****************************************************************************** dorismail 09-Mar-2009 09:54:58 Message No 0589 ****************************************************************************** Author: "Ferrage Pascale" Subject: DORIS Constellation Status Dear Colleagues, The purpose of this message is to summarize the current status of the DORIS on-orbit constellation as of February 2009 as well as plans for the future. You will find a detailled description of the DORIS missions on the DORIS official web site AVISO : http://www.aviso.oceanobs.com/en/doris/doris-missions/index.html, with a synthetic illustration on http://www.aviso.oceanobs.com/en/doris/doris-applications/index.html CURRENT ON-ORBIT CONSTELLATION ================================ Currently six DORIS contributor satellites are in flight, and their measurements are available at the IDS data centers. (1) SPOT-2: (CNES) was launched in 1990, with the first DORIS receiver for a 6-month experiment. More than 18 years after the launch, this receiver is still fully operational. It will be will be de-orbited in June 2009 (maneuvers will be performed in order to lower the orbit so that the spacecraft will re-enter the Earth's atmosphere within 25 years). URL: http://smsc.cnes.fr/SPOT/ (2) SPOT-4 (CNES) was launched in 1998, and is expected to continue until 2012. URL: http://smsc.cnes.fr/SPOT/ (3) JASON-1, the CNES/NASA TOPEX follow-on mission was launched on December 7, 2001 with aminiaturized second generation DORIS receiver, a GPS and LRA localisation system. Due to the South Atlantic Anomaly (SAA) effect on the Jason1 on-board Ultra Stable Oscillators (USO),a correction model has been developed (J.M. Lemoine and H. Capdeville, J. Geodesy, 2006) and is available on IDS website http://ftp.cls.fr/pub/ids/satellites/CORRECTIVE_MODEL_JASON1/ Mission URL: http://topex-www.jpl.nasa.gov/mission/jason-1.html (4) ENVISAT, (ESA) was launched on March 1, 2002 with a second generation DORIS receiver and a laser retroreflector array (LRA). Mission URL: http://envisat.esa.int/ (5) SPOT-5 (CNES) was launched on May 4, 2002 with a miniaturized second generation DORIS receiver. The mission should be extended to 2015. Mission URL: http://smsc.cnes.fr/SPOT/ (6) OSTM/JASON-2 (CNES/NASA/EUMETSAT/NOAA) - The TOPEX/Poseidon and Jason-1 follow-on ocean observation mission was launched on June 20 2008. JASON-2 takes on board the new DGXX DORIS receiver (7-channels: beacons simultaneous tracking capability has been raised up to seven beacons, USO new generation allowing a better frequency stability while crossing SAA, a better quality of MOE and Jason-2 useful for beacons location), and LRA and GPS as tracking systems. Mission URLs: http://www.osd.noaa.gov/ostm/ http://sealevel.jpl.nasa.gov/mission/ostm.html http://smsc.cnes.fr/JASON2/ From June 2008 to end of January 2009, the both satellites Jason-1 and OSTM/Jason-2 were on the same orbit with one minute shift. Then, thanks to five orbit change manoeuvers peformed between January 26th 2009 and February 14th 2009, Jason-1 is now located in an interleaved orbit with respect to Jason-2, with a time lag of approximately 5 days. This new tandem configuration better suits for real-time applications. CONFIRMED FUTURE DORIS MISSIONS: ================================== The future DORIS missions are numerous and should guarantee a constellation with at least four DORIS contributor satellites through 2020: (1) CROYSAT-2 (ESA): is to be launched in November 2009 with on board a DORIS DGXX Receiver + LRA, (3.5 years as nominal lifetime) URL: http://www.esa.int/esaLP/LPcryosat.html (2) HY2A (China Academy of Space), is to be launched in June 2010, with on board a DORIS DGXX + LRA + GPS (nominal life time of 3 years) URL: http://www.aviso.oceanobs.com/fr/missions/missions-futures/hy-2/index.ht ml (3) SARAL/ALTIKA (ISRO/CNES) is to be launched from mid-2010, with a DORIS DGXX + LRA (nominal lifetime of 5 years) (ISRO = Indian Space Research Organization, www.isro.org) URL: http://www.cnes.fr/web/CNES-en/5894-altika.php URL: http://www.aviso.oceanobs.com/en/missions/future-missions/saral/index.ht ml (4) SENTINEL3A (GMES/ESA) is planned for November 2012 (DORIS DGXX + LRA + GPS) (nominal lifetime of 7 years), Then sentinel 3B is planned for + 2017 URL: http://www.esa.int/esaCP/SEMYZS3XQEF_index_0.html URL: http://www.aviso.oceanobs.com/en/missions/future-missions/sentinel-3/ind ex.html PROPOSED FUTURE MISSIONS, OR MISSIONS AWAITING APPROVAL ------------------------------------------------------------------------ ----- (1) JASON3 (Eumetsat/NOAA/CNES) pending approval before end of 2009, is foreseen from mid 2013 (DORIS DGXX + LRA + GPS) (2) SWOT (Surface Water Ocean Topography) Mission is foreseen for end of 2016 (DGXX + GPS + LRA) URL: http://bprc.osu.edu/water/index.php URL: http://www.aviso.oceanobs.com/en/missions/future-missions/swot/index.htm l (3) HY2 Missions and DORIS on board are pending approval: HY2B 2012, HY2C 2015, HY2D 2019: DORIS + GPS + LRA (4) Sentinel 3C, D with DORIS+GPS+LRA from 2021: to be confirmed Please do not reply directly to this message, but send comments and suggestions to IDS.central.bureau@cls.fr