Project News

  • Exterior of the new SGSLR shelter at GGAOSGP officially takes ownership of the GGAO SGSLR shelter
    Release Date: 08/08/2019 The GGAO SGSLR shelter official inspection took place the morning of Tuesday July 30th. The official punch list for the inside was generated. Participating in this walk through were the Goddard Project Manager for the construction, Quality Assurance, Safety, the Construction team and SGP personnel (Long, McGarry, Donovan and Nelson). After the inspection, SGP officially took ownership of the shelter which is now Goddard building 228. The exterior walk through will occur after the outside stairs are complete.

    See more photos on the SGSLR @ GGAO blog.

  • 2019 ILRS Workshop Banner2019 ILRS Technical Workshop
    Release Date: 08/06/2019 The 2019 ILRS Technical Workshop will take place in Stuttgart, Germany, October 21-25. If you plan to attend, please register by August 15 (next Thursday) on the workshop website:

    If you have any trouble registering, please send an email to

    If you plan to present at the workshop, we ask that you also upload your abstract as soon as possible so we can commence planning the program.

    We are looking forward to seeing you all in Stuttgart!

  • retroreflectors on the surface of the moon.Reflectors placed on the moon by Apollo 11 astronauts 50 years ago continue to provide fresh lunar laser ranging data
    Release Date: 07/31/2019 Fifty years ago, Neil Armstrong, Buzz Aldrin and Michael Collins left behind arrays of prisms that reflect light back toward its source; the Apollo 14 and 15 astronauts also did so. Four telescopes at observatories in New Mexico, France, Italy and Germany fire lasers at them, measuring the time that it takes for a laser pulse to bounce off the reflectors and return to Earth. This allows the distance to be measured to within a fraction of an inch (a few millimeters), and scientists at the Jet Propulsion Laboratory analyze the results. Lunar laser ranging measurements have deepened our understanding of the dance between the Moon and Earth.


  • ILRS logoMichael Lefebvre, French pioneer and major actor in satellite geodesy, passes away
    Release Date: 07/26/2019

    Michel Lefebvre has passed away at his home on July 21, 2019 after a long illness.

    He was one of the French pioneers and a major actor in satellite geodesy.

    He contributed enormously to training the researchers and engineers of today in this discipline, at the time of the formation of GRGS (Groupe de Recherche de Geodesie Spatiale), which resulted from the cooperation of research teams at CNES (Michele’s team), Meudon Observatory and others. This was also the time of international satellite observing campaigns (ISAGEX, Trapol, Medoc, etc.) in which Michel was deeply involved.

    Michel always was eager to debate on new ideas, his energy and enthusiasm were incredible, which were essential to the development of our projects and our works over fifty years, also to the rising of vocations in our field. He had a strong charisma, though a warm personality, respectful of everyone’s viewpoint. His constructive spirit and creativity were striking and he was carefully listened to within national (CNES, GRGS, Bureau des Longitudes) and international (NASA, DLR, ESA) organizations.

    As a leading expert, he had a prominent and determining role in the realization of the first satellite altimetry missions, especially TOPEX-Poseidon. Michel set the stage for the creation of the Laboratoire d’Etude en Geophysique et Oceanographie Spatiale (LEGOS), and had decisive actions in changing the French oceanographic community. He established the Club of Argonauts, in which oceanographers and climatologists discuss scientific and societal aspects of climate change. He also was at the origin of GODAE (Global Ocean Data Assimilation Experiment) and of Mercator Ocean (the French center for ocean predictions and analysis).

    Michel has left his mark on many young people who started their career with him. They went their own way but kept good and fruitful relationship with him. His death brings back lots of memories to all of us. A strong personality has left us.

    Our thoughts are with his wife Claude and their children and grandchildren.

  • Cover of the Journal of GeodesyJournal of Geodesy Special Issue on Laser Ranging
    Release Date: 07/23/2019 The following peer-reviewed Journal of Geodesy articles were recently published online at the journal site. These are all part of the Special Issue on Laser Ranging which is preparation. Several more articles are in the review process and upon completion the printed version will be published.

    In the meantime we invite you to peruse all of these with the latest information on Laser Ranging and the ILRS:

    Information Resources Supporting Scientific Research for the International Laser Ranging Service, Noll, C.E., Ricklefs, R., Horvath, J. et al. J Geod (2018).

    Modernizing and Expanding the NASA Space Geodesy Network to Meet Future Geodetic Requirements, Merkowitz, S.M., Bolotin, S., Elosegui, P. et al. J Geod (2018).

    Assessment of the impact of one-way laser ranging on orbit determination of the Lunar Reconnaissance Orbiter, Löcher, A. & Kusche, J. J Geod (2018).

    Rapid Response Quality Control Service for the Laser Ranging Tracking Network, Otsubo, T., Müller, H., Pavlis, E.C. et al. J Geod (2018).

    The Next Generation of Satellite Laser Ranging Systems, Wilkinson, M., Schreiber, U., Procházka, I. et al. J Geod (2018).

    NASA's Satellite Laser Ranging Systems for the 21st Century, McGarry, J.F., Hoffman, E.D., Degnan, J.J. et al. J Geod (2018).

    Time and laser ranging: A window of opportunity for geodesy, navigation and metrology, Exertier, P., Belli, A., Samain, E. et al. J Geod (2018).

    Laser and Radio Tracking for Planetary Science Missions - A Comparison, Dirkx, D., Procházka, I., Bauer, S. et al. J Geod (2018).

    Satellite Laser Ranging to Low Earth Orbiters - Orbit and Network Validation, Arnold, D., Montenbruck, O., Hackel, S. et al. J Geod (2018).

    The ILRS: Approaching 20 years and planning for the future, Pearlman, M.R., Noll, C.E., Pavlis, E.C. et al. J Geod (2019).

    Laser geodetic satellites: a high‐accuracy scientific tool, Pearlman, M., Arnold, D., Davis, M. et al. J Geod (2019).

    Future SLR station networks in the framework of simulated multi-technique terrestrial reference frames, Glaser, S., König, R., Neumayer, K.H. et al. J Geod (2019).

    Operating two SLR systems at the Geodetic Observatory Wettzell: from local survey to space ties, Riepl, S., Müller, H., Mähler, S. et al. J Geod (2019).

    Version of a glass retroreflector satellite with a submillimeter "target error", Sokolov, A.L., Akentyev, A.S., Vasiliev, V.P. et al. J Geod (2019).

    The SAO and the CNES contributions to the International Laser Ranging Network, Pearlman, M., Brachet, G., Lefebvre, M. et al. J Geod (2019) 93: 869.

  • MOBLAS-5 at Yarragadee site.Shooting for the stars
    Release Date: 07/23/2019 Photographer Mogens Johansen visited Yarragadee and gives some practical tips on capturing the geodetic instruments against the night sky.

  • Haleakala siteResults of The National Geodetic Survey's local tie survey at the NSGN Haleakala site posted

    The National Geodetic Survey posted the results of their local tie survey at the NSGN Haleakala site on Maui, Hawaii. Vectors were measured between the SLR and GNSS station and ground marks to support the International Terrestrial Reference Frame and NGS's Foundation CORS program. The survey results, report, and SINEX file are available at the NGS website.

  • SGP logoSGP Project Manager Stephen Merkowitz interviewed by TVPerú

    SGP Project Manager Stephen Merkowitz was interviewed by TVPerú in Spanish for a story on the NASA Satellite Laser Ranging Station TLRS-3 in Arequipa, Peru that aired on TVPerú Noticias. A version of the story was also aired in Quechua:

  • ILRS logo2019 ILRS Technical Workshop first circular released

    The first circular for the 2019 ILRS Technical Workshop has been released. The workshop will take place October 21-25 in Stuttgart, Germany.

  • Team photo of the Baader and SGSLR teams in the domeSite Acceptance Test (SAT) for SGSLR Dome @ GGAO Successful

    The dome Site Acceptance Test (SAT) was performed Friday morning May 3rd and it was successful.

    Read the SGSLR @ GGAO blog.

  • SGSLR shelter at GGAO with dome installedDome for the SGSLR shelter at GGAO installed

    The dome for the new SGSLR shelter building at GGAO was assembled by the Baader Planetarium team in the GGAO parking lot. Once the dome was built, on May 1st a crane arrived to perform the lifting. The dome ring, followed by the dome itself, were lifted and installed on the roof.

    See more photos on the SGSLR @ GGAO blog.

    the shelter before the dome was installed.the shelter after the dome was installed

  • SGSLRJan McGarry gives SGSLR presentation to GSFC Astronomy Club

    Jan McGarry, NASA GSFC, gave a presentation to the GSFC Astronomy Club on April 09, 2019 highlighting the initial development and testing of the SGSLR system at Goddard’s Geophysical and Astronomical Observatory (GGAO). The talk also included background on SLR and NASA’s legacy SLR network, as well as the ILRS and SGP and future plans for the global deployment of SGSLR systems.

  • Observatory at HaleakalaCommercial power to TLRS-4 at Haleakala restored

    A winter storm damaged commercial power transmission lines to the observatories on Haleakala, Hawaii, USA on February 10, 2019. Commercial power to TLRS-4 at Haleakala has been restored.

  • VLBI antenna at McDonald ObservatoryNew MGO VLBI Antenna Passes Site Acceptance Test

    Intertronic Solutions Inc. completed the installation of the Space Geodesy Project’s new 12-meter VLBI antenna at the McDonald Observatory in Texas. An engineering room-temperature feed, developed and installed by MIT Haystack, was used to support the pointing tests. On February 15, 2019 several extragalactic sources were observed and the antenna successfully passed the Site Acceptance Test (SAT) on February 20, 2019. The MIT Haystack-developed cryogenic broadband signal chain will be installed in April after which the station will be ready to begin commissioning and participating in VGOS test sessions.

    DORIS antenna in the foreground with VLBI antenna in the backgroundThe rear side of the VLBI antenna on its mount with a few people standing around it.The underside of the VLBI antenna with a person in a left near the top.

  • Observatory at HaleakalaTLRS-4 at Haleakala without power

    A winter storm damaged commercial power transmission lines to the observatories on Haleakala, Hawaii, USA. Since February 10, TLRS-4 has been without power.

    The local electric power company estimates repair to take a minimum of 4 weeks and as long as 8 weeks. The team is exploring ways to power the site with a backup generator or by connecting to a nearby observatory that has backup power.

  • ILRS logoPlanning for the 2019 ILRS Technical Workshop has begun

    Planning for the 2019 ILRS Technical Workshop has begun! We ask that you mark your calendars and reserve the date for the next gathering of the ILRS community:

    Dates: October 21-25, 2019
    Location: Stuttgart, Germany

    The workshop will be sponsored by the DLR in Stuttgart, Germany. The program committee is actively working on the defining the theme and session topics for the workshop while the local organizers are planning the workshop logistics.

    The first circular for the workshop will be issued in the very near future.

    We hope you will consider attending the workshop!

  • Laser beam pointing at moonLunar Laser Ranging featured on the "Today" show

    NBC Sunday Today recently reported on lunar laser ranging activities at the APOLLO system in Sunspot NM.

  • Richard BiancaleThe Passing of Richard Biancale

    It is with profound sadness that we must announce to you the passing our colleague, Dr. Richard Biancale, geodesist, recently retired from the CNES in September 2018, and most recently working at the GFZ (Oberpfaffenhofen) with Dr. Frank Flechtner on GRACE Follow-On. We were informed of his death on Monday February 4, 2019 from a heart attack while skiing in the Alps.

    Richard had a long and distinguished career in Space Geodesy. He received his Ph.D. in 1978 from the University Pierre and Marie Curie in Paris (France) while working under Professor Cristoph Reigber at the Technical University of Munich (Germany). He worked as a research scientist at the University of São Paulo, at the DGFI (Deutsches Geodãtisches Forschungsinstitut) in Munich (Germany), and at CERGA (Centre d'Etudes et de Recherches en Géodynamique et Astronométrie) Grasse (France), before joining the French Space Agency, the CNES (Toulouse, France) in 1982 as a scientific engineer.

    Under the direction of Michel Lefebvre, one of his first jobs at the CNES was to define the DORIS tracking system for the TOPEX/Poseidon mission. Since 1984, he was very involved in the French-German cooperation on gravity field modeling, first with the GRIM models, and then with the EIGEN models after the launches of CHAMP and GRACE. He served as the scientific manager of the Stella laser geodetic satellite, launched in 1993. Under the direction of Dr. Georges Balmino, he became chief of the "Terrestrial and Planetary Geodetic Department" of the CNES in 1992. He received his "Habilitation" in 2006 and, starting in 2008, served as Executive Director of the Groupe de Recherche de Géodésie Spatiale (GRGS), a French national group that gathers 120 researchers from organizations involved in Space Geodesy studies.

    Over the course of his career he has supervised and inspired more than a dozen Ph.D students and served as a mentor to many colleagues and young scientists. Understanding the importance of training the next generation of scientists in satellite geodesy, he has taught geodesy for over 25 years at engineer schools (e.g. ENSG [École de la Géomatique/National School of Geographic Sciences], ENSTA [École Nationale Supérieure de Techniques Avancées]), at universities (e.g. Paris VI), and short training courses (e.g. GRGS Summer School).

    Throughout his career he has worked assiduously to improve the quality of geodetic data, and to advance the science obtained from these data. He was a strong proponent of the need for improving the International Terrestrial Reference Frame (ITRF), supporting the contributions to the IDS, IGS, ILRS, IVS and IERS. He has participated and led national and international proposals for new innovative space missions that would continue to advance the contribution of geodesy to science and society. Most recently, before and after his retirement from CNES, he worked to advance the proposal for the Tahiti Geodetic Observatory, a fundamental station including VLBI, SLR, GNSS and DORIS whose geographic location would be of prime importance to the ITRF and to the mm-level goals of the Global Geodetic Observing System (GGOS) in the next decade.

    As many of his colleagues noticed, Richard Biancale had a joie de vivre. He was a charming, free, passionate and cheerful man who embraced life whether it was in a fine restaurant after a scientific meeting, sailing around the Mediterranean or across the Atlantic on his catamaran, "RaphyO2", or visiting interesting cultural or natural locales. As his colleagues, we were all privileged to enjoy his friendship. We lament this tragic loss.

    To his family, including wife, Irmtraud, and four children, Raphaël, Philipp, Johannes & Jocelyne, we extend our deepest sympathy and most heartfelt condolences.

    Frank Lemoine
    (NASA Goddard Space Flight Center, Greenbelt, Maryland, U.S.A)
    Laurent Soudarin
    (Collecte Localisation Satellites, Ramonvile-Saint Agne, FRANCE)
    Jean-Michel Lemoine & Pascale Ferrage
    (Centre Nationale d' Études Spatiales, Toulouse, FRANCE)
    Jean-Paul Boy
    (EOST, University of Strasbourg, Strasbourg, FRANCE)