ESA ATL Plausibility Checks and Development

[Bahamut-255]

Payloads - Part I

Now that the launch vehicle of choice has been decided, it's capabilities determined. It's now time to work on what it's being built for. Payload.

OTL ESA had established itself as the leading Commercial Launch Service Provider in the 1990s with the Ariane 4 - which enjoyed a 97.4% success rating in its 116-launch history. IIRC only the Soyuz LV and STS enjoyed a better success rate and amore than 100-launch lifespan.

Now TTL LV and OTL Araine 4 have one thing in common, flexible payload range - though it's rather a lot higher in my case. So it, too, can be used for a wide range of missions.

Obviously, Commercial Launch Services are something that I wish to continue - let's face it, they'd have to be inexcusably retarded to not want in on that market - which generally means GTO orbits IIRC. I intend to accomplish that by way of a LOX/LH2 upper stage built by - my current favourites - France, using 2-4 HM7-type engines, depending on the size of the upper stage. This, IMHO seems completely reasonable since by the point they come into play, they are effectively clear of the atmosphere, so it's high Isp that would dominate, not high T/M ratios.

One additional advantage that TTL ESA would have over OTL ESA is the general lack of Hypergolic Propellant usage. So that should prevent the costs from shooting up as environmental regulations come into force in earnest IMHO.

Unmanned scientific missions are another possibility. Earth Orbit, Moon, Mars, the Asteroid Belt, Venus, Interplanetary Space. All should be more than doable using the proposed tech.

Next, we have the ISS - or whatever it will be ITTL - where ESA has one extra ace. Solaris, the Manned Spacecraft. Now adapting it to operate as an unmanned resupply craft - just as Progress was adapted from Soyuz both OTL and TTL - would seem to be the most likely means of achieving that goal. Though this would raise issues of sending larger goods and supplies, which would have to be done by someone else - on the other hand, putting too many eggs into the ESA Basket would turn this into ASB, so something does have to give somewhere. Given the scope and issues available there, I'll work on it in a separate post - where Space Station setups and scenarios will be covered in greater detail - this would be the initial evaluation.

I'm entering the more troubled waters here. So updates could well slow down for a while.

 

[e of pi]

Next, we have the ISS - or whatever it will be ITTL - where ESA has one extra ace. Solaris, the Manned Spacecraft. Now adapting it to operate as an unmanned resupply craft - just as Progress was adapted from Soyuz both OTL and TTL - would seem to be the most likely means of achieving that goal. Though this would raise issues of sending larger goods and supplies, which would have to be done by someone else - on the other hand, putting too many eggs into the ESA Basket would turn this into ASB, so something does have to give somewhere. Given the scope and issues available there, I'll work on it in a separate post - where Space Station setups and scenarios will be covered in greater detail - this would be the initial evaluation.

I've already said my bit about what this ESA launcher does to the odds of a Shuttle-derived heavy for NASA, but I'll repeat it here for good measure. Sidemount designs like Shuttle-C have a major advantage over inline designs, which is that other than the cargo pod all the hardware is identical to standard Shuttle. This limits to an extent how much can be done in terms of upgrades, but it makes the conversion process cheaper and quicker. I recall seeing cost and schedule estimates for sidemount versions of what became SLS in the range of 4 billion or so so, spread over about three years. The downside is the lack of upgrade options, since it's hard to add more first-stage engines and stacking an upper stage on a sidemount is very, very tricky--you essentially have to encapsulate it with the payload.

However, here, with ESA breathing down NASA's neck with their new launcher in the works, I could see NASA getting the go-ahead to proceed with a sidemount launcher to get their own heavy--it's cheap, it's easier, and it can fly side-by-side with the Shuttle. It lacks the ability to reach into the Saturn V range, but that's fine for what NASA's likely to have money to do. Having that available for NASA will also save costs on Freedom, less modules needed for the same job and this is early enough in that design process that the savings can really be exploited. If they start work in 1980, it could be pad-ready around 1985ish.

 

[Bahamut-255]

I've already said my bit about what this ESA launcher does to the odds of a Shuttle-derived heavy for NASA, but I'll repeat it here for good measure. Sidemount designs like Shuttle-C have a major advantage over inline designs, which is that other than the cargo pod all the hardware is identical to standard Shuttle. This limits to an extent how much can be done in terms of upgrades, but it makes the conversion process cheaper and quicker. I recall seeing cost and schedule estimates for sidemount versions of what became SLS in the range of 4 billion or so so, spread over about three years. The downside is the lack of upgrade options, since it's hard to add more first-stage engines and stacking an upper stage on a sidemount is very, very tricky--you essentially have to encapsulate it with the payload.

However, here, with ESA breathing down NASA's neck with their new launcher in the works, I could see NASA getting the go-ahead to proceed with a sidemount launcher to get their own heavy--it's cheap, it's easier, and it can fly side-by-side with the Shuttle. It lacks the ability to reach into the Saturn V range, but that's fine for what NASA's likely to have money to do. Having that available for NASA will also save costs on Freedom, less modules needed for the same job and this is early enough in that design process that the savings can really be exploited. If they start work in 1980, it could be pad-ready around 1985ish.

True. True. While a Side-Mounted Shuttle-Derived Launch Vehicle (SM-SDLV) has limited options for growth, it's development costs should be nice and low - by LV standards. The likely path is to see Station Freedom and SM-SDLV proposed at the same time. Using one to help justify the other. A scenario that is more likely to happen ITTL than OTL since a more ambitious - and better funded - ESA is getting geared up with some serious lifting ability. Something that - even though ESA and NASA are 'officially' allied - I don't see the US as liking that all that much if their capabilities are less.

The other tricky area is Challenger. Do I go with it? Avoid it? Switch to another Shuttle to off - along with its crew? And what that would mean in the years to come.

For ESA, while giving them a greater push to develop their own independant Manned Spaceflight Capability, it may slow down as a result of having to review their own operations - if only to allay public concerns.

As for NASA. A Shuttle grounding would be inevitable, with a subsequent investigation. If SM-SDLV development is ongoing at this point, it too, would likely see development stalled as STS is re-designed. Though the likelyhood of seeing it in proper use would be a good deal higher.

Though you're right about the upgrade options - or lack of them. IIRC, 79,000Kg to an ISS orbit and 35,000Kg to TLI was the best it could be expected to do. So the Hercules ASRMs may actually feature on TTL STS and SM-SDLV, as well as an improved SSME. But all that can be worked on when the time is right.

 

[e of pi]

True. True. While a Side-Mounted Shuttle-Derived Launch Vehicle (SM-SDLV) has limited options for growth, it's development costs should be nice and low - by LV standards. The likely path is to see Station Freedom and SM-SDLV proposed at the same time. Using one to help justify the other. A scenario that is more likely to happen ITTL than OTL since a more ambitious - and better funded - ESA is getting geared up with some serious lifting ability. Something that - even though ESA and NASA are 'officially' allied - I don't see the US as liking that all that much if their capabilities are less.

Yeah. As I said, once they get the nod a development timeline should be roughly 3-5 years. I'd go with a design that uses new-build cargo pods instead of converted orbiters like some proposals did, this shouldn't be a one-off development. Even with this, a SM-SDLV should cost about the same as a standard shuttle launch, but carry a bit more than 5 times the payload. About the only frill that might be worth the money would be a reusable pods for the engines, and that's only marginal so I wouldn't bother. Just build more RS-25s.

The other tricky area is Challenger. Do I go with it? Avoid it? Switch to another Shuttle to off - along with its crew? And what that would mean in the years to come.

Ah, Challenger. On the one hand, even with the design defects that allowed it, the accident is entirely avoidable. If they just don't launch in weather beyond the safety limits of the SRBs the specific failure cannot occur. However, given the pressures of schedule (which may be worse ITTL, what with ESA pressures and the heavy thrown into the mix) the reasons that Challenger was launched in such cold weather may actually be more present here. A foam-impact leading to a re-entry failure like Columbia also can't be ruled out, there were a lot of close calls in retrospect and they didn't really have good methods for checking out or repairing damage on-orbit. This does have one advantage, namely that the cargo vehicle would be unaffected.

When it comes right down to it, it's your decision. A loss at some point with those schedule pressures is almost unavoidable, but you get to decide what form that failure takes or whether you want to just pour some make-it-work juice over things and not have one.

As for NASA. A Shuttle grounding would be inevitable, with a subsequent investigation. If SM-SDLV development is ongoing at this point, it too, would likely see development stalled as STS is re-designed. Though the likelyhood of seeing it in proper use would be a good deal higher.

Yes. In fact, one time sidemount came close to happening was post Challenger, where NASA considered it as a way of decreasing launches and risk to crews.

Though you're right about the upgrade options - or lack of them. IIRC, 79,000Kg to an ISS orbit and 35,000Kg to TLI was the best it could be expected to do. So the Hercules ASRMs may actually feature on TTL STS and SM-SDLV, as well as an improved SSME. But all that can be worked on when the time is right.

Or it can be left alone. 79 tons is pretty freaking big--it's enough to launch modules of Skylab size, and with two launches and the right architecture you could probably pull off a lunar mission on the Apollo two-men-land scale. Make it three launches and you can add some more crew members, increase the mass landed and returned, and the stay duration on the lunar surface. This is part of what really annoys me about Ares V and SLS--if there's one thing we've gotten really good at in the past 30 years it's EOR assembly. Why not tap that experience for BEO instead of trying fruitlessly to achieve some mythical economical better-that-Saturn-V heavy? 50-80 metric tons is plenty, focus on the payloads instead.

 

[Workable Goblin]

Hercules ASRMs may actually feature on TTL STS and SM-SDLV, as well as an improved SSME. But all that can be worked on when the time is right.

Well, they did improve the SSME IOTL; they were up to what, the Block II by the time Columbia crashed? They had been planning to get to Block III and finally move 109% power from emergency only to routine, but there wasn't any point without the Shuttles being around anymore; although perhaps with SLS they will revisit that.

 

[e of pi]

Well, they did improve the SSME IOTL; they were up to what, the Block II by the time Columbia crashed? They had been planning to get to Block III and finally move 109% power from emergency only to routine, but there wasn't any point without the Shuttles being around anymore; although perhaps with SLS they will revisit that.

The bigger deal with Block III SSME, even more than the thrust improvement was an altered engine management computer that IIRC would have helped reduce engine turnaround time from two weeks to three days by pinpointing issues without requiring a full tear down or some such. Not something as important to SLS, of course, given the fire-and-forget nature of the RS-25E.

 

[Bahamut-255]

Yeah. As I said, once they get the nod a development timeline should be roughly 3-5 years. I'd go with a design that uses new-build cargo pods instead of converted orbiters like some proposals did, this shouldn't be a one-off development. Even with this, a SM-SDLV should cost about the same as a standard shuttle launch, but carry a bit more than 5 times the payload. About the only frill that might be worth the money would be a reusable pods for the engines, and that's only marginal so I wouldn't bother. Just build more RS-25s.

I've been giving some thought to the flight rate. I don't see it being very high until Space Station components are being launched. So one method is when they can only guarantee one more use out of an SSME, they store it for when a SM-SDLV launch is required - they can still build more when needed though.

As for the design. I think this one should do it.

While this is the newest design that featured in the Augustine Commission, IIRC, it was studied seriously post-Challenger, and combined with the greater payload volume, does make some sense.

Ah, Challenger. On the one hand, even with the design defects that allowed it, the accident is entirely avoidable. If they just don't launch in weather beyond the safety limits of the SRBs the specific failure cannot occur. However, given the pressures of schedule (which may be worse ITTL, what with ESA pressures and the heavy thrown into the mix) the reasons that Challenger was launched in such cold weather may actually be more present here. A foam-impact leading to a re-entry failure like Columbia also can't be ruled out, there were a lot of close calls in retrospect and they didn't really have good methods for checking out or repairing damage on-orbit. This does have one advantage, namely that the cargo vehicle would be unaffected.

When it comes right down to it, it's your decision. A loss at some point with those schedule pressures is almost unavoidable, but you get to decide what form that failure takes or whether you want to just pour some make-it-work juice over things and not have one.

Yes. In fact, one time sidemount came close to happening was post Challenger, where NASA considered it as a way of decreasing launches and risk to crews.

There was more than just the cold weather. There was also a vicious jetstream right in Challenger's path, which was the final death-knell for both Challenger and the crew. But to get all the safety improvements, one of those Shuttles will have to die IMHO. A foam-impact that either cripples or destroys - the more likely case - one of the shuttles could force them to make all the changes in one go, though that could mean a longer downtime for STS, and perhaps a boost for SM-SDLV.

Or it can be left alone. 79 tons is pretty freaking big--it's enough to launch modules of Skylab size, and with two launches and the right architecture you could probably pull off a lunar mission on the Apollo two-men-land scale. Make it three launches and you can add some more crew members, increase the mass landed and returned, and the stay duration on the lunar surface. This is part of what really annoys me about Ares V and SLS--if there's one thing we've gotten really good at in the past 30 years it's EOR assembly. Why not tap that experience for BEO instead of trying fruitlessly to achieve some mythical economical better-that-Saturn-V heavy? 50-80 metric tons is plenty, focus on the payloads instead.

Perhaps. But following the safety changes on STS post-Challenger OTL, the payload was reduced and they had to re-design the ET to get an acceptable payload to the ISS orbit. Though with SM-SDLV this need is lessened, they still might want it for re-supply purposes, and it would be logical to carry over those payload gains to SM-SDLV.

As for a return to the Moon? Orbiter, Lander, Hab. One launch each, with all rendezvous taking place in Lunar Orbit and Luna Firma. With only those pieces needing to be developed. Looks very workable.

 

[e of pi]

I've been giving some thought to the flight rate. I don't see it being very high until Space Station components are being launched.

That'd work pretty well. They only need about five flights total, two for tests and three for station. There've been 42 SSMEs built to date, with around 16 in service at any given time. (See chart here). They might need to specially build additional engines for a sustained lunar program, but other than that stockpiling should do initially.

As for the design. I think this one should do it. While this is the newest design that featured in the Augustine Commission, IIRC, it was studied seriously post-Chllenger, and combined with the greater payload volume, does make some sense.

As for a return to the Moon? Orbiter, Lander, Hab. One launch each, with all rendezvous taking place in Lunar Orbit and Luna Firma. With only those pieces needing to be developed. Looks very workable.

Yeah, it's very much of the type and would definitely do for your design. Here's an animation from the Augustine stuff showing that design doing a Constellation-equivalent mission with a 2-launch LOR/LOR architecture (Orion and Altair are separately injected to LLO).

As far as your points about safety...I sadly have to agree that it seems that in order to really get the picture, there will have to be a disaster similar to Challenger or Columbia.

 

[Bahamut-255]

That'd work pretty well. They only need about five flights total, two for tests and three for station. There've been 42 SSMEs built to date, with around 16 in service at any given time. (See chart here). They might need to specially build additional engines for a sustained lunar program, but other than that stockpiling should do initially.

Depends on the Station design. Though with SM-SDLV, they can send large-diametre segments - IOTL, the segment sizes were dictated by the volume limits of the respective LVs. Your alt-of-an-alt Freedom design makes for a good benchmark.

Yeah, it's very much of the type and would definitely do for your design. Here's an animation from the Augustine stuff showing that design doing a Constellation-equivalent mission with a 2-launch LOR/LOR architecture (Orion and Altair are separately injected to LLO).

This was also proposed in the USSR shortly before it fell. IIRC, Chief Designer Valentin Petrovich Glushko design and Energia-based Dual-Launch, Dual-LOR Lunar Mission just before he died.

As far as your points about safety...I sadly have to agree that it seems that in order to really get the picture, there will have to be a disaster similar to Challenger or Columbia.

I know. That's the part which really sucks. I'm considering having the Columbia-Type Failure and Loss-Of-Crew during one particularly cold December of 1985. Which not only forces an investigation, but can allow the SRB faults to be identified - before they kill off a crew.

 

[e of pi]

Depends on the Station design. Though with SM-SDLV, they can send large-diametre segments - IOTL, the segment sizes were dictated by the volume limits of the respective LVs. Your alt-of-an-alt Freedom design makes for a good benchmark.

Thanks kindly. That particular alt-alt-Freedom, FYI, uses a 6m segment diameters and roughly 60 ton main modules with ~20 ton secondaries, whereas the Augustine vehicle appears to have an 8m diameter capability and of course has a 79 ton capacity (less with a tug, but in that ballpark) and any secondary modules need to either fit Shuttle's 20ish tons (though they'd likely end up lighter--most Shuttle missions had excess mass due to payload bay volume and landing CoM constraints) or ESA's native 11to 36 tons capability.

I know. That's the part which really sucks. I'm considering having the Columbia-Type Failure and Loss-Of-Crew during one particularly cold December of 1985. Which not only forces an investigation, but can allow the SRB faults to be identified - before they kill off a crew.

I was thinking about this, and there may be a way to have an SRB o-ring failure that draws attention to the issue and causes Loss-of-Mission but not Loss-of-Crew: it seems possible in my relatively uninformed position that if the SRB had failed in such a way that the burn-through did not impinge on the external tank or the SRB attachment point that the vehicle might be able to make it through SRB sep, particularly if the burn-through occurred ten or fifteen seconds later in the flight than Challenger. Having had a visible burnthrough in the SRB and not sure of possible damage, I think they might call for an abort at that point, which probably means a trans-Atlantic rather than a return-to-launch-site. You have a dramatic failure of the SRB O-rings (it'd be very visible in news footage) plus the abort and according drama, so it's still enough to spur a serious review, but no loss-of-crew. It'd require a couple of things to go wrong in the least-bad way possible, but I think it's not entirely impossible.

 

[Bahamut-255]

Thanks kindly. That particular alt-alt-Freedom, FYI, uses a 6m segment diameters and roughly 60 ton main modules with ~20 ton secondaries, whereas the Augustine vehicle appears to have an 8m diameter capability and of course has a 79 ton capacity (less with a tug, but in that ballpark) and any secondary modules need to either fit Shuttle's 20ish tons (though they'd likely end up lighter--most Shuttle missions had excess mass due to payload bay volume and landing CoM constraints) or ESA's native 11to 36 tons capability.

I believe 7m diameter modules will be possible with the 8.41m diameter Cargo Pod, and perhaps up to 30m in length. That's a LOT of internal volume to work with.

As for the ESA LV. With the right payload shroud, 5m diameter modules can be accommodated.

Clearly, this opens up a whole host of possibilities for Station design.

I was thinking about this, and there may be a way to have an SRB o-ring failure that draws attention to the issue and causes Loss-of-Mission but not Loss-of-Crew: it seems possible in my relatively uninformed position that if the SRB had failed in such a way that the burn-through did not impinge on the external tank or the SRB attachment point that the vehicle might be able to make it through SRB sep, particularly if the burn-through occurred ten or fifteen seconds later in the flight than Challenger. Having had a visible burnthrough in the SRB and not sure of possible damage, I think they might call for an abort at that point, which probably means a trans-Atlantic rather than a return-to-launch-site. You have a dramatic failure of the SRB O-rings (it'd be very visible in news footage) plus the abort and according drama, so it's still enough to spur a serious review, but no loss-of-crew. It'd require a couple of things to go wrong in the least-bad way possible, but I think it's not entirely impossible.

The easiest way is to have the Field Joint Failure occur at the opposite side of the SRB, meaning the leaking exhaust misses the ET entirely. Though this still leaves a Columbia-Type Failure to occur IMHO.


Edit: Something else I missed earlier with SM-SDLV. Cassini/Huygens. With the new ESA LV and SM-SDLV, you got two options. Greater mass with ESA LV using OTL Slingshot Trajectory. Or use SM-SDLV and use only a Jupiter Flyby.

 

[e of pi]

I believe 7m diameter modules will be possible with the 8.41m diameter Cargo Pod, and perhaps up to 30m in length. That's a LOT of internal volume to work with.

I think that cargo fairing is much more like 7.5 to 8 m--it's clearly at least a slightly smaller diameter than the 8.4 m external tank. Still, that doesn't change your point that there's a huge amount of volume there, it's actually hard to imagine a payload that could fill it out in the 79 ton capacity of the vehicle. Maybe something spindly like solar arrays, but even those and trusses can be folded up pretty tight. The length could certainly come in handy for a truss design--just have two "arms" folded side-by-side inside the fairing, they just rotate out to be co-linear and extend their solar panels. You could basically do an ISS/Freedom truss in a single launch that way.

EDIT: Err...never mind about the payload diameter I was saying being smaller than 8.4 meters. I dunno what I was thinking of, that certainly is that size.

As for the ESA LV. With the right payload shroud, 5m diameter modules can be accommodated.

Hmm. 5m diameter, I'd expect you could do about a 10-15 m long module depending on initial load-out. That seems pretty reasonable as far as fairing proportions.

Clearly, this opens up a whole host of possibilities for Station design.

Clearly. As I said above, there's tremendous potential to streamline the truss assembly process, and of course the number of major modules will be substantially reduced from OTL. I wonder about crew capacity...with Shuttle doing rotations, you could theoretically have a crew rotating out 5 at a time (7 onboard shuttle, minus the two flight crew to fly it up and down). you could either have an ISS-size crew rotating out all at once, a smaller crew rotating more frequently (leaving some seats free for giving joyrides to politicians of import and whatnot), or potentially even a crew of 10--you could certainly launch the volume to house that many!

The easiest way is to have the Field Joint Failure occur at the opposite side of the SRB, meaning the leaking exhaust misses the ET entirely. Though this still leaves a Columbia-Type Failure to occur IMHO.

Yeah, that's roughly what I was suggesting. As for a Columbia-style failure...yeah. Harder to have some kind of illustrative incident happen without a Loss-of-Crew, and given how nonchalant NASA was with even fairly significant tile damage up until Columbia that may be the only way to have them take serious measures. Still, with the sidemount design for Shuttle, there's really not a lot that can be done beyond basic things like better inspection on-orbit and better plans for on-orbit tile repair. Maybe they see some kind of damage on the orbiter in the SRB accident that leads them to want to provide better capacity to check and repair the tiles on orbit, and that can circumvent the issue a little?

EDIT to reflect EDIT:

Edit: Something else I missed earlier with SM-SDLV. Cassini/Huygens. With the new ESA LV and SM-SDLV, you got two options. Greater mass with ESA LV using OTL Slingshot Trajectory. Or use SM-SDLV and use only a Jupiter Flyby.

Yeah, that's true, though I'm not really much on the unmanned side--it'd be interesting to hear what Truth or neopius think. Another thought is the potential for Mars probes--a 7m fairing and Viking-level tech can allow 2.3 tons on payload to the surface. Modern refinements to that can roughly double it, which is certainly enough for a Mars Sample Return without ISRU and still nowhere near massing out the launcher. The big constraining factor on using SM-SDHLV for more than LEO heavy lifting would be the lack of a really well-suited second stage. Centaur would work as an interim, but with a IMLEO of 79 tons you really need about a 45 ton fuel capability to get the most through TLI you can (35.5 tons). Centaur could only do about half that with its 20-ish ton fuel capability (depending on model, so I'm hedging) Something like ACES but developed earlier would do the trick. Take the Centaur principles and scale them up a bit.

 

[Bahamut-255]

I think that cargo fairing is much more like 7.5 to 8 m--it's clearly at least a slightly smaller diameter than the 8.4 m external tank. Still, that doesn't change your point that there's a huge amount of volume there, it's actually hard to imagine a payload that could fill it out in the 79 ton capacity of the vehicle. Maybe something spindly like solar arrays, but even those and trusses can be folded up pretty tight. The length could certainly come in handy for a truss design--just have two "arms" folded side-by-side inside the fairing, they just rotate out to be co-linear and extend their solar panels. You could basically do an ISS/Freedom truss in a single launch that way.

Another option I'm considering is this: Using a 5m diameter module but having a 2-2.5m truss pre-installed - I actually only just thought of it. This would allow the truss to function not only as a Solar Panel/Radiator Installation Mount, but as a Structural Stiffening Bracer as well. Something worth looking into IMHO.

EDIT: Err...never mind about the payload diameter I was saying being smaller than 8.4 meters. I dunno what I was thinking of, that certainly is that size.
Hmm. 5m diameter, I'd expect you could do about a 10-15 m long module depending on initial load-out. That seems pretty reasonable as far as fairing proportions.

I've been looking at the dimensions, and I can get 16-17m length modules fitted inside the ESA LV. But 14-15m length is reasonable for a little reserve margin.

Clearly. As I said above, there's tremendous potential to streamline the truss assembly process, and of course the number of major modules will be substantially reduced from OTL. I wonder about crew capacity...with Shuttle doing rotations, you could theoretically have a crew rotating out 5 at a time (7 onboard shuttle, minus the two flight crew to fly it up and down). you could either have an ISS-size crew rotating out all at once, a smaller crew rotating more frequently (leaving some seats free for giving joyrides to politicians of import and whatnot), or potentially even a crew of 10--you could certainly launch the volume to house that many!

Based on one of the designs I'm looking into here - look above - a crew size of eight is well within margins - while 10-12 is possible with the right design. Question is, how to have enough there to justify the larger crew size.

Yeah, that's roughly what I was suggesting. As for a Columbia-style failure...yeah. Harder to have some kind of illustrative incident happen without a Loss-of-Crew, and given how nonchalant NASA was with even fairly significant tile damage up until Columbia that may be the only way to have them take serious measures. Still, with the sidemount design for Shuttle, there's really not a lot that can be done beyond basic things like better inspection on-orbit and better plans for on-orbit tile repair. Maybe they see some kind of damage on the orbiter in the SRB accident that leads them to want to provide better capacity to check and repair the tiles on orbit, and that can circumvent the issue a little.

Which is why Columbia-type failure is the favoured option. TTL Station can always have storage space set aside for spare STS parts, the volume should be there, and it should be early enough to design one into it.

EDIT to reflect EDIT:
Yeah, that's true, though I'm not really much on the unmanned side--it'd be interesting to hear what Truth or neopius think. Another thought is the potential for Mars probes--a 7m fairing and Viking-level tech can allow 2.3 tons on payload to the surface. Modern refinements to that can roughly double it, which is certainly enough for a Mars Sample Return without ISRU and still nowhere near massing out the launcher. The big constraining factor on using SM-SDHLV for more than LEO heavy lifting would be the lack of a really well-suited second stage. Centaur would work as an interim, but with a IMLEO of 79 tons you really need about a 45 ton fuel capability to get the most through TLI you can (35.5 tons). Centaur could only do about half that with its 20-ish ton fuel capability (depending on model, so I'm hedging) Something like ACES but developed earlier would do the trick. Take the Centaur principles and scale them up a bit.

Definately going to need a new LOX/LH2 engine - and tanks - for SM-SDLV BEO stage. Though that is going to be a future design feature while the station gets priority. IIRC, USSR was able to design a 40,000Kg thrust, 460s Isp (vac), LOX/LH2 engine that made it to the hot-fire tests. License purchase perhaps? Unlikely, but always possible.

As for MSR. ESA LV can do it brute-force style too, just not as much. While ISPP systems could be tested at the same time. All of which, depends on if the funding is made available.

 

[e of pi]

Another option I'm considering is this: Using a 5m diameter module but having a 2-2.5m truss pre-installed - I actually only just thought of it. This would allow the truss to function not only as a Solar Panel/Radiator Installation Mount, but as a Structural Stiffening Bracer as well. Something worth looking into IMHO.

What I'm basically proposing is for your core module to basically be a 5m diameter can, with two pre-integrated truss components (each some 20 m long) folded along the sides. On orbit, this service core spreads it's wings, then deploys radiators and solar arrays from the trusses. The truss may still require a second or third flight to add the final length to each side, but the station with in one launch have the power capabilities ISS didn't have until about 2008. The can contains thrusters, computers, and basic life support, serving as the center for services on the station. If you have the mass, you might be able to sneak in the crew quarters, but I think you won't. The first check-out crew can carry a hab module up with them in Shuttle or a full hab/lab(/node?) can be launched independently with a second HLV. Basically, it the capabilities of the FGB and Unity node plus the entire ISS truss minus maybe P3/4 and S3/4.

I've been looking at the dimensions, and I can get 16-17m length modules fitted inside the ESA LV. But 14-15m length is reasonable for a little reserve margin.

Dimensions aren't the issue, mass is. IOTL, Shuttle has always had trouble packing mass into the payload bay--look at the studies on the Aft Cargo Carrier. Here, both ESA and NASA have launchers that offer truly enormous payload fairings, indeed much more volume than the launcher can manage in terms of mass. My estimate of 11 m was based on the general mass/cubic meter I've seen on ISS modules. You can lift a larger pressure hull, but only if you launch it very bare and spend additional flight fitting it out afterwards.

Based on one of the designs I'm looking into here - look above - a crew size of eight is well within margins - while 10-12 is possible with the right design. Question is, how to have enough there to justify the larger crew size.

True. They'll have a lot more equipment up there though, even if they only do a couple HLV-lifted modules. Needs more people to keep track of it. I think 8 people could find work.

Definately going to need a new LOX/LH2 engine - and tanks - for SM-SDLV BEO stage. Though that is going to be a future design feature while the station gets priority. IIRC, USSR was able to design a 40,000Kg thrust, 460s Isp (vac), LOX/LH2 engine that made it to the hot-fire tests. License purchase perhaps? Unlikely, but always possible.

You don't need a new engine, you just need 2xRL10. Heck, given that this is a space-only stage where T/W isn't you almost only need one: Delta IVH's upper stage gets by with 1 and it's nearly the same size class (30 ton to 45 for this stage). Anyway, no worries about clustering because the engine's reliable as hell, it's got an incredible Isp, and it's common with Centaur for better cost structure. For the tanks...45 metric tons of fuel breaks down to 6.5 tons of LH2 and 38.5 of LOX. A 5m LH2 tank about 5m long would carry that, go with a common-bulkhead design of constant diameter and your LOX will add another 2 m. I'm not sure off the top of my head what tank diameter toolings they'll already have, this may need it own tooling, but the production techniques used with that tooling will be largely common with Centaur. It's nothing special, just essentially a Big Centaur, but it's exactly what you need. And it'll be relatively cheap and quick too since it's just new tank toolings then integration. If it's authorized for development at the same time (~1980) as the HLV, it should be ready for ~1985, same as the heavy.

As for MSR. ESA LV can do it brute-force style too, just not as much. While ISPP systems could be tested at the same time. All of which, depends on if the funding is made available.

Indeed. Was just pointing out possibilities.

 

[Bahamut-255]

What I'm basically proposing is for your core module to basically be a 5m diameter can, with two pre-integrated truss components (each some 20 m long) folded along the sides. On orbit, this service core spreads it's wings, then deploys radiators and solar arrays from the trusses. The truss may still require a second or third flight to add the final length to each side, but the station within one launch will have the power capabilities ISS didn't have until about 2008. This can contains thrusters, computers, and basic life support, serving as the center for services on the station. If you have the mass, you might be able to sneak in the crew quarters, but I think you won't. The first check-out crew can carry a hab module up with them in Shuttle or a full hab/lab(/node?) can be launched independently with a second HLV. Basically, it the capabilities of the FGB and Unity node plus the entire ISS truss minus maybe P3/4 and S3/4.

You're right about one thing. Dedicated Crew Quarters will be seperate modules. At the size I'm looking at, 4-6 crew sleeping berths can be accommodated within a Habitation Module, along with proper hygiene facilities. I have the basic look in my head, but no real means of putting it down on paper - limited artistic capabilities and programmes will do that to you.

Dimensions aren't the issue, mass is. IOTL, Shuttle has always had trouble packing mass into the payload bay--look at the studies on the Aft Cargo Carrier. Here, both ESA and NASA have launchers that offer truly enormous payload fairings, indeed much more volume than the launcher can manage in terms of mass. My estimate of 11 m was based on the general mass/cubic meter I've seen on ISS modules. You can lift a larger pressure hull, but only if you launch it very bare and spend additional flight fitting it out afterwards.

Depends on how it's built, as you said. Using removable experiment racks will not only allow for greater flexibility over the lifetime, but if launched without any installed, can save some mass - not much though.

True. They'll have a lot more equipment up there though, even if they only do a couple HLV-lifted modules. Needs more people to keep track of it. I think 8 people could find work.

Which is why 8 is my benchmark minimum, while 12 seems to be possible. This, IMHO, could also allow for a few publicity boosting missions to be carried out - a new way of doing Teacher In Space perhaps?

 

[Bahamut-255]

Freedom/ISS Design - Part I

I think I've sorted the basic design for the Post-Mir Space Station. So here's what I have in mind.

Starting at the rear, a Service Module which will be primarily responsible for station keeping - via altitude sustaining reboost burns. Directly in front, the first Habitation Module, carrying four sleeping berths and a washroom, along with exercise equipment. Between these two modules will be a docking/airlock node mounted underneath to permit Shuttle dockings - obviously large enough to allow it to fit comfortably. In front of them, mounted sideways relative to the station structure, will be another pair of Habitation Modules, again, able to accomodate four crew members each. I'm also considering having the side-hab modules possessing their own docking ports for the ESA manned spacecraft - where they could serve as lifeboats. These first four modules will also carry the truss that the Solar Panels and Radiators will be mounted on. Not only that, but said truss would run across all the modules and therefore serve as a Structural Stiffing Bracer as well.

In front, there's a Node to permit extra modules to be attached. I'm eyeing a Solar/Space Observation Tower mounted on the top, and a pair of Science/Work Modules to the sides - possibly Russian Contribution - with some Bracers/External Experiment Mounts between those and the Hab Modules. Another Node in front of that would allow for two more Science/Work Modules to be mounted to the sides with one more docking port at the front. For underneath one of the Nodes, a Centrifugal Gravity Lab (CGL) could be mounted - provided the assymetrical torque-steer issues are resolved, though I already have that part covered. It's also possible to extend the Truss/Bracer along the top of the station to strengthen the station on the modules are fitted.

That would be the basic design I have for now. What I could use, though, is some visual representation - which I can't do - and some good feedback on the proposed design as it stands.

 

[e of pi]

I think I've sorted the basic design for the Post-Mir Space Station.

Well, the first issue is why they wait until it's a Post-Mir Station. If this is an evolution of Freedom plans, I think it could be on a track for more like a late-80s launch as opposed to late-90s. If NASA has SDHLV as well as Shuttle, I'd expect them to make use of it, and that should be reflected in significantly lower launch costs for the station. (After all, a SDHLV should be at least the same price as shuttle, maybe even slightly cheaper, and you can cut from 20 launches to 3 or 4.)

I'm going to go ahead and describe the station you laid out as I'm envisioning it, then critiquing that. If you have an issue with my understanding of the layout, note it, the same for if you feel a critique isn't justified. A quick primer on layout: take the fore-aft axis. Designate the direction down towards Earth as nadir. The direction opposite that is zenith. Orient yourself looking forward with your feet pointing nadir and your head pointing zenith, and the direction to your left is port, the direction to your left is starboard.

Starting at the rear, a Service Module which will be primarily responsible for station keeping - via altitude sustaining reboost burns.

And attitude control thrusters/gyroscopes. So, furthest aft is the Service Module. Moving forward from the Sm, we pass through a node on the way to the first Hab. I hope the airlock isn't in the line of travel, so that you can use it while still passing along the station? (More Quest than Skylab) I assume this airlock is thus zenith, with the Shuttle docking equipment nadir on the node? Part of me wonders why this can't just be part of the Service Module, the HLV should have the mass for all this to be integrated. Oh well, continue forward into the hab.

Directly in front, the first Habitation Module, carrying four sleeping berths and a washroom, along with exercise equipment.

Four berths, a toilet, and some exercise equipment? I think you can add either more bunks, or a full wardroom in the excess space, even if it's Shuttle-launched. If it's Europa XL or SDHLV....you could just do all the habitat stuff in that one module in that case.

In front of them, mounted sideways relative to the station structure, will be another pair of Habitation Modules, again, able to accomodate four crew members each. I'm also considering having the side-hab modules possessing their own docking ports for the ESA manned spacecraft - where they could serve as lifeboats.

So, moving forward from the first hab, we come to a node with two more habs coming off port and starboard? See the above about the need, but...whatever. If they're there, I'd lean to putting a docking port on the end--if nothing else, it means they can be the same as the first hab. Save on engineering costs.

These first four modules will also carry the truss that the Solar Panels and Radiators will be mounted on. Not only that, but said truss would run across all the modules and therefore serve as a Structural Stiffing Bracer as well.

To run across all four of these modules, the truss would need to be T-shaped, and it'd run directly over the modules? I don't think the stiffening you're going for is needed, and you'd have a lot better positioning for panels and less interference with dockings of Shuttles or the ESA capsules if you just run the truss out port and starboard from the service module. Also, another big thing this core station lacks? Any lab space at all.

In front, there's a Node to permit extra modules to be attached.

The same node as the habs are on, or a third node at that second node's forward port?

I'm eyeing a Solar/Space Observation Tower mounted on the top, and a pair of Science/Work Modules to the sides - possibly Russian Contribution - with some Bracers/External Experiment Mounts between those and the Hab Modules. Another Node in front of that would allow for two more Science/Work Modules to be mounted to the sides with one more docking port at the front.

Well, okay, there's the lab space, but you're breaking it up over a larger number of modules than you need to. You have 35 tons on the European side and up to 79 on the NASA side, why so many tiny modules? I'm not really sure how much point there is to an observatory module, manned stations make poor platforms. There's only two real benefits, servicing and power, but the restrictions on pointing and other major limitations make it a poor trade.

It's also possible to extend the Truss/Bracer along the top of the station to strengthen the station on the modules are fitted.

Again, you don't really need the truss for stiffening, you need it to get the solar arrays and radiators further out from the station, so this is really unnecessary.

That would be the basic design I have for now. What I could use, though, is some visual representation - which I can't do - and some good feedback on the proposed design as it stands.

I'd be willing to provide some visual representation, but I'd like to see the issues above fixed before I do. Additionally, I'd need a better idea of diameter and length of the various modules.

 

[Bahamut-255]

Well, the first issue is why they wait until it's a Post-Mir Station. If this is an evolution of Freedom plans, I think it could be on a track for more like a late-80s launch as opposed to late-90s. If NASA has SDHLV as well as Shuttle, I'd expect them to make use of it, and that should be reflected in significantly lower launch costs for the station. (After all, a SDHLV should be at least the same price as shuttle, maybe even slightly cheaper, and you can cut from 20 launches to 3 or 4.)

Well I'm looking at construction beginning in the mid-90s - about '94-'95 - about the point where Mir begins to suffer it's problems as it ages beyond its design life. Obviously I intend this one to have a much longer design life - 15 years minimum - though 20-25 years would be a lot better, excluding the 3-5 years construction time.

And attitude control thrusters/gyroscopes. So, furthest aft is the Service Module. Moving forward from the Sm, we pass through a node on the way to the first Hab. I hope the airlock isn't in the line of travel, so that you can use it while still passing along the station? (More Quest than Skylab) I assume this airlock is thus zenith, with the Shuttle docking equipment nadir on the node? Part of me wonders why this can't just be part of the Service Module, the HLV should have the mass for all this to be integrated. Oh well, continue forward into the hab.

Don't forget that the Shuttle has a tail rudder, so to dock it under the station, you need to make sure that it will fit comfortably - and not strike the station. Though having the required docking equipment as a part of the Service Module does make sense. You still need a module to allow the Shuttle to dock there, but the on-orbit process is simplified.

Four berths, a toilet, and some exercise equipment? I think you can add either more bunks, or a full wardroom in the excess space, even if it's Shuttle-launched. If it's Europa XL or SDHLV....you could just do all the habitat stuff in that one module in that case.

Wardrooms will feature, but the main benifit I'm looking at is a lot of space for plenty of varied exercise equipment, a large gally with a lot in the way of nutritional variety - I know you can do that with a small one as well, but a real, proper place for plenty to enjoy a good meal would be appreciated. With space provided for recreational facilities - games, computers for personal (if monitered) use and generally relaxing when not on duty. That can go a long way to supporting crew morale.

So, moving forward from the first hab, we come to a node with two more habs coming off port and starboard? See the above about the need, but...whatever. If they're there, I'd lean to putting a docking port on the end--if nothing else, it means they can be the same as the first hab. Save on engineering costs. To run across all four of these modules, the truss would need to be T-shaped, and it'd run directly over the modules? I don't think the stiffening you're going for is needed, and you'd have a lot better positioning for panels and less interference with dockings of Shuttles or the ESA capsules if you just run the truss out port and starboard from the service module.

The stiffening may well not be needed, but IIRC, OTL ISS suffered a major case of 'The Shakes' a while back and they're looking at how this will impact on Station Operating Lifespan. And with enough axial and nadir docking ports, zenith docking ports should not be needed - though this can be accommodated if redesign allows it, and if they're needed.

Well, okay, there's the lab space, but you're breaking it up over a larger number of modules than you need to. You have 35 tons on the European side and up to 79 on the NASA side, why so many tiny modules? I'm not really sure how much point there is to an observatory module, manned stations make poor platforms. There's only two real benefits, servicing and power, but the restrictions on pointing and other major limitations make it a poor trade.Again, you don't really need the truss for stiffening, you need it to get the solar arrays and radiators further out from the station, so this is really unnecessary.

I've taken another mental look, if I drop the two foward Nodes in favour of just one large Node directly forward of the Habitation Modules, I should be able to fit 6-8 Lab Modules - 3-4 on each side. Furthermore, that would allow 3-4 docking ports underneath - the nadir - and 1-3 on top - the zenith - since I shouldn't need to run the Truss Bracer all the way along the redesigned Node. So no prizes for guessing where the CG Lab is being moved to. I might even be able to get a second one of those fitted.

The Labs themselves mass 30,000-35,000Kg, so they can be launched either individually on the ESA HLV, or in pairs on SM-SDLV. Between the Labs, a series of External Experiment Pallets connected to the Node, Labs and Habs - for the rearmost pair of Labs - which can double-up as stiffening bracers.

The same node as the habs are on, or a third node at that second node's forward port?

I had referred to a seperate node, but as stated above, that's now a moot point, there's only one dedicated Node Module now.

I'd be willing to provide some visual representation, but I'd like to see the issues above fixed before I do. Additionally, I'd need a better idea of diameter and length of the various modules.

The basic diameters of the service module, habs and node are 5m. I haven't sussed the lengths yet but 20-28m is what I'm envisioning them at. While using all the available mass left over to carry the Truss Booms where the main Solar Panels and Radiators will be mounted - launched with the Truss to enable assembly at the earliest opportunity. The Labs are expected to be about 4.4m diameter and perhaps 14m length each. The CG Lab(s), 4.4x4.4m - as an initial approximation - so both could be launched at once by ESA LV. As for the Node, up to 30m length and 5m diameter - that depends on how much of the Truss and associated equipment would be sent with it.

This should hopefully cover most of the issues raised, and should allow for an extremely versatile and capable Space Station - i.e. NOT ISS - that can be in good use throughout its expected lengthy lifespan.

As well as the CG and microgravity experiments, there's one more I'm giving attention too. Long-term duration without re-supply. For that, they could raise its orbit higher to cut on atmospheric drag, and go for 6-9 months with no supplies sent of or crew rotated. This can be used to clear one hurdle for Manned Mars Missions in the future. And one more justification for its construction.

NB: You could always run that type of experiment on SpaceLab in your own ETS ATL. It's certainly worth giving some though to.

NNB: You'll have noticed that I've been going on-and-on about stiffening bracers. That's intentional. For me at the very least, that's an important psychological reassurance that there's something holding the whole thing together - yes, I do know that the modules themselves can do that well enough, but the extra bracing couldn't hurt from the standpoint mentioned.

 

[Bahamut-255]

ESA Post Europa LV - Named

Off-Topic from the past few discussions, but worth mentioning. I've recently selected a name for the Post-Europa LV that enters service in 1986-1988.

Argo.

Named after the ship used by Jason as he explored the Known World. That, and I like the sound of it.

As for it's designations based on it's design:


Argo(-U) - Base Version, (LOX/LH2 Upper Stage)

Argo-2P(-U) - 2 SRBs, (LOX/LH2 Upper Stage)

Argo-4P(-U) - 4 SRBs, (LOX/LH2 Upper Stage)

Argo-2L(-U) - 2 LRBs, (LOX/LH2 Upper Stage)

Argo-4L(-U) - 4 LRBs, (LOX/LH2 Upper Stage)

Argo-4LP(-U) - 2 SRBs & 2 LRBs, (LOX/LH2 Upper Stage)

Argo-H(-U) - CCBs, (LOX/LH2 Upper Stage)


I think that covers the entire range. Your thoughts on the Name and Number/Letter System to designate each variant?

Thanks to Shevek23 who came up with the LV name.

 

[Workable Goblin]

Off-Topic from the past few discussions, but worth mentioning. I've recently selected a name for the Post-Europa LV that enters service in 1986-1988.

Argo.

Named after the ship used by Jason as he explored the Known World. That, and I like the sound of it.
*snip*
Thanks to Shevek23 who came up with the LV name.

Great minds clearly think alike--e of pi and I already decided to use that to refer to *REDACTED* in our TL! But it's a great name, as you note, so I'm not saying you shouldn't use it or anything...just thought it was funny that we came up with the same name for different things independently!