A dataset provided by the European Space Agency

URL ftp://npsa01.esac.esa.int/pub/mirror/CASSINI-HUYGENS/DTWG/HP-SSA-DTWG-6-TRAJECTORY-V2.0
DOI 10.5270/esa-cp12sqr
Abstract N/A
Description Data Set Overview = This data set contains the revised trajectory data (DTWG#5) of the Huygens probe in the atmosphere of Titan and is decribed in [KAZEMINEJAD2011]. The DOCUMENT directory contains the files that provide documentation and supplementary information to assist in understanding and using the data products. Especially, the EAICD document describes the data set. Seven data products are archived in the DATA directory. Browse files in the BROWSE directory are JPG files providing quick-look view of trajectory data. Input files that were needed to compute the trajectory can be found in the EXTRAS directory. Warnings It should be pointed out that the reconstruction of descent trajectory of the Huygens probe is not coherent with the altitude profile retrieved from the Huygens radar altimeter. Different approaches/methods for descent trajectory reconstruction resulted in altitude and velocity profiles that show discrepancy, not consistent with uncertainty range r^ant to models and measurements. Significant effort was put in the investigation of the possible error sources using the two radar flight spares. These investigations also encompassed extensive laboratory tests at ESA/ESTEC with several weeks of vacuum exposure with intermediate measurements at ambient temperature (20 deg C) and two radiation exposures (1.14 krad and 1.35 krad Si). Pre-liminary tests results clearly show that the altitude counter oscillators show an increased output in vacuum which is relaxed again in ambient conditions. Based on these laboratory measurements a correction factor could be derived which allowed to significantly reduce the originally observed residuals. For further details on the RAU investigations contact Roland Trautner at ESA/ESTEC/RSSD (Roland.Trautner@esa.int). Software The data are stored as ASCII files and do not need any specific software. An update of the DTWG software (now v5.1) wa...
Instrument DTWG
Temporal Coverage 2005-01-14T09:05:52Z/2005-01-14T11:38:10Z
Version V2.0
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...
Date Published 2006-09-01T00:00:00Z
Publisher And Registrant European Space Agency
Credit Guidelines European Space Agency, 2006-09-01T00:00:00Z, HP-SSA-DTWG-6-TRAJECTORY, V2.0. https://doi.org/10.5270/esa-cp12sqr