On February 23, 2011 please join the Lunar Commerce Seminar Series for a talk by Doug Currie, entitled A LUNAR LASER RANGING RETROREFLECTOR FOR THE 21ST CENTURY
REFERENCES from the talk are listed here: http://lunarscience.arc.nasa.gov/articles/currie_references.
If you have any questions for the speaker, you can contact him personally.
See the posted description for the talk below.
A Lunar Laser Ranging Retroreflector for the 21st Century
Over the past forty years, Lunar Laser Ranging (LLR) to the Apollo Cube Corner Retroreflector (CCR) arrays has supplied most of the significant tests of General Relativity as well as providing significant information on the interior of the moon. Professor Currie will review the reasons for performing the Lunar laser ranging and discuss the methods used to obtain the data upon which the science has been established.
More precisely, the LLR program has evaluated the PPN parameters and addressed, for example, the possible change in the gravitational constant and the properties of the self-energy of the gravitational field. In addition, LLR has provided significant information on the composition and origin of the moon. These arrays are the only experiment of the Apollo program that are still in operation. Initially the Apollo Lunar Arrays contributed a negligible portion of the error budget used to achieve these results. Over the decades, the performance of ground stations has greatly upgraded so that the ranging accuracy has improved by more than two orders of magnitude. Now, after forty years, because of the lunar librations the existing Apollo retroreflector arrays contribute significant fraction of the limiting errors in the range measurements. The University of Maryland, as the Principal Investigator for the original Apollo arrays, is now proposing a new approach to the Lunar Laser CCR array technology. The investigation of this new technology, with Professor Currie as Principal Investigator, is currently being supported by two NASA programs and, in part, also by INFN/LNF in Frascati, Italy and ASI. Thus after the proposed installation on the next Lunar landing, either robotic or manned, the new arrays will support ranging observations that are a factor 100 more accurate than the current Apollo LLRRAs, from the centimeter level to the tens of microns level. The new fundamental physics and the lunar physics that this new LLRRA can provide will be described. Finally, In the design of the new retroreflectors, there are three major challenges. These will be described and the methods to mitigate these problems will be explained.
Douglas Currie is a Professor Emeritus in Physics at the University of Maryland, College Park. He was a key member of the original Apollo-era Lunar Laser Ranging Team, winning an Apollo Achievement Award for his work, and was Scientific Director of the Lunar Laser Ranging Station at Macdonald Observatory in 1969-1970. Professor Currie has been extensively involved with the development of unique new optical instrumentation and the application of this equipment to both astrophysical observing programs and DoD and Commercial Applications. He developed the “Two-Color Refractometer” method used to determine atmospheric refraction to provide corrections to ground-based astrometric measurements. He also developed a satellite package for space navigation using the two-color technique. He was on the IDT team for the WFPC of the Hubble Space Telescope. He has participated in over 20 papers on the analysis of the IDT team data, as well as observations of eta Carinae and the satellites of the outer planets using the WFPC on the Hubble Space Telescope. He has developed image processing software for the Hubble Space Telescope, for planetary astronomy and for other US Government applications. More recently, he has been observing and developing image-processing methods and software for Adaptive Optics. Over the past ten year, he has investigated the massive exploding star, eta Carinae. He has observed this object on various telescopes. Dr. Currie is a member of the NLSI LUNAR team lead by Dr. Jack Burns.
WHEN:Wednesday, February 23, 2011 18:00 GMT (10 AM Pacific)
HOW TO PARTICIPATE:
TO JOIN USING A VIDEOCONFERENCING SYSTEM:
Please RSVP to Ricky Guest (Ricky.Guest@nasa.gov) if you will be joining by Polycom. Do not connect to the teleconference if you will be joining by Polycom.
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Posted: Feb 10, 02:44 pm