Ares-1 second stage MYSTERY

On Dec 26, 9:56 am, gaetanomarano wrote:
On Dec 26, 2:17 pm, wrote:

The Saturn IB second stage weighed 256k lb and the J-2 thrust was 225k
lb. There was also the Apollo spacecraft weight on top too

BOTH your example are WRONG since a second or third stage engine could
have a low thrust only if it burns at very high altitude when the
rocket has already reached a close-to-orbital speed, while, the Ares-1
SRB is jettisoned t 55 km. and lower speed, then, it needs a powerful
engine to reach the orbit, that's why the early CLV was designed
around the SSME

the problem is that a 5th segment "could" add more thrust (then,
"should" lift more upperstages' mass) but no more burning time nor
more speed, then, the Ares-1 2nd stage engine MUST have the SAME power
of an SSME to carry a 10 mT heavier upperstages' mass

.

You are such an idiot
You are wrong again. You don't even know what "power" is as it
relates to launch vehicles.
you don't know how the 5 segment has more than 25% more "power" than
the 4 segment. It isn't just max thrust or burn duration. It is
total impulse.
That is how the J-2 can be used instead of the SSME. The current
propellant tanks of the upperstage are larger that the ESAS version,
which provides more total impulse to make up for the lower ISP of the
J-2

wrote:
On Dec 26, 11:37 am, gaetanomarano wrote:
On 26 Dic, 16:07, Alan Anderson wrote:

The maximum load of a crane is a matter of structural strength and force
applied through the cable, not of energy or power.
well, so, if the Ares-1 don't work, we can use a crane to launch the
Orion...

the SSME choice was a multi-years study while the J-2X is a LAST
MINUTE change



As usual, you are wrong on all accounts.

The SSME choice was NOT a multi-year study. Because it was not
throughly studied, the SSME was found not to be good as an upperstage
engine

That's so weird how ground started engines don't make good upper stage
engines, and upper stage engines don't make good ground started engines.

Strange, but true.

On 26 Dic, 20:22, wrote:

The SSME choice was NOT a multi-year study. *Because it was not
throughly studied, the SSME was found not to be good as an upperstage
engine

probably, the biggest mystery is to understand WHY I still reply to
your insults-only posts...

however... YOU are WRONG, since the early Ares-like study with the
SSME started in 1993:

http://www.geocities.com/launchreport/ares1.html

.

On 26 Dic, 20:34, wrote:

the 5 segment has more than 25% more "power" *than
the 4 segment.

WRONG, a real NASA-ATK 2003 test shows only 9% of extra thrust and 5
seconds of extra-burning time

The current
propellant tanks of the upperstage are larger that the ESAS version

WRONG AGAIN since the upperstages' extra-mass of the Ares-1 is only 10
mT and it's not only extra-propellent since at least HALF of that
extra-mass is due to the Orion and LAS extra-weight

.

On 26 Dic, 20:34, wrote:


your change of my threads subject is completely useless since the
Ares-1 will NEVER fly and NASA will abandon soon this project with the
excuse of "too much 1st stage vibrations" (or similar...


..

On Dec 26, 6:39 pm, gaetanomarano wrote:
On 26 Dic, 20:34, wrote:

your change of my threads subject is completely useless since the
Ares-1 will NEVER fly and NASA will abandon soon this project with the
excuse of "too much 1st stage vibrations" (or similar...

.

They may abandon it but it won't be for any of the reasons you say

On Dec 26, 6:35 pm, gaetanomarano wrote:
On 26 Dic, 20:34, wrote:

the 5 segment has more than 25% more "power" than
the 4 segment.

WRONG, a real NASA-ATK 2003 test shows only 9% of extra thrust and 5
seconds of extra-burning time


Read this idiot.

"only 9% of extra thrust and 5 seconds of extra-burning time" DOES
NOT define "power"

This chart that you posted on another site shows that you are wrong as
usual

http://www.thespaceport.us/forum/ind...dpost&p=217792

"Power" is total impulse

RSRB has 296.3 Mlbf-sec of total impulse
The 5 segment has 379.4 Mlbf-sec which 28% more. It is the same as
the difference in areas under the curves.

Just another example where you don't understand basic rocket science

On 27 Dic, 01:26, wrote:

Read this

not to answer to your insults but just to give some info to the thread
readers...

THIS is the ONLY real test of a 5-segments SRB:

http://www.nasa.gov/centers/marshall...03/03-186.html

and these are the LATEST Ares-1 specs:

http://www.ghostnasa.com/posts/IMAGES/012ares.jpg

just read them

..

On 27 Dic, 11:36, gaetanomarano wrote:

also, we are NOT talking here about the 1st stage power, but ONLY if
the SECOND stage has enough power when the 1st stage is jettisoned at
50-55 km.

..

gaetanomarano wrote:

also, we are NOT talking here about the 1st stage power, but ONLY if
the SECOND stage has enough power when the 1st stage is jettisoned at
50-55 km.

I think you're the only one still fixated on "power". That is not the
relevant figure of merit for this upper stage. What one needs is
energy: impulse, delta-v, Isp times propellant, however you wish to
determine it.

Note that the upper stage is already rising at rather a good clip when
it begins applying its own thrust. It has quite a lot of time to gain
velocity on its way to orbit before there is any need to worry about
losing altitude due to gravity. With enough impulse (and rest assured
that "enough impulse" is a design constraint, not a rhetorical device),
lower thrust is simply a tradeoff against cost and reliability.