ATK's Liberty rocket hopes to launch in 2015

Yes well, I'm still not clear what the love affair with solids is all
about. Obviously, from the pure thrust point of view and their simplicity,
they have a lot to commend them, but when you consider you cannot throttle
them, stop them once started, and their tendency to vibrate due to the
chaotic burning and changing internal capacity, they would seem to be only
of use for lifting a lot of heavy fuel such as they tend to be used for in
Shuttle and other boosters.


Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________


"Snidely" wrote in message
news:mn.52a87dc5560a86d4.127094@snitoo...
JF Mezei explained on 5/10/2012 :
http://www.bbc.co.uk/news/science-environment-18017216

-Uses an extended SRB for first stage (I believe only a 4 segment one)

[...]

Why not use an Ariane 5 rocket or Delta 4 and focus on the capsule ?


What do you think ATK makes, and how would this influence their
engineering decisions?

/dps "salt of the earth"

--
Who, me? And what lacuna?

On May 13, 3:22*am, "Brian Gaff" wrote:
Yes well, I'm still not clear what the *love affair with solids is all
about. Obviously, from the pure thrust point of view and their simplicity,
they have a lot to commend them, but when you consider you cannot throttle
them, stop them once started, and their tendency to vibrate due to the
chaotic burning and changing internal capacity, they would seem to be only
of use for lifting a lot of heavy fuel such as they tend to be used for in
Shuttle and other boosters.

Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
*graphics are great, but the blind can't hear them
Email:
__________________________________________________ _________________________*________________________ ___________

"Snidely" wrote in message

news:mn.52a87dc5560a86d4.127094@snitoo...



JF Mezei explained on 5/10/2012 :
http://www.bbc.co.uk/news/science-environment-18017216

-Uses an extended SRB for first stage (I believe only a 4 segment one)

[...]

Why not use an Ariane 5 rocket or Delta 4 and focus on the capsule ?

What do you think ATK makes, and how would this influence their
engineering decisions?

/dps "salt of the earth"

--
Who, me? *And what lacuna?

there was a thrust termination system? didnt the top open somehow to
end thrust?

but that doesnt end vibration or the nasties that add to
polution.......

In article ,
says...

Yes well, I'm still not clear what the love affair with solids is all
about. Obviously, from the pure thrust point of view and their simplicity,
they have a lot to commend them, but when you consider you cannot throttle
them, stop them once started, and their tendency to vibrate due to the
chaotic burning and changing internal capacity, they would seem to be only
of use for lifting a lot of heavy fuel such as they tend to be used for in
Shuttle and other boosters.

Don't forget their failure modes. Large solids go "boom" (case rupture)
occasionally. Unfortunately when they do that, they give you little to
no warning, making crew escape "challenging" at best.

Liquids can also go "boom", but at least with liquids, you can install a
health monitoring system so you have a very good chance of shutting down
a bad engine long before it would go "boom". Design your liquid fueled
launch vehicle with engine out capability and shutting down an engine
doesn't even impact the mission.

Jeff
--
" Ares 1 is a prime example of the fact that NASA just can't get it
up anymore... and when they can, it doesn't stay up long. "
- tinker

In article 38209e5e-89be-42e3-a34c-
, says...

On May 13, 3:22*am, "Brian Gaff" wrote:
Yes well, I'm still not clear what the *love affair with solids is all
about. Obviously, from the pure thrust point of view and their simplicity,
they have a lot to commend them, but when you consider you cannot throttle
them, stop them once started, and their tendency to vibrate due to the
chaotic burning and changing internal capacity, they would seem to be only
of use for lifting a lot of heavy fuel such as they tend to be used for in
Shuttle and other boosters.

Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
*graphics are great, but the blind can't hear them
Email:
__________________________________________________ _________________________*________________________ ___________

"Snidely" wrote in message

news:mn.52a87dc5560a86d4.127094@snitoo...



JF Mezei explained on 5/10/2012 :
http://www.bbc.co.uk/news/science-environment-18017216

-Uses an extended SRB for first stage (I believe only a 4 segment one)

[...]

Why not use an Ariane 5 rocket or Delta 4 and focus on the capsule ?

What do you think ATK makes, and how would this influence their
engineering decisions?

/dps "salt of the earth"

--
Who, me? *And what lacuna?

there was a thrust termination system? didnt the top open somehow to
end thrust?

On Ariane 5, I believe there is a thrust termination system. It was
designed from the beginning to be "man rated". In this case, "man
rated" means whatever ESA says it means instead of meaning whatever NASA
says it means. ;-)

On Liberty, I'd imagine that the first stage is relatively unchanged
from Ares I's design.

Jeff
--
" Ares 1 is a prime example of the fact that NASA just can't get it
up anymore... and when they can, it doesn't stay up long. "
- tinker