On May 19, 4:01 pm, cmad...{at}hiwaay.net (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.
>
> Ares I is the people lifter.  It will carry a capsule to low Earth
> orbit, which can then do multiple things.  It can reach ISS (since the
> Shuttle is going away, this will be our way to get people to and from
> the station).  It can also dock with other vehicles to go other places
> (the Moon for now, hopefully Mars later).
>
> Ares V is the heavy lifter.  It will put unmanned vehicles (or parts of
> vehicles) in orbit.  If it takes more than one launch to get the
> necessary vehicle in orbit, the people just wait for all the pieces to
> reach orbit and then ride up on an Ares I.
>
> >Alternately could NASA come up with its own rocket to launch the lot?
>
> That was essentially what we did in the 1960s with the Saturn V and then
> in the 1970s with the Shuttle - try to make one vehicle that can do
> everything.  That doesn't work very well.
>
> NASA is now trying to build a Honda Civic to carry people and a MAC
> truck to carry hardware.  They'll share some design pieces, but they are
> different vehicles.  What you are suggesting is instead trying to use a
> Ford Expedition to do everything, but it pretty much sucks at all jobs
> (can't carry as much hardware and is rather inefficient at carrying
> people).
>
> This is actually one of the proposals for the original Moon mission:
> build a people lifter and a heavy lifter.  You launch the heavy lifter
> (possibly multiple times) to get a long-range vehicle in orbit, then
> launch the people to take a ride.  That's probably the best way for
> long-term use, but there were too many unknowns in the 1960s with
> docking that could have caused the US to fall behind and miss the
> deadline (fully automated docking is still a challenge).

This is actually a very cool approach. In the original Space program,
the rockets and vehicles changed along the way to execute the main
task in manned flight (Getting skills, then getting skills and
technology into place to go for the moon, and thne finally going
there.) Saturn V was modified to put up the Skylab. The Shuttle was
meant for a Space Station (Space Station Freedom?) and orbital work
like satellite retireval/repair/launch and telescope placement/
maintenance.

With multiple stuff now going on, having multiple vehicles going makes
a lot of sense. In fact, the idea of multiple vehicles so a problem
with one doesn't ground the whole fleet of NASA makes sense too. Dare
I say, it is starting to get to the "Science Fiction" idea where
different types of space vehicles and vehicle types are in service to
do different things. (Why send a moon shuttle to do an Explorer ship's
mission, and vice versa?)

> --
> Chris Adams 
> Systems and Network Administrator - HiWAAY Internet Services
> I don't speak for anybody but myself - that's enough trouble.
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