DOCSLIB.ORG

The Lageos System

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Lageos System NASA TECHNICAL NASA TM X-73072 MEMORANDUM (NASA-TB-X-73072) liif LAGECS SYSTEM (NASA) E76-13179 68 p BC $4.5~ CSCI 22E Thls Informal documentation medium is used to provide accelerated or speclal release of technical information to selected users. The contents may not meet NASA formal editing and publication standards, my be re- vised, or may be incorporated in another publication. THE LAGEOS SYSTEM Joseph W< Siry NASA Headquarters Washington, D. C. 20546 NATIONAL AERONAUTICS AND SPACE ADMlNlSTRATlCN WASHINGTON, 0. C. DECEMBER 1975 1. i~~1Yp HASA TW X-73072 4. Titrd~rt. 5.RlpDltDM December 1975 m UG~SSYSEM 6.-0-cad8 . 7. A#umrtsI ahr(onninlOlyceoa -* Joseph w. Siry . to. work Uld IYa n--w- WnraCdAdbar I(ASA Headquarters Office of Applications . 11. Caoa oc <irr* 16. i+ashingtcat, D. C. 20546 12TmdRlponrrd~~ 12!3mnm&@~nsnendAddrs Technical Memorandum 1Sati-1 Aeronautics and Space Adninistxation Washington, D. C. 20546 14. sponprip ~gmcvu 15. WDPa 18. The LAGEOS system is defined and its rationale is daveloped. This report was prepared in February 1974 and served as the basis for the LAGMS Satellite Program development. Key features of the baseline system specified then included a circular orbit at 5900 km altitude and an inclination of lloO, and a satellite 60 cm in diameter weighing same 385 kg and mounting 440 retro- reflectors, each having a diameter of 3.8 cm, leaving 30% of the spherical surface available for reflecting sunlight diffusely to facilitate tracking by Baker-Nunn cameras, The satellite weight was increased to 411 kg in the actual design thr~aghthe addition of a 4th-stage apogee-kick motor. The number and diameter of the retroreflectors are now 426 and 3.81 a'.resvectively. The net effect of these partially compensating changes is not significant. The diffusely reflecting area was increased to 47% of the satellite surface. 17. IW Word, 6u@mstdby AumalS)) 18. Dimiknia, Strranent Unclassified - UnlimSted Cat. I8 10. SIEvitv clad. (01 this mport) 20. Sruity Mf.(of thh m) 21. ruo. of P- a. Ria' Unclassi fLed Unclassified 67 $4.25 ; The General LhfSOS Review ................................ 3 A . The Orbital Altitude ................................ 34 Bo The Orutal Intanat- ............................. 39 The I,AGHlS Retmmflectar MW........................ W A . The Retmreflectar .................................. 1. The Retrareflector Diameter ................... .. 41 2 . Coat~s........................................ 43 3 . The Dihedral Angle .............................. 43 B . The Retroreflector Array ............................ 45 1. The ,cess kpth ................................ 45 2. The Satellite Mameter And The Number of Retroreflectors ............... 45 3 . Wra Tracking ................................. 47 C . Test4,ng and Handling A.ocedures ..................... 5C A. The Orbit ........................................... 51 1. The Eccent~ricity................................ 51 2 . The Inclination ................................. 92 iii 3 . The Altitude .................................... 53 a . Resollance Effects Associated Kth a Specific Altitude Region .................. 53 b . General Considerations ................... ... 53 . 8. The Satellite Mass .................................. 55 C . Attitude Determination .............................. 55 V . Ac-1-nts ........................................ 59 VI . Rgerences .............................................. 60 . 1. U04tX Qgstem Nominal Baseline Parameters ................... 2 2. The General LACa310S Review. October ll. 1973. Atseadance ..... 4 3. HDPAP ObJectives ........................................... 5 4. Earth and Ocean Physics Application Program ................. 6 5 • h~re~mntRequi~~m~t~ Sv mmm....emmemme....m*mm*memm. 7 6 . Barth Qnamics Experiments .................................. 8 7 . System Capabilities an3 Wlestoines ......................... 9 8 . LAGXIS Program Objectives .................................. 10 9 . LAGms ............................**...*.*..*.**.....*.***.11 10. Orbit Selection Cansiderations ..............................12 ll. Planned and Possible Laser Sites ......................... 13 l.2. Possible Laser Sites ....................................... U, 13. San Andreas Fault Bxperintent ............................... 15 l4 . LAGS8 Mission Objectives .................................. 16 15. Mission Objectives ......................................... 17 16. Fact.ars Influencing 3Qhemeris Accuracg ..................... 18 17. Geopotential Model &mrs .................................. 19 18. Surface Force Model Bmrs ................................. 20 19. Radiation Perturbations vs Orbit Altitude .................. 21 20 . Hagnitudes of Peurbing Forces ............................ 22 2l Orbit Parameters ........................................... 23 22 . Error Budget For Range Measurements ................... .... 24 23 . Satellite PBFameters ...................................... 25 24 . Received Signal Levels ............................. 26 25 . Spherical Segment Retrmeflection Area ................... 27 Time History of The Echo Signal .......................... 28 Reflectivity Versus Angle of Incidence ................... 29 Beam Pattern at No& Incidence ......................... 30 Effective Reflecting of Segments of LA- ............... 31 Computed Probability Distribution of Retroreflected Pulses.32 Retroreflectcr Configuration ............................. 33 Estimated Orbit Perturbation Uncertainties For Certain LA- Alternatives .............................. 36 Estimated Relative Effectiveness of Alternative LkGEDS Orbits for Earth Dynamics Measurements ............ 37 The LAGIDS Retroreflector Review. October 29. 1973. Attendance ............................. 42 Retroreflector hay Gain as a Function of Dihedral Angle Offset ............................................. 44 Effect of Recessing Cube Corners ......................... 46 Signal Strengths ........................ ... ...... 48 LAGHIS Retroreflector Array Parameters ................... 49 ~IksonanceEffects Associated With A Specific Attitude Recion ................................. 54 Delta Launch Vehicle Capabilities ........................ 56 FOREWORD The LAGEOS system is defined and its rationale is developed. his report was prepared in February 1974 and served as the basis for the LAGEOS Satellite Program development. Baseline parameter values specified then and those actually selected for the design are as follows: Value Baseline Actual Parameter Feb. 1974 Design Altitude (km) 5900 5900 Eccentricity 0 0 Diameter of Satellite (an) 60 60 Weight of Satellite (kg) 385 411 Number of Retroreflectors 440 426 Retroreflector Diameter (cm) 3.8 3.81 Diffusely Reflecting Surface ($1 30 47 Dihedral Angle Offset (arc sec) 1.5 1.25 Recess Depth (rain) 1 1 Ratio of Moments of Inertia 1.1 1.03 The satellite weight was increased in the actual design as a result of launch vehicle modifications, which included the addi- tion of a 4th-stage apogee-kick motor. The smaller number of retro- reflectors is compensated for to a limited extent by the slightly larger retroreflector diameter. The net effect on performance is not significant. Covering the retroreflector mounting rings with aluminum, which detailed analysis of thermal and other factors showed to be feasible, increased by more than half the portion of the spherical surface area available for diffusely reflecting sunlight for Baker-Nunn camera tracking. Measuremt ~tsof a number of retroreflection patterns showed that a dihedral angle of 90° + 1225 gave an energy maximum in the aberration annulus, hence this value was used instead of a theoretical estimate which was the basis for the earlier figure for the offset. The smaller moment of inertia ratio resulted in suitable stability character- istics for the satellite, as well as a considerable simplification in the fabrication process. The LA- program, centered around the first new spacecraft in the NASA Earth and Ocean F'hysics Applications Program (BOPAP), is entering an implementation phase as various aspects of the Phase B Definition Study get underway at the Marshall Space Flight Center. (1) A review cf the LAGEXIS F?rogramls objectives and scientific and technical features is in progress. The initial aims have been to review the study entitled "Use of a Passive Stable Satellite for Earth Physics Applicationsn which had been conducted by the Srnithsonian Astrophysical Observatory (SAO), and to consider other views related to the orbit altitude and inclination and the satellite size and mass in order to provide a basis for the specification of the LAGEXIS System as a basis for the Phase B Definition Study. (2) These processes were begun at meetings on October 11, 1973, at which these latter points were discussed in considerable detail. Aspects of the SAO Study having to do with the retroreflectors themselves were considered at a meeting or. October 29, 1973. (2) Both meetings revealed the need for further imatigation cf a number of specific points. Various studies have been conducted or initiated in response to the needs indicated during these meetings and in subsequent discussions. Ter;F,ai;ive conclusions reached at these meetings and later on the basis of a number of the studies and additional discussions are described here, and the corresponding guantities are listed in Figure 1. These values LAGEos msm NOMINAL BASELINE PARAMETP;RS Altitude Inclination 110 deg Eccentricity 0 Diameter of Satellite 60 cm Weight of Satellite
Load more

Recommended publications
  • Lageos Orbit Decay Due to Infrared Radiation from Earth
    https://ntrs.nasa.gov/search.jsp?R=19870006232 2020-03-20T12:07:45+00:00Z View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by NASA Technical Reports Server Lageos Orbit Decay Due to Infrared Radiation From Earth David Parry Rubincam JANUARY 1987 NASA Technical Memorandum 87804 Lageos Orbit Decay Due to Infrared Radiation From Earth David Parry Rubincam Goddard Space Flight Center Greenbelt, Maryland National Aeronautics and Space Administration Goddard Space Flight Center Greenbelt, Maryland 20771 1987 1 LAGEOS ORBIT DECAY r DUE TO INFRARED RADIATION FROM EARTH by David Parry Rubincam Geodynamics Branch, Code 621 NASA Goddard Space Flight Center Greenbelt, Maryland 20771 i INTRODUCTION The Lageos satellite is in a high-altitude (5900 km), almost circular orbit about the earth. The orbit is retrograde: the orbital plane is tipped by about 110 degrees to the earth’s equatorial plane. The satellite itself consists of two aluminum hemispheres bolted to a cylindrical beryllium copper core. Its outer surface is studded with laser retroreflectors. For more information about Lageos and its orbit see Smith and Dunn (1980), Johnson et al. (1976), and the Lageos special issue (Journal of Geophysical Research, 90, B 11, September 30, 1985). For a photograph see Rubincam and Weiss (1986) and a structural drawing see Cohen and Smith (1985). Note that the core is beryllium copper (Johnson et ai., 1976), and not brass as stated by Cohen and Smith (1985) and Rubincam (1982). See Table 1 of this paper for other parameters relevant to Lageos and the study presented here.
    [Show full text]
  • The Evolution of Earth Gravitational Models Used in Astrodynamics
    JEROME R. VETTER THE EVOLUTION OF EARTH GRAVITATIONAL MODELS USED IN ASTRODYNAMICS Earth gravitational models derived from the earliest ground-based tracking systems used for Sputnik and the Transit Navy Navigation Satellite System have evolved to models that use data from the Joint United States-French Ocean Topography Experiment Satellite (Topex/Poseidon) and the Global Positioning System of satellites. This article summarizes the history of the tracking and instrumentation systems used, discusses the limitations and constraints of these systems, and reviews past and current techniques for estimating gravity and processing large batches of diverse data types. Current models continue to be improved; the latest model improvements and plans for future systems are discussed. Contemporary gravitational models used within the astrodynamics community are described, and their performance is compared numerically. The use of these models for solid Earth geophysics, space geophysics, oceanography, geology, and related Earth science disciplines becomes particularly attractive as the statistical confidence of the models improves and as the models are validated over certain spatial resolutions of the geodetic spectrum. INTRODUCTION Before the development of satellite technology, the Earth orbit. Of these, five were still orbiting the Earth techniques used to observe the Earth's gravitational field when the satellites of the Transit Navy Navigational Sat­ were restricted to terrestrial gravimetry. Measurements of ellite System (NNSS) were launched starting in 1960. The gravity were adequate only over sparse areas of the Sputniks were all launched into near-critical orbit incli­ world. Moreover, because gravity profiles over the nations of about 65°. (The critical inclination is defined oceans were inadequate, the gravity field could not be as that inclination, 1= 63 °26', where gravitational pertur­ meaningfully estimated.
    [Show full text]
  • Draft American National Standard Astrodynamics
    BSR/AIAA S-131-200X Draft American National Standard Astrodynamics – Propagation Specifications, Test Cases, and Recommended Practices Warning This document is not an approved AIAA Standard. It is distributed for review and comment. It is subject to change without notice. Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to provide supporting documentation. Sponsored by American Institute of Aeronautics and Astronautics Approved XX Month 200X American National Standards Institute Abstract This document provides the broad astrodynamics and space operations community with technical standards and lays out recommended approaches to ensure compatibility between organizations. Applicable existing standards and accepted documents are leveraged to make a complete—yet coherent—document. These standards are intended to be used as guidance and recommended practices for astrodynamics applications in Earth orbit where interoperability and consistency of results is a priority. For those users who are purely engaged in research activities, these standards can provide an accepted baseline for innovation. BSR/AIAA S-131-200X LIBRARY OF CONGRESS CATALOGING DATA WILL BE ADDED HERE BY AIAA STAFF Published by American Institute of Aeronautics and Astronautics 1801 Alexander Bell Drive, Reston, VA 20191 Copyright © 200X American Institute of Aeronautics and Astronautics All rights reserved No part of this publication may be reproduced in any form, in an electronic retrieval
    [Show full text]
  • Determination of the Geocentric Gravitational Constant from Laser
    VOL. 5, NO. 12 GEOPHYSICALRESEARCH LETTERS DECEMBER1978 DETERMINATION OF THE GEOCENTRI½ GRAVITATIONAL CONSTANT FROM LASER RANGING ON NEAR-EARTH SATELLITES 1 2 • Francis 3. Lerch, Roy E. Laubscher, Steven M. Klosko 1 1 David E. Smith, Ronald Kolenkiewicz, Barbara H. Putney, 1 2 James G. Marsh, and Joseph E. Brownd 1 GeodynamicsBranch, GoddardSpace Flight Center Computer Sciences Corporation, Silver Spring, Maryland 3EG&GWashington Analytical ServicesCenter, Inc., Riverdale, Maryland Abstract. Laser range observations taken on earth plus moon Ms/(Me + Mm) of 328900.50+ the near-earth satellites of Lageos (a -- 1.92 .03. Assuming the AU and the IAG value of c, e.r.), Starlette (a -- 1.15 e.r.), BE-C (a = 1.18 this yields a value of GM of 398600.51 + .03 when e.r.) and Geos-3 (a -- 1.13 e.r.), have been using an earth to moon mass ratio of 81.3007 combined to determine an improved value of the (Wong and Reinbold, 1973). geocentric gravitational constant (GM). The In this paper we use near-earth laser ranging value of GM is 398600.61 km3/sec2, based upon a in a new determination of GM. These results speed of light, c, of 299792.5 kin/sec. Using the basically confirm those obtained from inter- planetary and lunar laser experiments, but km/secIAGadopted scales valueGM to of 398600.44 c equallin• km /sec299792.458 2. The further reduces the uncertainty of GM. uncertainty in this value is assessed to be + .02 km3/sec2. Determinations of GM from the-data Near Earth Laser Ranging Experiment. The taken on these four satellites individually show experiment reported here was performed in the variations of only .04 km3/sec2 from the combined development of the recent Goddard Earth Models result.
    [Show full text]
  • A New Laser-Ranged Satellite for General Relativity and Space Geodesy IV
    A new laser-ranged satellite for General Relativity and Space Geodesy IV. Thermal drag and the LARES 2 space experiment 1,2 3 3 Ignazio Ciufolini∗ , Richard Matzner , Justin Feng , David P. Rubincam4, Erricos C. Pavlis5, Giampiero Sindoni6, Antonio Paolozzi6 and Claudio Paris2 1Dip. Ingegneria dell'Innovazione, Universit`adel Salento, Lecce, Italy 2Museo della fisica e Centro studi e ricerche Enrico Fermi, Rome, Italy 3Theory Group, University of Texas at Austin, USA 4NASA Goddard Space Flight Center, Greenbelt, Maryland, USA 5Goddard Earth Science and Technology Center (GEST), University of Maryland, Baltimore County, USA 6Scuola di Ingegneria Aerospaziale , Sapienza Universit`adi Roma, Italy In three previous papers we presented the LARES 2 space experiment aimed at a very accurate test of frame-dragging and at other tests of fundamental physics and measurements of space geodesy and geodynamics. We presented the error sources in the LARES 2 experiment, its error budget, Monte Carlo simulations and covariance analyses confirming an accuracy of a few parts per thousand in the test of frame-dragging, and we treated the error due to the uncertainty in the de Sitter effect, a relativistic orbital perturbation. Here we discuss the impact in the error budget of the LARES 2 frame-dragging experiment of the orbital perturbation due to thermal drag or thermal thrust. We show that the thermal drag induces an uncertainty of about one part per thousand in the LARES 2 frame-dragging test, consistent with the error estimates in our previous papers. arXiv:1911.05016v1 [gr-qc] 12 Nov 2019 1 Introduction: thermal drag and LARES 2 We recently described a new satellite experiment to measure the General Relativistic phenomenon know as frame dragging, or the Lense-Thirring effect.
    [Show full text]
  • LARES, Laser Relativity Satellite
    LARES,LARES, LaserLaser RelativityRelativity Satellite:Satellite: TowardsTowards aa OneOne PercentPercent MeasurementMeasurement ofof FrameFrame DraggingDragging byby LAGEOS,LAGEOS, LAGEOSLAGEOS 2,2, LARESLARES andand GRACEGRACE by ΙΙΙgnazio Ciufolini presented by Rolf Koenig (Univ. Salento) (GFZ) A. Paolozzi*, E. Pavlis* , R. Koenig* , J. Ries* , R. Matzner* , G. Sindoni*, H. Neumayer* *Sapienza Un. Rome, *Maryland Un ., *GFZ-German Research Centre for Geosciences-Potsdam, *Un. Texas Austin 17 Int. Workshop on Laser Ranging, Bad Kötzting, 16-3-2010 ContentContent BRIEF INTRODUCTION ON FRAME -DRAGGING and GRAVITOMAGNETISM EXPERIMENTS * The 2004 -2007 measurements using the GRACE Earth ’s gravity models and the LAGEOS satellites • * LARES: 2011 DRAGGINGDRAGGING OFOF INERTIALINERTIAL FRAMESFRAMES ((FRAMEFRAME --DRAGGINGDRAGGING asas EinsteinEinstein namednamed itit inin 1913)1913) The “local inertial frames ” are freely falling frames were, locally, we do not “feel ” the gravitational field, examples: an elevator in free fall, a freely orbiting spacecraft. In General Relativity the axes of the local inertial frames are determined by gyroscopes and the gyroscopes are dragged by mass -energy currents, e.g., by the Earth rotation. Thirring 1918 Braginsky, Caves and Thorne 1977 Thorne 1986 I.C. 1994-2001 GRAVITOMAGNETISM:GRAVITOMAGNETISM: ff ramerame --draggingdragging isis alsoalso calledcalled gravitomagnetismgravitomagnetism forfor itsits formalformal analogyanalogy withwith electrodynamicselectrodynamics InIn electrodynamicselectrodynamics
    [Show full text]
  • The Effect of Variable Gravity on the Fractal Growth
    1 Fractal Growth on the Surface of a Planet and in Orbit around it 1Ioannis Haranas, 2Ioannis Gkigkitzis, 3Athanasios Alexiou 1Dept. of Physics and Astronomy, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada 2Departments of Mathematics and Biomedical Physics, East Carolina University, 124 Austin Building, East Fifth Street, Greenville, NC 27858-4353, USA 3Department of Informatics, Ionian University, Plateia Tsirigoti 7, Corfu, 49100, Greece Abstract: Fractals are defined as geometric shapes that exhibit symmetry of scale. This simply implies that fractal is a shape that it would still look the same even if somebody could zoom in on one of its parts an infinite number of times. This property is also called self-similarity with several applications including nano-pharmacology and drug nanocarriers. We are interested in the study of the properties of fractal aggregates in a microgravity environment above an orbiting spacecraft. To model the effect we use a complete expression for the gravitational acceleration. In particular on the surface of the Earth the acceleration is corrected for the effect of oblateness and rotation. In the gravitational acceleration the effect of oblateness can be modeled with the inclusion of a term that contains the J2 harmonic coefficient, as well as a term that depends on the square of angular velocity of the Earth. In orbit the acceleration of gravity at the point of the spacecraft is a function of the orbital elements and includes only in our case the J2 harmonic since no Coriolis force is felt by the spacecraft. Using the fitting parameter d =3.0 we have found that the aggregate monomer number N is not significantly affected and exhibits a minute 0.0001% difference between the geocentric and areocentric latitudes of 90 and 0.
    [Show full text]
  • Impact of the Atmospheric Drag on Starlette, Stella, Ajisai, and Lares Orbits
    ARTIFICIAL SATELLITES, Vol. 50, No. 1 – 2015 DOI: 10.1515/arsa-2015-0001 IMPACT OF THE ATMOSPHERIC DRAG ON STARLETTE, STELLA, AJISAI, AND LARES ORBITS Krzysztof So´snica 1,2 1 Astronomical Institute, University of Bern, Bern, Switzerland 2 Institute of Geodesy and Geoinformatics, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland e-mail: [email protected], [email protected] ABSTRACT. The high-quality satellite orbits of geodetic satellites, which are deter- mined using Satellite Laser Ranging (SLR) observations, play a crucial role in providing, e.g., low-degree coefficients of the Earth’s gravity field including geocenter coordinates, Earth rotation parameters, as well as the SLR station coordinates. The appropriate mod- eling of non-gravitational forces is essential for the orbit determination of artificial Earth satellites. The atmospheric drag is a dominating perturbing force for satellites at low altitudes up to about 700-1000 km. This article addresses the impact of the atmospheric drag on mean semi-major axes and orbital eccentricities of geodetic spherical satellites: Starlette, Stella, AJISAI, and LARES. Atmospheric drag causes the semi-major axis de- cays amounting to about Δa = −1.2, −12, −14, and −30 m/year for LARES, AJISAI, Starlette, and Stella, respectively. The density of the upper atmosphere strongly depends on the solar and geomagnetic activity. The atmospheric drag affects the along-track or- bit component to the largest extent, and the out-of-plane to a small extent, whereas the radial component is almost unaffected by the atmospheric drag. Keywords: Satellite Geodesy, Atmospheric Drag, SLR, Mean Orbital Elements 1.
    [Show full text]
  • Lageos 2 Spin Rate and Orientation
    Lageos 2 spin rate and orientation Roger Wood 1, Toshimichi Otsubo 2 & Robert Sherwood 1 1 NERC Space Geodesy Facility, UK 2 Communications Research Laboratory, Japan Abstract The Herstmonceux photometer system (which allows brightness measurements of sunlit satellites to be made simultaneously with laser ranging) has been upgraded to provide 1 millisecond time resolution. Precise timing of solar glints from the front faces of the corner-cube reflectors on Lageos 2 over a 2-year period has yielded a detailed record of the slowing of the satellite's rotation and an accurate determination of the precessional behaviour of the spin axis. These data make possible precise modelling of the non-gravitational forces on the satellite and contribute powerfully to evaluations of their evolution in the long-term. Introduction Each Lageos satellite (see e.g. Minott et al. 1993) carries 426 retro-reflectors inset in the outer aluminium shell surrounding a solid brass cylinder. Each reflector is mounted with its front face perpendicular to the radius vector at the mounting point. Reflectors are distributed over the whole surface of the sphere in rings, equally spaced along lines of “latitude” (where the “equator” is the great circle perpendicular to the axis of rotation of the satellite). Immediately either side of the “equator” are rings of 32 reflectors: then, moving towards the “poles”, successive rings have 32, 31, 31, 27, 23, 18, 12, 6, 1 (at the “pole”) reflectors, giving a total of 213 in each hemisphere. 422 of the reflectors are made of fused silica and 4 of germanium. Figure 1 shows the resultant distribution of reflectors on the surface of the satellite.
    [Show full text]
  • Now 40, NASA's LAGEOS Set the Bar for Studies of Earth 5 May 2016
    Now 40, NASA's LAGEOS set the bar for studies of Earth 5 May 2016 satellite is passive, with no on-board sensors or electronics and no moving parts. Its brass core is covered by an aluminum shell that is dotted with 426 retroreflectors, making the satellite look like a giant golf ball. "LAGEOS is elegantly simple – a ball covered with reflecting prisms," said Stephen Merkowitz, manager of NASA's Space Geodesy Project at the agency's Goddard Space Flight Center in Greenbelt, Maryland. "But it set a new standard for laser ranging and has provided 40 years of continuity for these measurements." The satellite was launched from the Vandenberg The surface of LAGEOS is dotted with 426 cube-corner Air Force Base in California. The design, prisms to reflect laser pulses transmitted from ground development and construction of the orbiter was stations on Earth. One sector of a model is shown here. managed by NASA's Marshall Space Flight Center With LAGEOS, the accuracy of laser ranging in Huntsville, Alabama. measurements improved from about 3 feet (1 meter) to less than half an inch (1 centimeter). Credit: NASA's LAGEOS travels in a stable circular, pole-to-pole Goddard Space Flight Center orbit more than 3,600 miles (5,900 kilometers) above Earth's surface. At this altitude – medium Earth orbit – the satellite feels very little On May 4, 1976, NASA launched a cannonball- atmospheric drag and can be observed by ground shaped satellite that transformed studies of Earth's stations on different continents simultaneously. shape, rotation and gravity field.
    [Show full text]
  • Mass Variation Observing System by High Low Inter-Satellite Links (MOBILE) – a New Concept for Sustained Observation of Mass Transport from Space
    J. Geod. Sci. 2019; 9:48–58 Research Article Open Access R. Pail*, J. Bamber, R. Biancale, R. Bingham, C. Braitenberg, A. Eicker, F. Flechtner, T. Gruber, A. Güntner, G. Heinzel, M. Horwath, L. Longuevergne, J. Müller, I. Panet, H. Savenije, S. Seneviratne, N. Sneeuw, T. van Dam, and B. Wouters Mass variation observing system by high low inter-satellite links (MOBILE) – a new concept for sustained observation of mass transport from space DOI: https://doi.org/10.1515/jogs-2019-0006 Abstract: As changes in gravity are directly related to mass Received October 5, 2018; accepted March 10, 2019 variability, satellite missions observing the Earth’s time varying gravity eld are a unique tool for observing mass transport processes in the Earth system, such as the wa- *Corresponding Author: R. Pail: Technical University of Munich, ter cycle, rapid changes in the cryosphere, oceans, and Institute of Astronomical and Physical Geodesy, Munich, Germany, solid Earth processes, on a global scale. The observation E-mail: [email protected] of Earth’s gravity eld was successfully performed by the J. Bamber: University of Bristol, School of Geographical Sciences, GRACE and GOCE satellite missions, and will be contin- Bristol, UK ued by the GRACE Follow-On mission. A comprehensive R. Biancale: Centre National d’Études Spatiales (CNES), Toulouse, France team of European scientists proposed the next-generation R. Bingham: University of Bristol, School of Geographical Sciences, gravity eld mission MOBILE in response to the Euro- Bristol, UK pean Space Agency (ESA) call for a Core Mission in the C. Braitenberg: University of Trieste, Dptm.
    [Show full text]
  • Iris-LAGEOS 2 Mission
    1991 (28th) Space Achievement: A Global The Space Congress® Proceedings Destiny Apr 24th, 2:00 PM - 10:00 AM Paper Session II-A - Iris-LAGEOS 2 Mission Roberto Ibba Italian Space Agency, Rome, Italy Giovanni Rum Italian Space Agency, Rome, Italy Franco Varesio Italian Space Agency, Rome, Italy Enrico Buratti Italian Space Agency, Rome, Italy Pratizia Buratti Italian Space Agency, Rome, Italy Follow this and additional works at: https://commons.erau.edu/space-congress-proceedings Scholarly Commons Citation Ibba, Roberto; Rum, Giovanni; Varesio, Franco; Buratti, Enrico; and Buratti, Pratizia, "Paper Session II-A - Iris-LAGEOS 2 Mission" (1991). The Space Congress® Proceedings. 17. https://commons.erau.edu/space-congress-proceedings/proceedings-1991-28th/april-24-1991/17 This Event is brought to you for free and open access by the Conferences at Scholarly Commons. It has been accepted for inclusion in The Space Congress® Proceedings by an authorized administrator of Scholarly Commons. For more information, please contact [email protected]. Canaveral Council of Technical Societies Announces the Twenty-Eighth Space Congress April 23, 24, 25, 26, 1991 P.O. Box 321333, Cocoa Beach, FL 32932 COCOA iiACH. fl PAPER presented by Alenia Alenia Spazio IRIS-LAGEOS 2 MISSION »AUTHORS Roberta IBBA, Giovanni RUM (ASI) Franco VARESIO, Enrico BERUTO Patrizia BURATTI (Alenia) • ADDRESS ALENIA Alenia Spazio Corso Marche 41 10146 TORINO (Italy) • TELEPHONE ill.-71Ji.W5/ 7UQ.708 • FAX 011-723307/724807 •TELEX 221235 AERSPZ I 4-13 IRfS-LAGEOS 2 MISSION Roberta IBBA, Giovanni RUM Franco VARESIO, Enrico BERUTO, Patrizia BURATTI A.S.I. ALENIA(*) Agenzia Spaziale Italiana Alenia Spazio Roma - Italy Torino - Italy ABSTRACT The developing and launching of LAGEOS 2 must be considered an important step in the evolution of Italian space and scientific activities.
    [Show full text]