Doom doom, again, still, alas.

        http://www.aviationweek.com:80/aw/generic/story.jsp?id=news/required022708.xml&headline=NASA%20Needs%20A%20Bigger%20Ares%20V&channel=space

Design has fallen short of its necessary target weight to do 
its mission NASA style, and some very nasty options are 
being canvassed. As it is has 4 x Shuttle type SRB's 
extended from 4 to unproven 5 segment versions. Latest 
choices include adding an inert 1/2 segment per booster, or 
an active half segment to get more height for an increased 
evil Liquid Hydrogen *tank. Also mooted as possible is an 
extra RS-68 (total then 6) LH/LO motor. Detroit Diesel says 
'There's no substitute for inches'.


        Russell


* evil liquid Hydrogen is a special substance used by rocket 
engineers to make horrendously complex rocket stages that 
are far far far volumetrically larger than one could 
possibly imagine because the SG of LH is about 70 times that 
of gaseous air BUT about 14 times less dense than water. Add 
to that the complications of super cryo temperatures and 
super topping cycle engines run at a pressure that only a 
Russian rocket engineer could be happy with. The end result 
is an overall performance that is arguably inferior to what 
can be gained with the far far far less sexy LOX and kero.


        Russell








-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist