| |
 |
|
|
Science Forum Index » Space - Shuttle Forum » Rocket Scientists Acting Sneaky...
Page 2 of 3 Goto page Previous 1, 2, 3 Next
|
| Author |
Message |
| Revision... |
Posted: Wed Jul 16, 2008 8:34 pm |
|
|
|
Guest
|
"Jeff Findley"
Quote: The name DIRECT was chosen for the opposing launch vehicle proposal
because it uses hardware with more direct shuttle heritage than Ares I/V.
It sticks with four segment SRB's and ET diameter tankage for the first
stage.
Still sounds like re-inventing the Ariane. Everyone has to do their own
machine in-house.
If an SRB will work to launch the crew vehicle, then vague inhibitions about
a "stretched SRB" without substantive support are not adequate to justify a
larger hybrid vehicle, regardless of Griffin, preferences, legacies, etc.
** Posted from http://www.teranews.com ** |
|
|
| Back to top |
|
| Revision... |
Posted: Wed Jul 16, 2008 8:42 pm |
|
|
|
Guest
|
"Greg D. Moore
Quote: He gave you info about the "improved" design.
"These dissenting scientists and their backers insist they have created
an alternative rocket that would be safer, cheaper and easier to build
than the two Ares spacecraft that will replace the space shuttle.
"They call their project Jupiter, and like Ares, it's a brainchild of
workers at the Marshall Space Flight Center and other NASA facilities.
The engineers involved are doing the work on their own time and mostly
anonymously, with the help of retirees and other space enthusiasts."
Great ... so direct 2.0 is Jupiter....catchy name.
** Posted from http://www.teranews.com ** |
|
|
| Back to top |
|
| Revision... |
Posted: Wed Jul 16, 2008 8:45 pm |
|
|
|
Guest
|
"Tanker" <m1a1tanker at (no spam) earthlink.net> wrote in message
news:7Y-dnQxlFoyz3-PVnZ2dnUVZ_t7inZ2d at (no spam) comcast.com...
Quote: I live in Huntsville and it was in the local paper the Huntsville Times.
And I know a few engineers who have been laughing at this "under the table"
project for a few years.
So what is the joke.
One of the guys involved is not even an engineer.
Wow.
Quote: He is a toy rocketeer and has had several articles published about the
Ares which he doesn't even work on...wait he doesn't even work for NASA...
So what is this fellow's name? Man, hearsay is ok to a point but this is
time wasting nonsense. I have a duck. My duck likes cheese.
** Posted from http://www.teranews.com ** |
|
|
| Back to top |
|
| Revision... |
Posted: Wed Jul 16, 2008 8:50 pm |
|
|
|
Guest
|
Quote: I live in Huntsville and it was in the local paper the Huntsville Times.
And I know a few engineers who have been laughing at this "under the
table" project for a few years.
One of the guys involved is not even an engineer.
The article you quote says that engineers at NASA are working on a competing
project, not a non-NASA non-engineer.
** Posted from http://www.teranews.com ** |
|
|
| Back to top |
|
| Brian Thorn... |
Posted: Wed Jul 16, 2008 11:10 pm |
|
|
|
Guest
|
On Wed, 16 Jul 2008 20:24:29 -0500, "Revision"
<ttsREMOVE at (no spam) NOJUNKcharter.net> wrote:
Quote:
"Jeff Findley"
Ares I/V requires building and maintaining two completely separate launch
vehicles with very little in common. A cheaper choice would be a two
launch architecture where two identical launch vehicles are used to fly a
lunar mission. This is what the DIRECT proposal is all about.
Well that sounds absurd. I seriously doubt that the savings exist at all.
DIRECT is somewhat more costly if you compare one DIRECT crew launch
against one ARES I crew launch. The savings appear when you consider
the two launches needed per lunar mission. Two DIRECT launches (one
with an upper stage, the other not) are cheaper than an ARES I and an
ARES V together. Much cheaper.
Even better, DIRECT in theory achieves this at enormously lower
development costs and probably much shorter development time before an
ISS-capable version is available:
- No new Mobile Launch Platforms needed
- No Five Segment Booster development needed
- No Ares I upper stage development needed
- No retooling Michoud from Shuttle External Tank size to 33 ft. size.
- First stage engine already in service (RS-6
- No new barge needed to ship core stage to KSC
- Upper stage not needed until 2018 for lunar flights
- J-2X engine not needed until 2018 for lunar flights
While DIRECT has two Solid Rocket Boosters and therefore has a higher
risk, this is somewhat mitigated by DIRECT firing its main engine on
the ground before committing to flight (ARES I has an in-flight
ignition event, historically the point where a lot of rocket launches
have failed.)
Quote: If all you want to do is launch a crew pod, put it on a large solid and
launch it.
That's what ARES I started out being. It has turned into a nightmare
with performance shortfalls that have forced a reduction in the size
of Orion, while the ARES I itself has grown extraordinarily long... it
will be the tallest/thinnest rocket anyone has ever seen, and will
likely have serious controllability issues to be solved before first
flight. ARES I's upper stage is now about as large as many rockets'
first stages! ARES I has also now eliminated the original ground
landing for Orion due to weight concerns, which means reusability is
pretty much a pipedream now, and has oscillation/vibration problems
that have yet to be fully solved. All these problems go away with
DIRECT.
DIRECT certainly will have new problems all of its own, but its much
closer lineage to Shuttle means that they should be much closer to
previous flight experience and correspondingly easier to solve. And
that big performance surplus sure does make life easier for the Orion
guys. (We can work on cutting Orion weight later on, through flight
experience, instead of squeezing every last ounce out of it now just
to make the first ARES I launch work.)
Quote: I fail to see how putting the crew capsule on a large
Ariane-style rocket would work better or cost less.
You could put an MPLM in the fairing below the Orion on a DIRECT
launcher and carried cargo to ISS on the same mission, thus saving the
cost of a few Progresses or a couple of Falcon/Dragon launches or an
Ariane V / ATV launch. Or you could put a Hubble service package down
there and fly more Hubble repair missions.) ARES I has no excess
payload to allow this (it can barely lift Orion alone.)
Quote: If they really wanted to save cash they would buy a few Soyuz, but I
digress.
The cost savings are nice, but the faster development time is the
really enticing part. All that development work we wouldn't have to do
should get Orion in orbit a lot sooner than ARES I will. J-2X is the
present pacing item, and DIRECT won't need it until the lunar missions
begin at the end of the next decade.
Quote: What is the real rationale? "Lets build them so they look the same, and
therefore that is better?" If there is some objective reasoning or goal I
would like to know what it is.
Minimize development work, maximize commonality between the two launch
vehicles.
Brian |
|
|
| Back to top |
|
| Jeff Findley... |
Posted: Thu Jul 17, 2008 3:56 pm |
|
|
|
Guest
|
"Greg D. Moore (Strider)" <mooregr_deleteth1s at (no spam) greenms.com> wrote in message
news:osmdndVOBrH4AOPVnZ2dnUVZ_o3inZ2d at (no spam) earthlink.com...
Quote: "Jeff Findley" <jeff.findley at (no spam) ugs.nojunk.com> wrote in message
news:d6cc8$487e14b3$927a2cda$15018 at (no spam) FUSE.NET...
The name DIRECT was chosen for the opposing launch vehicle proposal
because it uses hardware with more direct shuttle heritage than Ares I/V.
It sticks with four segment SRB's and ET diameter tankage for the first
stage.
The "problem" with DIRECT is that it sounds great on paper. And as we all
know Ares I/V started that way.
I still think Ares is a mistake. But am not convinced that DIRECT is the
golden boy either.
If you understand aerospace engineering and actually read through what's
online, it's actually pretty easy to see how they get Ares I + Ares V
performance out of 2 launches of Jupiter 232.
One way they do it is by having the same people who've been building and
flying Centaur for decades design the upper stage (similar to NASA's EDS).
The downside of NASA's EDS is that it's using none of the weight saving
techniques used in Centaur. It's a bit baffling that they would ignore
these innovations (proven with literally decades of Centaur flights), but
you have to look at exactly what NASA center is designing the EDS then you
should understand.
Another way DIRECT gets their performance is by sticking two J-2X engines on
their Jupiter 232 upper stage, so it's more powerful, so the lower stage
doesn't have to be. Ares V, in the quest to get their theoretical
reliability numbers up, is dead set on using a single J-2X on their EDS. To
compensate, Ares V's lower stage needs 5.5 segment SRB's (maybe six) and six
RS-68 engines to loft the single engine EDS plus its payload.
If you compare 2x Jupiter 232 with Ares I plus Ares V you'll see that they
use essentially the same number of SRB segments and the same number of RS-68
engines but the Jupiter 232's need two more J-2X engines to lift
approximately the same payload to LEO to mount a lunar mission. I know
counting engines isn't the best way to approximate payload capacity, but
it's actually pretty close in this case and gives you a rough idea how
Jupiter 232 gets the performance it needs.
Jeff
--
A clever person solves a problem.
A wise person avoids it. -- Einstein |
|
|
| Back to top |
|
| Jeff Findley... |
Posted: Thu Jul 17, 2008 4:03 pm |
|
|
|
Guest
|
"Revision" <ttsREMOVE at (no spam) NOJUNKcharter.net> wrote in message
news:95143$487e9f42$23668 at (no spam) news.teranews.com...
Quote:
"Jeff Findley"
Ares I/V requires building and maintaining two completely separate
launch vehicles with very little in common. A cheaper choice would be a
two launch architecture where two identical launch vehicles are used to
fly a lunar mission. This is what the DIRECT proposal is all about.
Well that sounds absurd. I seriously doubt that the savings exist at all.
If all you want to do is launch a crew pod, put it on a large solid and
launch it. I fail to see how putting the crew capsule on a large
Ariane-style rocket would work better or cost less.
You're missing the point. For lunar missions, you have to launch one Ares I
and one Ares V or you can launch two Jupiter 232's. Which is easier to
launch, two vehicles where all stages are different, the MLP's are
different, etc. or two vehicles which are identical except for their
payload?
Quote: If they really wanted to save cash they would buy a few Soyuz, but I
digress.
What is the real rationale? "Lets build them so they look the same, and
therefore that is better?" If there is some objective reasoning or goal
I would like to know what it is.
If the point were to keep flying around in LEO I might agree (actually, I'd
say NASA should stick to EELV's), but NASA is trying to go to the moon and
keep congress happy by retaining as much of the shuttle workforce (i.e.
pork) as possible.
My personal architecture would use only EELV's and would direct NASA to
develop LEO fueling depots (LOX and LH2), eventually adding a lunar orbit or
L2 fuel depot.
Jeff
--
A clever person solves a problem.
A wise person avoids it. -- Einstein |
|
|
| Back to top |
|
| Jeff Findley... |
Posted: Thu Jul 17, 2008 4:06 pm |
|
|
|
Guest
|
"Revision" <ttsREMOVE at (no spam) NOJUNKcharter.net> wrote in message
news:8099a$487ea186$25104 at (no spam) news.teranews.com...
Quote:
"Jeff Findley"
The name DIRECT was chosen for the opposing launch vehicle proposal
because it uses hardware with more direct shuttle heritage than Ares I/V.
It sticks with four segment SRB's and ET diameter tankage for the first
stage.
Still sounds like re-inventing the Ariane. Everyone has to do their own
machine in-house.
If an SRB will work to launch the crew vehicle, then vague inhibitions
about a "stretched SRB" without substantive support are not adequate to
justify a larger hybrid vehicle, regardless of Griffin, preferences,
legacies, etc.
Call it what you will, but the US wants to maintain its own launch systems.
I'd personally prefer that all the shuttle infrastructure dies a quiet death
and NASA be forced to use the US's existing EELV's.
Jeff
--
A clever person solves a problem.
A wise person avoids it. -- Einstein |
|
|
| Back to top |
|
| Jeff Findley... |
Posted: Thu Jul 17, 2008 4:07 pm |
|
|
|
Guest
|
"Revision" <ttsREMOVE at (no spam) NOJUNKcharter.net> wrote in message
news:14a90$487ea438$26821 at (no spam) news.teranews.com...
Quote:
"Tanker" <m1a1tanker at (no spam) earthlink.net> wrote in message
news:7Y-dnQxlFoyz3-PVnZ2dnUVZ_t7inZ2d at (no spam) comcast.com...
I live in Huntsville and it was in the local paper the Huntsville Times.
And I know a few engineers who have been laughing at this "under the
table" project for a few years.
So what is the joke.
One of the guys involved is not even an engineer.
Wow.
My guess is he likes watching management's glowing PowerPoints and actually
believes them. More skeptical engineers talk between themselves and hear
about the challenges which either don't make the PowerPoint, or are glossed
over in the PowerPoint.
Jeff
--
A clever person solves a problem.
A wise person avoids it. -- Einstein |
|
|
| Back to top |
|
| J Waggoner... |
Posted: Tue Jul 22, 2008 2:23 am |
|
|
|
Guest
|
Or DAMN... you could update some weird rocket that was launched 10
times and upgrade it with modern technology. Seems like the Saturn V
was a pretty decent rocket for analog technology. Damn, there's that
Golden age getting in the way again!
On Thu, 17 Jul 2008 17:03:48 -0400, "Jeff Findley"
<jeff.findley at (no spam) ugs.nojunk.com> wrote:
Quote:
"Revision" <ttsREMOVE at (no spam) NOJUNKcharter.net> wrote in message
news:95143$487e9f42$23668 at (no spam) news.teranews.com...
"Jeff Findley"
Ares I/V requires building and maintaining two completely separate
launch vehicles with very little in common. A cheaper choice would be a
two launch architecture where two identical launch vehicles are used to
fly a lunar mission. This is what the DIRECT proposal is all about.
Well that sounds absurd. I seriously doubt that the savings exist at all.
If all you want to do is launch a crew pod, put it on a large solid and
launch it. I fail to see how putting the crew capsule on a large
Ariane-style rocket would work better or cost less.
You're missing the point. For lunar missions, you have to launch one Ares I
and one Ares V or you can launch two Jupiter 232's. Which is easier to
launch, two vehicles where all stages are different, the MLP's are
different, etc. or two vehicles which are identical except for their
payload?
If they really wanted to save cash they would buy a few Soyuz, but I
digress.
What is the real rationale? "Lets build them so they look the same, and
therefore that is better?" If there is some objective reasoning or goal
I would like to know what it is.
If the point were to keep flying around in LEO I might agree (actually, I'd
say NASA should stick to EELV's), but NASA is trying to go to the moon and
keep congress happy by retaining as much of the shuttle workforce (i.e.
pork) as possible.
My personal architecture would use only EELV's and would direct NASA to
develop LEO fueling depots (LOX and LH2), eventually adding a lunar orbit or
L2 fuel depot.
Jeff |
|
|
| Back to top |
|
| Jeff Findley... |
Posted: Tue Jul 22, 2008 9:01 am |
|
|
|
Guest
|
"J Waggoner" <jwaggon at (no spam) alltel.net> wrote in message
news:il2b84lhnmcrqljuh8680sm2ha2sgvgb4b at (no spam) 4ax.com...
Quote: Or DAMN... you could update some weird rocket that was launched 10
times and upgrade it with modern technology. Seems like the Saturn V
was a pretty decent rocket for analog technology. Damn, there's that
Golden age getting in the way again!
Not really. Everything related to the Saturn V, except for the plans and
other assorted reports, pictures, and etc. is long gone. The tooling,
workforce, and even many of the companies which built components for the
Saturn V are all long gone.
To bring back the Saturn V, you'd have to start from square one. In the
end, you might end up with something that looked like the Saturn V, but it
would be an all new launch vehicle with all new engines.
And all of this ignores the upgrades planned for the Saturn V which were
never completed, like the F-1A and J-2S engines, tank stretches, and the
like.
Better to stick with Atlas V and Delta IV since they're in production right
now.
Jeff
--
A clever person solves a problem.
A wise person avoids it. -- Einstein |
|
|
| Back to top |
|
| Greg D. Moore (Strider)... |
Posted: Fri Jul 25, 2008 10:37 am |
|
|
|
Guest
|
"J Waggoner" <jwaggon at (no spam) alltel.net> wrote in message
news:il2b84lhnmcrqljuh8680sm2ha2sgvgb4b at (no spam) 4ax.com...
Quote: Or DAMN... you could update some weird rocket that was launched 10
times and upgrade it with modern technology. Seems like the Saturn V
was a pretty decent rocket for analog technology. Damn, there's that
Golden age getting in the way again!
13 flights.
Several with major, near mission ending failures.
Apollo 6 nearly shook itself to death
Apollo 13 had a center engine cutoff on the 2nd stage early.
Others had minor issues.
And of course once you start "upgrading it" where do you stop before it
becomes all new technology?
Do you stick with the F-1 engines that haven't been built or flown in 3
decades, or upgrade to the F-1A which have never been flown, but give you
better performance?
What about replacing the insulation on the 2nd stage tank with more modern
materials?
You really want to replace the computers, so that's all new stuff.
At some point you sometimes just have to consider maybe starting over IS the
right thing to do.
--
Greg Moore
SQL Server DBA Consulting Remote and Onsite available!
Email: sql (at) greenms.com http://www.greenms.com/sqlserver.html |
|
|
| Back to top |
|
| Derek Lyons... |
Posted: Mon Aug 04, 2008 2:51 pm |
|
|
|
Guest
|
"Jeff Findley" <jeff.findley at (no spam) ugs.nojunk.com> wrote:
Quote:
"Greg D. Moore (Strider)" <mooregr_deleteth1s at (no spam) greenms.com> wrote in message
news:osmdndVOBrH4AOPVnZ2dnUVZ_o3inZ2d at (no spam) earthlink.com...
The "problem" with DIRECT is that it sounds great on paper. And as we all
know Ares I/V started that way.
I still think Ares is a mistake. But am not convinced that DIRECT is the
golden boy either.
If you understand aerospace engineering and actually read through what's
online, it's actually pretty easy to see how they get Ares I + Ares V
performance out of 2 launches of Jupiter 232.
<snip a lengthy discussion of how DIRECT/Jupiter uses Shuttle derived
hardware to be both a floor wax and a dessert topping.>
All very nice, but having zip point zero to do with Greg's point.
Paper rockets are always wonderful regardless of origin. The problems
start when you start trying to build real rockets and DIRECT/Jupiter
is not immune to this effect nor do I see any reason to assume it will
be.
D.
--
Touch-twice life. Eat. Drink. Laugh.
http://derekl1963.livejournal.com/
-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL |
|
|
| Back to top |
|
| Jochem Huhmann... |
Posted: Mon Aug 04, 2008 3:52 pm |
|
|
|
Guest
|
fairwater at (no spam) gmail.com (Derek Lyons) writes:
Quote: Paper rockets are always wonderful regardless of origin. The problems
start when you start trying to build real rockets and DIRECT/Jupiter
is not immune to this effect nor do I see any reason to assume it will
be.
Did anyone think that Ares I was wonderful when it still was a paper
rocket?
Jochem
--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery |
|
|
| Back to top |
|
| Derek Lyons... |
Posted: Mon Aug 04, 2008 5:48 pm |
|
|
|
Guest
|
Jochem Huhmann <joh at (no spam) gmx.net> wrote:
Quote: fairwater at (no spam) gmail.com (Derek Lyons) writes:
Paper rockets are always wonderful regardless of origin. The problems
start when you start trying to build real rockets and DIRECT/Jupiter
is not immune to this effect nor do I see any reason to assume it will
be.
Did anyone think that Ares I was wonderful when it still was a paper
rocket?
Ares was one of they very few exeptions, but early on mostly because
it had a NASA logo down in the title block of the drawings. The real
howling didn't start until the real world predictably started to
diverge from the paper one.
D.
--
Touch-twice life. Eat. Drink. Laugh.
http://derekl1963.livejournal.com/
-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL |
|
|
| Back to top |
|
| |
Page 2 of 3 Goto page Previous 1, 2, 3 Next
All times are GMT - 5 Hours
The time now is Tue Oct 14, 2008 2:55 am
|
|