Eyes Turned Skywards

Thanks for replies! To return to the question of the thermal conditions the Artemis mission components must face:

I'd guess no missions are planned to operate on the Lunar surface at night; I can see little need for it (unless the geological investigations would somehow benefit from scratching around a chilled surface, but I can't imagine how). OTOH any high-latitude missions, especially to the polar regions themselves (I am morally certain some of them have to be targeted there) will as pointed out face conditions quite similar to Lunar night in the lower latitudes. That is, there will always be some sunlight around and light reflected off illuminated peaks and ridges would generally be far in excess of Earthlight, even in most areas that aren't getting direct sunlight. The heat reflected or reradiated by these sunlit points will probably raise the temperature of the shaded areas considerably, but they will still be quite cold. And the terrain would probably yield many regions that are, by chance, deeply in shadow, even from secondary sunlight, and deeply cold--even some spots that never get warmed up at any point in the Lunar rotational cycle; the rock around there might be chilled deeply indeed, until geothermal heat conducted from below asserts itself. Since the Moon is tectonically dead, with any liquid layer being very deep down, that heat would be pretty feeble by Terran standards.

So, the question of EVA at night is moot, except as an emergency contingency in case the crew is stranded and yet can somehow survive. But the question of how well the spacesuits can handle cold and dark is still apropos, at least for polar missions.

And Toriek's question remains unanswered though we can hope it was going to be addressed when the update(s) that deal with the actual Artemis Lunar missions come up, whenever that will be. The habitat/lab lander must indeed sit through lunar nights and the question of just how cold the habitat gets each night on standby remains. The habitat is of course only meant to be inflated when the mission astronauts arrive to set it up; perhaps it is simply designed to get cold without damage to materials or supplies? Or kept above a critical temperature with modest heating of some kind?
 
Thanks for replies! To return to the question of the thermal conditions the Artemis mission components must face:

I'd guess no missions are planned to operate on the Lunar surface at night; I can see little need for it (unless the geological investigations would somehow benefit from scratching around a chilled surface, but I can't imagine how). OTOH any high-latitude missions, especially to the polar regions themselves (I am morally certain some of them have to be targeted there) will as pointed out face conditions quite similar to Lunar night in the lower latitudes. That is, there will always be some sunlight around and light reflected off illuminated peaks and ridges would generally be far in excess of Earthlight, even in most areas that aren't getting direct sunlight. The heat reflected or reradiated by these sunlit points will probably raise the temperature of the shaded areas considerably, but they will still be quite cold. And the terrain would probably yield many regions that are, by chance, deeply in shadow, even from secondary sunlight, and deeply cold--even some spots that never get warmed up at any point in the Lunar rotational cycle; the rock around there might be chilled deeply indeed, until geothermal heat conducted from below asserts itself. Since the Moon is tectonically dead, with any liquid layer being very deep down, that heat would be pretty feeble by Terran standards.

So, the question of EVA at night is moot, except as an emergency contingency in case the crew is stranded and yet can somehow survive. But the question of how well the spacesuits can handle cold and dark is still apropos, at least for polar missions.

And Toriek's question remains unanswered though we can hope it was going to be addressed when the update(s) that deal with the actual Artemis Lunar missions come up, whenever that will be. The habitat/lab lander must indeed sit through lunar nights and the question of just how cold the habitat gets each night on standby remains. The habitat is of course only meant to be inflated when the mission astronauts arrive to set it up; perhaps it is simply designed to get cold without damage to materials or supplies? Or kept above a critical temperature with modest heating of some kind?

From more reading on the Apollo A7LB spacesuits I really wonder how much the cold would be a issue. Already the liquid cooled under-garment is expelling heat. I would just think if it would be a issue the liquid garment could be adjusted to expel less heat to keep the astronaut warm. However I do remember a issue that heat could possibly become a issue. The Apollo Missions where timed to start basically at Lunar Morning. However I remember reading someplace that on the last 3 J Missions by the time of the 3-EVA it was getting warm enough that the cooling of the suits became a issue. I remember reading that the limiting factor on the EVA's wasn't necessarily Oxygen but the cooling water and that the cooling system would have a harder time keeping up during the 3rd EVA because it was getting warmer and warmer on the Lunar surface.

As far as the Lunar Module. The Altair Spacecraft was going to use a Fuel Cell however I don't remember reading in this timeline if the LM spacecraft power source was ever finalized.
 
One thing to note with Altair landers is that they weren't going to be loitering for two months. Fuel cells should be sufficient for the crew descent stage to provide power down from L2 and while in hibernation on the surface (provided you don't have boil-off issues around lunar noon) and the ascent stage should be okay with batteries once it launches.

I didn't know they were having suit issues during the later EVAs on the J class missions. I do recall that the lunar rover electronics had a nasty habit of overheating during the later EVAs, especially if any dust had got on the radiators (apparently lunar regolith is a disturbingly good insulator).

I've read that the Chang'e 3 lander and rover are supposed to curtail operations around lunar noon to keep their heat production down but I didn't know if that was just the Chinese being cautious or not. They also put radioisotope heater units in at least the lander to keep the electronics from freezing up during the night.

Basically the Moon is a horrible place. It's either too hot or too cold and that dust is murder on anything that moves.
 
I just noticed the combination of the "meatball" and "worm" NASA insignias!

I was wondering when someone would spot this :D It's something we were discussing for a while, that NASA would probably have a bit of a re-brand for the 'Artemis-era', but without Dan Goldin and his pathological hatred of the worm, it would be likely that that well-known branding would survive somehow - so the 'wormball' was created.

On the topic of lander thermal control, two notes. Firstly, the Altair descent stage apparently was designed for stays of up to 6 months on the surface for outpost cargo missions (though any cargo/hab would have to support its own thermal control).

Regarding noon on the Moon, this is a thermal problem for missions. With direct sunlight and all the reflected light from the surface, heat rejection is a major issue, so I'm not surprised the Chinese go quiet around noon - only Mad Dogs and Englishmen go out in the noon-day sun ;)

Wormball_sml.jpg
 
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That looks like a neat logo! I don't know if you can get away with using the worm logo without running into the NASA logo usage guidelines (I did, and created a fictional space agency), but I do think the logo looks cool.
 
On the topic of lander thermal control, two notes. Firstly, the Altair descent stage apparently was designed for stays of up to 6 months on the surface for outpost cargo missions (though any cargo/hab would have to support its own thermal control).

I was reviewing some documentation(Altair Lunar Lander Consumables Management) last night on the planned Altair lander. This part was interesting for me.

It is assumed that outpost landers would be connected to an LSS power source within 24
hours of landing to maintain vehicle systems until ascent.


So it seems like the Altair lander while being designed for stays up to 6-months it was assume that after landing it would be connected into a LSS power source which would be Lunar Surface Systems.
For the cargo lander.
Cargo landers operate on internal power for their entire mission with no power transfer from other elements.
Cargo landers remain powered for 24 hours after landing on the lunar surface. As for the outpost mission, it is
assumed that this provides enough time to connect the lander to an LSS power resource if necessary for payload
support.


So it seems like the 6 month long stays assumed that someone would connect the lander to a power source already on the moon.
 
That looks like a neat logo! I don't know if you can get away with using the worm logo without running into the NASA logo usage guidelines (I did, and created a fictional space agency), but I do think the logo looks cool.

Well, if we do it's a bit late now - all the stuff from before the mid-90s has the worm logo on it! Let's just hope Goldin's purge extended to the legal department ;)
 
By the way, just as a heads-up:

As the result of some family issues on my end, we will not be going to the Moon with Artemis 4 this week. That post wasn't going to be completed to the point I feel it needs, so it's waiting until next week when I should be able to give it the time it deserves. Instead, Workable Goblin's managed to pull off an incredible effort to get a post that was planned for later in the cycle ready for tomorrow. However, since I will be on the road, it may not update exactly at 1 PM Eastern. I'd like to thank you for bearing with us, and I hope you'll enjoy what we've got lined up for you this week. Hey, just think: if we've waited 40+ years to go back to the Moon in OTL, can't you wait one more week in this one? ;)

P.S. Remember, Nixonshead and I could use input on images you'd like to nominate as the "best" to represent his porfolio in this TL for the Turtledoves--we've got to narrow it down from everything amazing he's done to just one. A little topic to tide you over until I can get the post up tomorrow. :D
 
Part III, Post 19: The growth of mobile satellite communications in the US and Europe
All right everyone. After about 7 hours on the road today and no fewer than 5 states, it's finally that time again. :) I'm hoping to still be able to get the next Artemis post done for next week--I've had it percolating most of the day, but it'll depend on when and if I have time to write with the other stuff going on.

Also, secondly, just a reminder again that we would appreciate people's thoughts on which of Nixonshead's images should be selected to represent his portfolio in the Turtledove nominations. Just a reminder, they're all collected here on the wiki if you want a chance to review them all together--we're interested in any thoughts. Also, while on the topic, thanks go to him also for providing some technical insight and suggestions that ended up forming the base of a lot of this post.

Anyway, with that business out of the way, without further ado, let's get into today's post...

Eyes Turned Skywards, Part III: Post #19

Even though Motorola was the first to see the potential of a low-orbit constellation of satellites for telecommunications, they were far from the only company to put their hat in the ring in the first half of the 1990s. Dozens of companies, ranging from giants like TRW and RCA to tiny startups like Teleworld and Starcomm quickly followed Motorola into the field, with proposals ranging from Teleworld’s giant swarm of hundreds of satellites, intended to provide global high-speed internet service, to more modest systems intended simply to provide regional telephone service. While American companies were taking the lead, boosted by the strong American commercial space sector and the loosening of regulations that had taken place during the 1980s, firms and even sovereign governments from Japan to Brazil were following close behind.

What all of these promoters shared, however, whether they were a government agency or a private corporation, whether they were based in Tokyo or Los Angeles, was a firm conviction that the market was headed for even more explosive growth than had characterized the satellite business since the 1960s. Not only were there enormous potentials in developed countries, where a few dozen satellites could create a nationwide network potentially far more quickly and at a far lower cost than the already-conventional method of raising cellular towers and hooking them up by wire or microwave to existing telephone networks, but the potentially vast market of the developing world loomed on the horizon as a massive incentive. With the fall of the Soviet Union, the world seemed to be on the verge of a vast burst in economic growth, propelled by laws liberalized by the absence of a Communist counterpart, reductions in defense spending, and the opening up of new markets previously closed or nearly closed to Western firms. Visions of potential customer bases increasing from five hundred million to five billion people danced in the heads of promoters as they organized, thought, and planned.

Added to this simple growth of adding new customers to existing services was the possibility of adding new services, and customers with them. Almost as soon as the technology of computer networking was introduced, satellites had been used in experimental efforts to link them together, efforts that had only been boosted by the aging of satellite networks and the virtual retirement of older satellites, too small and low-capacity to be economically operated in their design role any longer, freeing them up for experimental use. If these were to become more than mere experiments or small-scale commercial applications, however, dedicated fleets of satellites needed to be created, designed around the provision of computer networking rather than telephony or television broadcasting. If such fleets were built, however, the vast amounts of broadband connectivity some visionary pioneers expected to be necessary for demand for services such as on-line video, Internet telephony, and other similar services would become cheap and widely available, allowing other firms to piggyback on the success of the constellation builders. It is no surprise that this possibility attracted the most interest from the emerging class of wealthy “Silicon Valley” pioneers--ignoring for the moment that most of them, and in particular the wildly successful founders of Microsoft, the most wealthy of them all, were from nowhere near central California--with the great-granddaddy of all the broadband systems, Teleworld, obtaining venture capital from Bill Gates, among others, before Paul Allen’s own ventures in the space field diverted further Microsoft interest.

Similarly, the possibility of global mobile telephone services, the market that had lured Motorola into entering the field to begin with, offered another lucrative opening to would-be constellation builders. While mobile telephony had been around in some form or another for decades, dating back to the era of car phones, the modern form of individually-carried cellular phones had only been commercialized in the 1980s, and coverage was largely limited to dense urban areas where the cost of erecting towers was outweighed by the density of possible subscribers. Many providers believed that extending coverage to suburban and rural areas would drive a significant increase in subscriber numbers, not only because of the new customers located in the additional signal footprint, but because of greater value to potential subscribers located in already-covered areas. Satellite-based provision of mobile service would drive this to its ultimate conclusion, covering not just suburban and rural areas, and not just a single country, but wilderness regions all over the planet, and even the ocean. Sailors, travelers, and those living in countries where no mobile service had yet been built could subscribe to the satellite service and garner the benefits of mobile telephony even though conventional infrastructure might not exist anywhere near them.

These two potential services, global satellite broadband and global mobile telephony, were the bedrock of all proposed constellation systems. Each and every one of them depended on one or the other as the foundation of their proposed system, and each one needed to capture some fraction, ranging from 5% to 25%, of the global market to make their business case. With more than twenty networks in the proposal stages by 1994, it was obvious, if never publicly mentioned, that some, at least, would fail. And, increasingly, it looked like some would fail without ever building, let alone launching, a satellite, for the easy climate many founders had anticipated immediately after Motorola’s interest was revealed had never truly arrived. With even the simplest networks requiring billions of dollars upfront for the development, construction, and launch of their satellites before turning a single cent of revenue, investors were skittish and concerned about the risks involved. Many investigated the satellite market, then chose to invest in seemingly safer terrestrial ventures; while no cellular network or fiber-optic line could possibly come close to the number of subscribers a satellite system might boast, they were equally cheaper and faster to build, offering the glittering possibility of obtaining revenue and even profits within a relatively short period of time, and at a much lower initial capital cost. With inadequate capital and pessimistic market studies coming out, the economic foundation of the constellations was beginning to crack and crumble by late 1994.

At first, the Christmas Plot seemed to undermine those foundations entirely. Venture capital dried up as spooked investors fled for safer investments, forcing several of the smaller constellations into bankruptcy, while the cascading effects of the sharp, though short, recession that followed did even more in. The most damaging aftereffect of all, however, was the Asian crisis of 1995-1996, where a combination of slowdown in capital inflows and reduction in demand from their primary overseas markets badly hurt emerging economies in Southeast Asia, dependant on exports and massive overseas capital injections to maintain high growth rates. As some of the wealthier of the so-called “developing countries,” and more tied to Western and especially American markets than many others, many of the constellations had aimed at breaking into Southeast Asia as their primary developing-world push. Others had obtained some degree of venture capital from countries involved in the crisis, mostly Taiwan and South Korea, and like the other firms that were no longer able to obtain capital collapsed into liquidation. Even Motorola’s giant Iridium platform and the smaller though still well-funded Starcomm and Gemini constellations found themselves severely pressured despite Starcomm actually launching its first satellite late in the year and the other two being well into the construction phase, and for a time it seemed that the whole sector might dissolve before accomplishing anything at all.

At this juncture, and without any apparent design, the United States government rode in to the rescue, like one of their cavalry units in a Western movie. In the wake of the Christmas Plot, the Federal Aviation Administration, like many of the other government agencies involved, had begun a study of their response to the disaster, both to identify points where they could improve their ability to deal with any future attacks and to head off outside criticisms of the administration. One problem that the resulting report identified was the primitive state of transoceanic air traffic control. Why, the report asked, in an age of satellite navigation (the Global Positioning System having recently been declared fully operational by the Air Force) and satellite communications (referring not only to Intelsat and Inmarsat, but several of the new constellations by name) was it acceptable for trans-oceanic flights to have nearly as little control as trans-continental flights in the 1920s or 1930s? The report called for the design and construction of a so-called “virtual” air traffic control system, relying on data relayed from positioning devices aboard aircraft transiting controlled airspace to provide positions to controllers who could then direct aircraft just as if they were crossing near-shore or overland areas. The relatively low precision offered by GPS was of little concern given the huge airspaces available for errors in trans-oceanic flights, and the advantages of controllers being more aware from moment to moment of what flights were crossing the oceans, hopefully allowing responses in minutes instead of hours in the future if one or more dropped off the grid, seemed compelling. The report even took a step further (and quite out of its mandate) and suggested that such a virtual ATC could replace most of the actual ATC hardware in the United States at a future date, saving on maintenance and operations costs for items like the network of VOR stations blanketing the United States with navigational signals.

While that particular suggestion was walked back under pressure from smaller domestic operators and general aviation users who feared the costs such hardware might generate, the more specific recommendation of developing a virtual ATC system was not. Indeed, the proposal gained interest from the President himself, and perhaps more importantly from the fledgling constellation industry. They saw, in the proposal, the possibility of a guaranteed userbase and income stream, heady stuff for an industry that had thought itself on the verge of collapsing only a few months earlier. Although a Department of Defense proposal to build a hardened dual-use (but primarily military) network briefly threatened the private operators, FAA and congressional coolness to the proposal, which would amount to a nationalized system and incur considerable expenses and delays above and beyond what was really necessary for the civilian part of the system. Whether or not the Air Force ever launched such a system, the FAA, at least, was going to stick to commercial operators.

By 1997, therefore, the pessimism of a year or two earlier had almost vanished from most of the operators. With the promise of fat government contracts ahead and hardware in many cases either in the factories or actually on the launch pads, a sense of sanguinity settled over management and investors. Aiding this optimism was the general economic recovery; the 1995 recession had undone some of the weaker firms, and the Asian crisis more, but neither incident lasted long or went to work on the pillars holding the economy up, and the economy was beginning to return to a more normal state. Indeed, internet usage had recently begun to rapidly increase, fulfilling every desire that promoters of the larger and more complex broadband systems could possibly want. The only stormclouds looming on the horizon came from the progress made by their terrestrial competitors, who had made giant strides in erecting cellular towers and building fiber-optic networks over the past few years, but even they weren't outrunning the leading satellite firms as they began to launch.

Indeed, the only place where American instigation of what would become known as the TOCNN contracts (for Trans-Oceanic Communications and Navigation Network) was unappreciated was overseas. In Europe, particularly, where the French had been studying and developing their own LEO constellation, there was consternation over the new American push to support satellite communications. While the intent of TOCNN could hardly be faulted, and indeed it would perhaps be a good idea for Europe to follow the lead of the United States here, it had, naturally, focused on contracting to American-based firms and, equally naturally, did not seem to distinguish between foreign and domestic-based carriers in applying the TOCNN receiver requirements. A virtual ATC would have little value, after all, if it was as blind to the existence of aircraft from Britain or Japan as if neither of those countries even existed. Unfortunately for the French, this would make for a huge foothold in the European market for those American firms chosen to service the TOCNN system; this might, perhaps, be leveraged to sell their more conventional and consumer-oriented products into the European market, preventing the Europeans from entering this important technology sector. Moreover, early reports of Defense interest, even if they ultimately came to nothing, led to further concerns that European firms and governments might become dependent on American-provided capabilities that might be deliberately degraded for foreign users, or even disabled entirely under some circumstances. While President Gore tried to reassure European governments that the American government had no intention of disabling the Global Positioning System, and even signed an executive order in late 1997 ordering the controversial “Selective Availability” capability turned off, these were still powerful arguments for governments wary of too much dependence on any outside power.

Therefore, the French proposal at a mid-1997 ESA ministerial meeting to expand their Taos system into a full global navigation and communications network (quickly dubbed a GCNSS, for “Global Communications and Navigation Satellite System”), they received an overwhelmingly positive response from the ministers of the other states, particularly the three other major poles of the ESA collaboration, Britain, Germany, and Italy. Almost immediately afterward ESA, together with the long-established Eutelsat communications satellite organization, began an in-depth study of the proposal, which in one fell swoop would end European dependence on both GPS and the rapidly growing American systems, especially if the FAA could be persuaded to accept so-called “Taos II” data as equivalent to TOCNN GPS and communication relays. Over the next year ESA and Eutelsat slowly ground through their analysis, considering possible customer bases, subscriber numbers, launch costs (whether by conventional Europa or the possible Sanger II system), and more. Ultimately, the Phase A study delivered in 1998 described a system which managed to combine the functions of both GPS and communications in a single network, but not efficiently, and not without a cost. For the complete, globally-available 24 active satellite network, a minimum of 3 billion ECUs, or somewhat less than 3 billion dollars, would be needed for construction, launch, and the first year of operations. Even with the arguments of national security and international competitiveness, most of the member governments blanched at incurring such a cost merely to duplicate existing services, and pushed ESA and Eutelsat to find a cheaper solution.

The result was the Global Communications and Navigation Enhancement Satellite System, GCNESS--or, as it would shortly become known, Marconi, after the Italian radio pioneer. ESA and Eutelsat had concluded that the most expensive portion of the overall system, not to mention the part least likely to bring in any significant revenue, was the navigation system, demanding highly precise time and orbital measurements and requiring radio transmissions which integrated poorly with the communications portion of the Taos II GCNSS plan. A MEO-based system, Marconi would integrate communications functions with a satellite-based correction system that would improve the precision of GPS measurements without completely replacing the American system. While less ambitious, this did have the virtue of being cheaper and faster to build than the Taos II system would have been, at only about a third the cost and time from launch start to Full Operational Capability. Despite a certain degree of reluctance to abandon the full navigation capability, work on Marconi was approved at the ministerial level in late 1999, with ESA serving as the technical lead manager of the project and Eutelsat as the primary customer and system operator.

Meanwhile, TOCNN was coming into its own. While the relatively limited Starcomm system had won the first TOCNN contract on an interim and experimental basis, the kind of virtual ATC the FAA envisioned required far greater bandwidth and much more communications capability than their limited system could provide. Iridium, finally in service as the decade closed, could provide that, and quickly won the second TOCNN contract; a fortunate bit of work, as the company (now independent of Motorola) was only days away from having to declare bankruptcy when it learned it had beat out Gemini for TOCNN 2. The unexpectedly rapid growth of terrestrial systems, combined with the adoption of the European GSM cellular phone standards (allowing roaming from network to network) had badly impacted subscriber growth, a problem not helped in some cases by inept marketing and corporate mismanagement. Now the major firms needed government contracts to stave off bankruptcy, instead of merely having them as valuable anchor customers, as they undershot their expected subscriber counts by factors of ten or more. Even if Iridium and Starcomm managed to avoid bankruptcy, Gemini and most of the other weaker providers were, like their counterparts a few years earlier, forced into it. Gemini, which had already built a considerable portion of its constellation and launched a few satellites managed to escape into Chapter 11, continuing as a distinct provider, but few others were so lucky.

Regardless of the fortunes of the individual providers, however, TOCNN was proving to be a great success. The availability of over-water communications and navigation data, together with more direct control by the major oversea control centers was considerably increasing the efficiency of traffic control nearer to major international airports, while airlines were finding the new communication channels useful for their own business operations. Now they could receive up-to-the minute information from their aircraft no matter where in the world they were located, and could even resell the data and voice connections that the TOCNN contracts required to passengers for hefty fees. The FAA hardly needed to push airlines to install TOCNN equipment as they realized the commercial benefits of doing so. Indeed, they quickly realized that the legally-mandated rollout completion date of 2005 would likely be beaten by several years. The only thing approaching a dark spot in the whole picture were foreign airlines, many of whom were waiting on Marconi as their TOCNN provider.

And if TOCNN was proving to be a crucial lifeline to corporations that had fallen in unexpectedly rough financial waters, it was far from being the only business most of them had. Starcomm’s relatively limited system, for example, was seeing great interest from the oil and gas industry to manage a new generation of more autonomous sensing and monitoring devices, while Iridium and Gemini were finding success, if more limited than hoped for, in a range of markets. While not mandated by federal law, the shipping industry was finding in the new system many of the same benefits as airlines in allowing speedy communications between a central office and a far-flung fleet of vessels, and passenger operators were exploiting some of the same opportunities as airlines in allowing fee-paying use of the connections. If, admittedly, the usage of satellites for these roles in ships was much older, dating back to the late 1970s, the constellations at least allowed more widespread and lower cost deployments of the capabilities.

Similar advantages were being found in the military, whose MEO Advanced Global Communications System, or AGCS, was proving to be as delayed and expensive as the FAA and airlines had feared. If lacking many of the features of the mil-spec system, Iridium and Gemini were at least available now, and they gained a certain following among the units deployed to fight terrorism by Gore’s administration. Elsewhere, the Natural Science Foundation was undertaking a major project to provide Iridium data and voice links at the McMurdo and Amundsen-Scott polar bases, which had previously relied on obsolete geostationary satellites which had begun to drift far enough from an equatorial orbit that they could be seen from Antarctica to relay communications. Iridium’s purpose-built network was of course much more reliable, not to mention less expensive for a government no longer required to pay specifically to keep certain otherwise useless satellites available.

Finally, of course, there were always the bread-and-butter individual customers which the networks had been intended for. If less successful in the relatively cellular-signal blanketed United States, Europe, and Japan than had been hoped, particularly as the disadvantages of satellite phones became more apparent to the general population, they were more successful among international business travelers (for whom the convenience of dealing with only one provider was enough to outweigh other problems) and, especially, those living in underdeveloped countries such as China or many of the countries of Latin America than had dared been dreamed of. After all, in many of those countries no cellular network yet existed, and owning a mobile phone--particularly an expensive phone, and one that would work anywhere in the world!--was something of a status symbol among the right group of people.

If they had not been all that was hoped for, as the next century opened a field of competitors still existed, still pushed forward--bloody and battered, perhaps, but there. With three major American networks completed and a European system under construction, it was clear that constellations were now going to permanently be part of the communications satellite landscape. The world had been changed.
 
Shevek,

We've given it some thought, but a rescue lander is sadly entirely entirely non-viable.

I thought that Shevek's discussion of this question was very helpful - as is usually the case - but I should make clear that I kinda figured that you, the authors, had reached the conclusion that a full-fledged rescue vessel would not be a viable proposition at this juncture - not worth the cost/benefit tradeoff for the Artemis sorties.

Perhaps, of course, once there's a permanent (or at least man-tended) base, where we're talking much longer-term stays, and even larger crew presence, such a vehicle would be worth funding and deploying. But NASA is not there yet.

Which is why I mooted the question only in the context of something like the LESS - not so much a real rescue vehicle, but just a limited, emergency means of escape to lunar orbit, something which would cost rather little in terms of development/construction costs and payload mass - even for 4 astronauts, and even with the CSM sitting at a Lagrange point rather than LLO.

I'm assuming the answer even to something like LESS is "no, sorry, that's not on the table, either," which is fine; of course, it's inevitable that NASA would reopen a study of it in the Artemis office, even if it didn't get past a few proposal papers and meetings. But I think it's clear that this is the most we might reasonably hope for in a "backup lunar escape" capability for any of the first six Artemis missions.
 
Which is why I mooted the question only in the context of something like the LESS - not so much a real rescue vehicle, but just a limited, emergency means of escape to lunar orbit, something which would cost rather little in terms of development/construction costs and payload mass - even for 4 astronauts, and even with the CSM sitting at a Lagrange point rather than LLO.

I'm assuming the answer even to something like LESS is "no, sorry, that's not on the table, either," which is fine; of course, it's inevitable that NASA would reopen a study of it in the Artemis office, even if it didn't get past a few proposal papers and meetings. But I think it's clear that this is the most we might reasonably hope for in a "backup lunar escape" capability for any of the first six Artemis missions.
The issue compared with a "minimal" escape vehicle like LESS for Artemis is that the definition of "minimal" changes when the goal is L-2, not LLO. That makes for a much harder challenge--you can get to lunar orbit and rendezvous with a capsule in the endurance of a simple EVA suit, but that's not possible during the duration (more than a day!) required of a trip from the moon to L-2. You could do plug-in support for the air, but not for other needs. That means a pressurized cabin and life support systems, and that'd run to a ton or so. Add in the more than a half ton of the crew themselves, and the payload would need to be about a ton and a half. Adding in a spaceframe and the tanks and fuel to make it to L-2, and it could be as much as 4 tons. Artemis has a fair amount of surface payload, but not enough for that. :eek:
 
The issue compared with a "minimal" escape vehicle like LESS for Artemis is that the definition of "minimal" changes when the goal is L-2, not LLO. That makes for a much harder challenge--you can get to lunar orbit and rendezvous with a capsule in the endurance of a simple EVA suit, but that's not possible during the duration (more than a day!) required of a trip from the moon to L-2. You could do plug-in support for the air, but not for other needs. That means a pressurized cabin and life support systems, and that'd run to a ton or so. Add in the more than a half ton of the crew themselves, and the payload would need to be about a ton and a half. Adding in a spaceframe and the tanks and fuel to make it to L-2, and it could be as much as 4 tons. Artemis has a fair amount of surface payload, but not enough for that. :eek:

Oh, I quite agree, e of pi - I alluded to that difficulty in my original post.

Something like LESS would *only* be feasible if you had the capability to divert the CSM (remotely, obviously) from L-2 to low lunar orbit ahead of time, ready for a quick rendezvous with the astronauts riding their LESS's. LESS was predicated on the short life support duration of the suits; the astronauts would time their liftoff such that rendezvous with the CSM would be relatively quick. Here, obviously, the CSM is a lot further away - it would, perforce, have to come to them, if you can't make their life support more robust.

Of course, that requires additional capability on the part of the CSM, additional delta-v to insert into lunar orbit, potentially some maneuvering to reach the astronauts, then to break lunar orbit...obviously complications that were not there for Apollo, and ones which would start to drive up the costs for this capability.

There's no question that the Artemis office *would* at least take a look at it, early on; and, most likely, conclude that the extra complications needed for twice the astronauts, and additional CSM capability just make it a non-viable proposition. But they'd think about it, at least. The astronauts will be a quarter million miles from home, at the bottom of a modest gravity well. Something like Archibald's Columbia rescue scenario just ain't an option here. And Mr. Goodwrench is not just over the next rille.

But my guess is that emergency rescue doesn't become a serious option until there's a base.
 
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There's no question that the Artemis office *would* at least take a look at it{LESS, that is--Sh23}, early on; and, most likely, conclude that the extra complications needed for twice the astronauts, and additional CSM capability just make it a non-viable proposition. But they'd think about it, at least. The astronauts will be a quarter million miles from home, at the bottom of a modest gravity well. Something like Archibald's Columbia rescue scenario just ain't an option here. And Mr. Goodwrench is not just over the next rille.

But my guess is that emergency rescue doesn't become a serious option until there's a base.

I still have a final suggestion to make on the subject of emergency rescue. Surely NASA would be remiss not to consider all options, on paper anyway, if only to rule them out. Having accepted that a rescue craft parked for years in Lunar space is out, I wondered how crazy it would be to have one "parked" on Earth. That would require a Multibody Heavy, already stacked and ready to go--and since it would not be known just what component of Artemis might fail, a complete CSM-LEM stacked on top. I thought it might work if that stack were meant to be the stack for the next mission but of course the missions come at a pace of just one a year, so that seemed quite absurd too.

So NASA is betting that nothing that causes a mission failure the Artemis craft components can't recover from well enough to get the crew back to Earth will happen, because they have designed in sufficient redundancy in vital components, and that is obviously the way to bet. Nevertheless the thought of Apollo 13 continues to haunt me, and it ought to haunt someone in NASA too. So is there anything to be done that wouldn't cost far too much that can change the prospect of an accident that would doom the astronauts to one they can survive?

Suppose some completely unforeseen, or more likely, foreseen but dismissed as wildly improbable, event happened that trapped the Artemis crew on the Lunar surface--or ruined their CSM while they were away--or otherwise deprived them of their ride home without immediately killing them in the process. Say the lander is hit by a meteorite and it holes one of the propellant tanks, for instance. Now what?

Presumably, if there is any prospect of the crew surviving long enough to benefit, NASA on Earth does go ape to scramble to get them home anyway. At that point, money would be no object; no President or Congress would deny the funds for an emergency rescue if it could do any good--indeed I expect all the nations involved in Artemis would open their purses as well. Clearly the means of bringing them home is at hand--it is a matter of sending the appropriate elements of an Artemis craft to them. That requires nothing more, and probably less than, a standard Artemis CSM-LEM stack, which can be launched on a standard Heavy to fly the LEM directly to the Moon while the CSM either parks at L-2 or assumes a lower orbit (if it has enough propellant to get to Trans-Earth Injection from there that is). Nothing to it--except the stack takes months, I gather, to build and assemble. The elements to make it exist--they are in the pipeline for the next mission. Even when the program is on its last mission it probably won't be too costly to delay final shutdown of the assembly line to make one last component, or one could have been made as a contingency anyway and is just being held back from its final role as a museum piece.

All the astronauts need to do is survive until the LEM (or CSM, whatever they need) arrives. For that they need supplies.

Suppose it were possible to place an emergency supply vehicle in low Earth orbit, mounted on a storable-fueled rocket that could bring it to TLI and then brake it suitably on approach to the Moon, so that the vehicle could finish the job of landing near the mission site, bearing a number of tons of supplies? What would such a vehicle be like?

I was going to sketch out an AARDV, fitted with landing legs and boosted by a hypergolic fueled rocket to Earth escape velocity, and estimate what the package came to. I inferred about 30 tonnes approaching the Moon, and backtracking got a rather enormous figure, over 200 tonnes, for the total stack waiting in orbit.:eek: I'm not sure I did that right, but backing up and looking at an old-style Apollo LEM sent in a Hohmann orbit, this is what I came up with:

Apollo 17's LEM, LM-12, massed 16,658 kg on launch. Supposing the upper stage were replaced with a storage pallet, and also extra tankage for the standard DME, which got an ISP of 311. Giving only rough figures here because a lot depends on details, I estimate that a 60 tonne all up package can give it the delta-V to land about 7800 kg on the Moon (having ejected about 4 tonnes of extra tankage when it runs dry); with 2134 of that being the dry structural mass of the standard Apollo LEM descent stage, we have over 5600 kg of emergency supply pallet on top. How much of that is actual useful supplies and how much is packaging I don't know. Anyway it should amount to several tonnes of useful stuff. This 60 tonne package can be placed into a 430 km orbit by a Multibody H02. This assumed a minimum energy Hohmann orbit; with a 71 tonne package instead, adding 11 tonnes of propellant we could nearly do an escape velocity trajectory, getting it to the Moon somewhat sooner; that is within the capability of an H03.

Would 3 or 4 tonnes of supplies, delivered between half a week to 10 days after they learned they were stranded, be enough to enable the crew to survive until another Heavy stack with an Artemis LEM can be launched and reach them? Or at any rate to hold out until another supply package can come?

I wouldn't count on a second supply package; if there isn't one already in orbit ready to go, it will require another Heavy to send it there--although to be sure a mere supply package can be boosted with a hydrogen-oxygen upper stage instead of the inefficient hypergolics I assumed above, so a smaller rocket could launch it--but probably still something in the Multibody or Vulkan range, not even a Europa 5 could do it, so we are still stuck with long assembly times. Not to mention that these assembly times must include making another supply lander!

I don't think the cost of such a contingency vehicle would be nearly as large as the prohibitive costs of grander alternatives I suggested earlier. The question is, would it buy the crew enough time to be rescued by a second Artemis LEM?
 
I don't think the cost of such a contingency vehicle would be nearly as large as the prohibitive costs of grander alternatives I suggested earlier. The question is, would it buy the crew enough time to be rescued by a second Artemis LEM?
The problem with the earlier ideas wasn't the per-flight cost, but rather the development cost. This still requires a hypergolic descent stage (even rebuilding the LM would require essentially redoing much of the detailed design after 30 years), and a large hypergolic trans-lunar injection stage. Removing the requirement for a duplicate ascent stage design saves some development, but adding the large hypergolic stage for EDS means the total development won't drop much. It would still cost billions of dollars to do the engineering development and test the vehicles sufficiently to be sure they'd be able to perform if required, and unlike the rescue lander, it can't even get them home. I'm sure NASA's considered such things ITTL, but when it gets down to it, the funding isn't there to raise the program cost by 10% to cover 1-in-1000 failures.
 
I"parked" on Earth. That would require a Multibody Heavy, already stacked and ready to go--and since it would not be known just what component of Artemis might fail, a complete CSM-LEM stacked on top. I thought it might work if that stack were meant to be the stack for the next mission but of course the missions come at a pace of just one a year, so that seemed quite absurd too.

?

The Saturn Heavy cannot get a CSM-LEM to the moon without a separate launch of the Earth-Depature stage. So this would require two stacks ready to go and a turn around of 39A and B in a really short time, less than 2-weeks.
 
The Saturn Heavy cannot get a CSM-LEM to the moon without a separate launch of the Earth-Depature stage. So this would require two stacks ready to go and a turn around of 39A and B in a really short time, less than 2-weeks.
Considering that the VAB has four assembly places, that is very possible to be done.

IIRC there has been a precedent IRL with a second shuttle standing by to rescue one in orbit should the need arise shortly after they resumed the shuttle missions to the ISS after Columbia.
 
Considering that the VAB has four assembly places, that is very possible to be done.

IIRC there has been a precedent IRL with a second shuttle standing by to rescue one in orbit should the need arise shortly after they resumed the shuttle missions to the ISS after Columbia.

It is doable but not as standard operating procedure. You would have to first off get the paid back into shape for the launch. During launch the pad suffers damage. You also have 3 mobile launch platforms. So at least one of them after launch you have to get the crawler out to the launch pad pickup the MLP get it back to the VAB and get both rockets stacked on mobile launch platforms. You can already have one stacked on the MLP. However this could still be a problem is that with a dual launch both crawlers have to be avialable to get the MLP's on the pad's back to the VAB in case a hurricane comes in or something else and the stack needs to be moved back. I am not sure if when they do the stacking inside the VAB if they stack with both the MLP and crawler together. So it can be done with a fairly quick turn around with a all out push. However I just don't see this quick turn around for a dual launch as SOP.
 
It is doable but not as standard operating procedure. You would have to first off get the paid back into shape for the launch. During launch the pad suffers damage. You also have 3 mobile launch platforms. So at least one of them after launch you have to get the crawler out to the launch pad pickup the MLP get it back to the VAB and get both rockets stacked on mobile launch platforms. You can already have one stacked on the MLP. However this could still be a problem is that with a dual launch both crawlers have to be avialable to get the MLP's on the pad's back to the VAB in case a hurricane comes in or something else and the stack needs to be moved back. I am not sure if when they do the stacking inside the VAB if they stack with both the MLP and crawler together. So it can be done with a fairly quick turn around with a all out push. However I just don't see this quick turn around for a dual launch as SOP.

Well, for starters, NASA will almost certainly need more crawlers.
 
I am not sure if when they do the stacking inside the VAB if they stack with both the MLP and crawler together. So it can be done with a fairly quick turn around with a all out push. However I just don't see this quick turn around for a dual launch as SOP.

Well, for starters, NASA will almost certainly need more crawlers.
The crawlers aren't required for stacking, as (like at the pad) the MLP rests on supports inside the VAB. They're only needed on the trip to or from the pad. Thus, two crawlers is sufficient. However, Freedom ops do essentially monopolize one of the MLPs--part of the reason why Artemis only calls for one dual-launch per year is the challenge of fitting that around the Freedom logistics schedule.
 
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