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As you can read in my article here and on my thread here I think that the "one-and-half" launch architecture is a very bad idea and that great part of VSE moon missions may fail due to a "sum of (little and stupid) delays" like happen in near ALL manned and unmanned launches.

In my article (and in the specific thread about that argument) I explain why the 95-days max orbital loither time of the LSAM/EDS is a too little figure to have a good number of successful missions.

I think that this is true and clear also using only LOGIC and the EXPERIENCE of thousands delays of near ALL launches and space plans: satellites, probes, ISS, Shuttles, etc.

But some users suggest me to give more "NUMBERS" and not only opinions and logical arguments to demonstrate that the risk of missions' fail is so high.

In the specific thread about that problem I already give some (easy to calculate) numbers that (clearly) reduce the max loither orbital time of the LSAM/EDS to about 30 days (inside the total 95 days planned).

30 days only to launch the CEV is an INCREDIBLY LITTLE figure if you think that a recent sat launch have had six delays in one week and that the change of a simple ECO sensor in the Shuttle's external tank has delayed the launch of 2+ months!!!

With 30 days in TOTAL to (ABSOLUTELY!!!) launch the CEV/CLV (two new and experimental vehicles that may have dozens of unknown problems!) the number of missions' fail can reach up to 70%!

The real problem is much more serious because NOT ALL the hours of these 30 days (only) can be used to launch the CEV/CLV but only a few "launch windows" of a few hours each.

Since I've not experience of rockets' launches, it's not simple for me to calculate HOW MANY "launch windows" (and of HOW MANY hours each) will be available to launch the CDV/CLV, then, I explain the problem here to solve it with the most expert users of this forums.

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These are the terms of the problem:

a) the total number of days available for the second launch is around "30"

b) the LSAM/EDS is already in orbit at 28.5 degree inclination, running at 28,000 kmh

c) to launch the max payload possible, the assembly orbit must be safe but low, maybe 200-250 km

d) while the LSAM/EDS runs at 28,000 kmh with its inclination, the earth runs by itself at the equatorial speed of 1670 kmh

e) the launch windows' width tolerance (on earth surface) maybe (I think) of about +/- 500 km (but I'm not sure of that)


With an LSAM/EDS that stay "fixed" in the sky (then, calculating only the earth's rotation) the solution is simple:

40,000 km earth circumference / (500x2) = 40 "launch windows" of (1440/40) 36 minutes each x 30 days = 1080 minutes = 18 hours ONLY in total in the 30 available launch days inside the 95 days of max loither orbital time.

But the LSAM/EDS will NOT stay "fixed" in the sky since it runs in orbit at 28,000 kmh...

Then... how many (real) hours will be available (in 30 days) to launch the CEV/CLV so it can rendez-vous with the LSAM/EDS?

(please use the simplest math possible... for me and for the other non-engineers users of this forum, thank you)

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right, it's not easy to solve!

I try here to calculate the final number ...but I'm not sure of the result...

at 250 km the orbital circumference is about 41,600 km

with an orbital speed of 28,000 kmh the LSAM/EDS will do a full orbit in about 90 minutes

I think that the "vertical tolerance" (with orbital inclination) may be larger than the "width tolerance" (because, if the CEV will enter the right orbit, it can use its engines to approach the LSAM/EDS), maybe +/- 3000 km (?)

Then, in the 90 minutes of the LSAM/EDS orbit, only 15% of them can be used to have a CEV/LSAM rendez-vous: less than 15 minutes per orbit

Now there is the most difficult number to find: "for how many hours (of the 18 max hours calculated in the previous post) the CEV/CLV will be in the right position (with the right horizontal and vertical/orbital max tolerance) to be launched so it can reach the LSAM/EDS?"

A simple solution may be: 15% of 18 hours, then less than 3 hours in total!

Probably it's not the right figure, probably the launch width and orbital tolerance may be wider (or closer...), etc.

But 3 hours ONLY in TOTAL (on 95 days of LSAM/EDS max orbital loither time) to launch the CEV are a very little time available to have a probability of successful VSE moon missions higher than ZERO!!!

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Gaetanomarano,

Although I have doubts about the VSE launch architecture myself, I have to say that the above calculations are completely irrelevant. Basically, to reach an orbiting outpost in LEO the launch window is 24 hours a day. That is because there is plenty of room for manouvering once you are in orbit. For instance, you could bring the CEV in a slightly higher orbit and let the LSAM catch up with you. Of course, all this takes a bit of fuel (delta-V), but I have no doubt the CEV and its booster will be designed to cope with this sort of situations.

Another thing I would like to note is that by using a SRB as first stage for the CEV booster (CLV) the total complexity of the system is drastically reduced. Most of the delays and problems we have with current big boosters come from the enormous amounts of cryogenic fuel that have to be stored and maintained. The CLV only has (relatively) small cryogenic fuel tanks in its second stage, so theoretically, it could be a pretty reliable 'easy' booster.

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CEV fuel... it can be used for an orbital mission not for a lunar mission because it will need for the (very important!) lunar orbit departure...

You can add more fuel to have a larger rendez-vous tolerance, but more fuel (that don't increase so much the time available) means a bigger CLV (in recent news I've read that a 5-segSRB+oneJ2X configuration is so critic that the CEV will need part of the SM fuel or the LAS to reach the orbit!!!)

With the figures planned for the CEV/CLV the fuel use will be very critic in a moon mission.

If too much fuel will be used to reach the LSAM/EDS, the mission will fail because the SM will not have sufficient fuel to come back from lunar orbit...

SRB... I'm not sure that a NEW 5-segment SRB (with many many changes) will be reliable only "because the Shuttles' SRBs was reliable".

But the main problem is that the second launch is not only an SRB, it will be a very complex machine (made of 1st stage, 2nd stage, interstage, LAS, SM and CEV) with thousands parts and sensors and ALL very NEW and EXPERIMENTAL.

I don't say that the missions will fail due to an SRB or CEV failure, but only for a "sum of (many) simple (and stupid) delays".

If you see how many delays will happen with to-day's reliable, well known, simpler (than CLV/CEV) launches (with rockets launched dozens times), you can easy imagine how many delays will happen with a completely new rocket, a few launches of experience and a capsule with four astronauts on the top...

All you have to do to perform a rendezvous is to get the two vehicles into the same orbital plane. After that it’s just a matter of allowing the vehicle with the smaller semi-major axis to catch up with the other. This may take several hours or even days depending on the separation between the vehicles and the geometry of the orbits.

If the LSAM/EDS is in an orbit with an inclination of 28.5 degrees, then there’ll be one launch window per day when Cape Canaveral rotates into position where a new launch can match the plane of the existing orbit. (If the LSAM/EDS is in a higher inclination orbit, then there are two launch windows – one when Canaveral passes through the orbital plane with the vehicle moving from north to south, and the other when moving south to north.) I don’t know how long each launch window will be, but I’m sure they’ll be pretty short. There isn’t much margin for error in getting the orbital planes to match.

If the first vehicle is launched on a northerly heading, then the resulting orbit will be one with an inclination greater than 28.5 degrees and the descending part of the orbit lying ahead to the east of Canaveral. A few hours after launch Cape Canaveral will pass again through this orbital plane and the second vehicle can then be launched on a southerly heading matching the plane of the first launch. By carefully selecting the orbits and the timing, the two vehicles can be placed in orbit separated by a short distance.

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true, but the problem is that the orbital plane will happen only 30 (of 95) days and only for a few minutes (36 minutes if the launch margin is +/-500km.) , then, will be sufficient that the CLV/SM/CEV will need time to change a defective (ECO-like) sensor, and...

exact, the orbital inclination for a lunar mission will be 28.5, then, one launch window per day, then 36 minutes (max) per day to launch the CLV/CEV, then only 18 "HOURS" in TOTAL (inside the 95 days)

but we must consider that the LSAM/EDS will not wait in the Cape Canaveral's sky... it runs while the launch windows, then...

very very critical!

I agree with you, this is (exactly) the problem of the one-and-half launch architecture

true, but with so little and critic launch windows the risk to lose $6 billion of hardware is very high!

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Actually I doubt the orbital inclination will be exactly 28.5 degrees. For instance, most of the Apollo missions where launched into a parking orbit with an inclination of about 32.5 degrees. At this inclination there will be two launch windows each day separated by a little less than 4 hours. This means you'll have 60 launch opportunities in a month, which seems like plenty.

Yes, it is true the timing is critical, but I don't see the problem being any worse than launching a Shuttle, Soyuz or Progress to the International Space Station. Occasionally these launches are delayed, but usually within a few days they go off without a hitch.

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Despite the old technology, the Apollo missions was successful thanks to its single-launch architecture, also, since all the moon-hardware of each mission was in the LEM, there was no need of the same orbital inclination (the only important thing was to launch the Apollo to land the LEM in the right place of the moon).

With the very expen$$$ive VSE moon-hardware this choice will be not possible because all the hardware must be landed in one or two places of the moon (to reuse it as many times as possible).

The only orbital inclination of all launches will be probably at 28.5 degree (some suggest to move the ISS in that orbit to use it as a lunar vehicles' assembly space-port!)

With the one-and-half launch architecture NO DELAY is allowed (certainly not the GIANT delays we have seen with the Shuttles, ISS, etc.), so, 6o launch windows or (more probably) only 30 launch windows of half hour each will be very little if (like with Discovery) the CLV must be disassembled and reassembled to change the 2nd stage engine or, also, a simpler part.

The launch of the Shuttles, Soyuz and Progress can't be compared with the LSAM/CEV because they are all "SINGLE" launch vehicles and the ISS is their "moon" ,not their "LSAM/EDS".

The "ISS-moon" runs in orbit and the Shuttles, Soyuz and Progress may have dozens of delays for months or years (like really happen!) because the ISS don't have an "expiration date" while the LSAM/EDS will be unusable for only 60 of the 95 days (due to moon day, travel, etc.) and, after the 95 days, it can't be never used yet, since it will have an "expiration date" (like foods!)

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If no delay is allowed, then why can vehicles get up to the ISS if they have any delays? That's an equally complex orbital rendezvous, and yet we achieve it all the time without difficulty (OK, we used to - however the problems have nothing to do with launching the vehicle to the right orbit). With the new vehicle's elimination of the need for massive cryogenic storage, it should eliminate many problems, and the lack of a parallel staging system eliminates even more. I fail to see what your issue is.

I try to better explain my opinion.

The "no delay is allowed" is related only with the "one-and-half" launch not with the single-launch of the SLV (my proposal) or the Shuttle, Soyuz and Progress.

As I explain in my previous post, the ISS can wait many months a new launch, while the LSAM/EDS will have an "expiration date" of 95 days.

Also, a launch to the ISS can be done in the daylight or in the night while a launch to the moon must start in the moon night so the LSAM will land in the moon day (and not all dates are good because the LSAM can't land in the last moon days).

The ISS has no "lunar" day-night, it's close to the earth and has no "expiration date" (or, exactly, a very long one) then, the Shuttle/Soyuz/Progress may have dozens of delays for many months because they may have INFINITE launch windows (not only "30") they can be launched when all systems are ok AND the launch windows is right.

You've seen... the Discovery is arrived to the ISS over 2.5 years after the Columbia accident and (after 2.5 years of research and delays) the Discovery have found the ISS in its orbit... because the ISS has no "expiration date" ...while the LSAM/EDS is like the milk, after its "expiration date" can be only thrown/burned in a trash can/atmosphere!!!
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I’m sorry but I just don’t see the big deal. We don’t launch the LSAM/EDS until we’re confident the CEV is ready to go. If there is a last minute glitch that postpones the launch, there will be a couple more launch opportunities each day thereafter. I can’t envision a delay of more than a few days unless a major malfunction occurs. In the unlikely event that occurs then we’ll be out the cost of a LSAM/EDS, but that is probably not our biggest problem in that case.

Gaetanomarano, I just think you’re getting all worked up over something that is very unlikely to happen. Is the scenario you describe any more risky that the LSAM ascending and docking with the CEV in lunar orbit? If we’re to return to the Moon, difficult and risky tasks are inevitable. I don’t see how the dual launch method can be avoided; there is just too much mass that must be lifted to orbit.

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Bob,

Just on a side note, why would the LSAM/EDS and the CEV be in different orbital planes? They are launched from the same site (I think), so I don't see the need or reason behind any significant difference in orbital plane.

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Launching from the same site along the same heading (azimuth) will result in orbits with the same inclination, but not necessarily the same ascending node. Say, for example, we launch due east from Cape Canaveral at 7:00 AM. We'd have an orbit with an inclination of 28.5 degrees (the latitude of Canaveral) with the orbit's ascending node 90 degrees west of Canaveral and the descending node 90 degrees east of Canaveral. Let's say we perform an identical launch three hours later at 10:00 AM. The resulting orbit will look the same as the first in relation to the launch site, but the launch site has moved. The Earth has rotated 45 degrees in the 3 hours since the 7:00 AM launch, thus the second orbit has ascending and descending nodes 45 degrees out of phase with the first orbit. The orbital planes are rotated 45 degrees to each other.

I'm sure you've noticed how the track of an orbiting spacecraft projected onto the Earth shifts to the west on each successive orbit. You can launch into the plane of that orbit only when the track passes over the launch site (that is, when the launch site rotates through the plane of the orbit). If the inclination of the orbit is less than the latitude of the launch site, the track will never touch the launch site, thus it is impossible to launch into that plane. If the inclination is greater than the launch site's latitude, the track will cross the launch site twice per day, thus there are two launch windows each day. If the inclination is equal to the launch site's latitude, then the track will just touch the launch site once per day, allowing only one launch window.

Edited to clarify explanation.

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Near all the manned and unmanned missions and programs (satellites, probes, ISS, Shuttles, etc. despite the experience of HUNDREDS' launches) have had, have and will have little and big delays because they are complex (and very expensive!) machines that can't be launched if not ALL is OK.

When the moon missions will starts, the CLV/CEV will have only a few launches of experience then may have dozens of unknown problems and delays before each launch.

Don't forget that the CLV will be all manned missions on an experimental rocket (and with a launch cost four times higher than a sat launch!), then, the caution (and delays) of unmanned launches will be multiplied by TEN.

But the main problem of the "one-and-half" launch is NOT "inside the rockets" but "inside the architecture".

With the "one-and-half" architecture, a few weeks of delay (that may happen many times) will kill the entire mission (and $6 billion...), while, with the single-launch architecture, also TWO YEARS of delays will NEVER kill the mission and burns billions!

Also, if the first two-four moon missions will fail due to a "sum of delays", NASA will be forced to STOP all missions and restart from ZERO with a different (and reliable) architecture that means 10+ years of research/delay, $20+ billion of extra R&D funds and the launch of the first new US' moon missions not in 2020 but in 2030 (when China, Russia, Europe, India, Japan, Egypt, Tonga, Brazil, etc. will already have their own hotels for tourists on the moon surface...)

Unfortunately I think that may happen (and will happen).

Not true.

I think that the entire VSE plan must be changed to be different that the (very risky) Apollo missions, but the comparison (between the LSAM/EDS/CEV docking and the LSAM/CEV docking in lunar orbit) can't be made for many reasons like...

1. the CEV/SM will have a stand-by orbital wait time of SIX months, twice the LSAM/EDS

2. the lunar orbit of the CEV/SM will be very low and very fast, also, it will be equatorial and without the problem of the earth rotation (since the moon don't rotate by itself); that means over 50 launch windows per day (and ALL good for a launch from moon surface!)

3. the LSAM lunar departure may happen in the moon day or night while the LSAM/EDS departure may happen ONLY in some days of the moon night (that reduces the 95 days orbital loither time to 30 days only)

4. the CEV/SM will be remote-controlled (while the LSAM/EDS will be only a "dumb" system), then, if the LSAM remains in a lower orbit and can't reach the CEV, the latter can be remote-controlled from earth (or from the LSAM) to fly towards the LSAM and dock with it!

Then, the LSAM/CEV rendez-vous and docking in lunar orbit will be 1000 TIMES more successful than the (very critic!) LSAM/EDS/CEV rendez-vous in earth orbit!

The only (big!) risk for the LSAM will happen if the moon departure's single engine will not work (since the astronauts will have oxygen, water, food and energy for only a few days).

This is the reason why I (and others) suggest to change also this part of the VSE/ESAS moon architecture.

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To what?

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The number of possible moon missions' architectures are probably near the number of heads that thinks about them...

But the main change I suggest already is in my article about the SLV: to send the moon-hardware for 5+ missions before the first manned mission with a cago-LSAM.

Of course, the cargo-LSAM must have also extra oxygen, food and energy to give two-three months (or more) extra life support to the astronauts (the only way to have the time for a rescue mission if something goes wrong).

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Bob,

Thanks for clearing up that orbital plane issue.

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How many manned launches have been scrubbed within 24-hours of the planned launch time that resulted in a subsequent delay of over one-month? I think you’ll find very few, if any. By the final hours of a countdown the vehicle has already gone through extensive check-out. The types of faults that occur during this time seem to result in delays of hours or days, not weeks or months. I suspect the LSAM/EDS will not launch until the CEV is well within its countdown and all systems are go. I think the chances of a long delay between LSAM/EDS launch and CEV launch is not unacceptably high. Could it happen as you suggest? Of course, but I think you’re over dramatizing the risk.

One possible and simple solution to the problem is to launch the CEV first. If the LSAM/EDS launch is scrubbed, then you bring the crew back down. The CEV is reusable and launched on a much smaller and less expensive rocket. If the mission is aborted after CEV launch, the amount of cost squandered is considerably less than if a CaLV/LSAM/EDS is wasted.

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"How many manned..."

The problem is that the launches of a moon missions are not like other launches, they must happen in some exact hours of some exact days of some exact months, the "30 days" available are not in a single, full month but distributed in over three months.

"the LSAM/EDS will not launch until the CEV is well within its countdown..."

I fell that this is not possible, in fact NASA has planned 30 days of orbital loither time (and, after the ESAS report, has extended it to 95 days!)

"One possible and simple solution to the problem is to launch the CEV first..."

I've already thought (months ago) to this alternative, but I've immediately excluded it.

I explain why:

The CEV/SM will have six months of orbital life but only in stand-by, without astronauts aboard, running in lunar orbit.

With four astonauts, the life support will ends within (I think) two weeks max.

Well, since the CaLV/LSAM/EDS is much more complex than CLV/CEV, it may have two, three, five, ten times more problems and delays than CLV/CEV.

Every time the delay of the (second) CaLV launch exceed two weeks, the astronauts must come back to earth and try again.

I think that you may agree with me that space flights (especially the launch and re-entry) are too dangerous to fly (also) WITHOUT ANY REASON!

If the CaLV will have ONE delay you must risk the life of two crews in one mission!

But, if the CaLV will have FIVE problems in SIX months (that may happen... see the Shuttle!) you must launch SIX crews for one mission, then, $6 billion of CLV/CEV hardware lost and a big risk for 24 astronauts... 20 of which will go in orbit (and risk their life!) FOR NOTHING, not even the satisfaction to walk on the moon!!!!!!

In other word, with the "one-and-half" launch architecture you have two (both bad!) options:

a) Launch the CaLV/LSAM as FIRST and risk to lose $6 billion of hardware and the moon mission.

b) Launch the CaLV/LSAM as SECOND and risk (without any good reason) the life of four or eight or twelve or more astronauts (if the CaLV/LSAM launch will delay one or two or three or more times).

THE ONLY WAY TO SAVE MANY BILLIONS, HUMAN LIFES AND MOON MISSIONS IS THE SINGLE-LAUNCH ARCHITECTURE
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Nice webpage with experts:
http://www.nasaspaceflight.com

http://forum.nasaspaceflight.com/for...=2320&start=16
Look at the all ET graphic. I would love that.

The moderator of a space-forum has said to me that 75% of the space-forums' users are the same (with the same or with different nicknames).

Well, I'm very glad if your "experts" on the space-forum you quote have my same opinion about the CaLV, but, if (before open the April 25 thread you quote) one or more posters have read my April 12 article on my website or my April 15 thread here, may be "gentle" to claim the source of the idea and/or post a link to my article or to my UniverseToday's thread... unfortunately, some "experts" are not so gentle...

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I'm sorry, but I read books, novels, and calmly-written internet pages. I can't even begin to read through all the shouting and color-coding here! I'd like to, but http://www.bautforum.com/member.php?u=12969, your over-emphasis has just got to go!

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If I set the budget, we'd have Ares and more. Unfortunately, I don't set the budget, and Ares is just too expensive and too far out for us to accomplish our goals within the budget we were given.

If we halt the ISS, all versions of Ares, and transport Orion and Altair aboard DIRECTv3's Jupiter family of Shuttle-Derived Launch Vehicles, we just might make it back to the Moon by 2020.

I'm sorry, probably my website has too colors, but that is the look I've decided for it. I don't like an aseptic blog-like style.

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I tend to agree; I find it all very distracting and difficult to read. I got through about 2/3rds of gaetanomarano's article and had to quit due to the eye strain. I think the point gaetanomarano is trying to make gets lost in all the dramatics.

The maneuver that is time critical is TLI. Getting the components into orbit is no more time critical than missions to the ISS. The CEV will have at least one launch window every day up until the last opportunity for TLI has passed. In fact, launching to the waiting LSAM/EDS will be easier than missions to the ISS. Because the ISS is at such a high inclination (51.6 degrees), the length of each launch window from Cape Canaveral is very brief – only minutes. Launch windows to the LSAM/EDS can be a couple hours in duration without significant loss of payload capacity.

The CEV will make only about 12 lunar orbits per day, not 50. And the Moon does rotate, once every 27.3 days. For long stays on the lunar surface there will be periods when the landing site is well outside the orbital plane of the CEV.

Can you provide a quantitative analysis to back up this claim? If not, then I suggest you not randomly throw out numbers that cannot be supported.

But in your article you argue that launch vehicle size is not indicative of reliability. If you are now arguing the CaLV is more likely to have problems than the CLV then you are contradicting yourself. And what evidence do you have to say the LSAM is more complex than the CEV?

I agree with the other users who say you need to support your argument with numbers. You are arguing subjectively about something that requires a quantitative analysis.

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If there's a delay, why can't the crew just hang out at the ISS until everything's fixed?

The ISS's orbit is too different from that which will be used for the lunar missions. It would require about a 23 degree plane change to reach the ISS. The propulsion system would have to provide over 3 km/s delta-v to perform this maneuver, which would use up all the propellant (if they even have that much to start with). A diversion to the ISS would mean the mission could no longer proceed.

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I see your point. I guess that's why the last space shuttle that blew up couldn't have got to the ISS even if it wanted to. What's up with that? I thought one of the justifications for the ISS is that it was to form a sort of waystation/lifeboat for eventual missions to more distant destinations. The ISS can be moved. Just hook up a space shuttle and move the ISS into a new permanent orbit where it can do some good. Any ground observation capability that would be lost could be made up by unmanned satellite.

I agree. Supplant the ISS missions with far cheaper unmanned missions, strap on some VHTWRR and move it to where it's going to do more good for the manned missions to the moon.

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If I set the budget, we'd have Ares and more. Unfortunately, I don't set the budget, and Ares is just too expensive and too far out for us to accomplish our goals within the budget we were given.

If we halt the ISS, all versions of Ares, and transport Orion and Altair aboard DIRECTv3's Jupiter family of Shuttle-Derived Launch Vehicles, we just might make it back to the Moon by 2020.

If you shift the ISS out of it's current orbit then it can't be reached by Soyuz and Progress. And how are you going to supply 3 km/s to some thing that masses 400 tonnes when its finished (and 180 tonnes now)?

Jon

The main reason for the high inclination of the ISS's orbit is because some of the major components were launched from Baikonur, which is located above the 45th parallel of latitude. It's easier to launch to high-inclination orbits from low latitudes than it is to launch to low-inclination orbits from high latitudes.

Fred

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