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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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