Re: Is Crew Launch Vehicle Too Big?
- From: "Ed Kyle" <edkyle99@xxxxxxxxxxx>
- Date: 17 Oct 2005 14:24:03 -0700
Douglas Holmes wrote:
> "Ed Kyle" <edkyle99@xxxxxxxxxxx> wrote in message
> news:1129474230.083122.321710@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> > According to information presented by Keith Cowing at
> >
> > "http://www.spaceref.com/news/viewnews.html?id=1069";
> >
> > the earth orbit CEV that will go to ISS might weigh in
> > at only 15.6 tonnes, yet NASA is developing a crew
> > launch vehicle for CEV that will be capable of boosting
> > nearly 23 tonnes to the ISS inclination. The new crew
> > launcher will have a gross liftoff mass (GLOW) of
> > about 800 tonnes - more than any other expendable launch
> > vehicle except Titan IV. If it were scaled down to a
> > size appropriate for the 15.6 tonne ISS CEV payload, the
> > launcher might have a GLOW less than 550 tonnes - less
> > than Proton and Delta IV Heavy and about the same as
> > Zenit and Atlas V 552.
> >
> Well I am not sure how much of it to count since it probably
> does not go all the way to orbit but you did not add in the
> 4,218 kg mass of the LAS.
> Even with full mass credit it is less then 20 tons.
LAS is jettisonned relatively early, so it is not
counted as orbital payload. The LAS mass is similar
to the mass of a payload shroud in that it is
jettisonned early enough that it does not much
impact the delta-v performance of the second stage.
>
> On the other side Boeing/Northrop is hinting their proposal
> will be much lighter. Only 10-15% more then Apollo. See
> http://space.com/spacenews/businessmonday_051017.html
> That would cut mass to only about 18 tons for a moon mission
> and 13-14 for an ISS mission.
>
> Put simply all of this again leads me to the conclusion that there is
> no need for the stick.
> Of course NASA could disqualify them for being to light for the Stick
The Stick could still do the job, but with a substantially
smaller and lighter (and presumably less-costly) second
stage.
- Ed Kyle
.
- References:
- Is Crew Launch Vehicle Too Big?
- From: Ed Kyle
- Re: Is Crew Launch Vehicle Too Big?
- From: Douglas Holmes
- Is Crew Launch Vehicle Too Big?
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