What about hubble?

[pioneer0333]

Nasa will not destroy hubble when it is replaced will they? The Russians destroyed MIR when they were ready to move on. I can only hope Nasa does not think the same way as the Russians when it comes to replacing things.<br /><br /> Maybe they could donate it to a college or something. Then that school could have a very usefull piece of equipment for students to use everywhere. <div class="Discussion_UserSignature"> </div>

 

[newtonian]

Pioneer0333 - I don't know.<br /><br />But I was hoping they would salvage it - perhaps even continue using it - if it is feasable, reasonable, etc.

 

[spacester]

IMO the Hubble Space Telescope belongs in a museum on the moon.<br /><br />Seriously. After the final repair mission, we should design a multi-engine (chemical & ion) tug that grapples it, shoots thru the VanAllen belts and puts it in a high mothball orbit until we can set it down at the lunar museum.<br /><br />The lunar gravity well is much more manageable for descent, we won't have Shuttle anymore anyway and nothing else will be around able to bring it to Earth, and we need lunar landers anyway.<br /><br />Plus it will provide another destination on the moon for tourists.<br /><br />It wasn't that long ago that many here had written off that beautiful instrument, because NASA was indeed planning to burn it up well before 2010. My suggestion here today is the same as it was then - it looks just a tiny bit less ridiculous, huh?<br /> <div class="Discussion_UserSignature"> </div>

 

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>Maybe they could donate it to a college or something. Then that school could have a very usefull piece of equipment for students to use everywhere.<p><hr /></p></p></blockquote><br /><br />You could count the number of schools capable of affording the maintance costs on a snake's fingers.... Any university who recieved Hubble would be able to afford controlling it and using it, but could not afford to send space missions to repair it or to reboost it. (Periodic reboosting is neccesary; Hubble *will* deorbit if left to its own devices.) <br /><br />EDIT: My personal preference would be for a Shuttle to capture Hubble and bring it safely down to Earth, stowed in the payload bay. I mean, they have to send a Shuttle up for it anyway, right? A robotic deorbit module has been ruled out, as I understand it, due to development costs, so the deorbit module has to be delivered via Shuttle. I would love to see Hubble sitting in the National Air & Space Museum. <img src="/images/icons/wink.gif" /> <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>

 

[unlearningthemistakes]

MIR might contain some secrets that they dont want to be exposed...( opinion ) <div class="Discussion_UserSignature"> <p>pain is inevitable</p><p>suffering is optional </p> </div>

 

[spaceinvador_old]

I think it should be destroyed. We do not need to spend anymore money on that semi piece of junk. It has costed us way more than thought and it has been problematic. I think we have better designs in the works anyways where that money could go to instead. <br /><br />Why don't we use it as a orbiting target to test some of our weaponry?

 

[formulaterp]

<font color="yellow">We do not need to spend anymore money on that semi piece of junk.</font><br /><br />It's not a piece of junk. Hubble has returned more science than any space-related project in history. <br /><br /><font color="yellow">I think we have better designs in the works anyways where that money could go to instead.</font><br /><br />You think wrong. The next generation telescope (JWST) is designed to work in the infrared portion of the spectrum, and it will cost more than the Hubble. There are no plans for a replacement scope which operates in the visible light spectrum.<br /><br /><font color="yellow">Why don't we use it as a orbiting target to test some of our weaponry?</font><br /><br />Probably because we don't have any such weaponry.<br /><br />And you mispelled invader.<br />

 

[pioneer0333]

I think NASA should take it as a challenge. They seriously need to prove that they can still do incredible things. We all know that NASA has lost a great deal of "public support", but the people I still believe in general want to see a new jump forward in space travel and exploration from NASA. All in all, public support would jump tremendously if they brought Hubble back. This mission will also give NASA a new "stage" or "level" sort of speak on advancements in technology.<br /><br /> If in less than ten years Kennedy can say we will go to moon and then do it. Surely we can achieve even greater things if we just look past the green paper with ink on it and just do it because we want to do it. I'm telling you now, that green piece of paper is what defines what the human species can and can't do. <br /><br /> Don't think about it.<br /> Just do it. <div class="Discussion_UserSignature"> </div>

 

[brellis]

that's a terrific idea! i wonder how much fuel it would take to boost it up there? <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[spacester]

Hehehehe, well seeing as you asked . . . <img src="/images/icons/laugh.gif" /><br /><br />I calculate a deltaV of 2.37 km/s to go from a 590 km circular orbit to a mothball orbit of 25000 km circular.<br /><br />The mass of Hubble is 11.1 tonne = 11100 kg<br /><br />The structural limits of Hubble limit us to an engine with less than about 13000 N = 1325 kgf; that’s a pretty small engine. If we assume kerosene/lox, we can assume Isp = 250 s. That’s enough information to see what fraction of our tug needs to be propellant.<br /><br />mo/mf = Propellant Fraction = e^(dV/(g*Isp)) = e^(2370/(9.81*250)) = 2.63<br /><br />mo/mf = (mi + mp) / mi = mp/mi + 1<br />mo = original mass<br />mf = final mass<br />mi = inert mass<br />mp = propellant mass <br />so<br />mp/mi = 2.63 – 1 = 1.63<br /><br />This means that the propellant needs to be 163% of the mass of the empty tug PLUS the mass of the Hubble itself.<br /><br />If we pull a number out of the air, say a 3000 kg empty mass tug delivered to LEO, <br /><br />mi = 11100 + 3000 kg = 14100 kg<br />14100 * 1.63 = 22983 kg is the amount of propellant we will need.<br />For a total mass of 25983 kg (EELV-class payload)<br /><br />A tug dry-massing 3000 kg but carrying enough prop to get the job done will have a “tank fraction” of 22983 / 25983 = 0.91. If we use 0.94 as the wet fraction of the full tanks, that makes for a mass of 22983 * .06 = 1378 kg for the empty tanks, leaving 3000 – 1378 = 1621 kg for the rest of the tug’s inert mass.<br /><br />With a thrust to weight ratio of, what 20:1 (??) and a gentle but effective thrust of 800 kgf, this little chemical engine might mass around only 40 kg. Something tells me this engine I describe is rather out of the box, but that’s what this back of envelope calc suggests so far. But let’s allocate 621 kg for the entire chemical rocket system dry mass.<br /><br />That leaves 1000 kg for the ion engine and its fuel (no oxidizer required, lol) and everything else. If we assume an Isp for the ion engines of 2000 s ( <div class="Discussion_UserSignature"> </div>

 

[igorsboss]

Nice!<br /><br />How much dV for a Hubble de-orbit burn?

 

[spacester]

<font color="yellow">How much dV for a Hubble de-orbit burn? </font><br /><br />You mean lunar de-orbit, right? <img src="/images/icons/wink.gif" /> Cuz my calculator keeps getting stuck when I think about burning up that big beauty in our atmosphere.<br /><br />The dV required to land from a lunar-radius circular orbit of the Earth will be equal to the escape velocity from the moon. Going all the way down the gravity well is the same as climbing all the way out of it. Escape velocity is 2380 m/s <br /><br />So refuel it and land it. And don't forget the oxidizer, lol. <div class="Discussion_UserSignature"> </div>

 

[harmonicaman]

I've always been hopeful that the Hubble could somehow be tugged down to the ISS, refurbished there at our leisure (or slowly dismantled and shipped back to Earth), and then returned to its working orbit.<br /><br />I know this is a complicated scenario, but it would give the ISS a real mission.

 

[spacester]

LOL, that's where I cribbed some of my data:<br /><br />Can Hubble be moved to ISS? <div class="Discussion_UserSignature"> </div>

 

[tplank]

OK. Here is my idea to save Hubble. Or more precisely, generate a pile of cash. Every time I hear about the "International Star Registry" or somesuch in a radio advertisement, I want to puke. So given the international value of Hubble, why not start a REAL star registry and charge for it. The proceeds to go, of course, to keeping Hubble from a firey death. If it is an international effort, looks like raising some significant cash is not hard to imagine. I would think that the astronomical community might consider going along for such a great benefit. <div class="Discussion_UserSignature"> <p>The Disenfranchised Curmudgeon</p><p>http://tonyplank.blogspot.com/ </p> </div>

 

[igorsboss]

<font color="yellow">You mean lunar de-orbit, right?</font><br /><br />Sorry, no, I meant terrrestrial de-orbit, so we can have a baseline to compare against.<br /><br />If it takes less-than-or-equal dV to lift Hubble to a parking orbit, then your idea should win.

 

[spacester]

Oh it takes much less dV to de-orbit Earth Orbit to disposal for sure. Of course, that means it burns up and a few chunks fall in the Pacific (Indian?) Ocean. Not much of a baseline <img src="/images/icons/wink.gif" /> <br /><br />I see the baseline approach as rather flawed for this analysis because the outcomes are so much different.<br /><br />But you must mean terrestrial de-orbit to a soft landing; well it's next to impossible on a practical basis. We're looking at ~9.5 km/s (hard to do!) and we have no vehicle to do it with and none on the drawing boards of even the most optimistic yet credible entity. So to me the first choice is to burn it up or mothball it. After the Science stops, of course.<br /><br />To be fair, the dV to the mothball orbit might be enough to, alternately, get HST low enough and slow enough that a ballute might work. But that looks like it’s going to be a Russian specialty, so best case is we’re looking at hiring the job done and taxpayers ain’t gonna go for that. Plus a Ballute does not get you a soft landing AFAIK.<br /><br />There’s no real need to go all the way past geosynch. I forget the altitude where you’re substantially above the upper Van Allen Belts; that would be good enough for the initial mothball orbit, good for maybe 10000 years (?). So my proposal is not necessarily a baseline either. Also, perhaps we can take our time thru the radiation-intense belts with ion engines and be just fine, I don’t know.<br /><br />I want to be clear that the purpose of this idea is manifold, not least of which is maximizing the value of Hubble as a national treasure. When the Science stops, the Instrument becomes an Artifact. But the Science has been so profound that the Artifact can become much more.<br /><br />I’ve got to believe that most everybody likes the idea of having HST in a museum, it’s just that they cannot see how that museum could be on the moon. They see it as impractical and it’s not a matter of thinking HST on Luna isn’t a cool idea. Am I <div class="Discussion_UserSignature"> </div>

 

[newtonian]

formulaterp - I agree with your post and again state I hope Hubble will be salvaged.<br /><br />Or replaced with something better in the visible light spectrum - whichever is less expensive.<br /><br />Certainly it would be reasonable to keep Hubble in operation until a better visible light spectrum replacement could be put in orbit.<br /><br />Could the JWST include a visible scope also?<br /><br />What does JW stand for? [and ST?]

 

[halcyondays]

JWST = James Webb Space Telescope. Although Webb was one of the more successful NASA Administrators, it says something that nowadays we name telescopes after bureaucrats and not astronomers/scientists.