Possible Lunar Lava Tube Skylights
Possible Lava Tube Skylights Discovered Near the North Pole of the Moon
“The pits were identified through analysis of imaging data from NASA’s Lunar Reconnaissance Orbiter (LRO). If water ice is present, these potential lava tube entrances or “skylights” might allow future explorers easier access to subsurface ice, and therefore water, than if they had to excavate the gritty ice-rich “regolith” (surface rubble) at the actual lunar poles.”
Good prospects for a follow-up lander mission, and maybe a landing sight for future human missions operating on reusable landers from that Deep Space Gateway (assuming they ever pay for them).
The notion of DSG- and indeed any sort of orbital space station- derives directly from studies in the mid-1950s. It was recognized then that no booster then-flying, or even on the drawing board, could ever take us to the places we wanted to go without some sort of refueling. As a result the notion of space stations was born.
As the decades passed, this fundamental thinking hasn’t been revisited. Yes, there’s much discussion about fuel depots; but these need not cary the huge price tags associated with manned facilities.
Nowadays things are different. The machine capable of obviating space stations- BFR- is no longer just a dream. And while it is true that BFR isn’t yet flying, it is also true that many of the significant constituent parts of BFR ARE flying. It is also true that SX has a hell of a record- always late, yes, but also successful. Columbus could have sailed in 1502 with no effect on history.
Michael Spencer wrore: “The machine capable of obviating space stations- BFR- is no longer just a dream.”
We are usually on the same page but I have to disagree with you. What you are implying is because we have buses that can transport a bunch of people we now will no longer need a laboratory. Just because we have a commercial bus in space there will still be a need for laboratories and other facilities the bus will travel to.
All it means to me is the facilities in space can be a LOT larger and hold hundreds of people.
Michael is saying that now the “bus” can take people directly to the place they want to study. Ie, if you want to study the moon, you go to the moon and build your labs there. Or do your field work on the moon and study your samples in labs on Earth. Or whatever combination works for you. Either way, the DSG or anything equivalent becomes pointless.
You don’t need a “lab” not at the site you want to study, in order to serve as a waystation because you literally can’t go point-to-point, Earth to lunar surface.
[Moreso, the BFS is large enough to serve as a space-station/lab in space. The only thing it needs is more power. So if there was demand for such a service, you might have a large solar array in orbit, which the BFS docks with.]
if you are doing micro gravity manufacturing or micro gravity research, like in LEO, that is 200 miles away there is no point in shipping it 230,000 miles away in the wrong gravity gradient.
I believe you underestimate what is possible in LEO2GEO if the BFR plays out.
I think you’re overestimating the demand for microgravity manufacturing/research.
considered humanity has barely scratched the surface with less than a few hundred of the entire species even worked and experienced zero gravity, I would say you are vastly UNDERestimating what we still have to learn.
I don’t agree. Yes, BFR (when and if it flys) could do direct lunar landings. But that doesn’t mean it’s the best choice.
Many forms of terrestrial transportation are specialized for efficiency. It’s theoretically possible to fly from Charlottesville, Virginia to Flagstaff, Arizona in a big, wide-body 777. At least, the runways are long enough. But those are tiny airports and the efficient approach is to take a small plane (potentially a prop rather than a jet) to Washington, a 777 from Washington to Las Vegas, and another small plane to Flagstaff.
A dedicated vehicle, designed to go from lunar orbit to the Moon’s surface and back, will always be more efficient than one also designed to launch from and land on Earth. The _next_ lunar landing with people on it may be a BFR (or, if they’ve settled on that name, New Armstrong.) But in the long run, I think regular service will involve a hub in lunar orbit and a specialized lunar lander.
That’s also, by the way, not a bad hub for a reusable Earth-to-Mars vehicle using electric propulsion. But I’m hesitant to say I like the Deep Space Gateway idea. It may be in the right place for a transportation hub and maintenance/refueling facility, but I have doubts about it being designed for to do that job well.
The lunar surface will be the major hub for moon-related travel. Ie, it will be the Las Vegas in your analogy, while Earth is Washington.
What you’re suggesting is that we build the major airport in Flagstaff, so the 40m tourists/yr fly in to Flagstaff airport, then switch to smaller prop-planes to fly the last miles to the Vegas airport. It makes no sense.
BFS is already a lander. That’s it’s primary purpose.
An orbital hub is only necessary if your transport vehicle isn’t capable of landing itself. With BFS, that’s no longer an issue. Building an entire other vehicle to duplicate a function that BFS will already perform is foolish.
No, that’s not what I was saying. Using my air travel analogy (which I admit it a bit of a stretch) you can fly a 777 in and out of the current Flagstaff and C’ville airports. You’d need to transfer some maintenance equipment, but the basic infrastructure like a sufficiently long runway exists. In the same way, BFR could land directly on the Moon.
But it would be a bad idea. It’s more efficient to use small, short-haul aircraft to a hub, change planes, and use the big, long-range aircraft for the hub-to-hub leg. In the same way, BFR to a lunar orbit hub and a specialized lunar lander would be more efficient than a direct landing by BFR.
BFR will (or would) have engines powerful enough for a few gs of acceleration, enough structural strength to handle that, and at least some extra hardware for atmospheric entry. For the trip from lunar orbit to the Moon, that’s all dead weight. Half a g and no design compromises for dealing with an atmosphere would be fine.
But I am thinking of the long term. In the short (or mid) term, direct landing with something like BFR may be the right choice. An orbital hub and a specialized lander aren’t required for the first (next) landings. In fact, a hub and lunar lander probably aren’t worth developing until/unless there is enough traffic. But given enough traffic, I think that would be the more efficient approach.
I pointed out in a different thread that I’m in NYC, having traveled here from Florida on a Bombardier CSeries. And isn’t that the way that the airline industry is headed? To use appropriately-sized airplanes that can provide point to point service without the annoyance of Atlanta? The hub-and-spoke concept, once a sensible way to run an airline, is dead, dead, dead.
Space stations, same (sure space stations might be useful for other tasks but as rocket-range extenders, not so much).
We use those lumbering 777’s (a very fine airplane to be sure) when we need to travel 7 or 8,000 miles (or even 9000 miles; I flew nonstop from Bombay to JFK on a 777-200LR; 17.5 hours!).
And isn’t that what we are facing when contemplating a run to Luna Station? That’s why we need BFR? A device big enough to be comfortable and make the trip in a single jump?
The aircraft analogy wasn’t a great one, but… One of the reasons for hubs was to avoid flying planes which were half empty (or flying fewer flights per day.) I assume the CSeries you were on was mostly full, since that’s almost always the case. Before we had small, long-range and fuel-efficient aircraft like that, the hub system allowed full and frequent flights from small airport to hubs, in things like a 737. In a way, I guess that was my point: It depends on the technology, but the most efficient means of transportation isn’t necessarily the most direct.
But if you are thinking of the next manned landing on the Moon, a direct flight might very well be the way to go. It’s possible, and bypasses the need to construct specialized landers and an orbital transport node. It would have to be a vehicle designed for six times the acceleration of a purpose-build lunar lander. Those engines and the implied structure all represent mass which could have been payload. So it would be inefficient. But it would work. It also might be a good way to deliver a lot of cargo, say an entire lunar base landed in one piece. But, in the long run, specialized vehicles and hubs could easily be more efficient for regular crew rotation and supplies. (Or, if you want to mine lunar water, export cargo hauling.)
Of course, we could even argue about that. I’ve seen a study of efficiency in rail versus truck transportation which say rail isn’t as good as it’s generally considered. That study included the cost and resources required for the infrastructure. Once the rails are laid and the roads build, rail is generally much more efficient. But including the cost of rail- and road-building, it may only be somewhat more efficient. The same would be true of lunar orbit hubs and lunar landers. Once the infrastructure is in place, I’m fairly sure that approach would be more efficient. But factoring in the infrastructure development costs, I guess it would depend on usage and other details.
I’d just like to mention this is great discussion regarding BFR, deep space gateway, fuel depots, Moon, etc.
It’s what I’m saying.
The moon is the major destination, not lunar orbit. Hence your analogy is exactly backwards.
Having a separate lander to ferry in/out of lunar orbit, with the BFS never reaching the moon, is like having a large aircraft stop in the middle-of-nowhere just short of a major destination, like Vegas, in order to shove everyone on to small commuter aircraft for the final leg.
You will not have a major destination (and hence hub) in lunar orbit. You will have a major destination (and hence hub) on the surface. So you will fly directly to that hub.
It’s not a bad analogy, it’s just that you are doing it backwards. It’s lunar orbit that is the middle-of-nowhere, fly-over town.
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By which time, you’ve already invested in BFS-centric infrastructure. In other words, by the time you have enough traffic to make it worth specialising, by definition you’ve already solved the problem.
Hence, I can’t see that it will ever make sense to invest in single-purpose lunar hoppers. If BFS works as advertised, then it is a general purpose truck. It works everywhere. It might be slightly less efficient than a bespoke lunar lander, but the difference will never be enough to justify the cost of paying to develop such a dedicated lander. Even in the future, it’d always be cheaper to modify previous-model BFS-type vehicles to do the specialist job, rather than develop a specialist vehicle that’s a bit more efficient.
For example (speaking of hub and spoke), if you have a few major settlements on the moon and a bunch of small outlying research bases, you might want dedicated hoppers to ferry between base and hub without relying on the main Earth-Moon run. But even there, I suspect you’d end up using BFS’s as the hoppers, simply because that’s what will exist and exist in numbers.
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The only “hub” in orbit (other than LEO, due to the need to refuel BFS), might be EML2 or ESL1 serving as a second refuelling hub for BEO runs; if and only if lunar propellant for BEO ever makes economic sense.
I think you’re confusing hubs with destinations. I note for example, that United Airlines uses Guam as a hub for much of their east asian traffic. Without implying anything negative about Guam, it isn’t a major destination in the same league as places like Hong Kong. In fact, many places which are now major destinations started out being a spot in the middle of nowhere which just happened to be a useful place for transport facilities of one sort or another. (Atlanta and Saint Louis come to mind, although, if you go back far enough, this is probably true of most costal cities as well.)
And yes, people do spend money developing infrastructure just for the same of a few percent higher efficiency. Some people have even gotten very rich doing so. And we don’t know enough about the BFR design to know if it would be just a few percent worse than specialized vehicles. One key factor is the demand for and nature of the services.
What if, for example, the requirement was supplying multiple, small stations rather than one large one? How often are crew rotations required? Or, if you are thinking in terms of colonies or tourists, do they want daily, weekly, or monthly service? Is there enough demand at that flight rate to fill the capacity of a BFR? Although there are some differences of opinion over what the “F” stands for, I think everyone agrees that “B” stands for “Big.” It would be very inefficient to fly them 80% empty. If that’s what the market calls for, smaller, specialized vehicles and a transport hub would significantly more efficient.
One thing I will agree about is the initial landings. (Well, not initial, since those were in 1969-1972… But you know what I mean.) Specialized vehicles and transportation facilities would be more efficient, but they are an investment in infrastructure. There is no point in making that investment until you have reason to think there will be enough demand to justify the expenses. At this point, we’re talking about exploration to figure out what, if any, demand there would be. That’s more sensibly done by vehicles which require minimal infrastructure and the minimum number of vehicle types. BFR or New Armstrong (if BO has decided on that name…) would fit that bill.
Not really. Economics isn’t engineering.
The only economic advantage of “more efficient” is if the original company or its rival can undercut on price by using a smaller vehicle. But that only works if the development/purchase/operating cost of the smaller specialist vehicle can be covered by the undercut.
How much will the development, purchase and operating costs for a lunar ferry be compared to BFS?
If the BFR launch cost is in the low millions and the development cost of a smaller dedicated lunar-orbit-to-surface ferry is a billion, then you would need potentially thousands of lunar flights per year in order to undercut just using BFS for the “last mile”.
And in all the analogies that people like to use on Earth, that’s exactly what happens; thousands of trips per week to each node in the network. If 90% of your payloads are 10 tonnes, 9% are 25 tonnes, and 1% are 50 tonnes, there’s enough work in the network to justify buying 900 10-tonne carriers, 90 25-tonne carriers, and 10 50-tonne carriers. And maybe even a couple of special super-heavies for the odd overweight payload.
But if you’re running one trip per week, then you can only afford one vehicle. And it has to cover 100% of your payloads. The fact that this makes it oversized for 99% of your payloads is irrelevant. Economically, it’s better to run one vehicle mostly empty than to have two vehicles, one of which sits unused 99% of the time.
Put simply, the cost of building BFR/BFS plus a dedicated lunar shuttle will never make economic sense. By the time the moon has enough traffic to justify specialist vehicles, BFS will be many design iterations in the past.
Look, I did say minimum development (and therefore a single vehicle, if possible) was probably the best solution for the next landings. And that specialized vehicles could more sense in the long run. I don’t see a fundamental disagreement here.
But I do see a whole lot of “if”s in you comment, leading to a “will never” conclusion. I’d rather say the orbital facilities and specialized vehicles are a second- or third-generation solution, which would only be viable if there were sufficient traffic to justify an investment in the infrastructure. But, given that traffic, I think it would definitely be more efficient.
The same mass economics that brought forth LOR for Apollo remains a reality today and forever. A DSG refueling & servicing facility supporting dedicated reusable lunar landing ferry vehicles is a straightforward engineering outgrowth/solution inside those physical constraints.
Buck Rogers rocketships work great in the movies; physical and economic realities have this annoyingly relentless tendency to rule them out as possible solutions for addressing actual engineering objectives/requirements.
Bob,
Engineering is a thing of beauty, an enterprise that is, as you correctly say, relentless.
Not being an engineer, I ask a real engineer (you) about the fundamental assumptions that support your conclusion. And one of those implicit assumptions is the availability machines capable of lunar landing from Earth departure (this would be where Mr. Rogers makes an appearance). My questions stem from that single notion, and the desire to explore ramifications of this ability in light of space stations.
We’ve discussed ISS, searching for an actual thing that ISS does, aside from teaching us how to build space stations. Hyperbole, I know. Still.
One doesn’t use a 3-axle dump truck to place mulch or soil into flower beds around a home. That’s what wheelbarrows or at most a Mule is appropriate for.
That you can pound a nail in with a sledgehammer is not justification for using such an inappropriate tool for a task better served by one expressly designed for said task. Earth launch & entry is one set of engineering demands. Flexible cislunar flight is another. Lunar descent & ascent yet another. And lunar surface ops another. Each points to a limited number of viable solutions that can be sustained.
One size fits all has rarely been a road to sustained success across different transportation venues. Even though they can do it (sometimes), cruise ships make lousy harbor ferries.
I was thinking a bit more narrowly, Bob: all other things being equal, wouldn’t a SRTL (single rocket to luna) be preferable, if possible?
Of course all other things are never equal.
Can the case be made that extending the range of a rocket with a space station is a bit of a Rube?
Apollo was driven by time-economics, not mass, and especially not cost.
Even then, Von Braun & Co wanted a EOR. His rivals wanted a super-heavy launcher to put an all-in-one lunar-lander+return-vehicle on the moon. No-one wanted LOR. But both models would have taken too long to develop. LOR, separate lander, and Saturn V was the compromise because of time not last gram engineering efficiency, and certainly not because of economics.
For SpaceX, economics matters more than anything else. If it’s not affordable, it might as well not exist.
LEO refuelling takes the role of EOR. That allows BFS to be an all purpose lander; just add fuel. That works for the moon as well as anywhere.
And having one core vehicle instead of three radically different single-purpose vehicles makes it affordable.
[To use your own analogy: You have to go through a lot of nails before it’s worth buying a nail-gun.]
It’s been 50 freakin’ years since Apollo. That model doesn’t work. Until we get our heads around the idea that cost is the only metric that matters, we will continue to repeat the same mistakes over and over and over.
Great! Excellent! Wonderful! Now let’s go.
Imagine if they were to find a small Union Jack flag like in the movie, and Moon claimed for Queen Victoria.
In which sensibility would prevail.
Something interesting for a rover to explore, only quarter million miles away with multiple launch windows per month (unlike Mars) though challenge to travel inside. Also natural cave to shield people from radiation.