Ares I (CLV) - status

RedStreak · 2006-08-01 20:41:36

Wait wait wait...what do you mean? Are you talking O-rings? Apart from Challenger there hasn't been a flight scrubbed by problems caused by the SRBs, and if so please correct me.

The problem with the shuttle was with the ET insulation - THAT after all was what caught on fire in the Challenger's case and cracked the Columbia heat shield.

The CEV would be atop the ET in this scheme. With the launch escape system in place I doubt there'd be any more risk to the astronauts than there would have been to those aboard Apollo. Now explain in better detail what worries you? And I hope its more than just fearing design overruns for a 3-segment SRV.

RedStreak · 2006-08-01 20:50:14

[This "backup" Ares-I plan has one really serious flaw, that it has a risk the same thing that Challenger did could happen here. Two three-segment SRBs would cost more than one five-segment booster too, plus the extra J-2 engine cost. I doubt that this plan will happen.

Of course the cost of two five-segment boosters on the CaCLV beats that of two three-segments anyday, which ought to be accounted for...AND the cost of modifying a 5-segment to accomidate a booster with the CEV atop in turn you seem to forget.

Each plan has a drawback. This version doesn't need a new crawler platform built and uses alot of the equiptment that'd be used for CaCLV - no cost for new development.

I like it because I'm willing to bet it can launch a larger CEV than alotted by the Ares-I and without modifying SRBs. And by that I mean we could stick with the old 4-segments and get the job done.

SpaceNut · 2006-08-03 21:12:33

So to make up for lost time if I follow the plans of using dual 3 segment SRB's is to make up for the upper stage. Problem is that the SRB will burn for less time than a 4 segment which even thou it can lift more mass it still will mean that the upper stage will need even more fuel to start its firing at the lower location.

The 5 segment hence by vertue of its extra segment will burn longer even if it is the same fuel as the current 4 segment design.

GCNRevenger · 2006-08-04 07:03:33

Yes I am talking about O-rings between SRB segments failing and the resulting leak of gasses igniting the main tank on the "alternate Ares-I" design. And it is the supersonic hot gasses that burned a hole right through the aluminum (aluminum melts rather easily for a metal) tank in the Challenger disaster. Hard ureathane foam doesn't burn that well, particularly in supersonic cold air flows.

Anyway, booster seal burnthrough has now happened on two occasions, once with Challenger due to low temperatures, and a second time with Atlantis. In the latter incident, they got lucky, and the leak faced away from the rest of the vehicle and was temporary.

Ares-I should be focused on crew launch with enough fuel for Lunar return for the CEV only, and do this as safe as is possible. It has to be qualitatively better than Shuttle, it has to be a whole different level of safety, it has to be trustworthy. So long as we use segmented solid rockets astride a fuel tank, every launch is going to be a sweat-to-orbit fearful thing. Each launch of the "Ares-IB" would have eight sets of SRB seals.

An escape system is also a false security, that reguardless how good it is or where the CEV is mounted, it would still be seriously life threatening to trigger one with enough acceleration to escape the explosion of a huge tank of liquid hydrogen. This possibility is signifigantly increased with the Ares-IB design because of the potential for booster burnthrough and the second J-2X. Plus reguardless how well the escape system works and with astronaut survival, having Ares-IB blowing up will not be good for the space program.

And we definatly, absolutely don't want to change the payload ratios of the "1.5" launch arcitecture! Absolutely not! If you have a heavier ~40MT Ares-I but a lighter ~110MT Ares-V, there will be one very signifigant change to the mission plan: the CEV will perform the Lunar orbit capture burn. What this means is that the Ares-V can no longer deliver unmanned heavy payloads (several tonnes less) to the Moon and manned flights would be more limited (equipment only ~1MT now) due to the lower hypergolic fuel efficiency. Ares-V is already borderline too small for anything useful on the Moon I think given its cost per sortie.

It would also make trouble for a future Mars plan; the present most plausable plan I think is the DRM-III plan or something similar to it. DRM-III calls for the use of nuclear thermal engines on the boost stage to get ships from Earth to Mars orbit, and this booster weighs about 80MT. Now, if NASA has a bigger 125MT class Ares-V, it could instead use chemical propulsion (simple nuclear engines save aprox 50% fuel) and radically reduce the cost and development time for Mars. Infact just take a stretch Lunar EDS stage with docking gear, swap out J-2X for RL-60, and then you could send 80-90MT to Mars easy, plus you would have more time to use it before fuel boiloff is a problem (nuke engines have faster boiloff).

I think not having to need nuclear engines for Mars, safer CEV launch, and really useful sized Lunar payloads makes the five-segment SRB and present Ares-I/Ares-V designs favorable versus the "Ares-IB"/Ares-V with four-segment boosters.

Oh, one last thing:

Problem is that the SRB will burn for less time

No, not nessesarrily. Solid rockets aren't a solid block of fuel, they all have a channel running through the center of the fuel grain along the whole length of the booster to increase the surface area. Solid fuels don't burn all that rapidly, so they need this extra area to give decent thrusts. The size and shape of this channel strongly influences burn time, so a three or five segment booster could burn for similar times.

cIclops · 2006-08-04 18:06:56

Details from Michael Cabbage's blog apparently from Marshall Space Flight Center

* NASA is designing the Ares 1 to lift off in much more marginal weather than the space shuttle. The goal is to create a vehicle more like Russia’s Soyuz booster, which has been launched in rain, high winds, fog and snowstorms.
* The first test flight of the rocket, dubbed Ares I-1, is scheduled for April 2009. The test will use an adapted four-segment booster from the shuttle program instead of the slightly longer five-segment version planned for operational flights. The second stage will consist of a dummy payload.
* The Ares 1’s Preliminary Design Review is scheduled for December 2007. The Critical Design Review is scheduled for July 2010. Before the first operational flight, five static firings of the new five-segment first-stage boosters are planned in Utah by the manufacturer, ATK. The first static firing is scheduled for June 2009.
* The "biggest unknown" for engineers remains how to control the Ares 1’s steering and roll during flight. Engineers are using computer models and other analyses to solve the problem.
* Despite the fact the Ares 1 is longer than the shuttle’s booster, it will fire for about the same length of time – roughly 128 seconds. The difference is that engineers have widened the nozzle on the Ares-1 to increase its thrust. After a 5-6 second pause for the second stage to clear the jettisoned lower stage, the second stage will burn for about 460 seconds. The total ascent time is about 10 minutes, 90 seconds longer than it takes the shuttle to reach orbit.
* The crew capsule will have an escape tower to carry astronauts to safety if a problem develops with the booster beneath them. The escape system will be effective anytime from launch until about 30 seconds after the first stage separates. That covers about the first two and a half minutes of flight.
* The Ares 1’s period of maximum aerodynamic pressure, or Max Q, will come about 58 seconds into flight when the rocket is traveling at 1.6 times the speed of sound some 40,000 feet above the ground.
* Astronauts will experience an estimated maximum of 3.25-3.5 times the force of gravity during the Ares 1’s launch. That compares to about 3 Gs for the shuttle. An emergency firing of the escape tower could reach more than 10 Gs. The limits are still being worked out.
* Like the shuttle’s boosters, the first stage of the Ares 1 will be reusable. However, it will plunge toward the ocean at speeds of Mach 6, compared to Mach 4 for the shuttle’s boosters. Engineers are looking at making the booster tumble to reduce the speed before the parachutes open.

SpaceNut · 2006-08-05 19:29:19

Schedule for lunar trips puts Marshall engineers to the test; Center busily gathers data on engine that will power upper stage of Ares I rocket

Green and orange flames and 20,000 pounds of thrust spewed out of a Marshall test stand for about 10 seconds Thursday as part of 50 tests to provide data on engine parts and the overall design of the J-2X engine.
Marshall engineers for two months have been testing different fuel mixtures to see how a rocket engine fuel injector plate will react under the stress of launch.
Across Marshall, about 540 people are developing elements of the Ares I crew launch vehicle and the Ares V heavy cargo lift vehicle - rockets to be used to return astronauts to the moon.

What seems to be leading to a delay:

Even though it is an Apollo-era design, the J-2X engine is an improved Saturn V upper-stage engine that never flew on a mission. Cook said the J-2X still faces a lot of design and test work. Hanley said the J-2X engine is one reason the Ares I rocket probably would not be completed before 2012.

GCNRevenger · 2006-08-05 19:48:41

sigh

Marshall Spaceflight Center needs six years to build an engine that we already have much of the design for?

Note that Marshall would have been awarded the contract for the CEV-SM/LSAM-acent methane rocket, which was canceld since they didn't seem to be up to the task in any reasonably efficient way... These guys sound, well, incompetant to me.

RedStreak · 2006-08-05 20:04:46

Yes I am talking about O-rings between SRB segments failing and the resulting leak of gasses igniting the main tank on the "alternate Ares-I" design. And it is the supersonic hot gasses that burned a hole right through the aluminum (aluminum melts rather easily for a metal) tank in the Challenger disaster. Hard ureathane foam doesn't burn that well, particularly in supersonic cold air flows.
Anyway, booster seal burnthrough has now happened on two occasions, once with Challenger due to low temperatures, and a second time with Atlantis. In the latter incident, they got lucky, and the leak faced away from the rest of the vehicle and was temporary.

Can't argue with that, but how many shuttle launches didn't have that happen by comparison? Even the reliable Protons and Soyuz or even the Ariane have similar problems once in a great while. As long as we understand what causes it and work to correct or handle the problem it ceases to be a problem.

Plus reguardless how well the escape system works and with astronaut survival, having Ares-IB blowing up will not be good for the space program.

Kinda a big duh, no offense. So long as the ground and the flight crews keep an eye on it it won't happen.

And we definatly, absolutely don't want to change the payload ratios of the "1.5" launch arcitecture! Absolutely not! If you have a heavier ~40MT Ares-I but a lighter ~110MT Ares-V, there will be one very signifigant change to the mission plan: the CEV will perform the Lunar orbit capture burn. What this means is that the Ares-V can no longer deliver unmanned heavy payloads (several tonnes less) to the Moon and manned flights would be more limited (equipment only ~1MT now) due to the lower hypergolic fuel efficiency.

So...how does improving the CEV decrease the LSAM's or EDS' thrust? I can understand if you mean adding mass to the CEV happers momentum or something but on an unmanned, solo-LSAM cargo mission its irrevelant since the CEV wouldn't be joining it.

It would also make trouble for a future Mars plan;

Ok this I disagree on. If I'm going to be stuck in a space tuna can for six+ months I'd prefer it to be larger. Unless the Mars Lander is based off of Mars Direct's BIG habitat landers it'd get on the astronauts nerves - not drive them insane nessicarily but it'd make the job stressful. Even if the command module remains the same size an increased size in fuel tanks increases not just delta-V but in how much radiation can be blocked.

Now, if NASA has a bigger 125MT class Ares-V, it could instead use chemical propulsion (simple nuclear engines save aprox 50% fuel) and radically reduce the cost and development time for Mars. Infact just take a stretch Lunar EDS stage with docking gear...

Hold on. I doubt nuclear drives in space will be reaildy apapted myself so I agree there but I'm not as certain about giving the Ares-V more "oomph", barring perhaps light-weight materials being developed nor stretching the EDS stage. Part of the idea is to maximize the architecture with what we got.

I wouldn't want a 3-segment booster myself, either a 4 or 5 in this scheme so payload lifted is maximized at minimal cost. If a flaw is found in the current CLV I'm saying this could make a back-up, particularly if NASA is desperate to meet the 2014 deadline.

GCNRevenger · 2006-08-05 21:39:24

"but how many shuttle launches didn't have that happen"

One of the goals of Ares-I is to be a whole differnt level of "safe," Shuttle is right on the border of not being safe enough to fly if the only things wrong with it are known problems. Ares-I must not be this way, it has to be trustworthy, and what was good enough for Shuttle is not good enough for it, particularly since this failure has happend in one of only 200 firings of the booster when used as designed (Atlantis) and has proven to have catastrophic consequences (Challenger).

"as long as... crews keep an eye on it it won't happen"

Even if the builders and crews do everything exactly right, there is still a chance the thing will blow up and fail. NASA can't afford, politically, to fly an Ares-I with comperable reliability to Shuttle. Its got to be so good that nobody worries about it, at least in comparison with Moon and Mars ships.

"So...how does improving the CEV decrease the LSAM's or EDS' thrust? I can understand if you mean adding mass to the CEV happers momentum or something but on an unmanned, solo-LSAM cargo mission its irrevelant since the CEV wouldn't be joining it."

I should have been a little better organized...

~If Ares-IB is built and the four-segment boosters used on Ares-V, this changes the payload ratio
~If Ares-IB has more payload and Ares-V has less, then the CEV will definatly be used to brake into Lunar orbit
~In the present Ares-IA/Ares-V arcitecture, the Lunar lander (LSAM) does the braking maneuver. It does this more efficiently with its Hydrogen engine versus the CEV's Hypergolics, which would have to be made up by cutting into the surface payload probably.
~If you wanted to send payloads unmanned to the Moon on Ares-V, they would suffer a ~15% payload penalty. They should not be any smaller.

"Ok this I disagree on"

Ummmm I am not talking sending astronauts in CEV capsules to Mars. I am talking this: DRM-III
A nice big 9m wide two-and-a-half story vehicle, massing with landing or Earth return fuel around ~85MT. It would be launched into Earth orbit to mate with a nuclear powerd boost stage launched previously, also weighing about 85MT. I think this mission plan is the best one presently, give or take.

Now, if you wanted to use chemical engines instead of nuclear engines for this booster, whether to save money or avoid political headaches (or both) to get us there faster/cheaper, it would weigh 50% more or around 125MT. Point being, Ares-V with four-segment boosters could not lift this.

When it comes time to build this booster, I was stating that the standard EDS stage used on Ares-V for Lunar missions might be modified to serve as the Mars booster. With more efficient engines, stretched fuel tanks, and docking hardware it would do the job.

I'm getting into this mainly to drop-kick people who hate the five-segment booster and are too easily swayed by how good the Ares-IB sounds without considering other consequences.

RedStreak · 2006-08-05 23:26:09

[i]When it comes time to build this booster, I was stating that the standard EDS stage used on Ares-V for Lunar missions might be modified to serve as the Mars booster. With more efficient engines, stretched fuel tanks, and docking hardware it would do the job.
I'm getting into this mainly to drop-kick people who hate the five-segment booster and are too easily swayed by how good the Ares-IB sounds without considering other consequences.

I have no problem with the 5-segment SRB, although I find it almost hypocritical how you support it while being critical of its lesser predecessor and its burn-throughs. With that logic I'd assume you'd be critical of SRBs of all segments...

All things considered my idea would be to amend the 'Ares I-B' concept to use the 5-segments instead of four, otherwise it'd be either a generic fuel tank or the first stage of Ares-V - either way with the CEV sittin on top. Utilize the 5-segments' increased thrust while simplifying the system.

Yes it'd all be atop a giant powder keg, but the CEV is in no less prone a position than any of the Mercuries, Geminis, or Apollos were before.

I don't know about modifying anything right now, but once we're landing on the Moon I'd advocate creating variations to let the architecture be adaptable; that'll have to be the case if we hope to move onto Mars as well. I've suggested a ReuseableLSAM concept for instance and you're suggesting biggers EDSes. We may see both applications in due time.

GCNRevenger · 2006-08-06 06:10:12

The burnthroughs themselves aren't a big enough problem to scrap the segmented booster, its a burnthrough igniting an adjacent fuel tank is the real danger. Not the failure of the seal, but the interaction of that failure with something else. In the present "Big Stick" design there is no big tank beside the booster like in the Ares-IB, so this isn't a problem.

Using five-segment boosters on Ares-IB wouldn't be very easy, the thrust would have to be reduced to keep the G-forces under control, which would mean a different fuel grain shape than the boosters needed for Ares-V. It would substantially add to the cost of each flight too, but besides all that there really isn't a good reason for a 40MT CEV.

In addition, something I didn't think of in the last post, that if you increase the CEV mass but use the same Lunar module mass as currently planned, the EDS stage would no longer have enough fuel to push both vehicles to the Moon. The LSAM would therefore have to be made lighter, and its already at the edge of being too light.

The big 10m Ares-V first stage would be way way too big for CEV too, and terribly expensive with five RS-68 engines and a gigantic load of fuel. Infact it would have so much fuel that it would need boosters to get off the pad and up to speed efficiently.

"Mercuries, Geminis, or Apollos"

None of which are safe enough! Look, Ares-I has to be better, it is going to be the sole way for America to get people into orbit for the next thirty years most likely, it has got to be better than what we've done before. All previous rocket/capsule combinations have been primarily to beat the Soviets to the Moon, not to be safe.

"I'd advocate creating variations to let the architecture be adaptable"

A most dangerous thing, since variations are expensive. One of the reasons why Shuttle has been such a monsterous money-eater is that they haven't been able to resist improving it, hundreds of millions of dollars are poured anually into Shuttle upgrades. NASA can't afford to do this with VSE, designs ought to be frozen with changes the exception and not the rule, this "instinct to tinker" has to be done away with this time.

Mars_B4_Moon · 2006-08-06 09:01:33

Let’s hope for a revival of the methane engine.

The CaLV is fine and looks great, but the CEV/CLV is a bit of a joke even if they have decided to give it a nice name

The budget is becoming a mess so deadline for any new construction or such to be delayed for a couple of years, cost escalation has been revised up to around $3 billion, while as others have said the astronauts are unhappy getting into a rocket that looks like a elephant payload trying to piggy back on top of a flea rocket, NASA has inevitably pushed to the same conclusions that every other critic had come to - well at least they gave it a nice name

GCNRevenger · 2006-08-06 11:40:40

"a bit of a joke" why? Whats wrong with it?

What budget mess? NASA didn't know how much the larger solid rocket booster would cost when they put together the tenative price tag and completion date. Unfortunatly the more concrete figure is somewhat higher, but this is not a sign of looming demise or anything. Furthermore, the development cost is insignifigant compared to how many Ares-I's will be purchased over the decades and the dual-use of its boosters with the Ares-V.

"while as others have said the astronauts are unhappy getting into a rocket that looks like a elephant payload trying to piggy back on top of a flea rocket"

Says who? Who are these "others?" Who are these "astronauts" that the "others" are getting their heresay from? And why is Ares-I's length this terrible unfixable problem? While the second stage has a much larger diameter than the first, it is very light since it will be filled with low density liquid hydrogen in thinner low pressure aluminum tanks. The size is irrelivent, the density is what is signifigant, and solid rocket fuel is very dense.

"NASA has inevitably pushed to the same conclusions that every other critic had come to"

Says who? Since when has NASA said any such thing? And the legion of NASA's critics are many, but supporters are few, particularly since NASA does not make a habit of countering negative opinions from said critics. The critics all hate NASA's plan unconditionally, there is nothing they can do right, except precisely what the critics want to see happen.

cIclops · 2006-08-06 14:40:41

NASA didn't know how much the larger solid rocket booster would cost when they put together the tenative price tag and completion date. Unfortunatly the more concrete figure is somewhat higher, but this is not a sign of looming demise or anything.

For the record, what is the current estimated cost of Ares I?

gaetanomarano · 2006-08-06 16:31:44

"backup" Ares-I plan has one really serious flaw, that it has a risk the same thing that Challenger did could happen here. Two three-segment SRBs would cost more than one five-segment booster too, plus the extra J-2 engine cost. I doubt that this plan will happen.

the Ares-II without the (ready available, cheap and reliable) 4-segments SRB makes no sense since the 3-seg. SRB may need the same time and money of a 5-seg.

the 4-seg. Ares-II don't have the same risks of the Challenger, because...

the (real) reliability of the 4-seg.SRB is 1 in 115 flights (or better, since the SRB rings' problem was solved after the Challenger accident) but the Ares-II (or my FAST-SLV...) is not side-mounted (the CEV can't explode with the ET nor be damaged by its foam) and the CEV has the LAS on its top

if the LAS failure will be (only) 1 in 10 max, that means the risk of failure of the Ares-II is 1 in 1150 flights

however, I don't think that a rocket based on to-day's (better but still unperfect) technology may never be so reliable to fail one time every 1000+ launches!

but, if we consider that all spaceflights are a risky job, the Ares-II reliability is sufficient and comparable with the Stick or an EELV

.

gaetanomarano · 2006-08-06 16:45:01

...it doubles the LOC risk due to SRB failure and the second J-2X would similarly double the LOM risk...

not true since the Ares-II looks very close to the Shuttle (without the side-mount and foam problems) that has two SRBs and three SSMEs

if the Ares-II will have (ONLY!) the same number of accidents of the Shuttles (only 1 in 115 flights due to the SRB) we can be VERY HAPPY since the Ares-II, at the (planned) orbital/lunar flight rate, needs 25+ years to fly 115 times!!!

I think that (only) ONE Ares-II failure (without risks for the crew, thanks to the LAS) between 2015 and 2040 will be a very good safety record!

.

gaetanomarano · 2006-08-06 16:58:12

For the record, what is the current estimated cost of Ares I?

the original R&D costs of the CLV was $5 billion +$2 billion for the 5-seg.SRB extra R&D costs = $7B total + the cost of the Ares-I hardware for each launch + the new launch pad, infrastructures, etc. + over $800M per year of (extimated) launch-structure costs (engineers, staff, etc.)

but in last week there is a news that say "the CEV development will costs 10-15 billions more than planned"

it's not clear if the extra R&D costs refer to the CEV/SM only or, also, to the Ares-I

however, there is an interesting article [ http://www.newscientistspace.com/articl … sions.html ] from NewScientistSpace about a Government Accountability Office [ http://www.gao.gov/ ] report evaluating the REAL costs of VSE/ESAS plan in the next 20 years up to $230 billion (not $104B like claimed in september 2005 nor $125B like claimed last months after some redefined R&D costs evaluations)

.

gaetanomarano · 2006-08-06 18:57:37

~110MT Ares-V, there will be one very signifigant change to the mission plan: the CEV will perform the Lunar orbit capture burn. What this means is that the Ares-V can no longer deliver unmanned heavy payloads (several tonnes less)...

no, because also the EDS and the cargo-LSAM are lighter

ESAS plan with 130 mT AresV payload: 45 mT cargo-LSAM with 21 mT of cargo

ESAS plan with 110 mT AresV payload: 38 mT cargo-LSAM with 18 mT of cargo

the difference is only -3 mT or 1/7th or 14%... that don't change so much

.

RedStreak · 2006-08-07 16:53:18

I suppose alot will ride on the success of creating a working 5-segment SRB; that seems to be established now. At this point it's hard to tell whether it'll be NASA's lynchpin or it's Achilles Heal in the future.

If it works it'll certainly aid in boosting loads into orbit while (hopefully) retaining reuseability. The SRB now that I think about it is plagued by being "the cause" of the Challenger disaster. It wasn't. It was the decision to launch Challenger on an unnaturally cold day after the STS froze overnight Sheer human stupidity is what I blame. Metal will expand in heat and contract in cold, that's its nature not its fault. Surely human thinking can do better.

SpaceNut · 2006-08-07 20:19:02

the Ares-II without the (ready available, cheap and reliable) 4-segments SRB makes no sense since the 3-seg. SRB may need the same time and money of a 5-seg.
Ares-II looks very close to the Shuttle

With the Ares-II you are talking about the Calv with the CEV added to it making it look more like Apollo which it will not be able to lift as we have already discussed.

Also any use of a 4 segment for the CLV/CEV would also require some engineering changes as well to the last segment closest to the upper stage. Which is the thread of discusion that we are in.

Items to note from cIclops post:

The first test flight of the rocket, dubbed Ares I-1, is scheduled for April 2009. The test will use an adapted four-segment booster from the shuttle program instead of the slightly longer five-segment version planned for operational flights.
Like the shuttle’s boosters, the first stage of the Ares 1 will be reusable. However, it will plunge toward the ocean at speeds of Mach 6, compared to Mach 4 for the shuttle’s boosters. Engineers are looking at making the booster tumble to reduce the speed before the parachutes open.

This will mean that engineering as well as testing if not a redesign of the connection of the segment joints will need to be done for implementaion of even the 4 segment for a Calv.

Also for the use of the 4 segment it will still need work on the last segment to mate it to the upper stage...

Comments made in
NASA Exploration Roadmap on the GAO..

A new report from the Government Accountability Office the watchdog arm of Congress warns NASA faces up to $14 billion in cost overruns on its moonship program by 2011, unless the agency changes the way it does business with contractors.
The GAO is so concerned it wants NASA to wait until 2008 to sign off on its moonship and moon rocket programs, giving the agency time to revise contract plans with contractors.
GAO-estimated pricetag of $230 billion by 2025, NASA's moon-Mars program.
It's also recommending that Congress restrict NASA spending to make sure it happens.
That would cause delays in the moon program that NASA doesn't want, so it's pushing ahead to:
Select Lockheed Martin or Grumman in September to build the shuttle's manned replacement, the Crew Exploration Vehicle.
Award contracts in October and November for construction of the first and second stages of the rocket that will carry the craft into orbit.

gaetanomarano · 2006-08-08 05:30:01

...use of a 4 segment for the CLV/CEV would also require some engineering changes...

true, but less work than build the 5-segments since they must only adapt the standard SRB, not redesign it from (near) zero (the new SRB needs changes to grain, dimension, nozzle, propellent shape, recovery system, etc.)

and don't forget the costs to (only) modify the standard SRB to a 5-segments version: $3+ billions!

also IF the adapted SRB will need the same time (but I don't believe) the R&D saving is SO HIGH that (with the same money) NASA can build the first 10-15 Ares-I... FREE

.

gaetanomarano · 2006-08-09 09:43:11

.

an interesting update about "Stumpy" (the 3-segments SRBs' Ares-I "backup plan") to all peoples that have read around of that concept

to know if it's a true NASA project (and have more info about it) I've sent a mail to the NASA Public Affair Office to ask about "Stumpy"

the Paul Foerman's answer is: "I am not familiar with a project named Stumpy. The best source of information for Project Constellation and the Ares I and Ares V vehicles is NASA's Exploration web site at: http://www.nasa.gov/mission_pages/explo … index.html "

then, the only NASA design of Ares-I is the "stick" in the 5-segments/J-2x version

.

RedStreak · 2006-08-09 14:16:10

Considering thrust, lift, and minimal development efficency I think we should narrow it down to either the 4-segment or the 5-segment for the CLV. "Stumpy" aka 3-seg. is out of the question despite its simplicity.

publiusr · 2006-08-11 15:24:00

sigh
Marshall Spaceflight Center needs six years to build an engine that we already have much of the design for?
Note that Marshall would have been awarded the contract for the CEV-SM/LSAM-acent methane rocket, which was canceld since they didn't seem to be up to the task in any reasonably efficient way... These guys sound, well, incompetant to me.

You have to understand that Marshall has been poisoned by the Goldin age, where the fans of big rockets like Bill Eoff were considered personal non grata--with the X-33 frauds running the show. If you believed in big, simple rockets--you weren't welcome. We are still picking up the pieces--and the MSFC bashers are exploiting it.

SpaceNut · 2006-08-11 20:11:10

Scrap The Stick Now a Jeffrey F. Bell There seems to be general agreement that the Vision for Space Exploration is in deep trouble piece.. but offers no solutions....

Of course he talks of the Frankenbooster pretests before we have the real thing to make the CLV...

New Mars Forums

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#101 2006-08-01 20:41:36

Re: Ares I (CLV) - status

#102 2006-08-01 20:50:14

Re: Ares I (CLV) - status

#103 2006-08-03 21:12:33

Re: Ares I (CLV) - status

#104 2006-08-04 07:03:33

Re: Ares I (CLV) - status

#105 2006-08-04 18:06:56

Re: Ares I (CLV) - status

#106 2006-08-05 19:29:19

Re: Ares I (CLV) - status

#107 2006-08-05 19:48:41

Re: Ares I (CLV) - status

#108 2006-08-05 20:04:46

Re: Ares I (CLV) - status

#109 2006-08-05 21:39:24

Re: Ares I (CLV) - status

#110 2006-08-05 23:26:09

Re: Ares I (CLV) - status

#111 2006-08-06 06:10:12

Re: Ares I (CLV) - status

#112 2006-08-06 09:01:33

Re: Ares I (CLV) - status

#113 2006-08-06 11:40:40

Re: Ares I (CLV) - status

#114 2006-08-06 14:40:41

Re: Ares I (CLV) - status

#115 2006-08-06 16:31:44

Re: Ares I (CLV) - status

#116 2006-08-06 16:45:01

Re: Ares I (CLV) - status

#117 2006-08-06 16:58:12

Re: Ares I (CLV) - status

#118 2006-08-06 18:57:37

Re: Ares I (CLV) - status

#119 2006-08-07 16:53:18

Re: Ares I (CLV) - status

#120 2006-08-07 20:19:02

Re: Ares I (CLV) - status

#121 2006-08-08 05:30:01

Re: Ares I (CLV) - status

#122 2006-08-09 09:43:11

Re: Ares I (CLV) - status

#123 2006-08-09 14:16:10

Re: Ares I (CLV) - status

#124 2006-08-11 15:24:00

Re: Ares I (CLV) - status

#125 2006-08-11 20:11:10

Re: Ares I (CLV) - status

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