Author Topic: Modelling Mars  (Read 122922 times)

Offline Finn Mac Doreahn

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Re: Modelling Mars
« Reply #520 on: 11/15/2016 06:31 PM »
I have been trying, unsuccessfully, to write "Beyond Ares" that shows what happens to the crew after they return.  So far, it involves only York.  The passage of the splashdown is part of it.  So far, I have some nice moments from the world wide tour they take, her meeting Neil Armstrong, Russia, White house dinner with the Reagans and Bush.  Here Bush asks her to serve on the Space Council when he gets elected.  They also meet JFK shortly before his death. 

Why I would love to see Ares 2, I envision a Lunar infrastructure.  A small shuttle to fly crew to a space station, which Gershon gets to test fly. Then a reusable Apollo taxi to a Lagrange point lunar station that has a reusable lander to go to the surface.  The Russians join the base plan during the Clinton years, using their upgrade N-1 to help in construction.  Then a lunar base that in 20 years, becomes a colony on the moon.  So by "today" we would have a 100 person base on the moon.  It would be then, with commercial flights to the base and the rise of those companies, like we see today, that plans to go to Mars return.  And with the experience of the Moonbase (Chaffee Base) that those plans become colonial. 

The final chapter has an elderly York, in 2030, watching the launch of one of those colony ships with her son, Ben.  So, like our Apollo program, we retreat from deep space to the moon, and only after decades of staying in lunar space, do we get back to Mars.  Sort of like how we retreat from the moon to low earth orbit.

Could you possibly post this on AH.com?

Offline Ronpur50

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Re: Modelling Mars
« Reply #521 on: 11/15/2016 11:41 PM »
I will eventually.  When I get enough done the way I want.

Offline RanulfC

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Re: Modelling Mars
« Reply #522 on: 11/16/2016 06:00 PM »
I have been told that the Ares patch shows up in Baxter's recent novel, Ultima.  Apparently it deals with an alternate timeline where Ares crashed.  It seams to be a story about multiverses.  And this crashed Ares timeline is just a quick mention.

Book 2 in the "Proxima" duo-logy according to the sites. And it appears it is all about 'alternate history' since the protagonist gets captured by 21st Century Romans who flew a Starship to their Proxima which is on the other side of the "gate" they find in the book "Proxima".
http://www.tor.com/2013/09/04/book-review-proxima-stephen-baxter/
http://www.tor.com/2014/11/25/book-review-ultima-stephen-baxter/

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline RanulfC

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Re: Modelling Mars
« Reply #523 on: 11/16/2016 07:54 PM »
Yeah.  I just love the challenge of Apollo to Mars with a Venus fly-by.

I feel the plan would be a bit insane IRL though, and there are ways to improve this mission.  Still, Baxter did a great job with scientific accuracy.

Personally, I feel Eyes Turned Skyward is a more realistic alt-history NASA.  No Mars missions in that, but also no Space Shuttle.  The Saturn V gets cancelled, but the Saturn 1B gets updated with a F-1A-powered first stage (Saturn 1C) and redesigned Apollo CSM (Block III), and NASA sticks to a long-term plan of space stations.  It's more of a compromise between these two worlds.  On the plus side, we go back to the moon in the '90s and establish bases there (on something called the Saturn Multibody and Saturn Heavy and the EOR approach), but no Mars mission.  It's interesting if you like alt history, and it's free for reading online (thought I don't know where).

If you hadn't known, (and for everyone's general information :) ) ETS has had some 'update' discussions with some KSP folks posting ETS component mods they did for KSP. Some really good stuff. We've also found out the Saturn 1C may in fact have been slightly more plausible than even the authors of ETS thought it was.
(They admitted that there was some problems with the single-F1 design but it turns out even as the "Saturn" was still the "Juno-V" the engineers had examined the possibility of using a single F1 in place of 4 of the H1 engines. They kept the outboard gimbled H1s for roll and directional control which solved most of the issues with the "plain" ETS Saturn-1C design)

I enjoyed Eyes Turned Skyward, but found it unbelievable due to the actual events of the real time line.  Baxter's seemed much more believable.  I did like the return to the moon aspects, but space stations are so dull.  They just go round and round.  Not high adventure, unlike the early days of Vostok, Mercury, Voskshod, Soyuz, Gemini, and Apollo.  Not going anywhere.

useful things can be done in LOE, don't get me wrong.

Baxter's is actually worse as when he wrote it no one was aware of Kennedy's regret at starting the Lunar Program and how much he was looking for a  way out of it. At the time most people generally assumed Kennedy was a "space cadet" and would have proposed something like a follow on Mars project. As it was he historically was looking for something, anything really, to avoid setting the Lunar Goal in the first place.

ETS makes a good case of avoiding the Shuttle decision while continuing to use the legacy Apollo hardware as much as possible. My problem with ETS is despite the "focus" on space station operations and support they then 'require' the Saturn Multibody and a heavy lift program to accommodate a Lunar Landing program very similar to, (though obviously a bit more robust) Apollo rather than actually using the already developed hardware and infrastructure.

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline RanulfC

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Re: Modelling Mars
« Reply #524 on: 11/16/2016 08:37 PM »
Batxer's Saturn VB is a logical progression of the Saturn V MLV program, so I think he went with his Saturn VBs having F-1As and J-2Ss.  His F-1As also had throtting capability because first-stage throttling was mentioned in the Ares ascent.  I can attest to this flying my Saturn VB in KSP RO, because without F-1A throtting and proper SRB thrust curves, I get dynamic pressure on ascent hitting over 50 kPa.

MLV-V-4(S)-B using F1As and J2T250Ks and Titan Boosters which is where he gets the "Saturn-VB" (its in there :) ) from and not the 1.5 stage S-1D stage which is what's confusing.
http://www.astronautix.com/s/saturnmlv-v-4s-b.html

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I should mention that on the Austronautix website, they mention a Saturn VB that's nothing like Baxter's.  It's just a modified Saturn V first stage called the Saturn 1D with jettisonable outer engines.  Just a fun fact. http://www.astronautix.com/s/saturnv-b.html

As note a bunch of confusion over the designations really, Baker noted that he actually tried to point out the 'differences' between his launcher (MLV-V-4(S)-B) by eliminating the "-" which is used for the Saturn V-B but as it appears no one noticed he's given up on trying to justify/explain it. (Much like how he's SO tired of hearing why the Apollo-N accident could not happen which he is WELL, very well at this point, aware of but he needed a reason for an all chemical mission rather than nuclear. From what I understand he'd have supported the idea of using an Orion drive but frankly that's probably TOO 'fiction' for a plausible book :) ) In essence the Saturn V-B was supposed to be a way t keep the Saturn-V S1 stage and use a version to replace the Saturn-1 with a bit more payload. Albeit at a much higher price but the price wasn't the point as much as keeping the Saturn-V alive.

On the architecture the LM stage should be able to use the S-IVB stage for both Lunar injection and braking since the LM is much lighter than the CM/SM. Really though you could even build a 'larger' LM using the Saturn Lunar Module Adapter section as a basis for a vehicle in a similar manner as suggested for using them for Space Station modules during the LESA and APP program studies.

If they wanted a much cheaper booster than the Saturn VB, but one that could send Apollo CSMs on lunar missions in two launches, I once read of a Saturn 1B replacement concept that would have a single F-1A on a new first stage derived from S-IVB tooling, with the J-2S equipped S-IVB upper stage, but that stage stretched a little for more propellant. This launcher could fly with zero, 2 or 4x Titan III derived solid boosters. The four booster version could get about 50 tons into LEO. Docking a CSM with an S-IVB launched separately could send that CSM to the Moon. A new Lander or an improved Apollo LM could be sent ahead on a separate 2x launch sequence. Though because the Apollo LM is much lighter than a CSM and it's propellant supply; it would need an additional propulsion stage to brake it into Lunar Orbit. Perhaps one derived from another LM Descent Stage, albeit a legless one.

Which one? VB or V-B? :)

The Saturn-1 replacement described as far as I know was mentioned in some of the Saturn-INT studies and expanded on in ETS but not seriously considered. (Mostly because it didn't use ENOUGH of the Saturn V components which again, was most of the point in the first place) I think it was using modified S1 or SII tooling because the S-IV tooling was in California while the others were in Mississippi which they were trying to keep open.

The "problem" was going to a new design mono-tank design for a "Saturn-1" stage didn't make a lot of sense either economically or technically even to mount and feed an F1 engine.

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This 50 ton launcher mission architecture has been similarly proposed as a future Chinese Design Reference Mission; not to mention for ESA as well. I would have some doubts that 4x enhanced Saturn 1Bs would be cheaper than a single Saturn VB, but some have suggested that 'bulk quantity' manufacture could standardize and help bring down costs.

Building more and flying more is (generally) been pretty much proven with various ELVs so it would make sense however in context in the "Voyage-verse" the whole point, (much as was heavily suggested OTL) the point is to keep as much "Saturn-V" production going as possible so in this case nothing about the "Saturn-1" would have survived 'post-Apollo' and the Saturn-V systems would be (and are) used as much as possible.

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline Nittany Tiger

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Re: Modelling Mars
« Reply #525 on: 11/18/2016 01:24 PM »
  Ranulf, I'm aware of the ETS mods for KSP.  I have Real Scale Boosters installed in my RO install, and it comes with some parts for the Saturn IC and Saturn MultiBody and some of the other rockets.  I used the RSB's F-1A throttling specs to determine my throttling range for the F-1As used by FASA, which is the mod I used to create my Saturn V-B.  I think the BDB mod has some ETS stuff and is getting more, though it's for stock KSP and not RSS/RO KSP. 

  I'm also aware that Baxter's Saturn V-B was based on a real study, which is why it's so easy to create the rocket with FASA because that includes parts for creating most if not all the Saturn V MLV designs.  The J-2Ts were aerospike engines and not typical Devall nozzle engines, and in Voyage, I think the Saturn V-B went with J-2Ss, which work fine when I use them on my Saturn V-B replica.  NASA probably just modified the MLV-V-4(S)-B proposal with J-2Ss instead of J-2Ts maybe to save cost or complexity because maybe the J-2S was easier to fit into the existing S-II and S-IVB designs than a J-2T owing to the J-2S piping being made to fit on the existing Saturn V upper stages.  I also figure the Saturn V-B being from the MLV program is why all of the stages get a M designation in front of them in the book (MS-IC, MS-II, and MS-IVB).

  In general, you can think of Kerbal Space Program as both a modelling game and a space flight game, because you can build any rocket you want and fly it around in space under the restrictions of Newtonian mechanics and simple gravity models.

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ETS makes a good case of avoiding the Shuttle decision while continuing to use the legacy Apollo hardware as much as possible. My problem with ETS is despite the "focus" on space station operations and support they then 'require' the Saturn Multibody and a heavy lift program to accommodate a Lunar Landing program very similar to, (though obviously a bit more robust) Apollo rather than actually using the already developed hardware and infrastructure.

IIRC, around the time of the revived lunar program in ETS, NASA didn't have anything heavy enough to do a lunar mission.  All they had was the Saturn IC, and they probably didn't want to bring back the Saturn V for obvious cost reasons.  Dunno if they could have lifted their lunar lander on a Saturn IC or not, or using another rocket, or if they needed to develop a heavy lifter like the Saturn Heavy.  Plus, with their plan, they wanted to loft a drive stage for TLI, which meant three launches for a lunar mission.

Another possibility would be to find a way to make the Saturn V cheaper and still get an equivalent payload capacity.
« Last Edit: 11/18/2016 01:35 PM by Nittany Tiger »

Offline RanulfC

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Re: Modelling Mars
« Reply #526 on: 11/18/2016 05:28 PM »
I'm also aware that Baxter's Saturn V-B was based on a real study, which is why it's so easy to create the rocket with FASA because that includes parts for creating most if not all the Saturn V MLV designs.  The J-2Ts were aerospike engines and not typical Devall nozzle engines, and in Voyage, I think the Saturn V-B went with J-2Ss, which work fine when I use them on my Saturn V-B replica.  NASA probably just modified the MLV-V-4(S)-B proposal with J-2Ss instead of J-2Ts maybe to save cost or complexity because maybe the J-2S was easier to fit into the existing S-II and S-IVB designs than a J-2T owing to the J-2S piping being made to fit on the existing Saturn V upper stages.  I also figure the Saturn V-B being from the MLV program is why all of the stages get a M designation in front of them in the book (MS-IC, MS-II, and MS-IVB).

 I seem to recall that they were stated to be J2S' which didn't actually make sense as the J2Ts had higher ISP and altitude compensation but most importantly allowed the Saturn MLV-V-4(S)-B to use the standard Saturn-V connections for the upper stages on the MLP and better fit through the VAB doors. (The aerospikes were much shorter than the J2 and allowed a shorter, more compact interstage which was required due to the first stage tank stretch) they used all the standard J2 fittings and gimbals though they had to redesign the thrust structure itself in general everything was pretty straight forward.

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In general, you can think of Kerbal Space Program as both a modelling game and a space flight game, because you can build any rocket you want and fly it around in space under the restrictions of Newtonian mechanics and simple gravity models.

I understand Orbiter is more accurate and somewhat more mod-able overall but KSP is neater and much easier to 'tweak' it seems to me. I have but have not used Orbiter btw.

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IIRC, around the time of the revived lunar program in ETS, NASA didn't have anything heavy enough to do a lunar mission.  All they had was the Saturn IC, and they probably didn't want to bring back the Saturn V for obvious cost reasons.  Dunno if they could have lifted their lunar lander on a Saturn IC or not, or using another rocket, or if they needed to develop a heavy lifter like the Saturn Heavy.  Plus, with their plan, they wanted to loft a drive stage for TLI, which meant three launches for a lunar mission.

Another possibility would be to find a way to make the Saturn V cheaper and still get an equivalent payload capacity.

Needed a heavy launch vehicle for a heavy lander and crew lander/surface station. No way to afford let alone justify bringing back the Saturn-V but you have enough left over technology, now being produced steadily so as to reduce costs, to build a three barrel "Saturn-1C" vehicle consisting of a single Saturn-1C core and two Saturn-1C boosters. They boost the cargo or manned lander into orbit. from there the cargo lander boosts itself to TLI while the manned lander needs to wait on another launch of dedicated TLI stage. Everything is expended and the crew capsule directly returns to Earth after the mission.

It's a decent "Apollo" like mission architecture, (and believe me we've discussed the various types and failings with the various "Apolloism" mentality that exist OTL and that ETS managed to turn into a working system) and a long as you don't mind repeating Apollo over and over again, (they do manage to get a 'base' out of it but its a very basic 'outpost' by the end with all the vulnerability to political whim that implies) and reinforce that "heavy-lift" is the only way to do space missions paradigm.

Resurrect the Saturn-V? They pretty much have to in order to keep going beyond the Moon, assuming of course they can parley the support from Congress and the public, the Saturn Multibody is pretty close to it's limits as it stands and the 'standard' architecture is to loft as few pieces as possible to assemble the flight. 5 to 7 Saturn-1Cs as a cluster booster and so on.

Or an enhanced Saturn-1C (similar to the DoD set up) starts delivering component to assemble to SS Freedom along with establishing a propellant depot and you build you Moon/Mars ship there. Worst comes to worst put up an 'assembly shack' based on modules you can loft on the Saturn-1C, (you did it with Freedom anyway) in a more effective orbit and do assembly there. You are under no TIME pressure but you are under budget pressure to do as much as possible with the money you have. Again however ETS made some basic assumptions and assumed government and NASA "Apolloism" would be difficult to overcome but less so to re-direct so...

This is why the time line "I" am trying to write the Saturn-1 and variants is the largest booster the US develops so that we have no means of 'skipping' right over learning how to work on-orbit and learning orbital assembly to go beyond LEO.

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline Nittany Tiger

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Re: Modelling Mars
« Reply #527 on: 11/19/2016 04:14 PM »
I seem to recall that they were stated to be J2S' which didn't actually make sense as the J2Ts had higher ISP and altitude compensation but most importantly allowed the Saturn MLV-V-4(S)-B to use the standard Saturn-V connections for the upper stages on the MLP and better fit through the VAB doors. (The aerospikes were much shorter than the J2 and allowed a shorter, more compact interstage which was required due to the first stage tank stretch) they used all the standard J2 fittings and gimbals though they had to redesign the thrust structure itself in general everything was pretty straight forward.

Yeah.  It would take much to adjust the Saturn V for use of the J-2Ts.  Plus, there are some questionable design decisions made in Voyage, mostly with the design of the MEM.  There might be some artistic freedom going on with using J-2Ss on the MLV-V-4(S)-B.  The Saturn V-B in Voyage is actually closer to the MLV-4-(S).

Just for fun, I put some J-2T-250ks on my Saturn V-B and launched it.  I found out that Realism Overhaul didn't add gimballing to the J-2Ts though for some reason, so my rocket had no steering in the second stage.  Should be an easy fix.





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I understand Orbiter is more accurate and somewhat more mod-able overall but KSP is neater and much easier to 'tweak' it seems to me. I have but have not used Orbiter btw.

Orbiter is free and has a pretty good modding community, but it has a super-steep learning curve and less useful and intuitive flight tools when compared to KSP.  It's much harder to plan a mission in Orbiter unless you know how to use some of the flight planning MFDs, which have their own steep learning curve.  Orbiter also doesn't have the same level of detail with rocket mechanics as KSP does with Realism Overhaul.  Orbiter just uses one fuel for everything.  Even stock KSP has different fuels for different types of engines, though they still keep it simple.  On the other hand, it's easier to do cinematic missions with Orbiter (like the ASMO add-on for Apollo flights, which include real audio).  Plus, many modded Orbiter craft come with autopilot programs, so there's no learning how to make orbit if you just want the excitement of doing a mission (and the real NASA used computers to fly everything).

KSP is a sandbox rocket exploration game, so it has a bunch of customization.  You build your own rockets and fly your own missions, and the base game is designed around reducing the learning curve as much as possible without making it too easy, so you get tools such maneuver node editors and a real-time map to plan missions.  Plus, you have tons of mods to add parts and bring the game closer to a simulator (RSS/RO), and it does a much better job simulating real rocket science than Orbiter (mods for different fuels, different engines, limited ignitions, throttle restrictions, etc.).  You can basically go to the VAB in KSP and build your own Saturn V in hours versus having to learn a modelling program and code to built it in Orbiter.  Or you can build your own rocket with Saturn V parts.  I personally spent less than an hour building the Saturn V-B and a bit more time on a rough Ares Command Stack.  Most of my time in making my craft was lost in details and fine-tuning, but it was still fun and rewarding to do and felt like building a model.  Only downside is that there is no perfect autopilot system for rockets.  Mechjeb does have an automatic ascent function, but it's tuned more for the stock game and thus it doesn't work as well for RSS/RO.  So you have to learn to get into orbit, which is very difficult in RSS/RO.  It took me many tries to finally do it, and I had 1000+ hours of experience in stock KSP.  Despite that, I feel KSP RSS/RO is more flexible and easier to play than Orbiter, and it's easier and more fun to set up missions such as the Ares mission.
« Last Edit: 11/19/2016 04:18 PM by Nittany Tiger »

Offline RanulfC

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Re: Modelling Mars
« Reply #528 on: 11/21/2016 08:47 PM »
No the real difference is it isn't half as fun to watch an Orbiter rocket doing flips over the cape while the crew, (who are not cute green people) scream in panic whereas...

Randy :)
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline Ronpur50

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Re: Modelling Mars
« Reply #529 on: 11/21/2016 09:57 PM »
Do these simulators take into account such things as boil-off of your propellants?  That still bothers me about Baxter's mission.  And the one model I did based on the Mars One Crew Manual.

Also, can you model NERVA?

Offline Nittany Tiger

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Re: Modelling Mars
« Reply #530 on: 11/22/2016 05:14 PM »
Do these simulators take into account such things as boil-off of your propellants?  That still bothers me about Baxter's mission.  And the one model I did based on the Mars One Crew Manual.

In KSP, yes, but not in stock.  It's part of the Real Fuels mod, and it's a base part of the Realism Overhaul mod set.  Liquid hydrogen boils off with time, especially if you don't use cryogenic tanks.  I actually had to go into the configuration file for the FASA Saturn V tanks and change their type to cryogenic to slow boil off down enough so that all my LH2 wouldn't boil off before the mission is finished.  Dunno if other cryo fuels boil off such as LO2.  They may, but not nearly as fast as LH2.

I figure in the Voyageverse, NASA would have added extra cooling and insulation to the tanks of the propulsion stage to limit boil-off as much as possible.  The tanks may even have been orange, not white.  IIRC, the book mentions boil-off as an issue that they accounted for by orienting the Ares craft facing the sun, and they had invented tech to deal with long-term storage of super-cooled fuels, so cryogenic Saturn V tanks in my simulation isn't breaking canon.  Plus, there's still boil-off, but it takes years to boil off the LH2 in the Ares propulsion stage instead of days with default tanks.

In Orbiter, at least in Orbiter 2010, they don't simulate fuel beyond having it as a single resource and adding weight to the vehicle.  It's really limited compared to even stock KSP.

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Also, can you model NERVA?

KSP has NERVA engines.  The stock game has one just called the LV-N Nerv which runs on liquid fuel and has incredible efficiency but not much thrust.  If the LV-N gets damaged or destroyed, it doesn't do anything like spread radiation and kill Kerbals.  Some mods include other kinds of nuclear thermal drives, and LH2 or other fuels to run them with, but I don't know of any that simulate engine meltdown and irradiation.

In Realism Overhaul, NERVAs run on LH2 or LH2 + Oxidizer if they're LANTR-style engines.  They also have limited enriched uranium the depletes over time.   I don't think they can melt down and irradiates Kerbals though unless there's a mod for it.  They might just explode if overheated like in stock and be more of an inconvenience than a death sentence.

I assume you're asking because of Apollo-N in the book, which I actually did want to recreate.

Offline Ronpur50

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Re: Modelling Mars
« Reply #531 on: 11/22/2016 10:30 PM »
Actually, my next model will be the Von Braun NERVA.  Hopefully starting soon.  I have the tubes and parts and just need to start cutting plastic.

On my model of Ares, I added insulation to the outside of the MS-II and MS-IVB as well as the ETs.  The book describes the tanks as both orange and white, and the faded to ivory when they arrive at Mars!  I left them ivory and white.
« Last Edit: 11/22/2016 10:32 PM by Ronpur50 »

Offline Nittany Tiger

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Re: Modelling Mars
« Reply #532 on: 11/23/2016 11:18 AM »
Cool.  I might do Van Braun NERVA shuttles as well after Ares.  Those would be better suited for a trip to Titan.

A third option, which might be "cheating," is nuclear pulse.

Offline MATTBLAK

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Re: Modelling Mars
« Reply #533 on: 11/30/2016 08:38 PM »
I've received my Ares patches from ronpur - they are excellent quality! Message the good man for ordering details...
"Those who can't, Blog".   'Space Cadets' of the World - Let us UNITE!! (crickets chirping)

Offline Ronpur50

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Re: Modelling Mars
« Reply #534 on: 03/10/2017 12:36 AM »
 With the completion tonight of Saturn I:SA-5, I have added another Saturn to my collection. The collection includes two fictional Saturns, including Ares.

Left to right: Modified Revell 1/96 scale. 1/200 AMT SA-501, 1/100 4-D Vision cutaway, And the 1/144 scale:Saturn VB from "Voyage", Saturn V from "Interstellar", Saturn V-Skylab, Saturn V-Apollo8, Saturn V-500F, Saturn IB-Skylab, Apollo 7-Saturn IB, Apollo 5-Saturn IB, Saturn IB-SA-203, Saturn IB-SA-201, Saturn I-SA-6 and finally:SA-5!!

And the first one I ever had, with me back in 1969!

Offline Nittany Tiger

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Re: Modelling Mars
« Reply #535 on: 03/10/2017 02:07 AM »
Did they really use a Saturn V to launch the ranger in Interstellar?  It was always hard to tell with the camera angles in the movie.

Offline Dalhousie

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Re: Modelling Mars
« Reply #536 on: 03/10/2017 06:40 AM »
Much like how he's SO tired of hearing why the Apollo-N accident could not happen which he is WELL, very well at this point....

Can you explain please?  because the more I read about NERVA the more plausible the accident seems and the more I am glad to was cancelled before something nasty happened.
"There is nobody who is a bigger fan of sending robots to Mars than me... But I believe firmly that the best, the most comprehensive, the most successful exploration will be done by humans" Steve Squyres

Offline Ronpur50

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Re: Modelling Mars
« Reply #537 on: 03/10/2017 10:45 AM »
Did they really use a Saturn V to launch the ranger in Interstellar?  It was always hard to tell with the camera angles in the movie.

Yes, it is.  The 1/72 model kit of the Ranger comes with a 1/144 scale version that fits a Saturn V model.

Offline Nittany Tiger

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Re: Modelling Mars
« Reply #538 on: 03/10/2017 04:23 PM »
Much like how he's SO tired of hearing why the Apollo-N accident could not happen which he is WELL, very well at this point....

Can you explain please?  because the more I read about NERVA the more plausible the accident seems and the more I am glad to was cancelled before something nasty happened.

I did a little research, and from what I can tell, a NERVA containment failure and meltdown is plausible, but the radiation exposure issue may not be.  This is because the liquid hydrogen would shield the crew from any radiation the NERVA produced, even in a severe containment failure.

In the Apollo-N accident, the S-N stage was still well-packed with LH2, so there was plenty of shielding between them and the failed NERVA rocket, and therefore they should have all survived the accident.

From http://large.stanford.edu/courses/2011/ph241/hamerly1/

Quote
Protecting the crew from radiation is as important as preventing a nuclear meltdown. Neutron shielding, which can weigh several tons, must be installed between the reactor and the crew, and the distance between the two should be maximized to take greatest advantage of the fact that radiation flux falls off with the square of the distance. Placing the fuel tanks between the crew and the rocket is a very effective way to shield the crew, since hydrogen makes an excellent neutron scatterer. [4]

Now this is not to say they weren't in danger during the failure as if they were to separate from their S-N stage and somehow the S-N stage rotated around after sep (which might be common), then they could have received a much higher dose of radiation.  They could have also been far enough away from the engine for attenuation to reduce the exposure though.

So, yeah, I'm sure Baxter got a load of "But the LH2 would have shielded them" comments, but he had to ignore that for the sake of the story.

EDIT: I should also mention that I'm sure NASA would have loads of safety features in the NERVA built-in even if the engine was built under a time crunch, such as automatic shutdown if a problem that could lead to a contamination failure were to develop.

Furthermore, Google Kiwi-TNT.  This was a NERVA-program test of a Kiwi reactor where they made one go critical on purpose to test the effects of a containment failure.  So IRL, the NERVA guys were thinking about "what if the engine explodes Chernobyl-style during use?" among other possible events of containment failure.

Quote from: Ronpur50
Yes, it is.  The 1/72 model kit of the Ranger comes with a 1/144 scale version that fits a Saturn V model.

I suspected the rocket they launched on in the movie was a Saturn V-derived rocket, but not an actual Saturn V.  Given the setting and events, I didn't think it would be practical for NASA to build more Saturn Vs for their missions, and they could only scrounge up two to three from displays and refurbish them for flight.
« Last Edit: 03/10/2017 04:55 PM by Nittany Tiger »

Offline Dalhousie

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Re: Modelling Mars
« Reply #539 on: 03/10/2017 09:06 PM »
Much like how he's SO tired of hearing why the Apollo-N accident could not happen which he is WELL, very well at this point....

Can you explain please?  because the more I read about NERVA the more plausible the accident seems and the more I am glad to was cancelled before something nasty happened.

I did a little research, and from what I can tell, a NERVA containment failure and meltdown is plausible, but the radiation exposure issue may not be.  This is because the liquid hydrogen would shield the crew from any radiation the NERVA produced, even in a severe containment failure.

In the Apollo-N accident, the S-N stage was still well-packed with LH2, so there was plenty of shielding between them and the failed NERVA rocket, and therefore they should have all survived the accident.

From http://large.stanford.edu/courses/2011/ph241/hamerly1/

Quote
Protecting the crew from radiation is as important as preventing a nuclear meltdown. Neutron shielding, which can weigh several tons, must be installed between the reactor and the crew, and the distance between the two should be maximized to take greatest advantage of the fact that radiation flux falls off with the square of the distance. Placing the fuel tanks between the crew and the rocket is a very effective way to shield the crew, since hydrogen makes an excellent neutron scatterer. [4]

Now this is not to say they weren't in danger during the failure as if they were to separate from their S-N stage and somehow the S-N stage rotated around after sep (which might be common), then they could have received a much higher dose of radiation.  They could have also been far enough away from the engine for attenuation to reduce the exposure though.

This is exactly what happens in the story.

Quote
So, yeah, I'm sure Baxter got a load of "But the LH2 would have shielded them" comments, but he had to ignore that for the sake of the story.

First of all he did not ignore it and secondly anyone who said that did not read the story.  The Bellcom report on the NERVA program was critical of what it saw as rather optimistic assumptions radiation shielding assumptions.  Not least that the shielding from the propellant went down as radiation increased.


Quote
EDIT: I should also mention that I'm sure NASA would have loads of safety features in the NERVA built-in even if the engine was built under a time crunch, such as automatic shutdown if a problem that could lead to a contamination failure were to develop.

Unfortunately when it comes down to it, safety features don't always work in a catastrophic accident.  besides it's not contamination that was an issue in the story, but radiation exposure to an unshield life core and its fragments.

Quote
Furthermore, Google Kiwi-TNT.  This was a NERVA-program test of a Kiwi reactor where they made one go critical on purpose to test the effects of a containment failure.  So IRL, the NERVA guys were thinking about "what if the engine explodes Chernobyl-style during use?" among other possible events of containment failure.

Read the reports several years ago.  This experiment produced one of the most serious radiation plumes up to that time.  It shows the rather cavalier attitude to safety exhibited by program, and referred to by Baxter. The test deliberately released 1.6 million Curies into the environment, as opposed to the far better publicised Windscale fire which accidently only released 33,000 Curies.  The core was basically vapourised.  There were other tests earlier on where the engines ejected bits of incandescent core through unscheduled rapid disassembly.  These would have been more like the Apollo-N accident.  I attach a photo of the Kiwi TNT test.  The glowing particles are core fragments.

One thing that Baxter does mention that I have not been able to confirm was the positive power profile and deliberate instability of the design, although both seem likely. 
« Last Edit: 03/10/2017 10:12 PM by Dalhousie »
"There is nobody who is a bigger fan of sending robots to Mars than me... But I believe firmly that the best, the most comprehensive, the most successful exploration will be done by humans" Steve Squyres

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