ISS Failed Reboost?

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backspace

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Since I don't know about the credibility of this website, just asking if anyone knows about the following:<br /><br />Russian Spacecraft Fails to Raise ISS to Designated Orbit<br />Created: 18.11.2004 11:27 MSK (GMT +3), Updated: 11:27 MSK<br /><br /><br />MosNews<br /><br /><br />The Russian transport spacecraft Progress failed to raise the International Space Station to its designated orbit on Wednesday, the Itar-Tass news agency quoted a top Russian space expert as saying.<br /><br />The head of the ballistic coordination group at the Mission Control Centre outside Moscow, Alexander Kireyev, said that the thrust generated by Progress M-50’s engines had not been sufficient to raise the ISS by almost 4.5 kilometers as planned. According to telemetric data, the orbit was raised by 2.7 kilometers, Kireyev said. <br /><br />According to him, this is enough to enable the docking of the transport ship which will be launched from the Baikonur launch pad on Dec. 23. <br /><br />“The ISS is now at the medium altitude of 358 kilometers,” Kireyev added. <br /><br />According to the Russian Mission Control Centre, the ISS fell by almost eight kilometers since the previous orbit adjustment at the end of September. Specialists have said increased solar activity is to blame.<br /><br />http://www.mosnews.com/news/2004/11/18/issnotlifted_.shtml
 
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najab

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I don't know anything about the MosNews site, but if it is true it's nothing to worry about. They need to start letting the orbit decay a bit anyway - at 350km it's too high for the Shuttle to reach! <img src="/images/icons/wink.gif" />
 
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najab

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Just did a quick check. The latest orbital elements I could find for ISS have it in a 354km x 361km orbit, so it sounds like your story was right.
 
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the_id

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Just as a matter of curiosity; if the ISS were damaged or for some other reason suffered orbital decay such that it could not be reversed, what would the involved governments do? Would they blow it out of the sky or simply plot its trajectory and run like hell?
 
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JonClarke

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Presumably dock a progress to it and deorbit it over the pacific, as was done with Mir.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>
 
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erioladastra

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it is not a big deal. Our plans (e.g. predicted communication links) were slightly off for a few days but there is no serious impact. It has happened before (for other reasons). ANother reboost will be scheduled.
 
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rogers_buck

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>> Presumably dock a progress to it and deorbit it over the pacific, as was done with Mir. <br /><br />Presumably they would evacuate the crew first. (-;<br /><br />
 
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rogers_buck

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Too bad they didn't point the thing the wrong way. We'd get to the moon six years sooner.
 
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backspace

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I got to thinking about this... given the configuration and the sheer MASS of the ISS, I think that to ENSURE that it all came down in the pacific you'd have to blow it to pieces shortly after decellerating it to re-entry speed (unless you came to a dead stop orbitally and then thrusted straight down, but I think you'd need a saturn 1b full of fuel to decellerate the ISS by that much at this point)... through the atmosphere intact it would tumble and break apart irregularly.. you'd get a pretty crazy debris pattern if you left the breakup to itself.. drag on an object that big would be like throwing a lego house into a tornado...
 
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CalliArcale

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You just aim it at the most remote part of the South Pacific. It's a sufficiently large target.<br /><br />Mind you, there were fishing vessels who lodged complaints with Rosaviacosmos when Mir was deorbited, since they were in the danger zone. But realistically, there was no other place to dump it, and none of them got hit.<br /><br />The ISS, if deorbited, would be much like Mir. It would indeed start tumbling and then break into pieces irregularily. But due to conservation of momentum, they'd land in approximately the same area. Part of the trick I believe is to make the deorbit trajectory relatively steep. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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backspace

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I guess I'm more concerned with the aerodynamics of the individual parts... for example, a big solar array might react alot different to atmospheric drag then say, a 3m steel sphere or cone. Drop feather, drop baseball. strange modules coming apart at random locations might not give you a perfect set of items all bearing the same drag coefficient. At 17,500mph and at 80km you've got a much wider area of uncertainty.<br /><br />As for MIR as an example, good point, but ISS is to MIR as Watermelon is to Plum.... Lots more mass...<br /><br />
 
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backspace

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And I agree, the Pacific is a pretty big target. - though part of me doesn't think progress would have enough fuel to move ISS into a reentry position and still have a lot of RCS thrust left to do a lot of fine-tuning. A lot of it would be crossed fingers.
 
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bobvanx

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Part of what we don't have a good intuitive sense for is just how easy it really is to drop a near-orbit object into a big target zone. ISS travels for thousands of miles across open ocean, just a couple hundred miles up. A de-orbit trajectory burn is really pretty straightforward. Does the Progress carry enough fuel to get the job done? I don't know. <br /><br />Aerodynamic effects (other than heating!!!) are going to be pretty minimal, too. Big, light structures are going to crumple up and disintegrate.
 
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CalliArcale

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<blockquote><font class="small">In reply to:</font><hr /><p>Does the Progress carry enough fuel to get the job done?<p><hr /></p></p></blockquote><br /><br />Probably, especially if it's done over a period of time. Alternately, one Progress could lower the orbit, and another could finish the job. Or the station could be allowed to get lower and lower naturally and then deorbited once it won't take as much energy to acheive it. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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scottb50

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With all the expense of ISS, and the fact it is not considered complete yet, it would be better to put it into a higher orbit rather than de-orbiting it. The energy needed would be close to the same anyway and even if it was boosted to an orbit Shuttle or Soyus couldn't reach, in the near term, it could still be used at a future point when we have the capability of getting back and forth. <div class="Discussion_UserSignature"> </div>
 
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najab

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Even more tangental - your link includes: "<i>The reason I ask is because there is no appreciable atmosphere beyond entry interface... (EI occurs at 121.9 km...</i>" - to which Henry responds "<i>Entry interface is an arbitrary height with no physical significance...</i>"<p>An important point for us layman-scientists (present company excluded of course, Doc) - if it's specified down to decimals it's either (a) totally arbitrary and made up; (b) a universal constant; or (c) converted from a totally arbitrary and made up figure specified in other units.<p>Sometimes it's (b), but usually it's (a) or (c)! Bear that in mind when making your arguments - eg: 121.9km is 75 miles.</p></p>
 
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drwayne

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I like (c) too.<br /><br />Big <img src="/images/icons/smile.gif" /><br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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drwayne

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As a humorous aside, I did some googling on orbit prediction programs, and came across an interesting site. Unfortunately, the orbitals were molecular, but if anyone has interest in stuff like Huckel models:<br /><br />http://www.shokhirev.com/nikolai/programs/prgsciedu.html<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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halman

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CalliArcale,<br /><br />I seem to remember that the airlock section of Skylab, which weighed about a ton, missed a city in Australia by little more than 100 miles. There were a few protests about that, I think.<br /><br />Perhaps it is just me, but I find it sad that we should even be speculating about how to destroy the only space station that we have. Any serious program to get humans off of this planet will require a space station to support refueling or transfers of payload. Of course these operations can be performed without having a space station, but if they are going to be done on a regular basis, probably it will be easier and cheaper to have a truck stop on the way to the stars. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>
 
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rogers_buck

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>> if anyone has interest in stuff like Huckel models: <br /><br />I used to, but it is such a pain glueing on the little berries and fins.
 
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drwayne

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Funny part is that I have some memories of building stick models of some purine molecules I was working on in grad school...they are probably still in the lab.<br /><br /><img src="/images/icons/smile.gif" /><br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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