https://lunarpedia.org/index.php?action=history&feed=atom&title=Farside_Communication 2026-04-27T12:07:22Z Revision history for this page on the wiki MediaWiki 1.34.2 https://lunarpedia.org/index.php?title=Farside_Communication&diff=24938&oldid=prev 2013-04-11T17:34:13Z

<p>addition</p> <table class="diff diff-contentalign-left" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 17:34, 11 April 2013</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l13" >Line 13:</td> <td colspan="2" class="diff-lineno">Line 13:</td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>There are various proposals for communications relay satellites, but it is a difficult problem to solve.    Earth has [[geostationary]] satellites which are in stable orbits, hovering constantly over a point on the Earth's surface.  Unfortunately, unlike Earth, the Moon has no equivalent of [[geosynchronous]] orbits.   </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>There are various proposals for communications relay satellites, but it is a difficult problem to solve.    Earth has [[geostationary]] satellites which are in stable orbits, hovering constantly over a point on the Earth's surface.  Unfortunately, unlike Earth, the Moon has no equivalent of [[geosynchronous]] orbits.   </div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>There are <del class="diffchange diffchange-inline">basically two </del>options for <del class="diffchange diffchange-inline">farside </del>relay satellites.&lt;Br&gt;  </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>There are <ins class="diffchange diffchange-inline">at least four </ins>options <ins class="diffchange diffchange-inline">available </ins>for relay satellites.&lt;Br&gt;  </div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>====Option 1) Located at [[GFDL:Lagrangian point|Lagrange Libration points]]====</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>====Option 1) Located at [[GFDL:Lagrangian point|Lagrange Libration points]]====</div></td></tr> <tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l23" >Line 23:</td> <td colspan="2" class="diff-lineno">Line 23:</td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This option would be to have a large constellation of several [[Molniya]] type low orbiting relay satellites in elliptical polar orbits.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This option would be to have a large constellation of several [[Molniya]] type low orbiting relay satellites in elliptical polar orbits.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">====Option 3) Halo Orbit Satellite==== </ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">The [http://en.wikipedia.org/wiki/Halo_orbit halo orbit] about the Earth/moon L2 point is roughly a circular path in the Earth/moon reference frame. The path lies in a plane perpendicular to the line going through the Earth's and moon's centers of gravity and about as far from the moon as the L2 point.  The Earth and the far side of the moon can both be constantly visible from such an orbit.  However the halo orbit is not dynamically stable so repeated stationkeeping adjustments would be required to maintain the orbit.  </ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"> </ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">====Option 4) Lissajous Orbits====</ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">[http://en.wikipedia.org/wiki/Lissajous_orbit Lissajous orbits] about L2 are also not dynamically stable and differ from the halo orbit in being differently shaped non periodic paths about the L2 point.  </ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"> </ins></div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===See also===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===See also===</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <!-- diff cache key lunarpedia_prod-mw_:diff::1.12:old-10849:rev-24938 --> </table>

Farred https://lunarpedia.org/index.php?title=Farside_Communication&diff=10849&oldid=prev 2007-10-07T14:37:05Z

<p>info</p> <p><b>New page</b></p><div>==Farside Communication==<br /> <br /> Communications between the Earth and the farside of the Moon is challenging, and currently impossible, because there is no line of sight between the Earth and the far side.<br /> <br /> ===Optical Fiber Cables===<br /> <br /> One option would be to install a large fiber optic cable across the lunar surface to a repeater station on the lunar limb.<br /> <br /> ===Chain of Microwave Towers===<br /> <br /> ===Communications relay satellites===<br /> <br /> There are various proposals for communications relay satellites, but it is a difficult problem to solve. Earth has [[geostationary]] satellites which are in stable orbits, hovering constantly over a point on the Earth's surface. Unfortunately, unlike Earth, the Moon has no equivalent of [[geosynchronous]] orbits. <br /> <br /> There are basically two options for farside relay satellites.&lt;Br&gt; <br /> <br /> ====Option 1) Located at [[GFDL:Lagrangian point|Lagrange Libration points]]====<br /> <br /> The problem here is that the [[GFDL:Lagrangian point|Lagrange points]] are many tens of thousands of kilometers from the lunar surface, which results in large space attenuation, adversely affecting the respective link budget, and introducing more round trip time delays.&lt;BR&gt;<br /> <br /> ====Option 2) Molniya Satellites====<br /> <br /> This option would be to have a large constellation of several [[Molniya]] type low orbiting relay satellites in elliptical polar orbits.<br /> <br /> ===See also===<br /> <br /> * [[Communication]]<br /> <br /> <br /> [[Category:Settlement]]<br /> [[Category:Components]]<br /> [[Category:Communications]]<br /> [[Category:Internet]]<br /> [[Category:Physics]]<br /> [[Category:Hardware Plans]]<br /> [[Category:Hardware]]<br /> [[Category:Architecture]]<br /> [[Category:Business]]</div>

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