ISS solar panels

[vgorelik]

<span style="font-size:10pt;font-family:Verdana"><font size="1">One of the ISS solar panel arrays is not pointing toward the Sun in latest pictures.&nbsp; Is this due to the damage to one of the SARJs, or simply a coincidence?&nbsp; If former, what are the contingencies in case of failure of the second&nbsp;SARJ?</font></span>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>One of the ISS solar panel arrays is not pointing toward the Sun in latest pictures.&nbsp; Is this due to the damage to one of the SARJs, or simply a coincidence?&nbsp; If former, what are the contingencies in case of failure of the second&nbsp;SARJ? <br />Posted by vgorelik</DIV><br /><br />Which latest pictures? When was it taken? From where?</p><p>Have you got a link to one of the pictures?</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[vgorelik]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Which latest pictures? When was it taken? From where?Have you got a link to one of the pictures? <br />Posted by MeteorWayne</DIV></p><p>I shouldn't have said "the latest," but there are quite a few similar to this one &nbsp;&nbsp;http://spaceflight.nasa.gov/gallery/images/station/assembly/html/s122e009880.html</p><p>&nbsp;</p>

 

[erioladastra]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I shouldn't have said "the latest," but there are quite a few similar to this one &nbsp;&nbsp;http://spaceflight.nasa.gov/gallery/images/station/assembly/html/s122e009880.html <br />Posted by vgorelik</DIV><br /><br />The starboard SARJ has been "broken" since last fall.&nbsp; They discovered severe vribrations and the race ring it rotates on is pitted and flaking apart.&nbsp; Cause not yet known.&nbsp; The plan is to lubricate, clean up and install new bearings on ULF-2 in the fall of 2008.&nbsp; Then see.&nbsp; Improved power analysis shows we are pretty good for awhile.&nbsp; Plans might be to install a new race ring.&nbsp; All still being worked out.

 

[vgorelik]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The starboard SARJ has been "broken" since last fall.&nbsp; They discovered severe vribrations and the race ring it rotates on is pitted and flaking apart.&nbsp; Cause not yet known.&nbsp; The plan is to lubricate, clean up and install new bearings on ULF-2 in the fall of 2008.&nbsp; Then see.&nbsp; Improved power analysis shows we are pretty good for awhile.&nbsp; Plans might be to install a new race ring.&nbsp; All still being worked out. <br />Posted by erioladastra</DIV><br /><br /><font size="2"><font face="Times New Roman"><font color="#606060">Thank you </font><span><font color="#800080">erioladastra</font><font color="#606060">,</font></span></font></font><font size="2"><font color="#606060"><font face="Times New Roman">&nbsp;</font></font></font> <p style="margin:0in0in0pt" class="MsoNormal"><font face="Times New Roman" size="2" color="#606060">It is nice to know that something is being done to fix this.</font></p><font size="2"><font color="#606060"><font face="Times New Roman">&nbsp;</font></font></font> <p style="margin:0in0in0pt" class="MsoNormal"><font face="Times New Roman" size="2" color="#606060">I wonder if the damaged panels are producing power and are still connected to the station&rsquo;s grid?<span>&nbsp; </span>If not, how halving of the available power affects the station occupancy and experiment capacities?<span>&nbsp;&nbsp; </span>What contingencies are considered in case of failure of the second SARJ?</font></p><font size="2"><font color="#606060"><font face="Times New Roman">&nbsp;</font></font></font><span style="font-size:10pt;color:#606060;font-family:'TimesNewRoman'">I know that Russian segment is to be equipped with a smaller array &ndash; similar to one that produced power to Mir.<span>&nbsp; </span>In case of failure of the second large US array, can the crew seek rescue in Russian segment? Or can this future&nbsp;Russian array provide minimal sustainable power to the entire ISS? </span>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Thank you erioladastra,&nbsp; It is nice to know that something is being done to fix this.&nbsp; I wonder if the damaged panels are producing power and are still connected to the station&rsquo;s grid?&nbsp; If not, how halving of the available power affects the station occupancy and experiment capacities?&nbsp;&nbsp; What contingencies are considered in case of failure of the second SARJ?&nbsp;I know that Russian segment is to be equipped with a smaller array &ndash; similar to one that produced power to Mir.&nbsp; In case of failure of the second large US array, can the crew seek rescue in Russian segment? Or can this future&nbsp;Russian array provide minimal sustainable power to the entire ISS? <br />Posted by vgorelik</DIV><br /><br />It is still producing power, just not the maximum amount.</p><p>IIRC, the russian array cannot feed power to the whole ISS, only the russiand segment, but I'm not sure.</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[ThereIWas2]

<p>The panels themselves are not damaged.&nbsp; Only the alpha joint rotation equipment is damaged.</p><p>The Russian secton uses an entirely different electrical system, running at a much lower voltage than the rest of ISS.&nbsp; Conversion between the two requires DC-to-DC conversion and is not particularly efficient.&nbsp; Also, the Russian panels are sized to power just that section.</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> <p><span class="postbody"><span style="font-style:italic"><br /></span></span></p> </div>

 

[vgorelik]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The panels themselves are not damaged.&nbsp; Only the alpha joint rotation equipment is damaged.The Russian secton uses an entirely different electrical system, running at a much lower voltage than the rest of ISS.&nbsp; Conversion between the two requires DC-to-DC conversion and is not particularly efficient.&nbsp; Also, the Russian panels are sized to power just that section.&nbsp; <br />Posted by ThereIWas2</DIV><br /><br /><span style="color:windowtext"><font size="2"><font face="Times New Roman">I understand that small Russian solar power generators are not a 100% substitute for the large US arrays. The question remains &ndash; would their output be sufficient for life support, altitude control, communication and docking functions?</font></font></span><span style="color:windowtext"><font size="2"><font face="Times New Roman">&nbsp;</font></font></span><span style="font-size:10pt;font-family:'TimesNewRoman'">If SARJ repair job is feasible &ndash; would it be possible to launch several sets of spare SARJ components with the remaining Shuttle missions to ISS for possible future repairs &ndash; I don&rsquo;t think that Progress can accommodate for large-size parts.<span style="color:#606060">&nbsp;<span>&nbsp;</span><span>&nbsp;</span></span></span>

 

[newtons_laws]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;If SARJ repair job is feasible &ndash; would it be possible to launch several sets of spare SARJ components with the remaining Shuttle missions to ISS for possible future repairs &ndash; I don&rsquo;t think that Progress can accommodate for large-size parts.&nbsp;&nbsp;&nbsp; <br />Posted by vgorelik</DIV><br /><br />If it were required to send up new SARJ components after shuttle retirement, and these were too large for Progress to carry, could the larger ESA Automated Transfer Vehicle carry them? <div class="Discussion_UserSignature"> </div>

 

[vgorelik]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>If it were required to send up new SARJ components after shuttle retirement, and these were too large for Progress to carry, could the larger ESA Automated Transfer Vehicle carry them? <br />Posted by newtons_laws</DIV><br /><br />I don't thik so - ATV uses Russian docking technology and equipment and all payloads are transfered through the hatch, which is probably smaller dia then some of the SARJ components.&nbsp; Unless these repair components are somehow attached to the exterior of the vehicle, which is also highly questionable and&nbsp;unrealistic.&nbsp; Additionally, these components would have to be moved from the Russian end&nbsp;of the ISS to the fartherst possible point on its exterior.&nbsp;

 

[Zipi]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I don't thik so - ATV uses Russian docking technology and equipment and all payloads are transfered through the hatch, which is probably smaller dia then some of the SARJ components.&nbsp; Unless these repair components are somehow attached to the exterior of the vehicle, which is also highly questionable and&nbsp;unrealistic.&nbsp; Additionally, these components would have to be moved from the Russian end&nbsp;of the ISS to the fartherst possible point on its exterior.&nbsp; <br />Posted by vgorelik</DIV><br /><br />Maybe HTV is able to carry those?</p><p>&nbsp;http://en.wikipedia.org/wiki/H-II_Transfer_Vehicle</p><p>At least is has an unpressurized cargobay, but I don't know how much SARJ weights and how big it actually is...</p> <div class="Discussion_UserSignature"> </div>

 

[Cygnus_2112]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I understand that small Russian solar power generators are not a 100% substitute for the large US arrays. The question remains &ndash; would their output be sufficient for life support, altitude control, communication and docking functions? </DIV></p><p>&nbsp;</p><p>Only of the russian segment and not the us </p>