Lunar fantasies

[krrr]

Most of you will be aware of the lunar flyby proposal by Energia which is promoted by Space Adventures (for 100M $ per "tourist" passenger).<br /><br />Basically, a Soyuz spacecraft would dock with a Zenit-launched Block-DM stage, which would then hurl the Soyuz into a free-return lunar flyby trajectory.<br /><br />As noted on astronautix.com, the Block-DM would barely be able to provide the necessary delta-v for trans lunar insertion (TLI), which is about 3150 m/s. So maybe the Soyuz' own propulsion would have to supply an additional kick (the Soyuz has a delta-v capability of 390 m/s).<br /><br />Anyway, I think a lunar <font color="orange">flyby</font>is not very cool. I wouldn't pay 100 million dollars for that.<br /><br />Lunar <font color="orange">orbit</font>is a different thing.<br /><br />There are different types of lunar orbits: a low lunar orbit (say a circular 100 km orbit) requires more than 800 m/s delta-v for braking into it (lunar orbit insertion, LOI), and a similar amount of delta-v to escape from it (trans-earth insertion, TEI).<br /><br />What I envision is a <font color="orange">highly elliptical lunar orbit</font>(HELO): For instance, a 12-hour orbit with a perilune of 100 km and an apolune of 8700 km. This requires only 300 m/s for LOI and less for TEI. Passengers (and scientific instruments) would have a close look at the Moon twice a day.<br /><br />Let's look at the payload capabilities of current (non-US) launchers:<br /><br />TLI:<br />Zenit+DM: 4 tonnes<br />Proton+DM: 4.5 tonnes<br />Proton+Breeze: 5.8 tonnes<br />Ariane 5 ECA: /> 7 tonnes<br />Proton+KVRB: ~ 8 tonnes<br /><br />EOR+TLI:<br />Zenit+DM: < 7 tonnes<br />Proton+DM: ~ 8 tonnes<br />Proton+Breeze: ~10 tonnes<br />Pro

 

[dobbins]

I Never thought Space Adventures expected to sell any lunar flybys at that price, that they just announced it as a PR stunt.<br />

 

[spacester]

Yup, I remember when it was commonly said that "the market for space tourism is exactly one individual", which was amended from one to two when Shuttleworth followed Tito. It seems clear that if Russia had the extra capability we'd have seen more $20M type customers.<br /><br />But even I will admit that $100 Million is getting a little ridiculous. Still this is an unknown market and hey, how do you find out how much the market will bear unless you aim high?<br /><br />It's like selling a used car: it only takes one buyer.<br /><br />***<br /><br />krrr, nice post! Thanks for the ideas and the numbers as well! Very cool!<br /><br />I like the HELO orbit - it's a nice trade between staying high in the gravity well, but getting close views too. What a sight that would be, watching the moon get bigger and bigger by the minute!<br /><br />Someday I need to run the numbers and look at the stack more closely, but the twist I would add to your scheme is to do the TLI after LEO assembly, where you would add a propulsion stage to the stack. This stage would get you the deltaV to do things more comfortably, and would double as a lunar surface lander. I'm thinking it would stay parked in HELO until LUNOX can be provided, so you would bring the methane needed for lunar operations on a cargo ship and you'd have your own lunar transportation system. <div class="Discussion_UserSignature"> </div>

 

[thinice]

I believe Proton with its hypergolic fuel will be never used for tourist flights. You can safely delete it from the list.

 

[holmec]

>Anyway, I think a lunar flyby is not very cool. I wouldn't pay 100 million dollars for that.<<br /><br />You have got to be kidding! Anyway Appollo 8 was not supposed to be a "cool" mission because there was no landing. But the veiw of Earth from the moon is absolutely breathtaking. Also your talking about a week in space for that trip. Not to mention a Soyuz never made that trip with a crew before. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[nacnud]

<font color="yellow">I believe Proton with its hypergolic fuel will be never used for tourist flights. You can safely delete it from the list.<br /><br /><font color="white">Why not? It would launch the Earth depature stage not the tourists themselves.</font></font>