DISR during the Titan descent arranged by detector system. Although the data are manipulated using a variant of IDL (Interactive Data Language, a product of Research Systems, Inc. of Boulder, Colorado.), the data are here presented in tabular or ASCII form for easy accessibility. The CCD_DARK_DATA datasets are the readout from covered columns of the CCD detector. Their values indicate the column dependent dark current being generated by the chip during the other measurements. The DERIVED_DATA_PRODUCTS directory contains reduced spectrometer data products as described below. The DESCENT_CYCLES datasets record key parameters at the beginning of each cycle of optimized data taking including the altitude and cycle type. There were about 110 Descent Cycles during the descent, and another 50 or so on Titan's ...surface. The HIGHER_LEVEL_DATA directory contains mosaic views of Titan generated from the DISR images. The HOUSEKEEPING (Housekeeping) datasets record DISR temperatures, voltages, and software indices. The IMAGERS directory contains tables of the detector readout values for each image pixel, after the image has been decompressed (lossy hardware compression). The IR_SPECTROMETER datasets contain the per pixel (wavelength) readout from each IR Spectrometer measurement. These readings have been summed into regions, relative to the azimuth of the sun, to allow for accurate determination of the light intensity in the directions of interest. LAMP datasets record when the calibration lamps and surface science lamp are powered, their applied voltage and current draw. The SLI_STRIP datasets are summed columns on each side of the side looking imager, used to determine the position of the sun as well as the tip of the probe. The SOLAR_AUREOLE directory contains the measurements of the light intensity field around the sun (the solar aureole). The data is presented as tables of pixel values. The SUN_SENSOR records the time when the sun passes in front of the DISR instrument. It has a double V aperture slit, which allows determination of the tip in the direction of the sun, by virtue of the crossing times. The sun sensor data is used to 'time' the taking of all other data sets relative to the sun (clocking to the sun azimuth). It's amplitude is also an independent measurement of the solar absorption at it's pass band (938nm). The data is presented as a table of the times (relative to DDB T0) that the sun passes in front of each of the 3 slits, as well as the detector reading in DN. The TIME datasets record the DISR internal clock time, and DDB time, at each Broadcast Pulse. The VIOLET_PHOTOMETER datasets contain a reading (amplitude) of the violet photometer. The VISIBLE_EXTRA_COLUMNS datasets record the values of the column of pixels on each side of the corresponding visible spectrometer. This data is used to compensate for light bleeding through (scattered light) from the adjacent CCD instruments. The VISIBLE_SPECTROMETER directory contains the data from the Upward Looking and Downward Looking Visible spectrometers as a table of values. The rows of the tables are the wavelength dimension, and the columns are spacial. In some cases the columns (spacial dimension) are summed to reduce noise. DERIVED DATA PRODUCTS = The following Derived Data Products have been included in the archive: DLIS/ULIS: A tabular presentation of the calculated light intensity at each wavelength of the IR spectrometers averaged over the field of view. DLV/ULV: Two sets of tables, one presenting the Net counts measured during the descent after the detector offset is removed. The other presents the average violet light intensity over the photometer's pass band assuming a quadratic spectral shape (see Violet calibration documents for details). DLVS/ULVS: Tables of the light intensity at each visible spectrometer wavelength, averaged over the field of view. DOCUMENT Directory This directory contains the documents which describe how the DISR was calibrated, and how to convert the data into physical measurements. It also contains information about the equipment used during calibration and the method for compensating for the detectors' dark current offsets. The supporting documentation contains information about the instrument design and science objectives. The DISR instrument calibration reports contain complete descriptions of each instrument detector system, the calibration data, methods, and algorithms for converting the instrument data numbers into physical units and intensities into data numbers. Reduced mean intensities over the field of view (FOV) are provided for the spectrometers. However for the broad band instruments (imagers, SA camera) the mean intensity over the FOV is not a useful number since the spectral variation is important, and the bandpass changes significantly during the descent. It is felt that the best scientific approach is to create models which reproduce data numbers rather than mean intensities. Although some lines of code exist as examples in the calibration reports and EXTRAS directory, no generic calibration software is available. Interpretation of the DISR data is model dependent and selection of the model parameters (i.e. atmospheric composition, intensity spectrum, surface reflectance, variation over the field of view) is key in deciphering the data. The scientist is encouraged to develop their own software to explore the physical interpretations of the DISR data. CATALOG Directory = This directory contains general information about the data set, such as involved personnel, instrument description, references, etc. INDEX Directory = as needed internally by archive Coordinate System = The DISR measurements were designed to be taken in the Titan coordinate system, relative to the Sun. Azimuths are relative to the Sun, with Counter Clockwise rotation (to the left) taken to be positive. Data Coverage and Quality = A good, although not entirely complete dataset was collected during the Titan descent. Most notably, only half of the DISR images taken were transmitted back to the Earth. However, even with this limitation, it has been possible to create a continuous view of the Titan descent, with no 'holes' in the construction. These assembled datasets are available in the EXTRA's directory of the archive. However, a primary result is the extensive loss of ability to perform stenographic analysis of the topography of Titan's surface. There we no incomplete or corrupted datasets. These would be removed by the error checking in the data link. Some datasets were lost after an extended time on Titan's surface as the link margin degraded, but in general the link, and probe telecommunications worked amazingly well. The signal to noise ratio in all of the data was better than targeted 100/1. A good spectral dataset was collected from the near IR to the Violet, with matching spectral overlap and good spacial coverage. From this data, coupled with the Solar Aureole measurements, it has been possible to measure the atmospheres's optical depth, model Titan's aerosols, determine methane absorption coefficients, and determine the heating rates. Additionally,with the image measurement we have also been able to calculate the winds and determine the reflectance spectra of the various materials that make up Titan's surface. Limitations = Besides the problems mentioned above, there were other unexpected limitations. The probe swing rates underneath the parachute were about 3 time faster than expected, especially high in the atmosphere. The results is that the DISR sun sensor was not able to maintain sun lock throughout the descent, and consequently not all data was taken at the proper azimuths relative to the sun. The sun sensor experience another problem in that it's detector became too cold during the descent, such that it's sensitivity was so low that it failed to operate below 30 km altitude above Titan's surface. A compensating windfall was the realization that variations in the AGC signal cause by the probes rotation could be used to deduce the instantaneous azimuth of the probe. This made reconstruction of the image and spectral field possible. The reverse in spin direction of the probe also caused unforeseen difficulties with the placement of measurements, particularly the IR spectra and the Solar Aureole (SA) Camera Measurements. We obtained no SA data with the sun behind the shadow-baffle, and actually very little SA data near the sun at low altitudes. Another difficulty was that an anomaly of the radar altimeter caused the loss of our coldest (lowest) calibration cycle, so the instrument performance had to be extrapolated over a fairly wide temperature range. Fortunately there was significant data taken over temperature in the laboratory to make this possible. _____________________________________________________________________________ Corrections Made to Earlier Datasets... = Revised Dataset: HP-SSA-DISR-2/3-EDR/RDR-V1.1 2014-02-06: Added missing Imager Responsivity tables under: \DOCUMENT\DISR_CALIBRATION_DOCUMENTS\IMAGERS\ABSOLUTE_RESPONSIVITY = Revised Dataset: HP-SSA-DISR-2/3-EDR/RDR-V1.0 Below is a list of changes made to archive version 1.0 to bring it up to version 1.1 (working toward version 2.0). Data Changes... No errors were found in the archived data; however a more photometrically accurate method of processing the Image data has been found, and the improved images have been added in the EXTRAS\IMAGE_ELEMENTS directory. Many improvements have been made to the supporting information contained in the label files. * A detailed list of the data changes... 1) Image elements with improved photometry have been added to the volume under: EXTRAS\IMAGE_ELEMENTS. Besides the raw imaged, improved flat fields, the dark current parameters, and the square-root compression tables have been added along with information on how to process the images. 2) Altitudes reported in the label files have been updated to reflect the newer Descent Trajectory Working Group (DTWG) release from June of 2011. 3) Label file values for Azimuth, Spin Rate, & E/W tilt are updated to be in line with the March 2013 Karkoschka analysis. 4) The probe Azimuth, Altitude & Tilt are reported at both the beginning and end of the observation (previously reported only at the beginning). 5) Added 'SPIN_RATE' keyword to most label files to allow the user to determine the direction of the azimuth progression. 6) The DISR temperature array has been expanded to include all available instrument measured temperatures (in Label Files), not just selected values as before, as some analyses have shown additional temperature dependencies. 7) Temperatures are reported at the mid-point (in time) of the measurement, rather than at the beginning. This allows more accuracy for long exposure measurements. 8) A better explanation of the azimuth definition is included in the DESCRIPTION elements. 9) The DESCRIPTION fields have been expanded to provide a more complete explanation of the dataset. 10) Where appropriate the 'EXPOSURE_TYPE' keyword was added to describe if the observation was automatically or manually exposed to help distinguish the calibration measurements. 11) The 'NULL_PIXEL' keywords were added to CCD measurements to allow determination of the dark-current offset. 12) A more complete data re-play that includes partial datasets was used. 13) Filenames and Product ID's have been revised to include more information. 14) Added reconstructed altitude, azimuth and spin information to DESCENT datasets to juxtapose real-time software values to the actuals. 15) Added XDR formatted images to the DATA/IMAGERS directory. 16) Replaced NASAView formatted (IMG) images with more generic TIFF images. 17) Added IMAGE_ID keyword to image labels to help user determine the format (MRI, SLI, HRI) of the dataset. 18) Added note to image labels pointing out the error in the on-board flat fields for the Medium Resolution Imagers (MRI). 19) Added 'MEASUREMENT_TYPE' keyword to IR spectrometer labels to help user determine the type of IR measurement (ULIS, DLIS, IR_COMB, IR,LONG, etc). 20) Added 'ROTATIONS' keyword to the IR spectrometer labels to help the user determine the spectrometer pointing history. 21) Added table column headers to make the data more understandable. 22) Added 'COLUMNS' keyword to the Visible Spectrometer label files to allow the user to determine the amount of column summing used. 23) Corrected many small errors including the syntax and offset for the pointers in the label files. * New Keywords Added... 1) SPACECRAFT_ALTITUDE_START = The reconstructed altitude of the probe at the start of the measurement. 2) SPACECRAFT_ALTITUDE_END = The reconstructed altitude of the probe at the end of the measurement. 3) PREDICTED_ALTITUDE = The real-time altitude (km) as predicted by the Huygens probe and relayed to the instrument via the Descent Data Broadcast (DDB). 4) AZIMUTH_START = The reconstructed pointing direction of the DISR instrument at the start of the observation. The angle is defined as being in a plane perpendicular to the Nadir vector (i.e. horizontal), measured in degrees Counterclockwise (CCW) from the vector to the Sun, as viewed from above. 5) AZIMUTH_END = The reconstructed pointing direction of the DISR instrument at the end of the observation. The angle is defined as being in a plane perpendicular to the Nadir vector (i.e. horizontal), measured in degrees Counterclockwise (CCW) from the vector to the Sun, as viewed from above. 6) AZIMUTH_NORTH_START = The same as AZIMUTH_START, except measured in degrees Clockwise (CW) from true North (Titan's spin vector) viewed from above, as one would for standard compass directions. 7) AZIMUTH_NORTH_START = The same as AZIMUTH_END, except measured in degrees Clockwise (CW) from true North (Titan's spin vector), viewed from above, as one would for standard compass directions. 8) SPIN_RATE = The approximate average spin rate (in RPM) of the Huygens probe during the measurement as determined by a polynomial fit to the local spin-rate observations. The sense is CCW positive in keeping with the original intended spin direction of the probe. 9) ROTATIONS = The number (or fraction) of spin revolutions the probe makes during the observation, CCW from above defined as positive. 10) SPIN_RATE_START = The instantaneous, re-constructed spin rate (in RPM) at the start of the observation, CCW from above defined as positive. 11) SPIN_RATE_END = The instantaneous, re-constructed spin rate (in RPM) at the end of the observation, CCW from above defined as positive. 12) HUYGENS:EW_TILT_ANGLE_START = The tilt of the Huygens probe spin axis at the start of the observation. The tilt is measured relative to the Zenith vector in the East/West direction. Positive tilt is defined as the spin vector being East of Zenith (i.e. the parachute being east of the probe). 13) HUYGENS:EW_TILT_ANGLE_END = The tilt of the Huygens probe spin axis at the end of the observation. The tilt is measured relative to the Zenith vector in the East/West direction. Positive tilt is defined as the spin vector being East of Zenith (i.e. the parachute being east of the probe). 14) DESCENT_CYCLE_NAME = The name of the descent cycle (Image, Non-Image, etc) that the observation was in. This can often effect data collection externalities such as azimuth timing, exposure time, column summing, etc. 15) NULL_PIXEL_2 & NULL_PIXEL_3 = Readout of covered pixels on the CCD chip which are needed to determine the dark current offset for the observation. 16) MEASUREMENT_TYPE = Distinguishes between sub-types within the DISR subinstruments, such as Upward Looking vs. Downward Looking for the Visible Spectrometer. 17) IMAGE_ID = Distinguishes type of image dataset; Medium Resolution, High Resolution, or Side Looking. 18) EXPOSURE_TYPE = Distinguishes between Auto-exposed observations and pre-planned, fixed exposure observations. Can be used to identify calibration exposures. * Documentation Revisions... 1) The EAICD has been substantially revised. 2) Added the Visible Spectrometer Calibration Document (\DOCUMENT\ DISR_CALIBRATION_DOCUMENTS\VISIBLE_SPECTROMETERS\VISIBLE_SPECTROMETER_CALDOC), which contains all the details about how the Visible Spectrometers were calibrated. 3) Added the Infra-Red Spectrometer Calibration Document (\DOCUMENT\ DISR_CALIBRATION_DOCUMENTS\INFRARED_SPECTROMETERS\IR_SPECTROMETER_CAL_DOC), which contains all the details about how the Infra-Red Spectrometers were calibrated. 4) Added clarification to section 2.1 of VISIBLE_SPECTROMETER_CAL_NOTES, (\DOCUMENT\DISR_CALIBRATION_DOCUMENTS\VISIBLE_SPECTROMETERS\ VISIBLE_SPECTROMETER_CAL_NOTES). 5) Fixed an error in the IR spectrometer calibration notes (IR_SPECTROMETER_CAL_NOTES) section 2, equation f, and in section 3, the DLIS FWHM equation. 6) Corrected figure 8 of the SUN_SENSOR_CALIBRATION_DOC. 7) Incorporated DISR Archive Users' Guide in DOCUMENTS section of archive.
Instrument DISR
Temporal Coverage 2005-01-14T00:00:00Z/2005-01-14T00:00:00Z
Version V1.3
Mission Description The majority of the text in this file was extracted from the Cassini Mission Plan Document, D. Seal, 2003. [JPLD-5564] The Cassini spacecraft, including the Huygens Probe, was launched on 15 October 1997 using a Titan IV/B launch vehicle with Solid Rocket Motor Upgrade (SRMU) strap-ons and a Centaur upper stage. The spacecraft used a 6.7-year Venus-Venus-Earth-Jupiter Gravity Assist (VVEJGA) trajectory to Saturn, during which cruise observations were conducted to check out, calibrate, and maintain the instruments as well as to perform limited science. After Saturn Orbit Insertion (SOI) (1 July 2004), the Huygens Probe separated and, on the third encounter with Titan, entered the satellite's atmosphere to make in situ measurements during an approximately 150 minute descent (14 January 2005). The Orbiter continued a tour of the Saturn system until mid-2008 collecting data on the planet and its satellites, rings, and environment. The Cassini Orbiter (CO) was a three-axis stabilized spacecraft equipped with one high gain antenna (HGA) and two low gain antennas (LGAs), three Radioisotope Thermoelectric Generators (RTGs) for power, main engines, attitude thrusters, and reaction wheels. It carried twelve orbiter instruments designed to carry out 27 diverse science investigations. The Huygens Probe (HP) was equipped with six instruments designed to study the atmosphere and surface of Titan. It entered the upper atmosphere protected by a heat shield, then deployed parachutes to descend slowly to the surface from an altitude of about 200 km. The instruments, with acronym and Principal Investigator (PI) or Team Leader (TL), are summarized below: Instrument Acronym PI/TL ----------------------------------------------- -----------Orbiter: Cassini Plasma Spectrometer CAPS Young Cosmic Dust Analyzer CDA Srama Composite Infrared Spectrometer CIRS Flasar Ion and Neutral Mass Spectrometer INMS Waite Imaging Science Subsystem ISS Porco... Magnetometer MAG Dougherty Magnetospheric Imaging Instrument MIMI Krimigis Cassini Radar RADAR Elachi Radio and Plasma Wave Science RPWS Gurnett Radio Science Subsystem RSS Kliore Ultraviolet Imaging Spectrograph UVIS Esposito Visible and Infrared Mapping Spectrometer VIMS Brown Probe: Aerosol Collector and Pyrolyser ACP Israel Descent Imager Spectral Radiometer DISR Tomasko Doppler Wind Experiment DWE Bird Gas Chromatograph Mass Spectrometer GCMS Niemann Huygens Atmospheric Structure Instrument HASI Fulchignoni Surface Science Package SSP Zarnecki Mission Phases LAUNCH 1997-10-15 to 1997-10-17 1997-288 to 1997-290 -----Cassini successfully lifted-off from the Cape Canaveral Air Station complex 40 on 15 October 1997 at 08:55 UTC. The solid rocket motors burned from liftoff to separation at 2 min 23 sec at an altitude of 68,300 m. Stage 1 ignition began at 2 min 11 sec at an altitude of 58,500 m, and Stage 2 ignition (and Stage 1 separation) occurred at 5 min 23 sec after liftoff at 167,300 m. During the first three minutes and 27 seconds of flight, the payload fairing shrouded the spacecraft, protecting it from direct solar illumination. The Centaur upper stage separated from the launch vehicle at 9 min 13 sec at 206,700 m. The first Centaur burn began at 9 min 13 sec and lasted approximately two minutes. This burn placed the Cassini spacecraft into an elliptical, 170 km by 445 km parking orbit with an inclination of about 30 degrees. After 17 minutes in the parking orbit, the Centaur fired again and launched Cassini toward Venus en route to Saturn. The injection C3 was 16.6 km^2/s^2. Immediately after separation from the Centaur (date?), the spacecraft's Attitude and Articulation Control Subsystem (AACS) pointed the HGA toward the Sun to achieve a thermally safe attitude in which the HGA served as an umbrella for the remainder of the spacecraft. X-band uplink and downlink was established through the LGAs, the Radio and Plasma Wave Science (RPWS) Langmuir Probe was deployed, instrument replacement heaters and main engine oxidizer valve heaters were turned on, and the Stellar Reference Unit (SRU), Imaging Science Subsystem (ISS), and Visible and Infrared Mapping Spectrometer (VIMS) decontaminations were started. TCM 1 1997-10-18 to 1997-11-14 1997-291 to 1997-318 ----The Trajectory Correction Maneuver 1 (TCM 1) phase comprised four one-week sequences. During most of the TCM 1 phase, the spacecraft was in a relatively quiescent state with the HGA pointed toward the Sun. Telemetry downlinked by the spacecraft was utilized to make an initial characterization of the spacecraft and to assess whether its various subsystems survived the launch. Deployment, decontamination, tank heating, and AACS checkout activities were started. Before the maneuver itself, the fuel and oxidizer tanks were heated in order to avoid an irreversible overpressure in the propellant lines. If the tanks fully pressurized before the spacecraft passed through the peak temperature regime, then (when the spacecraft did enter the maximum thermal environment) the tank pressure would climb without there being a way to bring it back down, possibly causing an overpressure. TCM 1 was an Earth injection clean-up maneuver placed at 25 days after launch. TCM 1 was executed using the main engine with a delta-V magnitude of 2.8 m/s. The burn sequence included holding the spacecraft off-Sun after burn completion to allow the spacecraft heating to be characterized in a relatively benign environment. INTERPLANETARY CRUISE 1997-11-14 to 1999-11-07 1997-318 to 1999-311 --------------------The Interplanetary Cruise Phase extended from 14 November 1997 to 7 November 1999. It consisted of three subphases: Venus 1 Cruise, Instrument Checkout 1, and Venus 2 - Earth Cruise. During most of this phase, Cassini's proximity to the Sun constrained the spacecraft to remain Sun-pointed, and communications were conducted using the Low Gain Antennas. The downlink capability of the LGAs at large spacecraft-Earth ranges was very limited. Between 30 and 150 days after launch, for example, the downlink data rate decreased from 948 to 20 bps. Beginning on 28 December 1998, the spacecraft approached opposition and the HGA could be pointed towards Earth for a period of 25 days while the Probe equipment temperature remained within the required range. This provided a high data rate window during which checkout activities could be accomplished. VENUS 1 CRUISE 1997-11-14 to 1998-09-13 1997-318 to 1998-256 -------------The Venus 1 Cruise subphase started on 14 November 1997 and continued through 13 September 1998. The subphase encompassed sequences C5 through C9 and included two TCMs, one planetary swingby, and three switches between LGA1 and LGA2. Most of the period was dedicated to engineering and instrument maintenance activities. VENUS 1 ENCOUNTER 1998-04-26 1998-116 The first Venus encounter occurred on 26 April 1998. The spacecraft approached Venus from a sunward direction, and closest approach occurred just after the spacecraft entered the Sun's shadow for a period of about 15 minutes. At closest approach, the altitude was 284 km, with a velocity relative to Venus of 11.8 km/s. The spacecraft was occulted from Earth for about 2 hours. The Earth occultation zone started about 15 minutes after the spacecraft left the Sun occultation zone. Accuracy for the Venus flyby was assured by using two TCMs (Trajectory Correction Maneuvers), 60 and 20 days before closest approach, and a clean-up maneuver 20 days after the flyby. INSTRUMENT CHECKOUT 1 1998-09-14 to 1999-03-14 1998-257 to 1999-073 --------------------The Instrument Checkout 1 subphase (ICO-1) started on 14 September 1998, continued through 14 March 1999, and consisted of sequences C10-C13. This subphase was characterized by the opposition that occurred on 9 January 1999, which allowed use of the HGA for downlink since the Earth and Sun were nearly aligned as seen from Cassini. All instruments scheduled checkout activities within the 25 day period centered on opposition. This was the first opportunity since launch to exercise and check the status of most instruments outside of routine maintenance. The 'Quiet Test', for example, allowed each instrument to monitor other instruments as they turned on and off and provided valuable insight into how to integrate science observations during the Saturn tour. During instrument checkout activities, the spacecraft autonomously went into a safe state. Accumulating star position errors from the slow turn required to keep the Sun on the -x-axis triggered AACS fault protection. Most of the instrument checkout activities were rescheduled after a 10 day safing period. Those that were not completed were rescheduled for the ICO-2 subphase during Outer Cruise. VENUS 2 - EARTH CRUISE 1999-03-15 to 1999-11-07 1999-074 to 1999-311 ---------------------The Venus 2 - Earth Cruise subphase started on 15 March 1999, 45 days prior to the second Venus flyby, and continued through 7 November 1999, which was 82 days after the Earth flyby. The subphase encompassed sequences C13 through C16, and included seven scheduled TCMs, two planetary swingbys, and 25 science activities in addition to normal engineering activities. Science activities included maintenance, calibration, checkout, and science observations using all of the Cassini instruments except INMS and CIRS. VENUS 2 ENCOUNTER 1999-06-24 1999-175 TCM-7 was executed 37 days before the Venus 2 Encounter. TCM-8 was scheduled 21 days prior to Venus 2, but it was canceled. DSN (Deep Space Network) coverage increased from one to three passes per day in support of the flyby. EARTH ENCOUNTER 1999-08-18 1999-230 The Earth flyby occurred 55 days after the Venus 2 flyby. The spacecraft approached the Earth from approximately the direction of the Sun. Closest approach occurred right after the spacecraft entered the Sun occultation zone. The occultation lasted approximately 30 minutes. The altitude at closest approach was 1175 km, with an Earth-relative velocity of 19.0 km/s. Trajectory correction maneuvers took place 43, 30, 15 and 6.5 days before closest approach, and a clean-up maneuver was executed 13 days after the flyby. Continuous DSN coverage began at the Venus 2 flyby and continued through the Earth flyby. A week after the Earth Encounter, DSN coverage dropped to one pass every two days. Five instruments conducted observations as Cassini passed through the Earth's magnetotail. OUTER CRUISE 1999-11-08 to 2002-07-07 1999-312 to 2002-188 -----------The Outer Cruise Phase consisted of four subphases: HGA Transition, Instrument Checkout 2, Jupiter Cruise, and Quiet Cruise. The Outer Cruise phase extended from 8 November 1999 (when the spacecraft reached a Sun range of 2.7 AU) to 7 July 2002 (about two years before Saturn Orbit Insertion). At 2.7 AU (1 February 2000), the HGA began continuous Earthpointing. The one planetary encounter in this phase was the flyby of Jupiter in December 2000. Science at Jupiter was an opportunity to test Saturn observation strategies with HGA data rates. HIGH GAIN ANTENNA TRANSITION 1999-11-08 to 2000-05-06 1999-312 to 2000-127 ---------------------------This subphase included sequences C17 to C19, operation of ISS and VIMS decontamination heaters, CDA dust calibrations, and Magnetosphere and Plasma Science (MAPS) observations after the HGA was pointed toward Earth. During the initial part of the subphase (C17 and part of C18), telecommunications were via LGA1, and the spacecraft was at the farthest distance from Earth before transitioning to the HGA for regular use. Therefore, data rates were very low and activities were kept to a minimum. C17 included standard maintenance and one Periodic Engineering Maintenance (PEM) activity. Activities during the LGA1 portion of C18 included a Periodic Instrument Maintenance (PIM); observations by ISS, VIMS, and UVIS of the asteroid Masursky near closest approach (1,634,000 km); and ISS dark frame calibration images directly following the Masursky observations. The HGA was turned toward Earth for regular use on 1 February 2000, during C18. Several activities took place during the rest of C18, using the greater telemetry capabilities available with the HGA: playback of the Masursky data and ISS dark frames, a Probe checkout, a Huygens Probe S-band Relay to Cassini Test, a Telemetry-Ranging Interference Test, MAG calibrations, and a PEM. Regular MAPS observations by CAPS, CDA, MAG, MIMI, and RPWS began within a few days after transitioning to the HGA. The first 6 weeks of C19 were used for a checkout of new Flight Software. The AACS version A7 software was uploaded near the beginning of this period, and the first 2 weeks were devoted to AACS tests. The next 4 weeks were originally scheduled for CDS tests of version V7.0. However, these tests were delayed to late July and August of 2000 to allow time for additional regression testing. During the AACS checkout period, MAPS activity ceased. Several activities took place during the last 3 weeks of C19: resumption of MAPS observations, three RSS activities (HGA pattern calibration, HGA boresight calibration, and USO characterization), CIRS Cooler Cover release, and a PIM. A few days before the end of C19, the command loss timer setting was increased slightly, to account for the 10-day period at the beginning of C20 during which superior conjunction made commanding problematic. INSTRUMENT CHECKOUT 2 2000-05-06 to 2000-11-05 2000-127 to 2000-310 --------------------The second instrument checkout subphase (ICO-2) was scheduled from 6 May 2000 to 5 November of 2000, after the Spacecraft Office had completed its engineering checkout activities. ICO-2 included instrument checkout that required reaction wheel stability and any instrument checkouts that were not successfully completed during ICO-1. But the CDS Flight Software V7 uplink and checkout, which was delayed from March, was rescheduled to late July through early September 2000, causing many ICO-2 activities to be compressed into a shorter and more intense period. Some activities were postponed until after the Jupiter observations were completed in 2001. The subphase began with a superior conjunction which precluded early science or engineering activities. MAPS instruments remained on; but data return was not attempted during conjunction. Two TCMs were scheduled for Jupiter targeting, in June and September. Engineering activities included the continuous use of reaction wheels and, beginning on 1 October 2000, dual Solid State Recorders (SSRs). There were no scheduled instrument PIMs during ICO-2 since all instruments had other activities that accomplished this function. Other engineering activities included two Reaction Wheel Assembly (RWA) friction tests, two PEMs, and an SRU calibration. Science activities began with the MAPS instruments continuing from C19. New flight software was loaded for eight instruments in late May, and a CDA software update was done in September. New Quiet Tests, while operating on reaction wheels, were done in July for most instruments. RSS Quiet Tests were done in September, and RADAR related tests were done in late June. A Probe checkout occurred in late July. Spacecraft turns were done for RADAR observations of the Sun and Jupiter in June and again in September. The star Alpha Piscis Austrinus (Fomalhaut) was also observed in September by VIMS with ISS and UVIS doing ride-along science. No other science turns were scheduled until October. On 1 October, science began using a repeating 5-day template to gather Jupiter science. This involved 11 turns in a 5 day period, including two downlinks. The turns in the 5-day template involved 4 orientations: Orbiter Remote Science (ORS) boresights to Jupiter, Z axis parallel to ecliptic HGA to Sun, rolling about Z axis Probe to Sun, rotating about X axis HGA to Earth, Probe offset from Sun for CDA, not rotating, downlink orientation JUPITER CRUISE 2000-11-05 to 2001-04-30 2000-310 to 2001-120 -------------The Jupiter Cruise subphase extended from 6 November 2000 to 29 April 2001 and included sequences C23 to C25. However Jupiter remote sensing observations actually began on 1 October 2000, in C22. JUPITER ENCOUNTER 2000-12-30 2000-365 The Jupiter flyby occurred on 30 December 2000 at an altitude of 9.7 million km. This gravity assist rotated the trajectory 12 deg and increased the heliocentric velocity by 2 km/s. The Jupiter relative speed at closest approach was 11.6 km/s. At closest approach, Jupiter filled the Narrow Angle Camera (NAC) field of view. Extensive Jupiter science was performed which required additional DSN support: up to two passes every five days, and a maximum of one pass every 30 hours in the 10 days on either side of closest approach. Science at Jupiter was an opportunity to test how to build and execute viable Saturn sequences. A problem with the RWAs occurred on 16 December 2000. Increased friction on one of the wheels caused the spacecraft to switch autonomously to the Reaction Control Subsystem (RCS) for attitude control. With the switch to RCS, hydrazine usage increased. Two of four joint CAPS-Hubble Space Telescope observations, a Jupiter North-South map, the Himalia 'flyby', and a UVIS torus observation were all executed on RCS before the sequence was terminated on 19 December 2000. MAPS data continued to be recorded at a reduced rate. All other planned science activities were suspended. After tests, RWA operation was resumed for attitude control on 22 December, with the wheels biased away from low RPM regions. The sequence was restarted on 29 December. QUIET CRUISE 2001-04-30 to 2002-07-08 2001-120 to 2002-189 -----------Quiet Cruise was a 14 month subphase that started at the end of Jupiter Cruise and ended two years before SOI. During this subphase, routine maintenance, engineering, and navigation functions were carried out. One Gravitational Wave Experiment (GWE) was conducted in December 2001, and one Solar Conjunction Experiment (SCE) was conducted in June 2002. SCIENCE CRUISE 2002-07-08 to 2004-06-10 2002-189 to 2004-162 -------------SPACE SCIENCE 2002-07-08 to 2004-01-11 2002-189 to 2004-011 The Space Science subphase began on 8 July 2002 and ran through 11 January 2004. TCMs 18 and 19, two GWEs (December 2002 and December 2003) and one SCE (June-July 2003) were conducted. APPROACH SCIENCE 2004-01-12 to 2004-06-10 2004-012 to 2004-162 The Approach Science subphase began six months before SOI and ended three weeks before SOI, when the spacecraft was approaching Saturn at a rate of 5 kilometers per second. Most of the activities during the Approach Science subphase were Saturn science observations and preparation for the Phoebe flyby, SOI, and Tour operations. The reaction wheels were turned on at the beginning of the subphase to provide a more stable viewing platform. By this point, the imaging instruments had begun atmospheric imaging, and making long-term atmospheric movies. CIRS began long integrations of Saturn's disk. At SOI - 4 months, Saturn filled one third of the NAC field of view and one half of the CIRS Far Infrared (FIR) field of view. The Saturn approach was made toward the morning terminator at a phase angle of about 75 degrees; VIMS gathered data on the temperature difference across the terminator. UVIS scans of the Saturn System began 3-4 months before SOI. Fields, particles, and waves instruments collected solar wind information and recorded Saturn emissions as the spacecraft neared the planet. Science data gathered during this period was stored on the SSR and transmitted back to Earth. Daily DSN tracking coverage began 90 days before SOI. The Phoebe approach TCM took place on 27 May 2004, 15 days before Phoebe closest approach. TOUR PRE-HUYGENS 2004-06-11 to 2004-12-24 2004-163 to 2004-359 ---------------The Tour Pre-Huygens Phase extended from the Phoebe Encounter through Saturn Orbit Insertion to separation of the Huygens Probe from the Cassini Orbiter. PHOEBE ENCOUNTER 2004-06-11 2004-163 The flyby of Phoebe occurred on 11 June 2004, 19 days before SOI. At closest approach (19:33 UTC) the spacecraft was 2000 km above the surface. SATURN ORBIT INSERTION 2004-07-01 2004-183 During Saturn Orbit Insertion (SOI) on 1 July 2004, the spacecraft made its closest approach to the planet's surface during the entire mission at an altitude of only 0.3 Saturn radii (18,000 km). Due to this unique opportunity, the approximately 95-minute SOI burn (633 m/s total delta-V), required to place Cassini in orbit around Saturn, was executed earlier than its optimal point centered around periapsis, and instead ended near periapsis, allowing science observations immediately after burn completion. The SOI maneuver placed the spacecraft in an initial orbit with a periapsis radius of 1.3 Rs, a period of 148 days, and an inclination of 16.8 degrees. After the burn, the spacecraft was turned to allow the ORS instruments to view the Saturn inner rings that were not in shadow. After periapsis, the trajectory just grazed the occultation zones behind the planet with the Earth and Sun being occulted by Saturn. After communication with Earth was re-established, the spacecraft remained on Earth pointed for nine hours to play back engineering and science data and to give ground personnel time to evaluate the spacecraft status. After SOI a pair of cleanup maneuvers was used to correct for errors in the SOI burn. The first was immediately before superior conjunction, at SOI + 3 days, and the second was after conjunction at SOI + 16 days. Probe checkouts were scheduled at SOI + 14 days, Probe Release Maneuver (PRM) + 4 days, and ten days before separation. The partial orbit between SOI and the first apoapsis was designated orbit 0. The next three orbits were designated a, b, and c. TITAN A ENCOUNTER 2004-10-26 2004-300 TITAN B ENCOUNTER 2004-12-13 2004-348 HUYGENS DESCENT 2004-12-24 to 2005-01-14 2004-359 to 2005-014 --------------HUYGENS PROBE SEPARATION 2004-12-24 2004-359 The probe was released from the Orbiter on 24 December 2004, 11 days after the second Titan flyby (orbit b). Two days after the Probe was released, the Orbiter executed a deflection maneuver to place itself on the proper trajectory for the third encounter. TITAN C HUYGENS 2005-01-14 2005-014 During the third flyby (orbit c), on 14 January 2005, the Huygens Probe transmitted data to the orbiter for approximately 150 minutes during its descent through the atmosphere to the surface. Because the Orbiter was looking at Titan through most of the corresponding Goldstone tracking pass, DSN support on this day was primarily through the 70-meter antennas at the Canberra and Madrid tracking complexes. While approaching Titan, the Orbiter made its last downlink transmission (to the Madrid station, DSS 63) before switching to Probe relay mode. The Orbiter then turned nearly 180 degrees to point its HGA at the predicted Probe impact point, and the Probe Support Avionics (PSA) were configured to receive data from the Probe. Some Orbiter instruments were put into a low power state to provide additional power for the PSA. The data from the Probe were transmitted at S band in two separate data streams, and both were recorded on each SSR. Following completion of the predicted descent (maximum 150 minutes), the Orbiter listened for Probe signals for an additional 30 minutes, in case they continued after landing. When data collection from the Probe was completed, those data were write protected on each SSR. The spacecraft then turned to view Titan with optical remote sensing instruments until about one hour after closest approach for a total observing window of TBD. The Orbiter then turned the HGA towards Earth and began transmitting the recorded Probe data to the Canberra 70-m antenna. The complete, four-fold redundant set of Probe data was transmitted twice, and its receipt verified, before the write protection on that portion of the SSR was lifted by ground command. A second playback, including all of the Probe data and the Orbiter instrument observations, was returned over the subsequent Madrid 70-meter tracking pass, which was longer and at higher ^ation angles. TOUR 2005-01-14 to 2008-06-30 2005-014 to 2008-182 ---The Tour Phase of the mission began at completion of the Huygens Probe and Orbiter-support playback and ended on 30 June 2008. It included dozens of satellite encounters and extended observations of Saturn, its rings, and its environment of particles and fields. TOUR SEQUENCE BOUNDARIES The table below shows spacecraft background sequences, orbit revolution, start epoch (including day-of-year in a separate column), and the length of the sequence. For completeness, all 'S' sequences are listed even though the first seven covered times before the Tour phase. Each orbit about Saturn was assigned a revolution identifier starting with a, b, and c, and then numerically ascending from 3 to 74; these were not synchronous with sequences, some of which covered only partial orbits. Full orbits began and ended at apoapsis; the partial orbit from SOI to the first apoapsis was orbit 0. Sequence Rev Epoch (SCET) DOY Duration In days -------- --- ----------------- --- -------S1 - 2004-May-15 00:00 136 35 S2 0 2004-Jun-19 01:38 171 42 S3 0 2004-Jul-30 23:05 212 43 S4 a 2004-Sep-11 19:10 255 35 S5 a 2004-Oct-16 18:40 290 28 S6 a 2004-Nov-13 16:59 318 33 S7 b 2004-Dec-16 15:03 351 37 S8 c 2005-Jan-22 10:38 022 36 S9 3 2005-Feb-27 00:36 058 41 S10 6 2005-Apr-09 05:15 099 35 S11 8 2005-May-14 02:50 134 35 S12 10 2005-Jun-18 01:34 169 42 S13 12 2005-Jul-29 22:36 210 32 S14 14 2005-Aug-30 21:53 242 39 S15 16 2005-Oct-08 15:57 281 35 S16 17 2005-Nov-12 17:01 316 35 S17 19 2005-Dec-17 14:21 351 42 S18 20 2006-Jan-28 11:23 028 42 S19 22 2006-Mar-11 00:35 070 42 S20 23 2006-Apr-22 05:15 112 42 S21 24 2006-Jun-03 02:39 154 42 S22 26 2006-Jul-15 00:06 196 35 S23 27 2006-Aug-18 22:06 230 39 S24 29 2006-Sep-26 19:53 269 26 S25 31 2006-Oct-22 18:26 295 33 S26 33 2006-Nov-24 16:30 328 42 S27 36 2007-Jan-05 13:50 005 43 S28 39 2007-Feb-17 10:52 048 40 S29 41 2007-Mar-29 08:04 088 37 S30 44 2007-May-04 22:00 124 37 S31 46 2007-Jun-11 03:10 162 33 S32 48 2007-Jul-14 01:06 195 29 S33 49 2007-Aug-11 23:20 223 42 S34 50 2007-Sep-22 20:51 265 40 S35 51 2007-Nov-01 18:40 305 42 S36 54 2007-Dec-13 16:15 347 39 S37 56 2008-Jan-21 13:35 021 26 S38 59 2008-Feb-16 11:51 047 36 S39 62 2008-Mar-23 01:50 083 27 S40 65 2008-Apr-19 07:18 110 42 S41 70 2008-May-31 04:27 152 35 SATELLITE ENCOUNTER SUMMARY This table summarizes the Cassini Orbiter satellite encounters; for completeness, all recognized encounters are included even though the first eight preceded the Tour phase. Rev identifies the orbit revolution as defined above. The three character ID for the encounter is in the second column; an appended asterisk (*) denotes a non-targeted encounter. The target, date and time, and day-of-year are in the next three columns. Altitude above the surface at closest approach, sense of the encounter (whether on the inbound or outbound leg of an orbit), relative velocity at closest approach, and phase angle at closest approach round out the columns. Rev Name Satellite Epoch (SCET) DOY Alt in/ Speed Phase km out km/s deg ---- ----- --------- ---------------- --- --- --- ----- ---0 0PH Phoebe 2004-Jun-11 19:33 163 1997 in 6.4 25 0 0MI* Mimas 2004-Jul-01 00:30 183 76424 in 22.3 80 0 0TI* Titan 2004-Jul-02 09:30 184 338958 out 8.3 67 a aTI Titan 2004-Oct-26 15:30 300 1200 in 6.1 91 b bTI Titan 2004-Dec-13 11:37 348 2358 in 6 98 b bDI* Dione 2004-Dec-15 02:11 350 81592 in 5.3 93 c cIA* Iapetus 2005-Jan-01 01:28 001 64907 in 2.1 106 c cTI Titan 2005-Jan-14 11:04 014 60000 in 5.4 93 3 3TI Titan 2005-Feb-15 06:54 046 950 in 6 102 3 3EN* Enceladus 2005-Feb-17 03:24 048 1179 out 6.6 98 4 4EN Enceladus 2005-Mar-09 09:06 068 499 in 6.6 43 4 4TE* Tethys 2005-Mar-09 11:42 068 82975 out 6.9 64 5 5EN* Enceladus 2005-Mar-29 20:20 088 63785 in 10.1 134 5 5TI Titan 2005-Mar-31 19:55 090 2523 out 5.9 65 6 6MI* Mimas 2005-Apr-15 01:20 105 77233 out 13.6 94 6 6TI Titan 2005-Apr-16 19:05 106 950 out 6.1 127 7 7TE* Tethys 2005-May-02 21:04 122 64990 in 10 118 7 7TI* Titan 2005-May-04 05:10 124 860004 out 10.2 153 8 8EN* Enceladus 2005-May-21 07:19 141 92997 out 8.1 81 9 9TI* Titan 2005-Jun-06 18:50 157 425973 in 5.8 82 10 10TI* Titan 2005-Jun-22 12:27 173 920423 in 3.7 65 11 11EN Enceladus 2005-Jul-14 19:57 195 1000 in 8.1 43 12 12MI* Mimas 2005-Aug-02 03:52 214 45112 in 6.5 83 12 12TI* Titan 2005-Aug-06 12:33 218 841452 out 3.8 62 13 13TI Titan 2005-Aug-22 08:39 234 4015 out 5.8 42 14 14TI Titan 2005-Sep-07 07:50 250 950 out 6.1 84 15 15TE* Tethys 2005-Sep-24 01:29 267 33295 out 7.7 76 15 15TI* Titan 2005-Sep-24 22:01 267 910272 out 10.7 148 15 15HY Hyperion 2005-Sep-26 01:41 269 990 out 5.6 45 16 16TI* Titan 2005-Oct-10 22:20 283 777198 in 9.7 65 16 16DI Dione 2005-Oct-11 17:58 284 500 in 9 66 16 16EN* Enceladus 2005-Oct-12 03:29 285 42635 out 6.6 75 17 17TI Titan 2005-Oct-28 03:58 301 1446 in 5.9 105 18 18RH Rhea 2005-Nov-26 22:35 330 500 in 7.3 87 19 19EN* Enceladus 2005-Dec-24 20:23 358 97169 in 6.9 133 19 19TI Titan 2005-Dec-26 18:54 360 10429 out 5.6 67 20 20TI Titan 2006-Jan-15 11:36 015 2042 in 5.8 121 21 21TI Titan 2006-Feb-27 08:20 058 1812 out 5.9 93 22 22TI Titan 2006-Mar-18 23:58 077 1947 in 5.8 148 22 22RH* Rhea 2006-Mar-21 07:01 080 85935 out 5.3 136 23 23TI Titan 2006-Apr-30 20:53 120 1853 out 5.8 121 24 24TI Titan 2006-May-20 12:13 140 1879 in 5.8 163 25 25TI Titan 2006-Jul-02 09:12 183 1911 out 5.8 148 26 26TI Titan 2006-Jul-22 00:25 203 950 in 6 105 27 27TI* Titan 2006-Aug-18 17:48 230 339190 out 4.8 121 28 28TI Titan 2006-Sep-07 20:12 250 950 in 6 45 28 28EN* Enceladus 2006-Sep-09 20:00 252 39842 out 10.3 116 29 29TI Titan 2006-Sep-23 18:52 266 950 in 6 90 30 30TI Titan 2006-Oct-09 17:23 282 950 in 6 81 31 31TI Titan 2006-Oct-25 15:51 298 950 in 6 25 32 32EN* Enceladus 2006-Nov-09 01:48 313 94410 out 14.1 27 33 33DI* Dione 2006-Nov-21 02:32 325 72293 out 12.3 144 33 33TI* Titan 2006-Nov-25 13:57 329 930525 out 4.5 114 35 35TI Titan 2006-Dec-12 11:35 346 950 in 6 124 36 36TI Titan 2006-Dec-28 10:00 362 1500 in 5.9 62 37 37TI Titan 2007-Jan-13 08:34 013 950 in 6 53 38 38TI Titan 2007-Jan-29 07:12 029 2776 in 5.8 73 39 39TI Titan 2007-Feb-22 03:10 053 953 out 6.3 161 40 40TI Titan 2007-Mar-10 01:47 069 956 out 6.3 149 41 41TI Titan 2007-Mar-26 00:21 085 953 out 6.3 144 42 42TI Titan 2007-Apr-10 22:57 100 951 out 6.3 137 43 43TI Titan 2007-Apr-26 21:32 116 951 out 6.3 130 44 44TI Titan 2007-May-12 20:08 132 950 out 6.3 121 45 45TE* Tethys 2007-May-26 20:57 146 97131 in 11.7 75 45 45TI Titan 2007-May-28 18:51 148 2425 out 6.1 114 46 46TI Titan 2007-Jun-13 17:46 164 950 out 6.3 107 47 47TE* Tethys 2007-Jun-27 19:53 178 16166 in 10.1 90 47 47MI* Mimas 2007-Jun-27 22:56 178 89730 in 16.2 110 47 47EN* Enceladus 2007-Jun-28 01:15 179 90769 out 9.4 55 47 47TI Titan 2007-Jun-29 17:05 180 1942 out 6.2 96 48 48TI Titan 2007-Jul-19 00:39 200 1302 in 6.2 34 49 49TE* Tethys 2007-Aug-29 11:21 241 48324 in 4.7 104 49 49RH* Rhea 2007-Aug-30 01:26 242 5098 out 6.7 46 49 49TI Titan 2007-Aug-31 06:34 243 3227 out 6.1 87 49 49IA Iapetus 2007-Sep-10 12:33 253 1000 out 2.4 65 50 50DI* Dione 2007-Sep-30 06:27 273 56523 in 5.6 47 50 50EN* Enceladus 2007-Sep-30 10:53 273 88174 in 6.1 99 50 50TI Titan 2007-Oct-02 04:48 275 950 out 6.3 67 51 51TI* Titan 2007-Oct-22 00:47 295 455697 in 4.1 29 52 52RH* Rhea 2007-Nov-16 19:52 320 78360 in 9.1 148 52 52TI Titan 2007-Nov-19 00:52 323 950 out 6.3 51 53 53MI* Mimas 2007-Dec-03 05:28 337 79272 in 14.8 138 53 53TI Titan 2007-Dec-05 00:06 339 1300 out 6.3 70 54 54TI Titan 2007-Dec-20 22:56 354 953 out 6.3 61 55 55TI Titan 2008-Jan-05 21:26 005 949 out 6.3 37 57 57TI* Titan 2008-Jan-22 21:06 022 860776 in 4.5 70 59 59TI Titan 2008-Feb-22 17:39 053 959 out 6.4 30 61 61TI* Titan 2008-Mar-10 19:15 070 922539 in 6.3 123 61 61EN Enceladus 2008-Mar-12 19:05 072 995 in 14.6 56 62 62TI Titan 2008-Mar-25 14:35 085 950 out 6.4 21 64 64MI* Mimas 2008-Apr-11 09:38 102 95428 in 16.9 137 66 66TI* Titan 2008-Apr-26 18:22 117 780589 in 5.5 94 67 67TI Titan 2008-May-12 10:09 133 950 out 6.4 35 69 69TI Titan 2008-May-28 08:33 149 1316 out 6.3 23 72 72TI* Titan 2008-Jun-13 04:17 165 372240 in 5.9 89 74 74EN* Enceladus 2008-Jun-30 08:07 182 99092 in 21.6 66 END OF PRIME MISSION 2008-06-30 2008-182 --------------------
Creator Contact CHARLES (CHUCK) SEE
Date Published 2006-07-15T00:00:00Z
Publisher And Registrant European Space Agency
Credit Guidelines European Space Agency, 2006, HP-SSA-DISR-2-3-EDR-RDR, V1.3, European Space Agency, https://doi.org/10.5270/esa-oqsg7fa