Positives of the ISS

[holmec]

<blockquote><font class="small">In reply to:</font><hr /><p>No thanx. This crisis is over, and should not reoccur.<p><hr /></p></p></blockquote><br /><br />Yes, of course. I was thinking in terms of designing future space station/ships. I think Bigelow's solar panels are one sided. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[holmec]

<blockquote><font class="small">In reply to:</font><hr /><p>ISS IMO could have been designed and built significantly more efficiently than it was.<p><hr /></p></p></blockquote><br /><br />Hindsight is 20/20. Isn't this one of the reasons to build the ISS, figure out how to do it better? <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[MeteorWayne]

And that is a good point. But still, rotating joints are just asking for problems if not needed.<br /><br />Maybe a shield that could go over? just and idea. <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>

 

[MeteorWayne]

Exactly, and that is IMHO, one of the great positives of the ISS. Today's repair was a perfect example of that. <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>

 

[holmec]

Yeah, or even simpler just rotate the craft. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[MeteorWayne]

Well, that wouldn't really work for the ISS. there's too much other stuff that depends on the position of the craft....and do you really want to be turning a football stadium to face the sun?<br /><br />How do you turn it?<br /><br />Where is the fuel?<br /><br />Or a half dozen flywheels the size of the orbiter?<br /><br />How will the structure respond to the torque?<br /><br />No No No, please, no <img src="/images/icons/smile.gif" /><br /><br /> <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>

 

[holmec]

<blockquote><font class="small">In reply to:</font><hr /><p>No No No, please, no <p><hr /></p></p></blockquote><br /><br />LOL! Well don't forget the large individual panels on the ISS do rotate independent of the rest of the station. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[MeteorWayne]

I know, but that is not the same as moving the mass of the whole station.<br /><br />Anybody know what that sucker weighs right now? <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>

 

[thereiwas]

From lunar orbit to LEO should not require any more propellant than going the other way. But the return propellant has to come from the moon.<br /><br />While high inclination LEO orbits for the station do not cost much more in delta-V to the moon, they do give you only 2 launch windows (and return windows) per month. A station in the same plane as the moon can launch or receive lunar flights many times per day, every day.

 

[mi2again]

" Well don't forget the large individual panels on the ISS do rotate independent of the rest of the station."<br /><br />And rotating the array to turn it away from the sun makes it aways in the dark making it harder to work on. Yes, it was in the dark for part of the orbit but for most of it, it was lit

 

[holmec]

<blockquote><font class="small">In reply to:</font><hr /><p>From lunar orbit to LEO should not require any more propellant than going the other way. But the return propellant has to come from the moon. <p><hr /></p></p></blockquote><br /><br />While that may work, and there might be other schemes that could work, it seems to be a financial problem. <br /><br />But why LEO? Why not a higher orbit for a spacestation/stop-off-hub? <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[thereiwas]

Depends what you mean by "low". ISS is <i>too</i> low - always needing reboosts. A compromise because of shuttle limitations. The higher the station orbit the less braking needed returning from the moon, but the higher the reentry velocity. I'd guess somewhere around 500 - 1000 km.

 

[holmec]

Nice info. You kind of wonder if after the ISS is complete and Shuttle is retired if they might try to take ISS to a higher orbit.<br /><br />But for a lunar stop off, I was more thinking in terms of the altitude of L1 or halfway between L1 and Earth. <br /><br />Possible benefits for that:<br />1. Could store fuel at that station<br />2. Could park the return capsule and take a lander to the moon.<br />3. There's less potential energy to sheer off on reentry so less of a TPS than from Lunar orbit.<br />4. This scheme will use less fuel than trying to get from lunar orbit to LEO.<br />5. A great view. Add a manned observatory to it.<br />6. What the hell, attach a hotel to it.<br /><br />Probably disadvantages<br />1. Cost more in fuel than and Apollo type opeation. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[mi2again]

"A compromise because of shuttle limitations."<br /><br />Incorrect, it is Soyuz/Progress limitations

 

[Huntster]

>>Anybody know what that sucker weighs right now?<br /><br />As of June 2007, it weighed 482,345 pounds (218,788 kg).(1) With Harmony attached, it now weighs somewhere in the realm of 514,000 pounds (233,146 kg).(2) <div class="Discussion_UserSignature"> </div>

 

[mi2again]

ISS is not designed for anything other than LEO. It uses GPS and the earthlimb for attitude and state vector determination. The thermal controls systems (passive and active) are designed for a LEO environment.

 

[thereiwas]

"Incorrect, it is Soyuz/Progress limitations"<br /><br />As Shuttle_Guy said in another thread, <font color="yellow">There is a mission in the manifest that is so tight on up mass that the prior mission is to leave the OBSS on the ISS for the next orbiter to pickup.</font><br /><br />That sounds like at the ISS orbital altitude (which is <i>too low</i>, the topic under discussion) the shuttle is at the limit of its capabilities. I acknowledge the high <i>inclination</i> of ISS is because of Russian launch locations.

 

[spacester]

(This was written earlier today but didn't get posted)<br /><br /><font color="yellow">With a lot of rocket fuel, . . . </font><br /><br />Exactly!<br /><br />You say it like it's a bad thing! <img src="/images/icons/wink.gif" /><br /><br />The NASA-derived minimum-mass-at-all-costs-mentality need not dominate our thinking forever.<br /><br />If you have a need for lots of rocket propellant, then you've established a strong market for rocket propellant, haven't you?<br /><br />It's a GOOD thing to be up there burning propellant and going places.<br /><br />We'll NEVER be a space-faring species - in the true sense - until we have actual true spaceships, and true spaceships do not have landing gear and wings. They trust the rest of the infrastructure to be there when they go places. They trust in their own ability to burn propellant and navigate to those places.<br /><br />Obviously, there would need to be a habitable station in LEO for this spaceship to return home to. It could even be called a Space Hotel.<br /><br />holmec, IIRC you and I are on a far different timeline in our visions. There is little point thrashing over that here. I think a Space Hotel is right around the corner, you don't, nuff said, IMO. <img src="/images/icons/laugh.gif" /><br /><br />golly, jim, i didn't even know you were banned. such a pity. not.<br /> <div class="Discussion_UserSignature"> </div>

 

[vulture2]

>>How do you go from Lunar orbit back to LEO?<br /> />>With a lot of rocket fuel, or a long time aerobraking. <br /> />>a. The propellant needed to enter LEO from lunar return is large <br /> />>b. The phasing to rendezvous with something in LEO reduces the opportunities<br /><br />Back in the old days when we actually developed new technology there were several studies on OTV return from GEO to LEO using a single aerobraking pass followed by three burns to raise perigee, adjust phase angle, and transfer to the rendezvous orbit. Return from Lunar orbit would have fairly similar dynamics. <br />. <br />here's an example<br /><br />I heartily agree with ThereIWas that the best orbit for a LEO transfer station is in a plane close to the plane of the moon's orbit.

 

[qso1]

ThereIWas:<br />Nobody but NASA can develop new vehicles?? There are probably people at Boeing, Lockheed, SpaceX, etc, who would argue that.<br /><br />Me:<br />You totally misquoted me, what I said was "NASA will still be needed to develop the vehicles to do those jobs which is basically development of enabling technologies as you mentioned." Now to further expand on that statement...NASA will be needed until Boeing, Space "X" or whoever sees a profitable reason to develop launch vehicles. See, I never said nobody but NASA can develop new vehicles...they simply won't until a profitable reason to do so emerges. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[qso1]

mi2again:<br />Yes, there is. They are called EELV's. NASA can just contract for a launch service vs a vehicle. Let industry determine the best method<br /><br />Me:<br />Who do you think builds the EELVs? The craft I'm referring to are the vehicles required to transport humans to mars. Nobody has built any and nor will they unless they see a profit making reason to do so in the case of private industry. If NASA gets a go ahead for mars, they will not only contract out the EELVs or whatever puts transit vehicles into earth orbit, they will most likely contract out the transit vehicle or vehicles as well. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[qso1]

holmec:<br />As I recall in 1972, a lot of people were disappointed when we stopped going. Of course that was in California. <br /><br />Me:<br />I'm sure a lot of people were dissapointed at the end of Apollo but the predominent voices were the "We can better spend the money on earth" crowd and they won the day. They may well not have been the majority. Nixon once referred to a certain segment of Americans as the silent majority. Unfortunately, they were heard less than the vocal opponents of Apollo and human spaceflight in general.<br /><br />You hit upon some other good points as well. Vietnam was definetily a factor. I'm not so sure about the cold war and Ivan because believe it or not, in the early 1970s...the DOD budget declined along with the decline of NASAs budget. Both eventually proceeded upward but NASAs upward percentage was not nearly as up as the DOD which enjoyed major increases with the Reagan Administration. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[holmec]

That's really cool. Thanks <img src="/images/icons/laugh.gif" /> <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[richalex]

"I guess that I am probably dreaming, but I always thought that the model described by the science fiction writers in the 1950's would be more efficient, therefore less expensive, than the single launch-direct flight model. The space station would act as a base and a hanger for a space craft designed to fly repeatedly to the Moon and back, ferrying people and supplies to the Moon. Unmanned craft could launch components to be assembled on orbit, and supplies to be transshipped. After equipment and supplies have been shipped to the Moon, launch the exploration crew, and ferry them to the Moon."<br /><br />That's a romantic notion, but I can think of a reason it isn't workable, namely, the inspection and servicing of space vehicles is a non-trivial task. In fact, a large amount of the expense of space flight is tied up in inspection, servicing and repair. It takes a brigade of workers weeks to months to get a space shuttle back in flying condition, and that's in an environment that does not require space suits or life support systems for most tasks. Although ships that remain in space might not need heat shield inspections to the degree the shuttles do, they will need some sort of servicing if humans have lived on them for several days.

 

[qso1]

I suspect we will eventually get to that model but the reason we haven't so far is that to generate artificial gravity, the station has to be pretty large as far as diameter. Its certainly workable. Its just a matter of whats more cost effective. When ISS was originally proposed, the cost was estimated to be $8B dollars although there were no specifics as to what that covered. Now the estimate ranges from $50B dollars to as high as $120B dollars and again, short on specifics. I sometimes wonder if we could have gotten a wheel station for $25 to 50B dollars in which case, it would be more practical cost wise. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>