Thanks for that. I wasn't real sure of the logistics inside of the VAB. That makes that it would rest on supports inside the VAB. With the Artemis missions and the Freedom missions going on things are a little busy at LC 39 A&B.
Thanks for that. I wasn't real sure of the logistics inside of the VAB. That makes that it would rest on supports inside the VAB. With the Artemis missions and the Freedom missions going on things are a little busy at LC 39 A&B.
Honestly, at this point I'm ready to throw in the towel and admit the odds are a hundred to one they'd ever need a rescue craft. Maybe a bit higher that missions will fail fatally--but some possible accidents will kill the crew instantly--there's a silver lining of a ghoulish sort!
Odds seem good nothing fatal will happen.
I'm still haunted by the idea that people sat down and did the same checks and came up with the same low odds for Apollo, and yet Apollo 13 still happened anyway. And thank God that Service Module was not the one picked for Apollo 8 or Lovell and the rest would have been dead right there. And not instantly but in a diabolically suspenseful and horrifying way at that.
However--I'm glad I worked out that it would take an entire Heavy launch just to get a single freaking Apollo LEM there (using storable propellants that is--it could be twice as much I suppose if we could only use hydrogen-oxygen...which requires a new facility in orbit to keep reliquefying the hydrogen). Even if we could double it, would as much as six tonnes of supplies be enough to keep 4 astronauts alive through the months, two or more Lunar nights, it would take to get their second LEM to them?
The killer need I suspect is power. We have yet to be told just what sort of power levels it would take to keep a habitat above freezing temperatures in the Lunar night, but I imagine it is not trivial. The Rescue Columbia timeline was certainly on my mind, and we quickly concluded, last late winter/early spring when that was being written, that after CO2 absorbers the next thing Columbia crew would need to survive would be power. I figured getting them oxygen and hydrogen for the fuel cells might be doable, and these provide the benefit of not only keeping the essential lights and fans running but also drinking water. The only alternative I saw to sending fuel cell reactant (and if necessary the fuel cell itsel) to power the habitat at night was some kind of radionuclide generator. Either option--keeping fuel cell reactant or any kind of nuke power--seemed terrible from the point of view of keeping it stored in orbit for years just in case it might be needed. And when we've sent the fuel cell reactants, if we somehow could--what room is left in the cargo for the other vital necessities they'd need?
Mind, I had yet other notions, but with payloads measuring less than 10 tonnes I had to admit no matter what, we'd be licked. They just can't hold out long enough.
The mission profile does allow a lot of redundancy as is; accidents that wreck one craft or the other might still let the crew get home. That's an advantage of parking at a Lagrange point after all--just a little push and you can fall back to Earth, provided the CM heat shield is still intact.
Which is why my first thought was to have a rescue craft based there; from there it can go anywhere. Of course what I really wanted parked there would be a depot.
Given that the program can't, for political reasons, propose to develop any permanent infrastructure I have to admit the authors seem to have come up with the best answers, and that further safeties just cost too much.
Odds seem good nothing fatal will happen.I'm still haunted by the idea that people sat down and did the same checks and came up with the same low odds for Apollo, and yet Apollo 13 still happened anyway. And thank God that Service Module was not the one picked for Apollo 8 or Lovell and the rest would have been dead right there. And not instantly but in a diabolically suspenseful and horrifying way at that.
However--I'm glad I worked out that it would take an entire Heavy launch just to get a single freaking Apollo LEM there (using storable propellants that is--it could be twice as much I suppose if we could only use hydrogen-oxygen...which requires a new facility in orbit to keep reliquefying the hydrogen). Even if we could double it, would as much as six tonnes of supplies be enough to keep 4 astronauts alive through the months, two or more Lunar nights, it would take to get their second LEM to them?
The killer need I suspect is power. We have yet to be told just what sort of power levels it would take to keep a habitat above freezing temperatures in the Lunar night, but I imagine it is not trivial. The Rescue Columbia timeline was certainly on my mind, and we quickly concluded, last late winter/early spring when that was being written, that after CO2 absorbers the next thing Columbia crew would need to survive would be power. I figured getting them oxygen and hydrogen for the fuel cells might be doable, and these provide the benefit of not only keeping the essential lights and fans running but also drinking water. The only alternative I saw to sending fuel cell reactant (and if necessary the fuel cell itsel) to power the habitat at night was some kind of radionuclide generator. Either option--keeping fuel cell reactant or any kind of nuke power--seemed terrible from the point of view of keeping it stored in orbit for years just in case it might be needed. And when we've sent the fuel cell reactants, if we somehow could--what room is left in the cargo for the other vital necessities they'd need?
Mind, I had yet other notions, but with payloads measuring less than 10 tonnes I had to admit no matter what, we'd be licked. They just can't hold out long enough.
The mission profile does allow a lot of redundancy as is; accidents that wreck one craft or the other might still let the crew get home. That's an advantage of parking at a Lagrange point after all--just a little push and you can fall back to Earth, provided the CM heat shield is still intact.
Which is why my first thought was to have a rescue craft based there; from there it can go anywhere. Of course what I really wanted parked there would be a depot.
Given that the program can't, for political reasons, propose to develop any permanent infrastructure I have to admit the authors seem to have come up with the best answers, and that further safeties just cost too much.
Hello Shevek,
In one sense I think you're right: NASA in either timeline is going to be a more risk averse entity than it was in the 60's. And extended missions to a place a quarter million miles away, where the possibility of a lifeboat capacity at Freedom, or hasty launch from the Cape, simply aren't possibilities, will - I would argue - pull NASA into looking at rescue options right out of the gate. And it would get every bit as much serious treatment and study as LESS did in the 60's, if not more.
Given the tight budgets and the more robust systems, to say nothing of how the mission profile (4 astronauts, a CSM further away at L-2) makes even a skimpy LESS type rescue option problematic, I won't gainsay the authors for concluding it ain't happening.The Artemis office will commission some studies, and even detailed proposals...but it seems less likely to go beyond that. Yet.
But I think it's going to be a far more credible question once NASA moves to building a base. At that point, the cost-benefits ratio really changes.
In one sense I think you're right: NASA in either timeline is going to be a more risk averse entity than it was in the 60's. And extended missions to a place a quarter million miles away, where the possibility of a lifeboat capacity at Freedom, or hasty launch from the Cape, simply aren't possibilities, will - I would argue - pull NASA into looking at rescue options right out of the gate. And it would get every bit as much serious treatment and study as LESS did in the 60's, if not more.
Given the tight budgets and the more robust systems, to say nothing of how the mission profile (4 astronauts, a CSM further away at L-2) makes even a skimpy LESS type rescue option problematic, I won't gainsay the authors for concluding it ain't happening.The Artemis office will commission some studies, and even detailed proposals...but it seems less likely to go beyond that. Yet.
But I think it's going to be a far more credible question once NASA moves to building a base. At that point, the cost-benefits ratio really changes.
Honestly, at this point I'm ready to throw in the towel and admit the odds are a hundred to one they'd ever need a rescue craft. Maybe a bit higher that missions will fail fatally--but some possible accidents will kill the crew instantly--there's a silver lining of a ghoulish sort!
I'm still haunted by the idea that people sat down and did the same checks and came up with the same low odds for Apollo, and yet Apollo 13 still happened anyway. And thank God that Service Module was not the one picked for Apollo 8 or Lovell and the rest would have been dead right there. And not instantly but in a diabolically suspenseful and horrifying way at that.
However--I'm glad I worked out that it would take an entire Heavy launch just to get a single freaking Apollo LEM there (using storable propellants that is--it could be twice as much I suppose if we could only use hydrogen-oxygen...which requires a new facility in orbit to keep reliquefying the hydrogen). Even if we could double it, would as much as six tonnes of supplies be enough to keep 4 astronauts alive through the months, two or more Lunar nights, it would take to get their second LEM to them?
The killer need I suspect is power. We have yet to be told just what sort of power levels it would take to keep a habitat above freezing temperatures in the Lunar night, but I imagine it is not trivial. The Rescue Columbia timeline was certainly on my mind, and we quickly concluded, last late winter/early spring when that was being written, that after CO2 absorbers the next thing Columbia crew would need to survive would be power. I figured getting them oxygen and hydrogen for the fuel cells might be doable, and these provide the benefit of not only keeping the essential lights and fans running but also drinking water. The only alternative I saw to sending fuel cell reactant (and if necessary the fuel cell itsel) to power the habitat at night was some kind of radionuclide generator. Either option--keeping fuel cell reactant or any kind of nuke power--seemed terrible from the point of view of keeping it stored in orbit for years just in case it might be needed. And when we've sent the fuel cell reactants, if we somehow could--what room is left in the cargo for the other vital necessities they'd need?
Mind, I had yet other notions, but with payloads measuring less than 10 tonnes I had to admit no matter what, we'd be licked. They just can't hold out long enough.
The mission profile does allow a lot of redundancy as is; accidents that wreck one craft or the other might still let the crew get home. That's an advantage of parking at a Lagrange point after all--just a little push and you can fall back to Earth, provided the CM heat shield is still intact.
Which is why my first thought was to have a rescue craft based there; from there it can go anywhere. Of course what I really wanted parked there would be a depot.
Given that the program can't, for political reasons, propose to develop any permanent infrastructure I have to admit the authors seem to have come up with the best answers, and that further safeties just cost too much.
It isn't a bad idea to keep a logistical lander on stand-by. However the short duration missions mean that realistically when the lunar surface mission is ended the planners are not going to plan on a extra 5-7 days of consumables on the surface in-case the Lander cannot lift off. A rescue mission doesn't become really feasible until you have a solid base camp where you have months of supplies on-hand. Yes you are right they got very lucky with Apollo 13.
As far as electrical usage. From the information I was able to gleam off the internet it looks like the electrical usage for a J-class mission was around 70kw. So this means that on average the LEM drew 1kw per hr over the duration of it's lunar stay. Now I would imagine that the power draw varied a bit. I would probably say that maybe a minimum of say 300-400w per hour to keep the LEM above freezing in a lunar night and stand-by communication. So say a power draw of around 8kw a day. So you are probably looking at around 110-120kw to survive a lunar night. Just some ball park figures.
Hi everyone. Sorry for the delays this week. The schedule shuffle and some prior commitments unfortunately meant I wasn't able to devote the time and attention I'd normally like to for this week's illustration, nor to get it vetted by the authors for cannonicity (so for now this is just the fevered outpourings of my own imagination!), but I promised you an update so an update you shall have A look at Europe's future Marconi global satcom and navigation overlay spacecraft.
A look at Europe's future Marconi global satcom and navigation overlay spacecraft.A few more ball-park figures (please feel free to correct stupid mistakes or invalid assumptions!)
(Remembering the physicist's approximation: A cow= a sphere
) Taking a hab/cargo lander as approximating a cylinder of 7m diameter and 10m height, we get a surface area of about 300m^2.Assuming a minimum design temperature of 5deg Celsius = 278K (ensuring no liquids freezing), and further assuming the hab is wrapped in MLI to give it an overall emissivity of 0.015, then plugging that into the Stefan-Boltzmann equation, I get an overall emission of just over 1.5kW of heat during a lunar night.
By further assuming that the Moon's surface averages about 120K over that whole period, and that only the ground directly below the lander radiates heat, with a emissivity of 0.72, we could subtract 325W of heating from the Moon - except that the MLI on the lander will work both ways, so only about 4W of lunar heat gets through - d'oh! So we still have an overall power need of 1.5kW (or about 1.82GJ over 2 weeks of darkness).
Next assumptions: The day and night are equally long, and the system for converting solar energy to stored energy to thermal energy is overall 5% efficient (remembering that the solar arrays alone can have an efficiency of about 20% in the mid-90s). We need to average 1.5kW of solar power during the day to keep the lander warm at night, but let's round that up to 2kW to give some spare capacity. With a solar constant of 1.63kW/m^2, that means we need just under 30m^2 of solar array area to cover our keep-alive needs, say two arrays of 3x5m each.
Sound reasonable?
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Sounds reasonable. A Shuttle-type fuel cell will have the capacity for that (4-12 kW/unit, at 115 kg--figure that gets broken down here to three cells each making 1.3 to 4 kW and massing about 40 kg each). According to here, to produce 220 amps at 28 V (about 6 kW) during Shuttle ascent, the cells each consume about 4.6 lbs on reactant per hour. Given this and our lower needs, I calculate that about 250 kg should provide sufficient for 2 kW for a 14 day night (4.6 lbs/hr * (2000/6000) * 14 days is 230 kg, then add some margin), which can be electrolyzed during the day to recycle for the next night. Maybe call the entire system, (all this plus the tanks and electrolysis bank plus the solar arrays)...I think about 700 kg total seems reasonable, and it fits nicely into our payload calculations.A few more ball-park figures (please feel free to correct stupid mistakes or invalid assumptions!)
(Remembering the physicist's approximation: A cow= a sphere
Assuming a minimum design temperature of 5deg Celsius = 278K (ensuring no liquids freezing), and further assuming the hab is wrapped in MLI to give it an overall emissivity of 0.015, then plugging that into the Stefan-Boltzmann equation, I get an overall emission of just over 1.5kW of heat during a lunar night.
*snipped*
Sound reasonable?
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Interesting. I was wondering what you where going to do for a power system. However Fuel Cells seemed the most reasonable. Also interesting that you are using Solar Power to be electrolyzed during the day by solar panels. So will the actual lander also use fuel cells or just batteries because of it's lower power requirements?
Turtledove Voting Open!
Voting for this year's Turtledove Awards is now open!
Eyes Turned Skywards has been nominated in the Continuing Cold War Category. Vote here!
My CGI illustrations (all of them, in the end!) have been nominated under Other Artwork (1 of 2). Vote here!
So get to the polls and let's see Eyes get the recognition it deserves!
Voting for this year's Turtledove Awards is now open!
Eyes Turned Skywards has been nominated in the Continuing Cold War Category. Vote here!
My CGI illustrations (all of them, in the end!) have been nominated under Other Artwork (1 of 2). Vote here!
So get to the polls and let's see Eyes get the recognition it deserves!
I voted and voted and voted
Nixonhead is far a head in the competition 65.71% ! second is Napoleon53 with 28.57%.
for Eyes turned Skywards is in two category
2014 Turtledove Poll Continuing Modern
2014 Turtledove Poll: Continuing Cold War Period
by the way in section "New World War 2 (1933-1945 AD) category"
is How Silent Fall the Cherry Blossoms by Geon
can you guy vote also for him ? thanks
Nixonhead is far a head in the competition 65.71% ! second is Napoleon53 with 28.57%.
for Eyes turned Skywards is in two category
2014 Turtledove Poll Continuing Modern
2014 Turtledove Poll: Continuing Cold War Period
by the way in section "New World War 2 (1933-1945 AD) category"
is How Silent Fall the Cherry Blossoms by Geon
can you guy vote also for him ? thanks
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Hello e of pi,
I'm anxious with excitement, but real life comes first.
But you can just save us a lot of time by telling us on which mission they find the mysterious black monolith...
I'm anxious with excitement, but real life comes first.
But you can just save us a lot of time by telling us on which mission they find the mysterious black monolith...
Morning all,
The tension and excitement is building as we await the first crewed Moon mission for over a quarter century. Down at the Cape, launch control is making their final checks for what promises to be an historic mission
The tension and excitement is building as we await the first crewed Moon mission for over a quarter century. Down at the Cape, launch control is making their final checks for what promises to be an historic mission
I think that's the first proper depiction of the Saturn H03 for this TL.
Excellent work as always.
Excellent work as always.
Superb use of light to achieve photo-realism on this one, Nixon. A perfect addition to the timeline.
Saturn Multibody may not be as majestic as the Saturn V - it is a rather clunky and awkward looking thing when you get right down to it - but it's surely a more versatile launch system.
Always good to see your renderings, nixonshead!
I do think it's kind of humorous how it is necessary to put a US flag on all three of the first stage booster modules!
I guess that is because when they make them in the Boeing factory, they don't know which ones are going to be side boosters and which are going to be cores, so the flag paint job is part of the standard package?
Now that's "churning them out like sausages!"
You know what we have neither seen depicted, nor heard, IIRC, any specific mention of the use of? The intermediate versions that use solid fuel boosters attached to the core--the various Mxy where x=2 or 4 and y=2 or 3.
I presume DoD has been launching some of those from time to time. Maybe the solids come with a standard USAF marking?
Or have there been deep space probes that did use them and were mentioned, presumably with some kind of Centaur 3rd stage? I'd have to go back over the probe updates for that I guess.
------
Edit to add belated question---
Presumably that's a habitat/lab lander under that shroud; is the Pegasus stage that will boost it on to Luna also there under the shroud? IIRC the hab/lab is one launch, with its translunar booster included; perhaps not fully fueled since the hab/lab masses less than the full CSM/LEM stack and the Pegasus is sized to move the latter to the Moon; rather than make 2 Pegasus designs they simply scant the fuel so it is adequate to move the hab/lab and both can go up on one Heavy.
But I'm not sure the shroud is long enough for both; I suppose it could also be the Pegasus for the manned stack.
I do think it's kind of humorous how it is necessary to put a US flag on all three of the first stage booster modules!
I guess that is because when they make them in the Boeing factory, they don't know which ones are going to be side boosters and which are going to be cores, so the flag paint job is part of the standard package?
Now that's "churning them out like sausages!"
You know what we have neither seen depicted, nor heard, IIRC, any specific mention of the use of? The intermediate versions that use solid fuel boosters attached to the core--the various Mxy where x=2 or 4 and y=2 or 3.
I presume DoD has been launching some of those from time to time. Maybe the solids come with a standard USAF marking?
Or have there been deep space probes that did use them and were mentioned, presumably with some kind of Centaur 3rd stage? I'd have to go back over the probe updates for that I guess.
------
Edit to add belated question---
Presumably that's a habitat/lab lander under that shroud; is the Pegasus stage that will boost it on to Luna also there under the shroud? IIRC the hab/lab is one launch, with its translunar booster included; perhaps not fully fueled since the hab/lab masses less than the full CSM/LEM stack and the Pegasus is sized to move the latter to the Moon; rather than make 2 Pegasus designs they simply scant the fuel so it is adequate to move the hab/lab and both can go up on one Heavy.
But I'm not sure the shroud is long enough for both; I suppose it could also be the Pegasus for the manned stack.
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Nixonshead was working off the image off the wiki, and put the flags where they are on that. There probably ought to only be one, on the second stage or the core like Delta IV Heavy IOTL. This is a bit of a test image, we've been working on tweaking some of the details including--yes--the markings, as well as the surface finish. (For the record, the side boosters are produced with their use as boosters set--they're slightly lighter, having less internal reinforcement since they're not supporting hundreds of kilograms of upperstage and payload.)Always good to see your renderings, nixonshead!
I do think it's kind of humorous how it is necessary to put a US flag on all three of the first stage booster modules!
I guess that is because when they make them in the Boeing factory, they don't know which ones are going to be side boosters and which are going to be cores, so the flag paint job is part of the standard package?
Now that's "churning them out like sausages!"
Oh, and as for any solid-lofted payloads...read more carefully.
Just remember, any DoD payloads would be classified, so you'll have to find hints in other posts and data. The Saturn H03 widebody fairing developed for Freedom is 10m in diameter and about 20m long in the barrel alone--it had to carry the 27m long Freedom truss segments. Pegasus is about 10m overall with the various payload adaptors, and the lander is another 8 or 9 (I don't have measurements off of Nixonshead's final models, so he'd have the final data on that). If anything, Artemis might use a slightly shorter version of this monstrous fairing, with about an 18m barrel. However, I just checked, and the wiki representation of the Multibody doesn't have the proper fairing length (it's only a 16m barrel or so), so this might be wrong on Nixonshead's model through my failure to update the image.
Anyway, to address the underlying question, the fairing is long enough to comfortably contain Pegasus, a lander, and an Apollo capsule up at the taper, with the Apollo itself exposed in position for abort if required. The image just needs some tweaking to reflect this.