The GIANT mistake of the (too small) Orion's Service Module!

gaetanomarano · 2006-09-13 18:25:21

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I think that the NASA/ESAS/LockMart Orion's Service Module design has a GIANT mistake built-in!

I explain my opinion in my latest article here: www.gaetanomarano.it/articles/013orionSM.html

The new Orion's SM design is different from Apollo since (now) it can't perform (both) the Lunar Orbit Insertion and Trans Earth Injection with MANY safety and operational problems for the astronauts and moon missions.

The most dangerous issue of this (bad!) choice is that, if the LSAM engines will fail in LOI, the Orion will have not sufficient propellant to enter the lunar orbit or ONLY the propellant for that operation (without the LSAM docked) but NOT for TEI to come back to earth!

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GCNRevenger · 2006-09-13 18:40:19

Dude, I don't think you know anything about orbital mechanics:

If the Lunar orbit insertion burn isn't almost totally completed, the CEV will never enter Lunar orbit at all, not be stranded there.

And, because if LOI doesn't suceed in slowing down LSAM/CEV, its remaining velocity will be that much less needed to swing around the Moon to speed up for trans-Earth injection. Again, the less you slow down with the LOI burn, the less you have to speed up again for TEI, if any.

And why did you only figure out this now? The reason why the CEV is smaller is because the switch from Methane/Oxygen to Hypergolics means you can pack comperable amounts of fuel into a smaller volume, not an overall decrease in the CEV's Delta-V. It never had the ability to do LOI and TEI in the first place from the 1.5 arcitectures' inception, the LSAM was always going to perform LOI and the CEV was always only going to do TEI.

A big reason for the CEV-SM's small size compared to Apollo is also due to its wider diameter and no bulky Hydrogen tanks for fuel cells, just solar cells folded up under the skirt.

gaetanomarano · 2006-09-13 19:45:47

If the Lunar orbit insertion burn isn't almost totally completed, the CEV will never enter Lunar orbit at all, not be stranded there.

the Orion missions are not like the Soyuz tourists' fly-around missions or the SMART-like crash (or land-direct) missions
they will have a lunar insertion trajectory and will discover only in the last minuts if the LSAM engines will work or not
also, you must look at the full list of problems of a small SM:
- no rescue missions (after the surface missions end) with a remote-controlled Orion
- no small cargo sent around the moon
- no emergency life support (or fuel, istruments, etc.) sent to an orbital LSAM, Orion or Lunar Space Station
- no (manned or unmanned) Apollo-8-like flights for tests, LSS crew rotation, orbital science, etc.
- no big (experiments, instruments, moon samples, etc.) 3+ mT cargo-return from lunar orbit/surface but only a (30 times small) 220 lbs. Orion cargo
- less lunar life support and/or exploration hardware sent on the moon (to have TWICE the exploration time and quality with the SAME price!)
- a bigger AresV that must use the 5-segments SRB
- etc.
the Apollo-like SM has so many safety and operational advantages that I (really!) wonder why it was not adopted from the first ESAS plan!!!

and don't forget that a bigger SM needs a 40 mT paylaod Ares-I able to launch one ISS-Orion + one SM-light + 15 mT of cargo with a SINGLE rocket (like FOUR-FIVE cargo+crew launches for the price of ONE!!!) or... a small cargo lander on the moon (without spend 5+ times to launch an AresV+cargoLSAM) or... 40 mT interplanetary probes, or... two new ISS modules with ONE launch... etc.

...the CEV is smaller is because the switch from Methane/Oxygen to Hypergolics...

no, this is one (and the less important) reason, the main reason is that (now) the SM will perform only the TEI then (compared with the Apollo weight) it needs less than half the propellant

the LSAM was always going to perform LOI and the CEV was always only going to do TEI.

this is exactly the wrong thing of the Orion design that I suggest to modify!

A big reason for the CEV-SM's small size compared to Apollo is also due to its wider diameter

no, it's smaller (first) because its weight will be under 10 mT with (about) 7 mT of propellant (les than half of the smaller Apollo SM)

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SpaceNut · 2006-09-13 20:33:26

they will have a lunar insertion trajectory and will discover only in the last minuts if the LSAM engines will work or not

Does not matter which engine were not to fire since it does the braking by having the engine facing away from the destination, If it fails then you have no time to turn the CEV/LSAM around to fire the other vehicles engine anyways.

the Apollo-like SM has so many safety and operational advantages that I (really!) wonder why it was not adopted from the first ESAS plan!!!

The boil off of hydrogen is one reason for not going with the old design and another is what happened with apollo 13.

GCNRevenger · 2006-09-13 21:02:22

sighs

The Apollo missions chose their trajectory carefully: that if no LOI burn was performed, the vehicle would slingshot around the Moon and return to Earth with no other action required. No action required.

Now, reguardless how much of the LOI burn suceeds or fails, every bit the LOI burn doesn't slow you down is that much less the TEI doesn't have to speed you up again for the return to Earth, so this really isn't a safety problem.

No LOI burn? CEV coasts back to Earth. Partial LOI burn? CEV probably coasts back to Earth, but has plenty of unused TEI fuel just in case. Nearly complete but not properly alligned LOI burn? Still have TEI fuel for the return trip. No safety problem.

Rescue mission? Dude, the Ares-I rocket can't push CEV out of Earth orbit twards the Moon, it doesn't have the push, and was never intended to have it. Only the Ares-V EDS stage does that. Furthermore, if you just wanted to send a CEV capsule one-way to the Moon, burning the fuel saved for TEI for TLI instead, it wouldn't be enough since Earth's gravity is stronger... This pretty much nixes the first four items on your list.

Why do we need big multi-tonne mass returns from the Moon? Isn't 220lbs enough for Moon rocks? Where would you fit all that material in the capsule anyway? Won't it mess up the already notoriously difficult center of gravity ballencing? All that mass would be a safety hazard, don'tcha know, and make it harder for the parachutes to safely land the capsule too.

Your other criticisms about the surface payload don't deal with CEV-SM persay, rather dealing with the distribution of masses between the Ares-I and Ares-V launch vehicles. But even if you did make Ares-I bigger and Ares-V smaller where the CEV performs the LOI burn instead, it wouldn't help any: the EDS would still have to push the same amount of mass out of Earth orbit, so you would only be trading a lighter LSAM for a heavier CEV, there would be no increase in payload. Actually since the LSAM uses liquid hydrogen fuel for LOI and landing while the CEV uses the much less efficient hypergolics, you would wind up with less payload and not more.

Oh by the way, the thing that limits practical stays on the Moon is power and not so much life support, stays are limited to a week since thats how long solar power is practical for. A week in a small area should be plenty anyway, this notion that you'd get "twice the science" is nonsense.

Also, you wave your arms and make many exclamation marks about the importance of ISS payloads: mass is not all important with ISS payloads, volume is[/i], which is why CEV blows Progress out of the water, and a single 25MT CEV will provide plenty of this. There is no reason to send up a 40MT class vehicle.

I also meant that the CEV was smaller compared to its original version due to the switch in propellants, not compared to Apollo.

Anyway: there is one main big reason why LSAM must be able to do the LOI, which is so it can deliver payloads without the CEV, which is vital to base building. This will enable payloads in excess of 20MT to be deliverd to the surface, which is just what we need.

And supply missions to a hypothetical Lunar base using a bigger 40MT Ares-I? Why? The large payload of the LSAM in manned mode should permit them to bring most of the supplies they will need for 6mo with them on the lander. Much of what they will need will be Oxygen (for breathing and water) which can be dug up from the ground anyway.

And have you ever noticed how all your plans seem to lead to "make rocket bigger and more expensive than nessesarry?"

gaetanomarano · 2006-09-13 22:29:51

If it fails then you have no time to turn the CEV/LSAM around to fire the other vehicles engine anyways.

probably in the old manually-driven Apollo, NOT in the advanced and computerized Orion where all standard and emergency choices will be done in microseconds

The boil off of hydrogen is one reason for not going with the old design and another is what happened with apollo 13.

IIRC (is this the acronym of "if I remember correct"?) the explosion in the Apollo 13 was of the fuel-cells' tanks (that was LOX-LH2 like the LSAM fuel...) NOT the engines' tanks that was hypergolics (IIRC)

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gaetanomarano · 2006-09-14 03:06:44

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just a premise: you like it or not, the ESAS plan is NOT the ONLY (nor the PERFECT) way to build and launch a rocket or to perform a moon mission

peoples better than you and me have developed many different vehicles and missions' architectures

many NASA chiefs and engineers (equivalent to Griffin) have suggested different (good) ways to come back on the moon, build a lunar outpost, etc.

also the ESAS plan have received different proposals (and CEV designs) developed by ENGINEERS of BIG aerospace companies!

then, your blind defence of the ESAS plans (also in the minute details!) as a "religion" is only stupid and ridiculous!

open your mind!

there are many different (good) ideas around!

NASA will not give any medal to you for your fantic defence of the ESAS plan!

well, the answers...

The Apollo missions chose their trajectory carefully: that if no LOI burn was performed, the vehicle would slingshot around the Moon and return to Earth with no other action required.

probably they will use this kind of trajectory for the Orion but we can't know their decision now, also, a bigger SM has many other advantages

...the Ares-I rocket can't push CEV out of Earth orbit twards the Moon...

I perfectly know that (since it's obvious) the (small or big) Orion needs a small EDS for TLI but it can be launched with the same superAres-I at a reasonable cost (the money saved, compared with an AresV/bigEDS/LSAM will be in the order of billion$) ...maybe, around 50% more of an orbital Ares/Orion launch

for the send-only cargo-missions the propellant saved can be used to send more payload

Why do we need big multi-tonne mass returns from the Moon?

first of all... 220 lbs. are a VERY POOR result for a so risky and expensive mission!

second... that cargo can be used in the same way YOU have suggested (in another thread) for the ISS' cargo-CEV: send back big experiments

third... the center of gravity of a lunar cargo-Orion at reentry will be the same of the ISS version, then, if the latter will work, also the lunar version can (and NASA engineers know how put the payload in the capsule!)

...the EDS would still have to push the same amount of mass out of Earth...

the standard moon missions remains the same

...the thing that limits practical stays on the Moon is power and not so much life support...

I think to "power" as part of the life support

...mass is not all important with ISS payloads, volume is[/i], which is why CEV blows Progress out of the water, and a single 25MT CEV will provide plenty of this. There is no reason to send up a 40MT class vehicle.

1. the 25 mT CEV is NOT all usable payload, the cargo-Orion can send only 3 mT to the ISS

2. the Ares-I diameter already is larger than the Shuttle's cargo-bay (and a bigger Ares-I may be even larger) then, it can give (both) big VOLUME and big MASS

...will enable payloads in excess of 20MT to be deliverd to the surface, which is just what we need...

this is one of the most absurd claims I've read around!

how you can say that 20 mT is "what we need" if no one (not even NASA) know (now) the use of that payload!

it's ONLY the (evaluated) payload the cargo-LSAM can land!

we don't know (nor can know) now if that payload will be "what we need" or "HALF what we need" or "TWICE what we need"!!!

...to a hypothetical Lunar base using a bigger 40MT Ares-I...

an LSS is not hypothetical but can be real and it doesn't need 20 mT of resupply (sent at very high price with the AresV/LSAM) buit only a few tons (like the bigger ISS)

...make rocket bigger and more expensive than nessesarry...

only a little bit bigger but not more expensive (using ready available engines and motors, of course)

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GCNRevenger · 2006-09-14 07:39:57

you like it or not... peoples better than you... your blind defence... as a "religion"... is only stupid and ridiculous...
... open your mind... there are many different (good) ideas around...

Ah yes, that special brand of argument. How is it that whenever someone says "open your mind" they really mean "agree with me?" And even in this case, "agree with me or you are a stupid dogmatic parrot of people I don't like."

Sure there are other ideas around, I just don't think any of them are as good as the ESAS plan: the plan gives access to LEO for ISS or future Mars ship use, it gives us a heavy lifter powerful enough for Mars, it gives us heavy payload delivery to the Moon, and uses the right engines and so on. There are other ideas, they just aren't as good, so yes I advocate the plan.

There are plenty of engineers who have similar skills to M. Griffin, but Griffin's job is not to design things, his job is to manage. And this is his job because he was appointed to the position by the elected government, and these other engineers were not. Because of the need for a "final say" on the ESAS plan and the authority granted by this appointment, that means Griffin's word carries with it more weight than these other engineers.

The ESAS plan is the way it is for a number of reasons:

-CEV is kept small so the best Ares-I design can lift it, and to minimize TLI mass, so Hydrogen LOI is desireable. But, CEV's capsule is larger & heavier than the three-piece Soyuz style, since the CEV is reuseable.
-The LSAM can perform LOI so that it can deliver large masses to the Moon without the CEV, which is important for base building.
-Ares-V is the size it is because this is the largest practical rocket that can be built for a reasonable cost, both in development and per-flight, which is just big enough for the 1.5 arcitecture and for future Mars ships.

this is one of the most absurd claims I've read around!

The usual "OH BUT WE DON'T KNOW!!!" business:

-Why wouldn't NASA use the safer free-return trajectory like they did with Apollo? Griffin said this will be Apollo on Steroids too.
-20MT is a good minimum mass; the ISS modules weigh around 20MT, and we know they are as small as you can build and still be practical. Surely NASA can make a nuclear powered ISRU plant, digger robot, and a heavy-duty pressurized rover for about this amount or less. 20 is a good number, why is it not a good number?
-Why can't the LSAM deliver 20MT? Thats only 15% of the Ares-V payload, and using more efficient propellants than Apollo did. In theory, you could deliver 20-25% of LEO payload to the Lunar surface, so 15% shouldn't be a big problem.

220 lbs. are a VERY POOR result for a so risky and expensive mission!... that cargo can be used in the same way YOU have suggested (in another thread) for the ISS' cargo-CEV: send back big experiments

Why is 220lbs poor? Thats quite a bit of Moon rock, and besides the most important things brought back from the Moon will be a little stack of flash memory cards with data, not rocks.

I never suggested that it was critical for scientific gear to be brought back, you are a liar gaetano.

an LSS is not hypothetical but can be real

How do you know that, huh?

only a little bit bigger but not more expensive (using ready available engines and motors, of course)

60% larger is not "a little bit" gaetano, and what readily available engines? Three-segment SRBs aren't available any more than the five-segments, SSME is ruinously expensive, RL-10 doesn't have the thrust, and J-2X is already being called for. If you want kerosene engines, only the Russian RD-180 is available, small EELV SRBs are too dangerous for people, and RS-68 lacks specific impulse and man rating features.

the Ares-I diameter already is larger than the Shuttle's cargo-bay... then, it can give (both) big VOLUME and big MASS

Why? Is this important? Food, clothing, space suits, scientific gear all don't weigh very much but they are all fairly bulky. The manned CEV could also deliver water instead of TEI fuel if that is a problem.

There will also be no reason to send the CEV to Lunar orbit by itself for some time, namely when we have a base, LOX supply, and a reuseable lander. Therefore, there is no reason to tailor the present ESAS plan around such an option.

cIclops · 2006-09-14 08:09:25

There are plenty of engineers who have similar skills to M. Griffin, but Griffin's job is not to design things, his job is to manage. And this is his job because he was appointed to the position by the elected government, and these other engineers were not. Because of the need for a "final say" on the ESAS plan and the authority granted by this appointment, that means Griffin's word carries with it more weight than these other engineers.

And Griffin's role is critical. After so many years of superb yet unfocused space science and manned space flight he has woken NASA up and given it a clear purpose: Exploration. This simple change has put everything into focus. Instead of dozens of independent and unrelated projects, now there is a primary objective. And to accomplish this NASA needs an architecture. ESAS is capable of generating the elements to ensure that Earth-Moon-NEO-Mars space can be accessible to the best instruments available - ourselves. ESAS is also capable of change. As new elements are produced by NASA and privately, they can be added to the architecture. All this requires vision, money and will to do it, and Griffin has taken the first steps to make it so.

SpaceNut · 2006-09-14 08:23:25

As you noted gaetanomarano it was the oxygen tank for the fuel cell power system that went. The ESAS plan duration of use also is the reason for why we will be using solar rather than fuel cells in the CEV. Which that change makes the CEV lighter...

NASA Glenn working to keep power on in space

The switch to solar offers several advantages. Losing the fuel cells' bulky, pressurized hydrogen and oxygen tanks will make Orion safer and smaller. Any reduction of mass, in turn, means the spaceship will need to carry less fuel to get where it's going.

Another reason for not going with the fuel cells as in apollo in the SM.

Going solar also made the most sense for Orion's long-duration moon missions. NASA plans to have astronauts eventually spend up to half a year at a lunar base. A lander will take them down to the surface while Orion's empty crew and service modules orbit overhead, awaiting the journey back to Earth.
The ship will need "keep-alive" power to prevent its electronics from freezing during the long layover. If fuel cells were to supply that energy, Orion's service module would have to pack six months' worth of hydrogen and oxygen. All a solar system would require are the unfolding sunlight collectors and batteries to store the electricity.

GCNRevenger · 2006-09-14 08:34:47

There are plenty of engineers who have similar skills to M. Griffin, but Griffin's job is not to design things, his job is to manage. And this is his job because he was appointed to the position by the elected government, and these other engineers were not. Because of the need for a "final say" on the ESAS plan and the authority granted by this appointment, that means Griffin's word carries with it more weight than these other engineers.
And Griffin's role is critical. After so many years of superb yet unfocused space science and manned space flight he has woken NASA up and given it a clear purpose: Exploration. This simple change has put everything into focus. Instead of dozens of independent and unrelated projects, now there is a primary objective. And to accomplish this NASA needs an architecture. ESAS is capable of generating the elements to ensure that Earth-Moon-NEO-Mars space can be accessible to the best instruments available - ourselves. ESAS is also capable of change. As new elements are produced by NASA and privately, they can be added to the architecture. All this requires vision, money and will to do it, and Griffin has taken the first steps to make it so.

Specifically, it requires enough willpower to overcome the disparate plans of headstrong engineers that you seem to want to lionize, gaetano. The best solution is the one that works and is actually competed, even though it may not be the most efficient solution.

gaetanomarano · 2006-09-14 09:12:39

I just don't think any of them are as good as the ESAS plan: the plan gives access to LEO for ISS or future Mars ship use, it gives us a heavy lifter powerful enough for Mars, it gives us heavy payload delivery to the Moon, and uses the right engines and so on. There are other ideas, they just aren't as good, so yes I advocate the plan.

THIS is exactly a "dogmatic" answer
I've read some (not all...) posts you write also in other threads
well, you don't accept the smallest idea nor a microscophic change to the ESAS !
the different ways to do the same thing are not "150 stupid" and "ONE perfect" (ESAS)
ESAS is only one of dozens different possible (good) plans to accomplish the same mission!
Ares-I and V are NOT the only (nor the best) way to build a rocket (and MANY peoples on MANY sites, blogs and forums clearly say that they appear "designed" more by politcs and elections than engineers..........)

-20MT is a good minimum mass...

again... this is NOT the "minimum", "maximum", "right", "sufficient" payload
it is ONLY the calculated max payload of a cargo-LSAM
no one know to-day how it will be used and if it will be sufficient or not
"20" is (now) a "good number" EXACTLY like "15" or "23" or "17"
it's only another dogmatic claim to say that nothing can be changed in the ESAS plan!

...Thats quite a bit of Moon rock...

and nothing else than rocks... you close the doors to any future development of lunar science
you've said in another thread (about my suggestion to use only the Progress for ISS cargo and not the expensive cargo-CEV) that a CEV is larger so it can send/return hardware that a Progress can't, etc.

How do you know that, huh?

when the operations in space become longer and complex they need some orbital space stations (on earth, lunar and mars orbit)

...and what readily available engines...

again, THE DOGMA !
there are many different ways to build a rocket and ALL possible versions of Ares-I need to man-rated (also the current version!)

...Why? Is this important...

an additional ISS cargo-module give MANY different options to use
they must only need to use the better cargo for every mission

...and a reuseable lander...

this is exactly the best reason to have an autonomous Orion to send only the crews, not a new LSAM at every mission

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gaetanomarano · 2006-09-14 09:21:24

...ESAS plan duration of use also is the reason for why we will be using solar rather than fuel cells in the CEV...

I agree on the choice of solar panels and that it is one of the reason of a lighter CEV but it's not the most important weight reduction
the main reduction is the CEV fuel from 18+ mT of the Apollo SM (or 25+ of a bigger Orion SM) to a mere 7 mT

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GCNRevenger · 2006-09-14 15:01:33

THIS is exactly a "dogmatic" answer

The sheer depth of your hypocritical attitude defies credibility, gaetano, you are just grandstanding now.

Why is my opinion invalid? I believe the present ESAS plan is the best of all the ones that I have seen, from you or other engineers that you idolize. I have seen no changes, especially not from you, tha make the plan any better yet to date. There are a few other plans, direct flight with one mega rocket, Lunar orbit rendezvous with two medium/heavy rockets, T/Space's Earth orbit rendezvous/tanker concept and so on.

There are other opinions, but not all opinions are equal, and I think the present ESAS plan is a good plan. Other people are entitled to their opinion, but it is not "dogmatic" for me to have my opinion only because it is the present preferred plan. It is also mine to judge whether other opinions have merit, and yours imparticularly do not.

These other engineers who say the Ares-I and Ares-V rockets were deisgned by politicians, and they are entitled to hold that opinion, just as I am entitled not to share nor respect it. The ESAS plan is a good plan from an engineering prespective, and a fairly good plan from the political prespective too, why is this a bad thing?

NASA must ballence the political requirements with the fiscal and engineering requirements of whatever plan Griffin choses, to make a plan that is formed in an entirely apolitical fasion is not a good thing, and infact is probably suicidal for NASA since it relies on political support to exist. Engineers are but one of the three types of people that should put together the plan.

it is ONLY the calculated max payload of a cargo-LSAM
no one know to-day how it will be used and if it will be sufficient or not

Nonsense, this is just your "oh but we don't know know" thing again. ISS modules weigh around 20MT, and if you are building a base, then it makes sense that your modules shouldn't be any smaller than ISS sized ones. So 20MT is a nice round figure for the minimum all-payloa mass for the LSAM/Ares-V. It is no coincidence that this figure is the target mass for the current ESAS plan, since they thought of this too.

and nothing else than rocks... you close the doors to any future development of lunar science

Haha yeah right. I am laughing at you by the way, not with you. Moon rocks and data are the only thing of value that the ESAS plan should try to return, and sizing the CEV for this makes sense. Nobody is going to be doing any Platinum or Helium mining using the ESAS plan! And why return scientific instruments to Earth? That is a huge cost and trouble just so you could refurbish a worn out drill or whatever, bringing extra Moon rocks is much more valuble than a box of rock hammers. Instruments should only be reused once we have to stop lugging them to or from the Moon, namely when we have a perminant Lunar base, and not before. How does not having this capability prevent "future development of Lunar science?"

Now, if you are talking ISS cargo return, the CEV will be the only way to return materials to Earth, unless you put a few kilos of stuff sitting beside a cosmonaut in a Soyuz. In any event, only sample containers need to be returned, the equipment itself is worthless back here on the ground anyway. Chuck old equipment in the ATV and dump it as trash, which it is, and return samples only to Earth and they won't weigh all that much. By the time the CEV is ready to go, the ISS will be so old that it wouldn't make sense to use CEV to ferry equipment back to Earth for repair.

when the operations in space become longer and complex they need some orbital space stations (on earth, lunar and mars orbit)

Why? Whats wrong with bases on their surface?

an additional ISS cargo-module give MANY different options to use

Such as?

this is exactly the best reason to have an autonomous Orion to send only the crews, not a new LSAM at every mission

No. A reuseable lander is a long time away, and its more important that the non-reuseable method be efficient and actually suceed, unlike a version with double the payload needed. We might not even use Ares-I or CEV to ferry crews to such a hypothetical lander.

GCNRevenger · 2006-09-14 17:10:09

I want to further question this notion of returning scientific equipment from the Moon to Earth; why would you want to do that? Aren't the rocks much more valuble than the equipment?

Secondly, where to put it all? The CEV is roomy for a capsule, but it is not all that big. If you wanted to bring back a wheeled multi-meter drilling rig, the most expensive thing I can concieve a mission taking, you woud have to break the thing down and take it through the LSAM module to get it into the CEV, and then, where it fit?

No, rocks, just rocks. And 220lbs of rocks is plenty.

Commodore · 2006-09-15 05:54:19

The CEV is primarily an Earth to LEO craft. Once it docks with the LSAM, its a towed craft. No more, no less.

cIclops · 2006-09-15 10:54:37

The CEV is primarily an Earth to LEO craft. Once it docks with the LSAM, its a towed craft. No more, no less.

According to the ESAS, Orion's (CEV) service module will provide the propulsion to return from LLO to Earth.

Jack Chandley · 2006-09-15 11:53:28

sighs
The Apollo missions chose their trajectory carefully: that if no LOI burn was performed, the vehicle would slingshot around the Moon and return to Earth with no other action required. No action required.

I would like to add to this to mention that this is the case ONLY if they are using a free-return trajectory. After Apollos 8, 10, 11 and 12, NASA has decided that use of the FRT was not necessary. Apollo 13 actually did not use a FRT, which is why the correction burns were required. All flights following Apollo 13 required FRT again.

13 just had it bad no matter what way ya looked at it, huh?

GCNRevenger · 2006-09-15 14:00:09

I stand corrected then, but the CEV would have two seperate sets of engines both capable of making such adjustments in the event that NASA doesn't use the FRT for some reason.

gaetanomarano · 2006-09-16 09:45:03

...I believe the present ESAS plan is the best of all the ones that I have seen, from you or other engineers that you idolize...

"believe" is (exactly) the right word when talking of the ESAS plan since it has so many mistakes that, "believe" in the ESAS plan, needs to have FAITH

...other engineers who say the Ares-I and Ares-V rockets were deisgned by politicians, and they are entitled to hold that opinion, just as I am entitled not to share...

also the fishes of the ocean know that both rocket are designed thsi kind NOT because it is the best way to build them but ONLY because it is the best way to recycle the Shuttle hardware, contractors, workers, etc.

then, talking of their "perfection" is simply ridiculous

...ISS modules weigh around 20MT...

the fact that ISS module weight like the LSAM payload is only a coincidence
20 mT is (simply) the max payload the AresV/EDS/cargoLSAM ca launch
if we will discover (in future) that a lunar module weights MORE than an ISS module, we need two launches to send it since the AresV can't lift a bigger LSAM
my opinion is that NASA can build a good lunar module with weights between 10 to 30 mT (of course, the latter is better, but the first is sufficient for the job)

...20MT is a nice round figure...

exactly, it's ONLY a "nice round figure", not the "minimum" nor the "maximum" nor the "right", only the "nice"

...rocks and data are the only thing of value that the ESAS plan...

answer in my next post

...Chuck old equipment in the ATV and dump it as trash, which it is, and return samples only to Earth and they won't weigh all that much...

then, an ISS' cargo-CEV/Orion is unnecessary (as I've claimed many times)

Whats wrong with bases on their surface?

nothing... I only think that both (orbital and surface) base are necessary

an additional ISS cargo-module give MANY different options to use
Such as?

if you ask a NASA or ESA or Russia engineer or scientist you can receive hundreds good ideas about "how use 15 mT of extra-cargo to space"!

...reuseable lander is a long time away...

it's not an important point to know how "long time away" is a reusable lander since, soon or later, it always NEEDS an autonomous Orion for crew rotation

then, it's better to build the Orion with a bigger SM now, since to-day's design will remain unchanged in the next 30+ years!

.

gaetanomarano · 2006-09-17 21:27:32

No, rocks, just rocks. And 220lbs of rocks is plenty.

I think that a (small SM, TEI-only) Orion is like a (single purpose) "CorkScrew", while, a (big SM, multi purpose) Orion may be the "SwissKnife" of space exploration!

I explain my opinion in details (with a curious image and a list of TEN advantages of the bigSM Orion) in my latest article [ "CorkScrew Orion or SwissKnife Orion?" ] here: http://www.gaetanomarano.it/articles/014swissCEV.html

in the same article I give some ideas to use a cargo-return-Orion (not only for moon-rocks) but also for (very useful) biological experiments

.

Jack Chandley · 2006-09-18 08:22:52

I stand corrected then, but the CEV would have two seperate sets of engines both capable of making such adjustments in the event that NASA doesn't use the FRT for some reason.

...which is not a bad idea at all.

At forst, when I considered the CEV, I thought to myself "Whatta f*^%ing cop-out. Old technology-bleech."

And then I thought about it. For a long time, I have looked at the Russian space progrm, and commented about how great it was thet they kept with proven technology, and only made small modifications to it to keep their program flying for what is, by comparison, nickles and dimes, in comparison to the US budget.

Russia even built their own shuttle, Buran, and flew it once. They realized immediately that it was way too expensive, and it never flew again. IIRC, Buran was actually destroyed a few years ago when the hangar it was being stored in collapsed.

And when we started to follow this path (CEV/ARES), I initially acted with disgust.

Now that I've had a chance to really think about it, I'm glad that they are looking backwards to something proven and (what will ultimately be..) cheaper than the space shuttle.

So, we had it right in the first place. Kinda makes you wonder where we'd be if we hadn't built the shuttle, and kept with what we had. But there is no sense in thinking too much about that, as there were a lot of seperate developments that benefitted the space program that arose from the shuttle. BUt in the monetary and human costs, the shuttle has been quite expensive.

GCNRevenger · 2006-09-18 09:58:22

"Blah blah blah"

So, apparaently I am not capable of sharing an opinion with NASA, and have to have blind unreasoning faith in them, while I wouldn't need it if I were to parrot gaetano's viewpoint as gospel truth. Right.

Again, the design of the ESAS hardware must take into account three different things if NASA is to succeed: the engineering, the cost, and the political support. NASA would be suicidal to design the rockets with any one or two of these in mind, and a failure to suceed in all three areas will mean the end for manned spaceflight. Political support is critical, to pretend otherwise is irrational.

NASA has done a fine job I think in this respect, the rockets & vehicles are capable of doing the job, the operating costs should be sustainable, and the projects presently enjoy fairly strong political support. The ESAS plan will never be "perfect" in any one or two of these areas, but it is probably the best plan on the table.

the fact that ISS module weight like the LSAM payload is only a coincidence

No it isn't, there is a good reason why the target payload is aproximatly 20MT. There is no reason for practical sized modules to weigh lots more on the Moon than the ISS, and infact probably less since they won't need meteor armor.

then, an ISS' cargo-CEV/Orion is unnecessary

then, an ISS' cargo-CEV/Orion is unnecessary

GCNRevenger · 2006-09-18 10:53:15

No, rocks, just rocks. And 220lbs of rocks is plenty.
I think that a (small SM, TEI-only) Orion is like a (single purpose) "CorkScrew", while, a (big SM, multi purpose) Orion may be the "SwissKnife" of space exploration!
I explain my opinion in details (with a curious image and a list of TEN advantages of the bigSM Orion) in my latest article [ "CorkScrew Orion or SwissKnife Orion?" ] here: http://www.gaetanomarano.it/articles/014swissCEV.html

in the same article I give some ideas to use a cargo-return-Orion (not only for moon-rocks) but also for (very useful) biological experiments

I skimmed through your "hot dog suicide bomber" themed website gaetano, and it is right up there with your usual standards of pointless drivvel:

1: The CEV's design is not set in stone forever, but one of the main costs of Shuttle is the constant upgrading
2: Being able to perform LOC as well as TEI is not a big safety bennefit as previously explained. It does not by any stretch "double" the reliability of the mission, since the LOC burn is probably the lowest risk of all.
3: Most of your reasons nessesitate a Lunar space station, which is not part of the plan, nor does it really affect the CEV's design much. Wrong thread.
4: If Orion can reenter from high speed safely, why bother lugging fuel to slow down?
5: Fuel to accomplish large plane changes is unessesarry; multiple Lunar landings on one sortie is unlikely due to the fuel constraints of the lander, and if you have all this fuel it makes much more sense to just fly suborbital from a central surface base. Solar flare risk of long missions without a base is also a concern.
6: There is no need for even the TEI fuel for ISS reboost, it can't possibly require 6MT of fuel every six months, even hypergolics.
7: In the future, if we wanted to send the CEV only to Lunar orbit, the CEV still wouldn't need to be lots larger if it rode on a miniature EDS stage burning more efficient Hydrogen. Stretching the CEV-SM to include TLI fuel is silly since you would have to use low-effiency hypergolics

Oh, another thing:

The possible use of a 3+ mT cargo-return-Orion are INFINITE and UNIMAGINABLE now!

Oh but you don't know(!!!) You don't know know, so why should we go to much more trouble to build a bigger Ares-I and CEV-SM? You can't even fit 3MT of Moon rocks by volume in the CEV capsule much less anything else. And why would you need three tonnes of rocks? One-week missions shouldn't need but 220lbs, and a Lunar base will do most of the analysis at the base, not Earth.

And please, free-standing biology experiments on the Lunar surface? Come on. Even if you did have them, they would be at the Lunar base, and wouldn't need transport back to Earth since they would be studied on the Moon.

gaetanomarano · 2006-09-21 07:33:13

...the political support...

all space agencies (also ESA) are under political influence and their choices are often compromises, but the "best rocket compromise" never is the "best rocket design"

...operating costs should be sustainable...

ESAS espected and real costs will be very high (not "sustainable") and may kill the entire plan more than its (many) design flaws

...there is a good reason why the target payload is aproximatly 20MT...

now it's only the max possible payload of a cargo-LSAM, nothing more, nothing less

...if the ISS is going to do any sort of science outside study of humans, they will need to be able to return at least some sample mass...

a very good example of your pro-ESAS-as-is propaganda: the cargo-Orion is useful for ISS "to return at least some sample mass" but is useless to do the same thing to carry lunar samples (for hundreds laboratories on earth) and ISS-like experiments that come from the Moon (that is thousands and thousands times bigger than ISS!!!)

...why should we have orbital bases at all if we have surface bases...

the reason is simple: an orbital module can be launched in 2020 and may cost a few billions while a lunar base needs many launches, many cargo-LSAM (since 2/3 of their weight is propellant to land and lander structures) a very high price (10+ times an orbital base) and needs ISRU fuel to be moreb efficient than and orbital base, so, it may be real only around 2030

...return on investment...

ISS, ESAS, etc. are not private ventures, there is not (nor will be) any "return on investment" or profit... 15 mT to ISS are only useful for efficient and cheap launch of the things (experiments, resupply, hardware, spare parts, etc.) the ISS will need

Why must it remain unchanged for so long?

the same reason the Space Shuttle remained unchanged in last 25 years: "money"
change a vehicle or a rocket cost very much money, so, both Orion and SM (like the Shuttle) will change only in some details like its electronics

.

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Re: The GIANT mistake of the (too small) Orion's Service Module!

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Re: The GIANT mistake of the (too small) Orion's Service Module!

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Re: The GIANT mistake of the (too small) Orion's Service Module!

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Re: The GIANT mistake of the (too small) Orion's Service Module!

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Re: The GIANT mistake of the (too small) Orion's Service Module!

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Re: The GIANT mistake of the (too small) Orion's Service Module!

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Re: The GIANT mistake of the (too small) Orion's Service Module!

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Re: The GIANT mistake of the (too small) Orion's Service Module!

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Re: The GIANT mistake of the (too small) Orion's Service Module!

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Re: The GIANT mistake of the (too small) Orion's Service Module!

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Re: The GIANT mistake of the (too small) Orion's Service Module!

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Re: The GIANT mistake of the (too small) Orion's Service Module!

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