SLS Rocket + Orion + Apollo LEM

Tom Kalbfus · 2014-12-06 11:20:08

Can we conduct an Apollo mission with these components? There were a few Apollo Lunar Excursion Modules left over from the Apollo Program. By the time the SLS is operational the current Administration will be gone. What say we test out these mission components by launching another Apollo Mission, call it Apollo 18. We could send two Astronauts to the Moon's surface to collect some more Moon rocks. That would be a good test of the SLS and Orion Capsules before we try something more ambition with them. There is LM-9.
http://en.wikipedia.org/wiki/Apollo_Lunar_Module
Of course we could build a new Lunar Module. It just seems silly not to use the Orions and SLS for Lunar Missions, since we'll have those components anyway. Obama says "No" because it was Bush's idea, well Obama will be gone in two years, and we don't have to listen to "Prince Obama" anymore.

Impaler · 2014-12-06 14:10:00

But congress doesn't and DIDN'T listen to 'Prince Obama', congress completely resurrected the Constellation program in all but name. We have Orion completely unchanged from Constellation plan, SLS as a barely modified Ares V and the only vehicle really gone is the 'man on the end of a roman-candle' Ares I which was floundering in development long before Obama went after it. If they had wanted to resurrect the moon-lander they could have done so.

Congress never appropriating the funds for the Altair moon lander development even when Bush was in office.

But that hasn't stopped them from funding far more expensive stuff the current administration doesn't want. After expending a great deal of effort 'canceling' Constellation and then seeing it resurrected the Obama administration has stopped trying to get congress to not fund things the administration doesn't want, rather they just try to get congress to minimally fund the things they DO want (Commercial crew and ISS).

On the technical side, their are huge difficulties mating the LEM to the Orion, the physical couplings, the operating pressures etc. Then their is just the lack of living experience with the LEM, the people who made it are literally DEAD, you can't safely fly a craft that no one knows how to fix or build. That recent Antares rocket with it's 'sitting in a warehouse for 40 years' Russian rocket engines, has probably soured everyone on the idea that surplus parts from that era are usable.

Finally their is just the 'die of embarrassment' factor of NASA trying to use a surplus LEM, the whole program has been criticized as an uninspired re-hash of Apollo, to literally use Apollo surplus parts would push this characterization over the top and shame NASA beyond belief.

Tom Kalbfus · 2014-12-06 14:33:06

But gee, it looks like a Saturn V, and we know what the Saturn V was used for, if this thing ends up sitting on the launch pad and it looks like a Saturn V with two solid rockets mounted on the sides.

And we got this, looks like an Apollo Capsule with solar panels. If we have these two things and the next President is looking at these things and wondering what to do with them, how hard would it be to build a lunar lander? Its a no brainer isn't it, going to the Moon is easy especially if you have an SLS which can lift 130 to orbit and an Orion Capsule, the cheap thing to do is build a LEM and land men on the Moon. Mars is a different order of magnitude, you will need multiple launches of the SLS to get a Mars expedition off the ground, but the Moon is low hanging fruit, you just need a LEM and its One SLS, One Orion, and One LEM, plus 3 astronauts and you can have Apollo 18, 19, and 20.

RobertDyck · 2014-12-06 15:04:43

That sounds good Tom, but unfortunately won't work. Saturn V could lift 118 metric tonnes to LEO. SLS Block II will lift 130t.

But the Apollo CSM had a launch mass of 28,800kg in lunar configuration (full propellant tanks), plus 4,200kg for the launch escape tower. The Lunar Module 15,200kg initial (Apollo 11), and 16,400kg final (Apollo 17).

The Orion capsule mass 8,913kg, ATV-based service module 12,337kg, the launch abort system approximately 16,000 pounds = 7,250kg. That total adds up to 28,500kg. The Altair lunar module mass is 45,864kg.

Oops! The lunar module needs a serious diet. Otherwise you're looking at orbital assembly.

Last edited by RobertDyck (2014-12-06 15:05:50)

Impaler · 2014-12-06 15:17:04

I'd argue it looks more like shuttle with SRB's and a core that is the old external tank (just wait untill they stop painting it white and it will be more obvious) but operationally it is indeed like Saturn V with mission elements stacked on top.

Certainly the present vehicle set of SLS + Orion is 100% optimized for the Moon, IF they are completed went into operation and not used to do the one mission they were designed for that would be a crying shame. How much time and money a lander needs is not something I know, but I don't think they are cheap and simple systems, do we have numbers on how much the original LEM cost to develop relative to the Apollo capsule so we could make an extrapolation from Orion? Or maybe some early estimates on what Altair was going to cost and how long it would take?

Personally I don't think brief sorties to the moon are all that compelling, at a minimum they need to go to thouse polar locations to be sufficiently 'new'. Something like a surface base is the kind of thing I can see being a good return with the sorties being done from the base in sub-orbital hops, you would be restricted to just the polar region, but that's where the action is now and sub-orbital hops are so much lower Delta-V that you can do a lot of exploring with delivered propellent or ISPP. An occupied base (even if just occupied intermittently for say a month at a time) also gives us data on human health in fractional G, and if health is good at 1/6th G then we can be confident that the rest of the spectrum up to 1 G is safe as well. Finally you can sell the whole thing as 'staying on the moon longer then any man has ever done', without some kind of superlative (farther, faster, longer) the public has no interest in the moon which was the problem with Constellation's PR efforts.

A reusable landing craft should be examined, they are quite viable on the moon using L2/O2, it's been assume that such a craft is kept at a moon orbiting station but this might not be necessary, perhaps the vehicle can just hibernated in a low frozen orbit to be docked with and refueled by each mission. Thus my mission could just consist of Orion + over-sized TLI stage that will have residual fuel to offload to the lander. If a lander can't hibernate completely alone then a hibernation assistance module might be used. It might just be some solar, some batteries, some communication equipment and a tube for passing astronauts through as the Orion and lander are docked at each end. It can also have the pumping equipment to move propellent into the lander and if that requires EVA for attaching lines then the tube just needs a hatch to become an air-lock. Something like an ISS node should be able to handle all that and would be less costly then deploying a whole mini-station at L2.

Last edited by Impaler (2014-12-06 15:24:59)

Tom Kalbfus · 2014-12-06 17:14:13

RobertDyck wrote:

That sounds good Tom, but unfortunately won't work. Saturn V could lift 118 metric tonnes to LEO. SLS Block II will lift 130t.
But the Apollo CSM had a launch mass of 28,800kg in lunar configuration (full propellant tanks), plus 4,200kg for the launch escape tower. The Lunar Module 15,200kg initial (Apollo 11), and 16,400kg final (Apollo 17).
The Orion capsule mass 8,913kg, ATV-based service module 12,337kg, the launch abort system approximately 16,000 pounds = 7,250kg. That total adds up to 28,500kg. The Altair lunar module mass is 45,864kg.
Oops! The lunar module needs a serious diet. Otherwise you're looking at orbital assembly.

Still less that 130 tons.

Impaler · 2014-12-06 18:13:47

Here is a nice link with some thoughts on a reusable lander and some cost estimates/quotes on Altair. http://newpapyrusmagazine.blogspot.com/ … lunar.html

It looks like congress needs to immediately allocate some money for the lander ~1 BIL a year for 7-8 years. This could come from the winding up of Orion development over the next few years as it's spending about that much, one good thing about capsules is they don't have a whole lot of ongoing maintenance costs, unlike rockets which need huge standing workforces, so SLS will basically never stop consuming the 3 Billion per year that it's currently costing (which was the point why Shelby saddled us with it to give his state endless pork). It's been suggested the Orion might be reusable so your not even building a new one from scratch each flight either, though I am skeptical reuse will be viable, no capsule has ever been reused so it would be a real milestone to do that.

Alternatively some of the Block II SLS development can be curtailed as it would not be necessary to bring a full lander along if we have a reusable lander waiting in the vicinity of the moon. That lets you use the FULL capacity of the vehicle to put the landing in position which should be doable with just Block I. The mission hardware to do the manned mission is then just Orion and a slightly larger stage which should be both simpler and cheaper to fly per mission but also lighter and thus again removes the need for the Block II, it can wait until it's needed for Mars or some other super-sized LEO payload (huge monolithic station?).

The option I like least is taking the funding out of ISS or Commercial Crew. The manned LEO program is finally where it should be, with MOST money spent on the actual science being done on the station and a delivery cost that is going down, any savings from cheaper transport should go back into science or else your punishing the program for saving money. Obviously and additional billion added to NASA's budget without taking it out of any other program is budget NIRVANA and unlikely to happen, still we can hope.

And this is really not even an increase in assembly/docking over the current Apollo-style architecture. In Apollo they had to dock/extract the LEM with the CM before departure to the moon. With a pre-positioned lander you just do that docking at the moon and then dock again to recover the crew after the sortie, it's a double lunar-orbital rendezvous rather then 1 earth side dock/extract and 1 lunar rendezvous/dock. Sure having the LEM right under the butt of the CM means they didn't need to fly around and FIND it in LEO or around the moon, but that is not very hard, Gemini did it repeatedly and we do it routinely now on the ISS so we should not be afraid of that.

Also the service module is not only developed by ESA, it's going to be provided by ESA as in-kind payment for their share of ISS, basically it is FREE to NASA. I think the agreement is 1 per year (and we could just stick it in storage until were ready to use it), so your actually looking at fairly low per-mission costs for just the Orion/service module part of the mission stack, if the lander can be cheap too then the mission looks quite affordable and you can then launch the mission more often and get good amortization on the rocket which is the big cost driver.

Last edited by Impaler (2014-12-06 18:15:16)

RobertDyck · 2014-12-07 13:49:33

Tom Kalbfus wrote:

Still less that 130 tons.

The Encyclopedia Astronautica description of Saturn V

LEO Payload: 118,000 kg (260,000 lb) to a 185 km orbit at 28.00 degrees. Payload: 47,000 kg (103,000 lb) to a translunar trajectory. Success Rate: 100.00%. Launch data is: complete.

Assuming SLS will get the same ratio, and based on the report that SLS will be able to lift 130,000 kg to LEO, it should be able to lift 51,780 kg to a translunar trajectory.

And I have to question whether the ATV-based service module has sufficient propellant to slow the entire lunar stack into lunar orbit, then inject the CSM into trans-Earth trajectory. It would probably require the original service module designed for Orion. But Boeing ran out of money, spent it all on the capsule (Orion command module) plus Launch Abort System. According to Wikipedia, that Service Module will mass empty 3,700 kg, with 8,300 kg of fuel. That service module has lower dry mass, but more propellant. I have no way of calculating whether the Orion service module would have enough propellant for the Lunar orbit insertion and departure. But replacing it with one that has higher dry mass and less propellant? That's questionable. With the Orion 606 Service Module:
Capsule 8,913kg + SM 3,700kg + fuel 8,300kg + LAS 7,250kg = 28,163kg

Now add the Altair lunar module:
28,163kg + 45,000kg = 73,163kg

That's above the 51,780kg that SLS can throw into TLI. Need to trim off 21,383kg. And don't forget the fairings. So you should reduce Altair by 22,000kg.

SpaceNut · 2014-12-07 19:32:37

We need to compare apples to apples when looking at the total comparison as just only a pieces will not work....
http://en.wikipedia.org/wiki/Saturn_V is a 3 stage rocket while the http://en.wikipedia.org/wiki/Ares_V is a 1.5 to 2 .5 stage rocket for orbital to lunar missions.

The Ares V Lite is meant to be a cargo unit as it would use the RS68 engines as oposed to the RS25 for manned flight. So a 2 launch docked in or is plenty of craft to do the missions....

RobertDyck · 2014-12-07 21:32:49

Huh? Impaler claimed "SLS as a barely modified Ares V". But when Ares V was first proposed, it was to use SSME as well. Then modified SSME. Then Boeing Rocketdyne sales people convinced NASA to use their RS-68 engines. One excuse was NASA engine guys wanted to expand SSME to be 50% more powerful, while Rocketdyne sales people pointed out RS-68 is already that big. In fact, RS68 was optimized as an expendable engine; no need for redesign. So NASA management selected it. Then NASA engine guys claimed it had to be "man rated". But they used that excuse to add features from SSME that were missing from RS-68; basically turning it into the enlarged SSME they always wanted. Huge waste of money. Then Obama cancelled it. Then Congress resurrected it, but with 5 unmodified SSME. Good! But NASA current plans are to use 5-segment SRBs instead of the Shuttle's 4-segment, giving ATK development money. And to eventually replace them with an advanced SRB. And with additional thrust from SRBs, they intend to reduce engines form 5 to 4. Although Wikipedia describes the upper stage with 4 RL10 engines, NASA's website lists 2 J-2X engines.

The original Ares designed by Robert Zubrin and David Baker would use a pair of 4-segment SRBs, 5 SSME, and the upper stage would have 2 J-2S engines. The J-2 was used for the second and third stages of Saturn V. The J-2S was the updated version when Mars Direct was first written. The J-2X is the updated version today. So SLS is basically the Ares rocket for Mars Direct.

But Tom's post talked about using SLS and Orion to return to the Moon. Yea, SLS block 1 could deliver equipment to LEO for assembly. But Tom also suggesting using a surplus Apollo LM. Interesting idea. He said LM-9 is the only one left. The website he linked states LM-9 is on display at KSC Apollo/Saturn V Center. But it also states LM-2 only requires "optical alignment telescope and flight computer", and is on display at "the National Air and Space Museum, Washington, DC". You would replace the computer with a modern one anyway. And LM-13 is partially completed, restored, and on display at "Cradle of Aviation Museum, Long Island, New York". Interesting idea.

RGClark · 2014-12-07 21:33:31

RobertDyck wrote:

That sounds good Tom, but unfortunately won't work. Saturn V could lift 118 metric tonnes to LEO. SLS Block II will lift 130t.
But the Apollo CSM had a launch mass of 28,800kg in lunar configuration (full propellant tanks), plus 4,200kg for the launch escape tower. The Lunar Module 15,200kg initial (Apollo 11), and 16,400kg final (Apollo 17).
The Orion capsule mass 8,913kg, ATV-based service module 12,337kg, the launch abort system approximately 16,000 pounds = 7,250kg. That total adds up to 28,500kg. The Altair lunar module mass is 45,864kg.
Oops! The lunar module needs a serious diet. Otherwise you're looking at orbital assembly.

Impaler's idea was not to use the Altair. A LEM sized lander could be made for far less than the $10 billion Altair especially if made by the commercial space approach.

Bob Clark

SpaceNut · 2014-12-07 21:58:09

The thought of cloning the old lander shell is nice; with new hardware, control would and should be quite easy if you have one that can be taken appart in order to make all the pieces from....

RobertDyck · 2014-12-08 00:03:18

Well, the old Apollo LM was actually risky. I heard an Apollo astronaut say the shell was aluminum alloy as thick as 5 sheets of kitchen aluminum foil. If you dropped a screwdriver with the point down, it would go through. And several Apollo documents stated the LM was certified for 5 decompress/recompress cycles. Beyond that, it was not safe. The fictional movie Apollo 18 showed astronauts sleeping in the LM. One would sleep on the floor, while a second would sleep cross-wise above in a hammock. There weren't even seats, just stirrups for your feet. Lunar gravity was so low that seats were deemed not necessary. Astronauts stood while landing. There was a shelf behind the standing area; the hammock hung in that shelf area, with half the body of the upper astronaut above the lower one, in a "T".

I suspect one reason the Altair lunar module is heavier was that it would carry all 4 astronauts. But the other reason was increased safety. The ability to decompress/recompress multiple times would greatly increase safety.

It would be kind of nice to see the old LM fly again. However, don't expect it to do much more than Apollo. You realize I really want to use SLS for Mars.

LM-10 Interior Photos Final closeout photos before launch.
LM-9 Detail Photos of Ascent stage antennas and ascent engine.
Lunar Module Technical Drawings with dimensions, but unfortunately resolution is so low you can't read anything. This site hasn't been updated in many years.

Last edited by RobertDyck (2014-12-08 12:18:11)

Tom Kalbfus · 2014-12-08 06:18:00

RobertDyck wrote:

Well, the old Apollo LM was actually risky. I heard an Apollo astronaut say the shell was aluminum alloy as thick as 5 sheets of kitchen aluminum foil. If you dropped a screwdriver with the point down, it would go through. And several Apollo documents stated the LM was certified for 5 decompress/recompress cycles. Beyond that, it was not safe. The fictional movie Apollo 18 showed astronauts sleeping in the LM. One would sleep on the floor, while a second would sleep cross-wise above in a hammock. There weren't even seats, just stirrups for your feet. Lunar gravity was so low that seats were deemed not necessary. Astronauts stood while landing. There was a shelf behind the standing area; the hammock hung in that shelf area, with half the body of the upper astronaut above the lower one, in a "T".
http://chapters.marssociety.org/winnipe … ollo18.png
I suspect one reason the Altair lunar module is heavier was that it would carry all 4 astronauts. But the other reason was increased safety. The ability to decompress/recompress multiple times would greatly increase safety.
It would be kind of nice to see the old LM fly again. However, don't expect it to do much more than Apollo. You realize I really want to use SLS for Mars.
LM-10 Interior Photos Final closeout photos before launch.
LM-9 Detail Photos Photos of Ascent stage antennas and ascent engine.
Lunar Module Technical Drawings with dimensions, but unfortunately resolution is so low you can't read anything. This site hasn't been updated in many years.

Opportunities for going to Mars are fewer than for going to the Moon. We can establish a space station on one of the Moon's poles. the Moon would make an excellent platform for astronomy, at each pole you get half the sky. If there is a solar flare, you just duck into a crater and your protected by the moon's crust. The trip between the Moon and the Earth is quick, you don't really need anything more than an Orion, you don't need a transfer vehicle. My guess is the Lunar North Pole would be best, because then you have a constant line of sight with the Earth's northern hemisphere, the Earth's disk will be half above and half below the Lunar horizon, the half you want to communicate with is in the Northern Hemisphere.

Easier to exchange base personnel, if we have the right vehicles, we can exchange them as frequently as with the ISS.

Impaler · 2014-12-08 19:18:01

RGClark wrote:

Impaler's idea was not to use the Altair. A LEM sized lander could be made for far less than the $10 billion Altair especially if made by the commercial space approach.
Bob Clark

Lunar COTS has been suggested by a lot of folks and even has it's own advocacy page that I can't find at the moment, it would almost certainly be cheaper then the Altair lander too. Ideally NASA should just structure the contract as "take all the remaining volume/mass available under the Orion on the SLS and give us a landing of 4 astronauts to any point on the moons surface for as long a duration, lowest cost over 10 missions as possible", full stop. That gives the developer total flexibility to use disposable or reusable landers and to put the lander in place by some means other then SLS if they so choose.

According to Roberts earlier math on what SLS can throw to the moon were looking at only 23mt left for the lander. If were using a reusable lander in LLO then nearly that entire 23mt could be propellent in a stretched TLI stage to offload to the lander. If a propellent line connecting the Orion module to the TLI stage is present at launch then the crew can connect that through the interior of the lander to it's propellent tanks and the whole propellent transfer can be done without EVA!

The original Altair concept was for Earth-orbital rendezvouses, that and the higher ISP of Hydro-Lox was basically how it achieved a 4 person rather then 2 person landing vs the original LEM while using a comparable sized initial rocket. Now that the heavy Orion and all of it's very heavy accouterments need to go on the SLS their is not enough mass left for the Altair or any vehicle of comparable mass. With only 23mt your looking at a vehicle hardly any larger or more capable then the original LEM, that means 2 person landing and a very brief duration, this just isn't very compelling, if Apollo on steroids was laughable imagine what kind of reaction you get from a strait up equivalent to Apollo landings. The LEM had around 10mt combined propellent for both stages, and dry mass of around 6mt. A vehicle with the same ratios that receives 23mt propellent would have a dry mass of nearly 14mt which would have a fighting chance of housing 4 people. Basically a reusable lander and propellent transfer looks to me to be the only way to recapture the capability of the Altair within the mass constraints of the SLS+Orion. And this dry lander is actually VERY reasonable as a throw mass to the moon, it would not remotely stress the SLS so their would be some left over mass for the 'hibernator' module I described earlier if SLS is used, or alternatively (and presumably much cheaper) would be a smaller rocket to put it into place.

Last edited by Impaler (2014-12-08 20:20:38)

Void · 2014-12-08 21:15:46

I really can't fault NASA. They have done something with the cards that were delt to them. They have some hardware. Thats better than having nothing.
Just what if this is true?
http://www.lockheedmartin.com/us/produc … usion.html
Granted I have been taken in by fantasy before, but if there is a chance, then what do you get when you blend what NASA is building, and what might be with fusion power?
I don't think they are so wrong.
Maybe the Moon and Mars and more.

Last edited by Void (2014-12-08 21:18:02)

RobertDyck · 2014-12-08 21:46:38

I looked at a reusable lunar vehicle. The idea was to go from LEO to lunar surface and back. Use ISS as a bus station. Reduce mass to enter Earth orbit with aerocapture and aerobraking. For the heat shield, use a Nextel 440 fabric parasol, with titanium alloy ribs. I suggested the same thing to go from Mars orbit to Earth orbit. But one goal was to refill propellant tank on the lunar surface, and don't refill at LEO. Instead bring enough propellant to go from lunar surface to lunar surface. Unfortuantely the math showed it requires a rediculously high Isp. It would require advanced propulsion of some sort. Nuclear thermal with lunar LOX for propellant *MIGHT* be able to do it. Even that looks iffy.

Another option is to leave the aerocapture/aerobraking parasol in LLO. And when departing for Earth, drop off lunar landing legs, pick up the parasol. That requires a stop in LLO. Is it worth it? Could you go direct from lunar surface to Earth orbit?

Of course this would mean you don't need SLS/Orion. You could use SLS to deliber bulk cargo for construction. But if a reusable vehicle can dock with ISS, then any craft capable of ferrying astronauts to ISS could be used.

GW Johnson · 2014-12-09 14:16:44

To make a Nextel 440/titanium rib parasol work, you need 3 things: (1) some sort of insulation of very low thermal conductivity between the cloth and the ribs (otherwise the ribs will overheat due to the conduction path from fabric to rib), (2) a high emissivity form of the Nextel cloth so that re-radiation thermally has a prayer of equalling peak convective heating during the entry pulse, and (3) a low enough ballistic coefficient to limit the Nextel cloth hot-side face temperature to about 2000 deg F (about 1090 C) to prevent alumino-silicate solid phase change with severe shrinkage cracks and material embrittlement. Or, if this is a one-shot throwaway parasol, you may let it reach about 3000 deg F (about 1650 C), which is close to its meltpoint.

Temperature-wise and mechanical property-wise, titanium is no better than low-alloy steel. It's just lighter in density by roughly half. It has very poor properties as a casting or a forging, and is not generally ductile enough for forming operations, quite unlike steel.

Any insulation between fabric and rib will necessarily be porous to obtain that low conductivity, and thus rather weak in compressive strength. How do you plan to keep the heat shield pressure loads from destroying your insulation?

Those engineering objections are why I tend to be very skeptical about flexible heat shield concepts.

GW

RobertDyck · 2014-12-09 16:24:09

Well, NASA has been working on a deployable fabric heat shield. Let them do it. I thought of using Nextel 440 because that's the fabric of DurAFRSI, an advanced thermal blanket developed by Ames Research Centre. But NASA is working on a carbon fibre parasol. Current focus is for Venus. If it works, then why not use it for aerocapture at Earth. That means return from either the Moon or Mars. And my intention is reusable.

Adaptive Deployable Entry and Placement Technology (ADEPT): Progress in Payload Separation Risk Mitigation for a Deployable Venus Heat Shield
Appears to be published in 2013, in a journal of American Institute of Aeronautics and Astronautics. This paper is hosted by the NASA technical report server.

RobertDyck · 2014-12-25 19:17:26

I found more information. According to Orion Flight Test Press Kit, the fairings consist of 3 panels "each of those panels weighs more than 1,000 pounds (450 kilograms)".

So that gives us exact mass. Orion capsule 8,913kg + ATV-based service module 12,337kg + launch abort system 7,250kg + fairings 3 * 450 kg. Total 29,850kg. Compare that to Apollo: CSM 28,800kg + launch escape tower 4,200kg = 33,000kg. That's 3,150kg lighter. Orion can carry one more astronaut than Apollo, and it's 9.5% lighter. Good job!

Again, assuming SLS block 2 can throw 51,780kg to TLI, then calculate available mass for a lunar module. 51,780 - 29,850 = 21,930 kg. That includes lunar module + fairings for the lunar module. Previously mentioned fairings only cover the service module. Still looks like an old Apollo LM would fit.

Impaler · 2014-12-26 00:27:53

Like I said a Landing of that size (2 man) and of that brevity (3 days) is just too short to not be a crushing embarrassment to NASA, systems now need to have SOME claim of improved capability to justify their HUGE costs. Something that size has no more chance of happening then putting a cement block in the fairing of the SLS 'because it fits'. A missions math needs to work on the public relations column AND the launch mass column to be viable.

Either we find a way to do an effective (4 man, 1 week) landing withing the remaining mass budget of SLS OR we do a rendezvous with another vehicle that originated from another launch. That other launch could be another SLS if this is a 'no commercial boys allowed' exploration class snobbery issue and Congress doesn't care about price, or it could be a whole full blown Lunar COTS, either one works.

RobertDyck · 2014-12-26 00:49:07

Impaler wrote:

a Landing of that size (2 man) and of that brevity (3 days) is just too short to not be a crushing embarrassment to NASA

I have a radical idea: Mars

Since before Obama was elected, I said the Moon is "Been there, done that." President Obama himself repeated those words. But if you want to crunch the numbers, I can do that. And this demonstrates that Orion is optomized for one misison only; it is not "Multi-Purpose Crew Vehicle". And media announcements during the Orion test launch called it the ship that will take humans to Mars. Ha! Never going to happen. Although it's practically the same mass as Apollo, it's way to heavy for a capsule. We discussed a couple alternatives for Mars in other threads.

GW Johnson · 2014-12-26 16:14:22

I don't know what the researchers did with Nextel 440 to create "DurAFRSI blanket", but I do know what Nextel 440 is. It is a woven alumino-silicate textile very little different from the Nextel 312 I used in the mid-1980's. 440 is what they sell today, and does exactly the same job that 312 did back then. These are fire-curtain cloths for aircraft engine nacelles. They temporarily turn the heat of an engine fire away from the aluminum structure just long enough for your fire extinguisher to work, or for you to bail out. And that's about it.

All alumino-silicates have a solid phase-change transition in the vicinity of 2350 F material temperature, which means they embrittle, they shrink, and therefore they (very seriously) crack and completely fall apart upon cooldown. The fire curtain application is very definitely a one-shot deal. I've already seen it in test, long ago.

I think you might have an easier (bur more expensive) time trying to use yttria-stabilized zirconia fiber, in woven fabric form, as your flexible heat shield fabric. One manufacturer that I know lists a max operating temperature limit of 4000 F for his zirconia products. That's in the range of operating temperatures at "realistic" ballistic coefficients for Earth entry from LEO. Whether structural strength is enough to take the airloads in a "parasol-type heat shield" is anybody's guess, as far as I know. But I have very VERY serious doubts about that.

Like RobertDyck, I have a VERY real problem with the way NASA advertises its Orion as the capsule that will "take men to Mars". No, it is not. NO CAPSULE CAN.

You have to have a rather big habitat with lots of living space, and it has to arranged correctly. That's because the trip time to Mars is measured in months, and the mission time in years, versus a lunar mission measured in days, no matter how you measure it.

We have known that no capsule can do the Mars/asteroid/any other beyond-cis-lunar-space-mission, since the 14-day flight of Gemini 7 with Frank Borman and Jim Lovell in the mid 1960's. Their original flight plan was for 21 days, but 14 was all they could mentally take under the super-cramped conditions of a Gemini capsule. That shortening of the mission was suppressed at the time, and still is.

NASA's modern problem is partly of their own making, but mostly due to the US Congress. The things that get funded at more than pittance levels are dictated by Congress. That's precisely why there is an SLS and an Orion: "pork" for the districts of very influential Congressmen and Senators. Follow the money yourself, I am not lying about this. It's exactly why all the other things they do that are good, are chronically short on budget.

NASA's most egregious failure of all (worse than the attempted Challenger coverup, worse than the totally-egregious mismanagement that led to the Columbia disaster, and even worse than the Apollo-1/Apollo-204 fire) was not resisting the Congressional takeover of NASA funding priorities. Oh, well, too late now!

GW

RGClark · 2014-12-26 16:37:46

Is the Nextrel 312 the material used in your proposed lightweight heat shields GW?

Bob Clark

RobertDyck · 2014-12-26 19:28:14

3M™ Nextel™ Woven Fabric 312

Woven from strong continuous alumina-boria-silica fibers, this fabric retains its strength, with little shrinkage, at continuous temperatures up to 2012°F (1100°C).

3M™ Nextel™ Woven Fabric 440

3M™ Nextel™ Ceramic Fibers 440 are an alumina-boria-silica fiber that contain mullite crystals. At 2% boria, these fibers contain less boria than Nextel™ Ceramic Fibers 312. These strong, continuous fibers are woven into fabrics that retain strength with little shrinkage at continuous temperatures up to 2500°F (1370°C).

I saved a document with description of DurAFRSI. It's from the Ames Research Center website, but that section of the website doesn't exist any more. Here is the image...

It's a thermal quilt, intended to replace AFRSI. It has metal foil outer covering for smooth air flow. One layer of Nextel 440 fabric on top and sides, two layers on bottom. Inside is batting of Saffil; another ceramic fibre. A wire screen of Inconel 617 is added to the top of the quilt. It's "quilted", meaning the sandwich is sewn together, with threads of Nextel 440. Then traditional brazing compound is added to the screen, and Inconel 617 foil laid on top. That is put in a furnace to melt the brazing compound. This brazes the wire screen to the foil.

DurAFRSI was demonstrated on X-37.

Last edited by RobertDyck (2014-12-27 11:59:54)

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