Using the ISS/Shuttle to go to both the Moon/Mars

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larper

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Wow. I don't know where to begin in pointing out all of the wrongness in that post. <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>
 
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marcel_leonard

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Maybe you should try pointing out some of that "wrongness" out there genuis!!!<br /><br />Some of you are talking about making propellant on the moon; if we don't find a substantial amount of water on either the [hopefully near the polar regions of both sites] Moon/Mars we won’t be setting up any bases of operation, or making propellant anytime soon. <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>
 
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larper

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Ok, here is one:<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>I don’t have the exact figures but it is possible for the CEV to rendezvous with the ISS and continue on to the moon without much more additional fuel using Kepler’s laws. <p><hr /></p></p></blockquote><br /><br /> <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>
 
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strandedonearth

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Here's another: Escape velocity is nearly 26,000mph, compared to the orbital velocity of 17,500mph.<br /><br />Galileo and Voyager used "gravity assists" to gain speed in a slingshot maneuver past planets that they are not in orbit around. You can't get an assist from a planet you are already orbiting.
 
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marcel_leonard

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Thanks for pointing that out: I was relying on memory to serve me on the 17,500 mph. As to the orbital mechanics; gravity assists do apply to CEV docking w/ the ISS and very single mission we send to the Moon/Mars. So put that in your peace pipe and smoke it...<br /><br />After all this discussion on what is, or isn’t possible about a mission to the Moon/Mars I am surprised that no one mentioned first locating water on both sites. I would think that finding water would be a crucial part of any long term base of operation. <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>
 
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nibb31

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<monty python mode=on><br />Oh no they don't!<br /><monty python mode=off /><br /><br />IIRC, gravity assist was used for the 1st time for Voyager, and is definitely not used for "every single mission we send to the Moon/Mars". <br /><br />If it was so easy to use gravity assists to fly off to the moon, then why did NASA need a honking big Saturn IVB to send people there? You can't just float to the moon once you're in LEO.<br /><br />Some Mars missions (MRO) use aerobraking on an excentric orbit over a long period (6 months) to slow down into a low operational orbit, but that has nothing to do with gravity and is too risky and time consuming for a manned mission.<br />
 
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scottb50

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I would think a hybrid braking system would work on return to LEO. Rather than braking directly into an orbit enter an elongated orbit and aerobrake to get rid of a major part of the energy and motors to circularize the orbit. One 6-10 hour braking orbit would save a lot of propellant. <div class="Discussion_UserSignature"> </div>
 
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nibb31

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I agree, but aerobraking is risky. You have a very narrow window and if you miss it you either skip off the atmosphere or you plunge into the atmosphere. If your mission profile was to dock in LEO with a re-entry vehicle, then your return vehicle doesn't have a TPS for re-entry and you're toast.<br /><br />If you're designing a craft that has a TPS, then you might as well aim for a direct re-entry because it is much more forgiving.
 
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willpittenger

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<blockquote><font class="small">In reply to:</font><hr /><p>gravity assist was used for the 1st time for Voyager, and is definitely not used for "every single mission we send to the Moon/Mars".<p><hr /></p></p></blockquote><br />Actually, it was Mariner 10 to Mercury. The Pioneer 10/11 missions also used the concept. I agree on the Moon. However, it is conceivable that a really, really heavy mission to Mars would do a flyby of Earth to get there. The key to a graviational boost is entering an orbit that takes you towards and object at a fairly high rate of speed. Such a Mars mission might happen such that the craft gets half way or more to the Martian orbit area (except Mars is not there) and returns to Earth for the flyby.<br /><br />If your spacecraft is heavy enough and limited enough on thrust, that might be the fastest way to get there. This is especially true if you are unable to leave when Mars is in the optimal position for your Delta V capability. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>
 
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willpittenger

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To avoid confusion, Apollo did not attempt to reenter orbit when returning. They skipped that completely. Big time saver and you waste no more fuel than the Aerobraking. In fact, Aerobraking might use more fuel. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>
 
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willpittenger

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1. If you build a robot generic enough, it can keep doing more experiments. Hopefully with today's technology, we can make better robots for this type of experiment than the life detection experiments that flew on Viking. (Those were abysmal failures.)<br /><br />2. The Viking missions were enough for Zubrin and others to conclude we can make fuel on Mars from soil. That was without any samples -- which we still do not have. On the other hand, we have some 800 pounds of the Moon right here on Earth. We may not even need a robot to do the experiment. As such, I think we can prove if we can or can't make fuel from lunar regolith far more conclusively than with Martian soil. In fact, I expect we could get a probable rate of production. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>
 
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marcel_leonard

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<i><font color="yellow">crazyeddie-<br />"I suggest you take your own advice, if you want to avoid looking like a bit of a fool."</font>/i><br /><br />There is nothing foolish in my statement that all space missions are subject to gravitational forces and assists. The only foolishness here is a bunch of people here who never took a college physics course pretending that they know the true nature of gravity. Even Einstein, and Newton had enough sense to know they had yet to figure out what causes gravity; this is why Coulomb’s law for electromagnetic force, and Newton’s formula for gravitational force are identical. <br /><br />[Fe = K(Qq /r^2); Fg = G(Mm/r^2)]<br /><br />So <font color="red">crazyeddie</font>if you've figured out the force of gravity you need to stop playing w/ the SDC message board; go to Sweden to pick your check for a million dollars, and your Nobel Prize...</i> <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>
 
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j05h

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<i>> There is nothing foolish in my statement that all space missions are subject to gravitational forces and assists.</i><br /><br />As several others pointed out, a craft in orbit around any large body is subject to it's gravity. The craft does not get a boost from it - it needs to break free, perform a solar orbit and re-encounter the large body to gain a gravity assist. That you refuse to grasp this is staggering. CEV doesn't need a "gentle push" to break orbit, it needs a fairly involved and powerful burn for TLI. <br /><br />You keep going on about physics classes when it's obvious you haven't got a clue what your discussing. <br /><br /><i>> So crazyeddie if you've figured out the force of gravity you need to stop playing w/ the SDC message board; go to Sweden to pick your check for a million dollars, and your Nobel Prize...</i><br /><br />CrazyEddie and others aren't claiming any special knowledge about gravity's nature, they are just pointing out basic, commonly understood (or misunderstood in your case) facts about spaceflight. I wish we had an orbital mechanics expert on this board to set you straight, but then you'd just diss on him, too. Oh, for the days of sci.space.policy.<br /><br />I've got to stop feeding the troll.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
 
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marcel_leonard

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<font color="yellow"><i>J05H-<br />"I wish we had an orbital mechanics expert on this board to set you straight"</i></font><br /><br />In case you didn't know <i>orbital mechanics</i> comes out of understanding the physical properties of <i>statics</i> [bodies at rest], and <i>dynamics</i> [bodies in motion]; which is why I <i>"keep going on about physics classes"</i>... <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>
 
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nacnud

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What are you two fighting about? I can't work out what you're each saying.
 
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j05h

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> What are you two fighting about? I can't work out what you're each saying.<br /><br />I'm not fighting, I'm just stunned at the technobabble going on. He's saying take a physics class, I'm saying he's buzzword compliant and nothing more. <br /><br />This is my last, last post to this trolly thread. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
 
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craigmac

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You bring up an interesting point about first finding H2O on both the Mars, and the moon. Didn’t scientist at the JPL discover water at the poles of both bodies?
 
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marcel_leonard

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The goal of an Orbital Space Plane and returning to the moon using the CEV can be made one and the same. All we have to do is substitute the current building plans for OSP proposed by Boeing. We keep the current plans for the Lunar Landers launch while using the OSP to rendezvous with the ISS while the CEV continues directly to the moon with no delay. Upon return they dock w/ the ISS were they use the OSP to back to earth. <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>
 
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larper

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<blockquote><font class="small">In reply to:</font><hr /><p>Upon return they dock w/ the ISS were they use the OSP to back to earth. <p><hr /></p></p></blockquote><br />How does the CEV enter LEO and dock with ISS? <br /><br />Now, I agree that leaving your Earth Landing Vehicle docked to ISS (or just leave it in LEO) is perfectly possible. But, what does it save you? <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>
 
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bamabuc

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Reassembling the craft in orbit would require too much personnel, equipment, time, and training. It costs a lot more to build on orbit because you have to pay to get all those people to space.
 
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scottb50

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Not if the docking system is simple and automatic and can be hand flown with a HUD flight director and visual cues from any control station in any Module forming a Vehicle or Platform. Quick, easy and safe docking and undocking is the key to commercial use. Time is money. <br /><br />It should be simple to take Modules to LEO, as cargo, and dock them to Vehicles going to the moon, Mars, asteroids or Platforms in various Earth Orbits. Once the Vehicle reaches lunar or Martian orbit the Modules are transferred to a Landing/Ascent Vehicle and taken to the surface. Undock from one Vehicle and dock to another. Plug and Play.<br /><br />The LAV brings up returning Modules, that dock to the Vehicle returning to LEO. Modules are transfered to Descent Vehicles for return to Earth. Passenger Modules included.<br /><br />There is no way you could get enough to orbit in a single launch to get to Mars anyway and if you want to get more than two people to the moon for a few days or researchers and miners to an asteroid forget about it, it's going to take multiple launches to assemble Cyclers or Direct Vehicles, but once the Core Vehicle is in place it's just a matter of docking Modules to the Core, undocking them at a destination and docking returning Modules in their place for the return to LEO, for a Cycler. The Direct Vehicle would be identical, but it would pretty much stay in one piece except for Modules used on the body visited, and those left for future use. <div class="Discussion_UserSignature"> </div>
 
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marcel_leonard

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Shuttle Guy please read my messages before you so eagerly try and disagree w/ me. The OSP will only be traveling to the ISS not to the Moon. After the CEV returns from lunar orbit instead of going directly home it will dock w/ with the ISS in order to return the crew aboard the OSP back home. <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>
 
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larper

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I understood you perfectly. So again, I ask my question: How does the CEV enter LEO and dock with the ISS? <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>
 
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marcel_leonard

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The gravity fairies will take over safely gliding the CEV towards the ISS after the crew has completed their lunar mission. One thing to look at is that we’ve already been to the Moon; part of CEV’s commission is to eventually prepare us for a mission to Mars. One that by the way some assembly in orbit will be require because of the scope of this mission equipment and crew compliment. If we don’t utilize the ISS as an assembly platform, more than likely we’ll have to build one.<br /><br />The other thing to look at is a reusable vehicle to ferry men, and materials back/forth into orbit. The CEV maybe the most efficient way for a straight shot to the Moon since its only a three day trip, but a Martian launch will take close to a year and six months to arrive in orbit around the red planet. That’s a long time to sit in a four man Apollo styled module eating baby food, and relieving your bowl movements in their Depends Adult Diapers. If the year and half trip to Mars doesn’t kill some of the crew there is no doubt that smell will cause a few casualties...<br /> <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>
 
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