Chris Adams wrote:
> Once upon a time, Andrew Swallow   said:
>> Chris Adams wrote:
>>> Once upon a time, Andrew Swallow 
 said:
>>>> Two different design of rockets for the same mission
appears expensive. 
>>> They aren't two different designs for the same mission.  First, there
>>> are a number of shared pieces between the designs.  Second, the missions
>>> are different.
>> They were the same mission the last time I looked - going to the moon.
>> The cargoes were different.
> 
> But that isn't the only mission.  There's also "take people to ISS",
> which Ares I will also be used for.

That is only a back up mission.  NASA's plan is to send cargo to the ISS 
is via Falcon 9 rockets with people travailing in SpaceX's Dragon capsule.
http://www.nasa.gov/mission_pages/exploration/news/COTS_selection.html>

>  Down the road (hopefully), there
> will be "take people and cargo to Mars" - multiple Ares V launches
> followed by an Ares I launch.

An Ares_V can lift the Orion capsule and people, just put less fuel in 
the tank.  The cost of buying a few extra Ares_Vs will be less that the 
cost of developing the Ares_I.

> 
>> And gets to the moon a couple of years earlier and at a lot cheaper price.
> 
> If all you want to do is recreate the late 1960s and land a few people
> on the Moon and bring them home, that's great.  NASA is aiming to build
> an actual flexible program; one that can carry people to ISS, land them
> on the Moon (eventually with supplies to build a semi-permanent base),
> and eventually send them to Mars.

The Moon village and landers will be launched by Ares_V (or Jupiter) 
rockets.  So will the Mars village and Earth Departure Stage.

Using the ISS to test the Orion's docking and rendezvousing abilities is 
a good idea.  This means that Orion can be used as a rescue craft if 
things go wrong on the ISS.  Also the astronauts can be diverted to the 
International Space Station (ISS) if something goes wrong on Moon or 
Mars trips.

Andrew Swallow
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