Re: gaetanomarano is once again showing his lack of basic knowledge

On 29 Dic, 06:19, behlin...@xxxxxxxxx wrote:


This is where you are completely clueless.  The difference in the
force of gravity between sea level, 50  km and 100 km is minor.
Gravity decreases at 1/radius squared.  This means that gravity at
100km is 97% of what it is at sea level

that confirms the 2nd stage needs an SSME-class engine


The delta-IV booster does not put the upperstage in "near orbital
speed" , only 62 % of it

62% of the orbital speed is enough to need only a small engine for the
final job


The Ares I is no different than the shuttle.  At SRB jettison, the
mass of the orbiter and ET with propellants is greater than the thrust
of the 3 SSME's.  For Ares-1, at SRB jettison, the upperstage and
Orion are going higher and faster than the shuttle and the upperstage
with the J-2 has a higher thrust to weight ratio.

I'm ready to see it fly... :)


for the CLV, the SSME was only paired with a four segment SRB, but
since the Ares-I uses a 5 segment SRB that provides increase of 28%
more total impulse, the J-2 can be used.

the (expected but not real, so far) extra-power of the 5-segments SRB
should allow more upperstages' mass but (see the specs of both
rockets) doesn't add more speed nor an higher altitude (just a few
km.)

that's why the 5-seg.SRB has only 5 seconds more burning time than a
standard SRB

then, the Ares-1 second stage NEEDS the SAME engine of the CLV... an
SSME or TWO J-2X or a resized/SSME-class "J-2Y"

.
.

Relevant Pages

  • Re: gaetanomarano is once again showing his lack of basic knowledge
    ... to use a small engine since the force of gravity is ... force of gravity between sea level, 50 km and 100 km is minor. ... The delta-IV booster does not put the upperstage in "near orbital ... For Ares-1, at SRB jettison, the upperstage and ...
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