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NASA’s Lunar Space Station Is a Great/Terrible Idea

129 points by howard941 7y ago

inflatableDodo 7y ago
Sounds like it could be good if you want to go there repeatedly, bad if you just want to get there as fast as possible again.
lettergram 7y ago
It’s kind of ridiculous how often NASA has to reallocate their focus. Personally, I’d like to see a longer term 5 - 10 year plan that is voted on by congress and basically the funds are deposited in an escrow. It’s insane the waste that occurs from random political moves like this. I understand the need to be able to direct NASA, but that should be in addition to the described 5 - 10 year plans. This would give the flexibility needed, while at the same time ensuring skills and contractors are maintained and long term visions are still possible. I kind of view the “gate” in its current state as NASA knowing it’s the correct choice technically and trying to politically make it viable. Shouldn’t we listen to the experts here?
- Ididntdothis 7y ago
  Since Bush every incoming president has set up a “vision” that scraps all previous work and which then in turn gets scrapped by the next guy. I wonder how the people working there can keep motivated knowing that most of their work is just for show. Seems unmanned missions are fine but manned missions are just a mess.
  - gyaniv 7y ago
    The problem is that since there's always a switch between Republican and Democrats, each president has a different perspective on the overall NASA mission (plus each one wants to leave a big mark), so they keep changing. I think what the people actually working there try to do (as it can be seen here) is find a way to fit what they have already done, with what the new mission statement is, so that they won't have to scrap everything they have done, only the limited amount. That's good is some senses (less wasted work), but the result is then usually not the most fitting solution.
    - lukeschlather 7y ago
      I don't think it's accurate to say there are any partisan components to the NASA mission. I guess the exception is the Republican party is trying to cut Earth observation satellites because the data coming back is politically inconvenient. However that's a pretty small part of NASA's budget.
  - magduf 7y ago
    From what I've heard, a lot of people have left NASA as a result of the month-long government shutdown this year. NASA is a political football, and it's not going to get any better: it just takes too long to see a big mission (i.e., manned ones) through, so they're never going to get done with the way our government is running these days. The probes are usually OK because those can get done a lot quicker.
    - justin66 7y ago
      > From what I've heard, a lot of people have left NASA as a result of the month-long government shutdown this year. I've got two friends there, a civil servant and a contractor, and I've heard no such thing. That doesn't mean it isn't true, but I'm curious whether there's any data to back this up. You'd have to be careful looking at that data, too: a lot of people are retiring from NASA simply because they're old. Nothing that's happened to NASA lately is a new phenomenon.
      - magashna 7y ago
        Total conjecture, but seeing as how the private space industry has ramped up, it would make sense to leave during such a hostile administration
        WillPostForFood 7y ago
        Is the current administration hostile to NASA? Today, the President signed the Consolidated Appropriations Act of 2017, which funds the U.S. government for the remainder of the fiscal year. NASA received $19.65 billion—its best budget since 2010—and the Planetary Science Division saw its budget increase to $1.846 billion—its best budget in more than ten years. http://www.planetary.org/blogs/casey-dreier/2017/fy2017-planetary-science-just-got-its-best-budget-in-years.html http://www.planetary.org/blogs/casey-dreier/2017/fy2017-plan...
        magduf 7y ago
        They also are pushing NASA to send men to the Moon before Trump leaves office, without also giving them the budget necessary to do such a task (which honestly, with any budget, is still a ridiculously short schedule). They already had one main guy at NASA just quit because he knew this plan was unrealistic.
  - deleted 7y ago
    [deleted]
  - johnchristopher 7y ago
    I am working in a different industry (which calls itself an industry but is a joke and a god sent heaven for marketing consulting gig) but with the same kind of political minefield. Public servants get demotivated and set to mediocrity. Hired cattle gets demotivated and try to get out. Only managers and middle managers are driven by the ego boost coming from "changing things".
- chasingthewind 7y ago
  I was talking with my daughter about this yesterday and it really occurred to me that it's probably important to look at NASA through a realist lens. Here's their Vision and Mission statement: [0] Vision: We reach for new heights and reveal the unknown for the benefit of humankind Mission: Drive advances in science, technology, aeronautics, and space exploration to enhance knowledge, education, innovation, economic vitality and stewardship of Earth Given the history of using the space program as a tool of political/nationalist/defense goals it's probably more realistic to simply act as if the stated purpose of the agency is really a kind of "marketing" that is significantly independent of the "lived experience" so to speak. At minimum I would expect that a mental model of NASA that ignored the vision and mission statements would result in much better predictions about what NASA was likely to do. I should add that I consider all of this deeply unfortunate and I'm not defending it in the least. [0] https://www.nasa.gov/careers/our-mission-and-values https://www.nasa.gov/careers/our-mission-and-values
  - mcguire 7y ago
    Don't forget the employment project for aerospace engineers.
- clarkmoody 7y ago
  As a governmental entity, NASA will never be removed from politics. A million different things could completely derail any sort of 5-10 year plan, not to mention that as soon as NASA got a "guaranteed" fund-for-5-years-and-leave-us-alone budget, every other federal agency will clamor for that too. Long-term planning requires alignment of incentives. In government, the incentives of top officials are short-term in the extreme: get re-elected at all costs; grow next year's budget at all costs (e.g. waste all the ammo at the end of the year). Of course, more authoritarian states often tout their 5 Year Plans, but you're making quite a few tradeoffs of civil and economic liberties to get there. Until there is market-driven demand for humans to be on or around the Moon, politics will dominate the story.
  - nerdkid93 7y ago
    > Until there is market-driven demand for humans to be on or around the Moon, politics will dominate the story I don't know if I've ever thought this before, but wow. That's a great argument
    - whatshisface 7y ago
      Weirdly, you'd think that politicians would want to look smart by successfully administrating public projects.
  - 0xffff2 7y ago
    Of course people (including many at NASA) have been speculating about how to generate market-driven demand for a very long time (at least for as long as NASA has existed in the case of reports coming from there). The more I learn about the (lack of) history in commercialization of space, the more I doubt I will actually see significant exo-terrestrial colonies within my lifetime.
- hackeraccount 7y ago
  Oddly I agree with your description but not the solution. NASA doesn't need longer term goals - it needs shorter term goals. I'd say don't fund anything that takes longer then a single presidential term. That would limit what's possible but increase the likelihood that something will get finished. If the president says my goal is to land humans on Venus (with asbestos booties naturally) in 20 years then odd are in 4 years the new non-crazy president will scrap that goal and change it to land on Jupiter in 20 years. And then it will be to put a flag on the Sun. And so on. With 4 year goals the goals may be idotic but they will probably be finished because it'll be a single lunatic from start to end. It's also possible that from one crazy administration to the next there could a chance to build on what was accomplished so at the very least something will be accomplished.
  - dear 7y ago
    Or set up a large enough endowment fund that can only be used for that particular mission.
  - 0xffff2 7y ago
    This would be nice if it was possible, but 4 years is simply too short of a timeline to do things like the moon-return project. We might as well shut down the manned space program at that point.
- yellowapple 7y ago
  > Shouldn’t we listen to the experts here? When have politicians ever actually listened to experts?
  - mcguire 7y ago
    The brilliant thing about experts is that you can pretty easily find one to say anything you want said.
    - inflatableDodo 7y ago
      The market is thriving right now for thinktanks that specialise in delivering policy based evidence. Of course I could have shortened this by just writing, 'The market is thriving right now for thinktanks'.
superkuh 7y ago
It's terrible because they effectively canceled the asteroid retrieval mission (ARM) when they chose to fund the proposals that did not include any de-spin mechanisms. This leaves them with literally 3 possible asteroids to try to bring in. Useless. The point of the lunar gateway was to have a close (in time) place for resources and the like. But without any ability to capture and bring in asteroids it's just a waste of space.
- inlined 7y ago
  It could be that they’re fighting for tangible progress that would let them repropose something like ARM that now has a cheaper marginal cost.
- csours 7y ago
  Is there a sweet spot of asteroid size/energy required to adjust orbit/danger (etc, obviously I don't know all the parameters) Like, you don't want to waste time going after a bunch of tiny asteroids, but if they're too big it would take too much delta-v to move them. Or I might be wrong entirely.
crispyambulance 7y ago
All this "get back to the moon" stuff makes me wonder what the purpose of going to the moon actually is. It's definitely different for different people. If the whole point of the endeavor is just another space race exercise to demonstrate American prowess like the we did in the 1960's-- perhaps that's a waste of effort? Do we really need that symbolic achievement at such an enormous cost? Not to mention the opportunity cost of having to drop more scientifically productive robotic missions? The fact that the dithering idiocy of our current "administration" is even uttering anything about a moon mission sort of makes me think they see this as just a baloney "show-the-world" stunt. What if, instead, there was a focus on true science, unmanned missions, and perhaps steps towards actual space applications: mining, asteroid protection, and staging for permanent space installations ?
- gyaniv 7y ago
  I don't think the 'space race' notion can really apply here, since at least in some of the plans for their mission, they planned on doing it in a joint effort with several other space agencies (including the Russian). I agree that it really does seem like at least the official objective of the current administration (mostly the white house) only care about showing the world/the country/someone else that they're the best, that they have done everything, etc, etc, etc. Just like I think it's clear why they wanted to land on the moon specifically until 2024. I would like to believe that at least for (most of) the people actually working in NASA, they view their work in a more focused way (science, global cooperation and improvements), and it can be seen by the projects that for example are currently being researched by the NASA astronauts in the ISS.
- juliangoldsmith 7y ago
  The purpose is likely to generate interest in space, and to rebuild the technology the US had to conduct missions there. The average person doesn't care much about a probe landing on a comet, even if it is extremely impressive technologically. If you can show people walking on a celestial body, the average person can put that into perspective.
- deleted 7y ago
  [deleted]
Causality1 7y ago
Going back to the moon is just busy work to distract from the fact they don't have the funding or the ambition to get to Mars.
- reallydude 7y ago
  Going back the moon is the logical next step in going to Mars. You don't send off materials and bodies in the hope that years later it will work out. https://en.wikipedia.org/wiki/List_of_missions_to_the_Moon https://en.wikipedia.org/wiki/List_of_missions_to_the_Moon It took many attempts to get a successful moon mission where we landed. How many more before we could dig into the rock for a habitat? Now multiply the time by the round trip to Mars. The fantasy of being on Mars in X years is fraught with dangers that include our own imperfection in execution. Don't expect a man on Mars in your lifetime, at least not one who comes back.
  - mytailorisrich 7y ago
    Indeed, the Moon is the best location to develop and perfect technologies to settle on another planet and to live there autonomously. Because it's very near it's obviously much faster and cheaper to ship things there, and it allows near-instant communication back and forth. Once the technologies are mature it will just be a question of longer shipping to mars or anywhere else.
    - Causality1 7y ago
      No, earth is the best place to develop technologies to settle on another world. Planning a moon base when we can't even build and run a sealed biosphere on earth is like looking for sponsors for your F-1 team before learning how to drive a car.
      - mytailorisrich 7y ago
        Earth is a good place to develop and simulate but at one point we need to put this into practice and learn a lot in the process. To use your F-1 analogy: At one point you need to build and an actual car and to drive it on an actual track.
Mvandenbergh 7y ago
The thing about the original moon landing programme was that it had a great clarity of outcome and timeline. What: Land a man on the moon and return him safely When: Before the decade is out That meant NASA could really focus and throw out everything that wasn't directly on that path. Reusability - take too long, we'll build each craft from scratch. Permanent mission - Too complicated, keep the missions very short. Multi-launch architecture - Nope, too complicated again. Launch it all together. Crew size? Two on the moon so they could help each other, one in the CM to aid in docking. Want a larger crew? Sorry, no. Three is the minimum so that's what you get. Complicated re-entry vehicles? Nope. We know we can make ablative work. What is NASA's manned programme for now? Maybe the Moon. When, who knows? Maybe Mars. What architecture, when, how, for how long? Who knows. Moon orbit? For what, when? who knows. It's impossible to run a clear programme if you don't know what it's for!
- jpadkins 7y ago
  constraints help drive engineering decisions!
- mikeash 7y ago
  On one hand, this got everyone to focus and things happened fast. On the other hand, the result was only what was asked for. We went half a dozen times and then that was it. You want bigger missions? A base? Mars? Nope, not what we’re going for. Without JFK’s challenge, I’m sure we would have taken longer, but maybe it would have been more sustainable.
  - pgeorgi 7y ago
    > You want bigger missions? A base? Mars? Nope, not what we’re going for. Could be specified as well: "Internationally organized base station (ISS style) on the Moon by 2030, permanently staffed after 2032, an experimental ecosystem to work towards self-sustaining O2 and food generation set up by 2037, usable as launchpad for Mars missions by 2045" That would at least provide clarity on priorities but it's risky: the success would make you famous forever (see JFK) but so would failure. On the other hand, it requires the next 7 administrations to support a programme that will make _you_ famous, not them.
contactlight11 7y ago
The whole idea of the Senate Launch System (SLS) is flawed from the start. When NASA has been at its finest, it has been on the edge of innovation. Think Apollo, Shuttle, ISS, all the Mars Landers, the Voyagers, Cassini, New Horizons, etc. So why is NASA wasting billions to make a rocket, something we've known how to do reliability for more than 50 years? The reason is simple - politics. NASA is a political agency. They suffer from the same short-sighted, narrow focus thinking that a lot of other areas in policy live with. This is what hamstrings NASA the most, the constant change in directive, especially with regards to human spaceflight. There are commercial alternatives that can already provide heavy lift capability, or at the very least are well positioned to take $1-3B and get one with even heavier capabilities flying. NASA is far too risk adverse these days to be building a rocket or a crew vehicle. They figured this out for commercial crew, why can't they figure it out for other architectures? Imagine NASA being able to cut the $2.5B/year line item that SLS has ballooned to and redirect that to other human spaceflight goals. Leaving commercial companies to build does not mean NASA is entirely removed from the process, for example ULA/SpaceX have been heavily reliant on knowledge transfer and oversight from NASA on their path towards commercial crew. Honestly, having just graduated from a top aerospace/electrical engineering school and having experience in the industry myself, this is why you see the top talent going to places like SpaceX, Blue Origin, and a whole host of other commercial companies. These companies have a clear vision that NASA lacks. The NASA centers recent graduates gravitate towards are Caltech/JPL and APL/Goddard because they operate (almost) entirely independently from the rest of bureaucratic monster with serious research and a get-it-done attitude. A lot of the work at other facilities is farmed out to commercial companies, leaving a lot of NASA people in oversight/paperwork heavy jobs. This is not a blanket statement, but there is certainly a lot of "one technician doing the work and 5 engineers watching him" going on. So if you follow the idea that NASA belongs at the forefront of research, what type of work do they do? Well, they are research heavy and build only the most advanced tech as a result. They research Mars and build rovers/architecture to further that research and get humans there. They conduct research on the ISS to further medicine for people back on Earth and learn about long term "0g" exposure. They research deepspace travel and build lunar gateways and architecture to support that. They build drones to go to Titan, build probes to fly by outer planets, etc. And then, they pay a commercial company to fly it for them (just because NASA did the bulk of the research that enables current rockets to be so successful does NOT mean they have to continue being the one making the rocket. Yes SLS has Boeing as a primary contractor, but the point is it's branded as a NASA rocket).
jpadkins 7y ago
I think one of the great potentials of commercial space exploration (and exploitation) is better long term focus (and stable leadership). Changing the mission every 4 or 8 years is not conducive with this stage of space exploration.
newintellectual 7y ago
NASA is a terrible idea. Shut it down.
LinuxBender 7y ago
Would building a lunar space station get us closer to being able to deflect mass extinction sized asteroids?
- moate 7y ago
  Of course it would. But the important question is "how much closer". That would be much harder to answer.
  - LinuxBender 7y ago
    Is there anyone from NASA or SpaceX here that could offer some opinions on how much closer we could get to deflecting / mining mass extinction asteroids?
yellowapple 7y ago
One of the things the anti-station crowd misses is that giant rockets like Apollo are pretty expensive and wasteful. Apollo was great for getting us to the Moon first, but not necessarily for continuing to go there. An ideal would be at the very least a place for the lander to dock and refuel during the return trip. Then you don't have to haul a lander on every single mission, and thus can use a smaller/cheaper rocket with just the (reusable!) crew module.
quanticle 7y ago
This might be a radical idea, but after reading that article, my thought was, "At this point, the most merciful thing to do might be to put NASA out of its misery." Specifically, this would entail: - The US government getting out of the business of designing launchers: We'd acquire launchers the same way the Air Force gets airplanes: define requirements and solicit bids. This isn't perfect (see: F-35), but it's a darn sight better than the current SLS process. After all, in World War 2, it's not as if the US Army Air Corps (and later, the US Army Air Force) designed every plane that it acquired. It put out requirements and solicited designs from aircraft manufacturers like Boeing, Curtiss, Vought, Douglas, etc. Now that rocketry is no longer an unproven and speculative endeavor, we should do the same, and seek to build up multiple competing rocket manufacturers - Giving near-Earth science to NOAA: Right now, Earth-focused satellites are split between NASA and NOAA. Giving a single agency responsibility for Earth-focused scientific satellites will ensure that they have a single clear voice advocating on their behalf - Sending the astronaut program back to the Air Force (or maybe create the much ballyhooed "Space Force") - Creating a new, smaller, more focused organization for exploration of deep space (i.e. space beyond Earth's gravity well). While this organization could wear NASA's logos, I think it would be better if there were a clean break with the past and the organization got a new name and new branding
- stcredzero 7y ago
  define requirements and solicit bids. This isn't perfect (see: F-35) Isn't the F-35 program criticized for short-circuiting a major part of the traditional procurement process? I'm not so sure you can completely compare the traditional procurement process and what happened with the F-35.
- cheeko1234 7y ago
  This is a terrible idea. NASA is still the best agency in the world for moving humanity forward, even with bureaucratic inefficiencies. No other agency will have the funds to do what NASA does for non-military reasons. For every tax dollar spent, the U.S. still gets about 7 times the return.
  - DataGata 7y ago
avmich 7y ago
For long time NASA announced a space program after space program only to be canceled at an unfortunate moment. We have to understand that our problems with advancing manned spaceflight are mainly organizational. And because of that, it's beneficial to focus efforts not on a grand goal, which may not survive the next budgetary fight in Congress, but instead on capabilities which can mostly be used for whatever goal we'll have in mind at any particular moment. We're well on the way along this idea already. Whatever payload can be used for on LEO, we already have means to get some 20 metric tons there reliably. This, as Heinlein put, is already half-way to anywhere in the Solar system. We also work on manned spacecrafts, which, while useful for getting to ISS and back, can also be used - mostly - for much more distant trips, to near-lunar space and more. We're growing a network of automatic stations, which can provide early reconnaissance for various sky bodies, navigational beacons and relays. A bunch of companies have growing experience with controlled landing and launching of one-stage rocket devices. Gateway has a good property in that it's another component on the way to the Moon - and elsewhere - which has higher chances to survive another organizational shakeup because it's easier to build Gateway than to mount a sizable manned program to the Moon surface. Gateway is an ISS on steroids - in terms of getting to a much higher point - but not much more in terms of complexity, and we became pretty good with building and maintaining ISS. A smaller ISS in Moon vicinity can be less risky and less expensive than many other projects. As for usefulness - given that Gateway is in place, it's much easier to manage risks for more bold manned and unmanned projects on the Moon. Here I disagree with Griffin - he doesn't seem to recognize organizational challenges which Gateway allows to solve. Gateway has benefits in easier construction (you don't need to land heavy modules on the Moon), better understanding of international cooperation (e.g., ESA will get experience launching modules towards the Moon), uses other than Moon (for later stages, when we might have some flow of materials from the Moo surface), easier return to Earth (so less risks), better coverage of Moon surface in terms of accessibility etc. IMO, not bad for something which actually has a better chance to get funded to completion than existing alternatives.
- cheeko1234 7y ago
  Finally, a sensical comment. You're exactly right. Given the constraints of politics/funding, NASA can't pull off long-term & ambitious goals like they used to in the 60s-70s, and the administrator of NASA, Jim Bridenstine, knows that. Using your term: ISS on steroids, the next stepping stone would be the Gateway on steroids: an orbiting station around Mars. Here's a cool pdf from NASA that goes into details: https://arstechnica.com/wp-content/uploads/2019/05/2019-Why-Gateway-v5.pdf https://arstechnica.com/wp-content/uploads/2019/05/2019-Why-...
jessriedel 7y ago
> Aware of such criticisms, NASA is defending the Gateway. In May, the agency quietly distributed a white paper titled “Why Gateway?” [PDF] that makes the case for the space station. Casey Handmer's take on that document, the best I know and strongly critical, is here: https://caseyhandmer.wordpress.com/2019/05/05/the-lunar-gateway-nasas-version/ https://caseyhandmer.wordpress.com/2019/05/05/the-lunar-gate...
- DuskStar 7y ago
  > The SLS is derived from the shuttle core propulsion system, but despite adding a stage and 30% more fuel somehow lost 40% of its lift capacity. If you know how this happened, please let me know. That is a massively sick burn right there.
PaulHoule 7y ago
Polls show that ordinary people don't care about the Moon and Mars. There is actually more support for planetary protection from asteroids, space-based observation of both Earth and Sky (people love the Hubble), resource utilization in space, etc... That is, the real Gerard K. O'Neil stuff. If it were me I would set a goal of building a sunscreen at the Earth-Sun L1 point (e.g. planetary protection) using lunar or asteroid materials -- something like the lunar gateway would be an ideal crossing point for that. Space-solar power could be a byproduct of these efforts. This should have the urgency of Space Battleship Yamato (aka Star Blazers.) The lunar gateway is also essential to long-term deep space exploration. One place where Obama was totally wrong was going to Mars without going to the Moon first. Since a Mars mission is going to be isolated from Earth for so long, we need to know that all of the technology is completely reliable and the best way to do that is get it to the point where going to the Moon is like riding the bus. Radiation exposure in deep space is a known problem with the known solution of using space resources to build a radiation shield. This could be lunar or asteroidal rock and ought to be an early goal. I am also very curious about Lunar geology and also the possibility that the moon has hidden sources of volatiles. People talk about the water, but you also need Carbon and Nitrogen as well as Phosphorous and Potassium to grow plants and run an economy. (Also you can't breath pure oxygen unless you want to end up like the Apollo 1 astronauts)
LoSboccacc 7y ago
on one hand I agree that a lunar base would be a cheaper option for a wealth of reasons including not having to refuel orbit keeping rockets, however, landing supply is far more risky than docking supply, which compound with the mission's distance and scope: failing a shipment is always an eventuality, but losing it at launch is far worse than losing it on arrival, in the first case you know immediately, in the other you know 2-3 weeks later, and that influences how large your stockpile needs to be. what I'd say would be useful is if this station was the stepping stone for a lunar space elevator. then it would be a great investment and a true stepping stone for a permanent lunar presence, but a stationary orbit around the moon is impossible (too far, you'd fall on earth), so the tether would actually have to anchor the station.
whatshisface 7y ago
The genius of LOP-G is that it can be converted back to an asteroid intercept platform (its original purpose) should the next president decide to change NASA's mission yet again.
jbattle 7y ago
Given the exponential nature of Tsiolkovsky's rocket equation, I don't understand why its not common to perform multiple launches from the ground to LEO, and then rendezvous in orbit and go to the moon, or mars, or whereever. If I'm understanding the mechanics properly (informed mostly by kerbal space program!) the biggest "expense" in traveling most places is getting into LEO. And every doubling of payload requires more than doubling of fuel. All of which requires significantly larger and more complex rockets. Either I'm misunderstanding the true costs of launches (I know the fuel itself is relatively cheap) or I'm underestimating the complexity of linking two spacecraft in a robust and rigid connection while in orbit.
- jessaustin 7y ago
  TNSTAAFL. I think you're misunderstanding that equation? You're trying to get to orbit, so hold v and delta-v constant. Then you have the ratio of "wet" to "dry" masses constant. So the more you're launching, the more fuel it takes, and that is linear. I don't see how physics would work otherwise?
  - manicdee 7y ago
    The ratio of wet and dry masses for a launch vehicle also depends on ISP, thrust, and aerodynamics. You can have an extremely high ISP and thus a lot of theoretical delta-v but you waste it all because your thrust ratio is below 1 and the vehicle can’t leave the ground. Over a certain size you can’t build up anymore and have to make the vehicle flat. This is because a certain surface area of exhaust nozzle can only provide so much thrust. So you get to about 100m and then your rocket can’t leave the ground because the mass of propellant is higher than the available thrust. Then there’s thrust to weight, meaning that to get off the ground and about two minutes into your launch it is far more important to have a lot of thrust than to have high efficiency. The rule of thumb for KSP players is 1.2 thrust to weight on the ground. You will fight gravity losses and end up with about 0.2g acceleration off the pad. This increases gradually as the mass of the vessel is burnt off. Later in flight the major force to overcome is atmospheric drag. The faster you go, the worse it gets. Fat rockets will have a harder time. So you can’t go too wide, you can’t go too tall, and there are many trade offs to be made along the way. But the short version is no, you don’t hold v and delta-v constant. There are many more variables to consider when launching a rocket from a standing start where gravity and an atmosphere are involved. Rockets do not scale linearly.
bushdid911 7y ago
Wow. Not even nuclear powering it.....
philwelch 7y ago
Out of curiosity, why isn't the gateway being planned for the Earth/Moon L1 point?
Animats 7y ago
The earth-orbiting ISS is only marginally useful. Who needs another money drain around around Luna? Moon Direct probably makes the most sense. It needs only the Falcon Heavy (about $150 million per launch) as a booster. That's a real rocket that's flown. No need for NASA's vaporware Space Lanch System ($14 billion spent so far over 8 years, still unfinished, zero launches.) Apollo did it with one giant launch, but now that assembling systems in orbit has been done many times, there's no real reason to build something the size of the Saturn V again.

129 points by howard941 7y ago

Sounds like it could be good if you want to go there repeatedly, bad if you just want to get there as fast as possible again.

lettergram 7y ago

It’s kind of ridiculous how often NASA has to reallocate their focus. Personally, I’d like to see a longer term 5 - 10 year plan that is voted on by congress and basically the funds are deposited in an escrow. It’s insane the waste that occurs from random political moves like this. I understand the need to be able to direct NASA, but that should be in addition to the described 5 - 10 year plans. This would give the flexibility needed, while at the same time ensuring skills and contractors are maintained and long term visions are still possible. I kind of view the “gate” in its current state as NASA knowing it’s the correct choice technically and trying to politically make it viable. Shouldn’t we listen to the experts here?

Ididntdothis 7y ago
Since Bush every incoming president has set up a “vision” that scraps all previous work and which then in turn gets scrapped by the next guy. I wonder how the people working there can keep motivated knowing that most of their work is just for show. Seems unmanned missions are fine but manned missions are just a mess.
- gyaniv 7y ago
  The problem is that since there's always a switch between Republican and Democrats, each president has a different perspective on the overall NASA mission (plus each one wants to leave a big mark), so they keep changing. I think what the people actually working there try to do (as it can be seen here) is find a way to fit what they have already done, with what the new mission statement is, so that they won't have to scrap everything they have done, only the limited amount. That's good is some senses (less wasted work), but the result is then usually not the most fitting solution.
  - lukeschlather 7y ago
    I don't think it's accurate to say there are any partisan components to the NASA mission. I guess the exception is the Republican party is trying to cut Earth observation satellites because the data coming back is politically inconvenient. However that's a pretty small part of NASA's budget.
- magduf 7y ago
  From what I've heard, a lot of people have left NASA as a result of the month-long government shutdown this year. NASA is a political football, and it's not going to get any better: it just takes too long to see a big mission (i.e., manned ones) through, so they're never going to get done with the way our government is running these days. The probes are usually OK because those can get done a lot quicker.
  - justin66 7y ago
    > From what I've heard, a lot of people have left NASA as a result of the month-long government shutdown this year. I've got two friends there, a civil servant and a contractor, and I've heard no such thing. That doesn't mean it isn't true, but I'm curious whether there's any data to back this up. You'd have to be careful looking at that data, too: a lot of people are retiring from NASA simply because they're old. Nothing that's happened to NASA lately is a new phenomenon.
    - magashna 7y ago
      Total conjecture, but seeing as how the private space industry has ramped up, it would make sense to leave during such a hostile administration
      - WillPostForFood 7y ago
        Is the current administration hostile to NASA? Today, the President signed the Consolidated Appropriations Act of 2017, which funds the U.S. government for the remainder of the fiscal year. NASA received $19.65 billion—its best budget since 2010—and the Planetary Science Division saw its budget increase to $1.846 billion—its best budget in more than ten years. http://www.planetary.org/blogs/casey-dreier/2017/fy2017-planetary-science-just-got-its-best-budget-in-years.html http://www.planetary.org/blogs/casey-dreier/2017/fy2017-plan...
        magduf 7y ago
        They also are pushing NASA to send men to the Moon before Trump leaves office, without also giving them the budget necessary to do such a task (which honestly, with any budget, is still a ridiculously short schedule). They already had one main guy at NASA just quit because he knew this plan was unrealistic.
- deleted 7y ago
  [deleted]
- johnchristopher 7y ago
  I am working in a different industry (which calls itself an industry but is a joke and a god sent heaven for marketing consulting gig) but with the same kind of political minefield. Public servants get demotivated and set to mediocrity. Hired cattle gets demotivated and try to get out. Only managers and middle managers are driven by the ego boost coming from "changing things".
chasingthewind 7y ago
I was talking with my daughter about this yesterday and it really occurred to me that it's probably important to look at NASA through a realist lens. Here's their Vision and Mission statement: [0] Vision: We reach for new heights and reveal the unknown for the benefit of humankind Mission: Drive advances in science, technology, aeronautics, and space exploration to enhance knowledge, education, innovation, economic vitality and stewardship of Earth Given the history of using the space program as a tool of political/nationalist/defense goals it's probably more realistic to simply act as if the stated purpose of the agency is really a kind of "marketing" that is significantly independent of the "lived experience" so to speak. At minimum I would expect that a mental model of NASA that ignored the vision and mission statements would result in much better predictions about what NASA was likely to do. I should add that I consider all of this deeply unfortunate and I'm not defending it in the least. [0] https://www.nasa.gov/careers/our-mission-and-values https://www.nasa.gov/careers/our-mission-and-values
- mcguire 7y ago
  Don't forget the employment project for aerospace engineers.
clarkmoody 7y ago
As a governmental entity, NASA will never be removed from politics. A million different things could completely derail any sort of 5-10 year plan, not to mention that as soon as NASA got a "guaranteed" fund-for-5-years-and-leave-us-alone budget, every other federal agency will clamor for that too. Long-term planning requires alignment of incentives. In government, the incentives of top officials are short-term in the extreme: get re-elected at all costs; grow next year's budget at all costs (e.g. waste all the ammo at the end of the year). Of course, more authoritarian states often tout their 5 Year Plans, but you're making quite a few tradeoffs of civil and economic liberties to get there. Until there is market-driven demand for humans to be on or around the Moon, politics will dominate the story.
- nerdkid93 7y ago
  > Until there is market-driven demand for humans to be on or around the Moon, politics will dominate the story I don't know if I've ever thought this before, but wow. That's a great argument
  - whatshisface 7y ago
    Weirdly, you'd think that politicians would want to look smart by successfully administrating public projects.
- 0xffff2 7y ago
  Of course people (including many at NASA) have been speculating about how to generate market-driven demand for a very long time (at least for as long as NASA has existed in the case of reports coming from there). The more I learn about the (lack of) history in commercialization of space, the more I doubt I will actually see significant exo-terrestrial colonies within my lifetime.
hackeraccount 7y ago
Oddly I agree with your description but not the solution. NASA doesn't need longer term goals - it needs shorter term goals. I'd say don't fund anything that takes longer then a single presidential term. That would limit what's possible but increase the likelihood that something will get finished. If the president says my goal is to land humans on Venus (with asbestos booties naturally) in 20 years then odd are in 4 years the new non-crazy president will scrap that goal and change it to land on Jupiter in 20 years. And then it will be to put a flag on the Sun. And so on. With 4 year goals the goals may be idotic but they will probably be finished because it'll be a single lunatic from start to end. It's also possible that from one crazy administration to the next there could a chance to build on what was accomplished so at the very least something will be accomplished.
- dear 7y ago
  Or set up a large enough endowment fund that can only be used for that particular mission.
- 0xffff2 7y ago
  This would be nice if it was possible, but 4 years is simply too short of a timeline to do things like the moon-return project. We might as well shut down the manned space program at that point.
yellowapple 7y ago
> Shouldn’t we listen to the experts here? When have politicians ever actually listened to experts?
- mcguire 7y ago
  The brilliant thing about experts is that you can pretty easily find one to say anything you want said.
  - inflatableDodo 7y ago
    The market is thriving right now for thinktanks that specialise in delivering policy based evidence. Of course I could have shortened this by just writing, 'The market is thriving right now for thinktanks'.

superkuh 7y ago

It's terrible because they effectively canceled the asteroid retrieval mission (ARM) when they chose to fund the proposals that did not include any de-spin mechanisms. This leaves them with literally 3 possible asteroids to try to bring in. Useless. The point of the lunar gateway was to have a close (in time) place for resources and the like. But without any ability to capture and bring in asteroids it's just a waste of space.

inlined 7y ago
It could be that they’re fighting for tangible progress that would let them repropose something like ARM that now has a cheaper marginal cost.
csours 7y ago
Is there a sweet spot of asteroid size/energy required to adjust orbit/danger (etc, obviously I don't know all the parameters) Like, you don't want to waste time going after a bunch of tiny asteroids, but if they're too big it would take too much delta-v to move them. Or I might be wrong entirely.

crispyambulance 7y ago

All this "get back to the moon" stuff makes me wonder what the purpose of going to the moon actually is. It's definitely different for different people. If the whole point of the endeavor is just another space race exercise to demonstrate American prowess like the we did in the 1960's-- perhaps that's a waste of effort? Do we really need that symbolic achievement at such an enormous cost? Not to mention the opportunity cost of having to drop more scientifically productive robotic missions? The fact that the dithering idiocy of our current "administration" is even uttering anything about a moon mission sort of makes me think they see this as just a baloney "show-the-world" stunt. What if, instead, there was a focus on true science, unmanned missions, and perhaps steps towards actual space applications: mining, asteroid protection, and staging for permanent space installations ?

gyaniv 7y ago
I don't think the 'space race' notion can really apply here, since at least in some of the plans for their mission, they planned on doing it in a joint effort with several other space agencies (including the Russian). I agree that it really does seem like at least the official objective of the current administration (mostly the white house) only care about showing the world/the country/someone else that they're the best, that they have done everything, etc, etc, etc. Just like I think it's clear why they wanted to land on the moon specifically until 2024. I would like to believe that at least for (most of) the people actually working in NASA, they view their work in a more focused way (science, global cooperation and improvements), and it can be seen by the projects that for example are currently being researched by the NASA astronauts in the ISS.
juliangoldsmith 7y ago
The purpose is likely to generate interest in space, and to rebuild the technology the US had to conduct missions there. The average person doesn't care much about a probe landing on a comet, even if it is extremely impressive technologically. If you can show people walking on a celestial body, the average person can put that into perspective.
deleted 7y ago
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Causality1 7y ago

Going back to the moon is just busy work to distract from the fact they don't have the funding or the ambition to get to Mars.

reallydude 7y ago
Going back the moon is the logical next step in going to Mars. You don't send off materials and bodies in the hope that years later it will work out. https://en.wikipedia.org/wiki/List_of_missions_to_the_Moon https://en.wikipedia.org/wiki/List_of_missions_to_the_Moon It took many attempts to get a successful moon mission where we landed. How many more before we could dig into the rock for a habitat? Now multiply the time by the round trip to Mars. The fantasy of being on Mars in X years is fraught with dangers that include our own imperfection in execution. Don't expect a man on Mars in your lifetime, at least not one who comes back.
- mytailorisrich 7y ago
  Indeed, the Moon is the best location to develop and perfect technologies to settle on another planet and to live there autonomously. Because it's very near it's obviously much faster and cheaper to ship things there, and it allows near-instant communication back and forth. Once the technologies are mature it will just be a question of longer shipping to mars or anywhere else.
  - Causality1 7y ago
    No, earth is the best place to develop technologies to settle on another world. Planning a moon base when we can't even build and run a sealed biosphere on earth is like looking for sponsors for your F-1 team before learning how to drive a car.
    - mytailorisrich 7y ago
      Earth is a good place to develop and simulate but at one point we need to put this into practice and learn a lot in the process. To use your F-1 analogy: At one point you need to build and an actual car and to drive it on an actual track.

Mvandenbergh 7y ago

The thing about the original moon landing programme was that it had a great clarity of outcome and timeline. What: Land a man on the moon and return him safely When: Before the decade is out That meant NASA could really focus and throw out everything that wasn't directly on that path. Reusability - take too long, we'll build each craft from scratch. Permanent mission - Too complicated, keep the missions very short. Multi-launch architecture - Nope, too complicated again. Launch it all together. Crew size? Two on the moon so they could help each other, one in the CM to aid in docking. Want a larger crew? Sorry, no. Three is the minimum so that's what you get. Complicated re-entry vehicles? Nope. We know we can make ablative work. What is NASA's manned programme for now? Maybe the Moon. When, who knows? Maybe Mars. What architecture, when, how, for how long? Who knows. Moon orbit? For what, when? who knows. It's impossible to run a clear programme if you don't know what it's for!

jpadkins 7y ago
constraints help drive engineering decisions!
mikeash 7y ago
On one hand, this got everyone to focus and things happened fast. On the other hand, the result was only what was asked for. We went half a dozen times and then that was it. You want bigger missions? A base? Mars? Nope, not what we’re going for. Without JFK’s challenge, I’m sure we would have taken longer, but maybe it would have been more sustainable.
- pgeorgi 7y ago
  > You want bigger missions? A base? Mars? Nope, not what we’re going for. Could be specified as well: "Internationally organized base station (ISS style) on the Moon by 2030, permanently staffed after 2032, an experimental ecosystem to work towards self-sustaining O2 and food generation set up by 2037, usable as launchpad for Mars missions by 2045" That would at least provide clarity on priorities but it's risky: the success would make you famous forever (see JFK) but so would failure. On the other hand, it requires the next 7 administrations to support a programme that will make _you_ famous, not them.

contactlight11 7y ago

The whole idea of the Senate Launch System (SLS) is flawed from the start. When NASA has been at its finest, it has been on the edge of innovation. Think Apollo, Shuttle, ISS, all the Mars Landers, the Voyagers, Cassini, New Horizons, etc. So why is NASA wasting billions to make a rocket, something we've known how to do reliability for more than 50 years? The reason is simple - politics. NASA is a political agency. They suffer from the same short-sighted, narrow focus thinking that a lot of other areas in policy live with. This is what hamstrings NASA the most, the constant change in directive, especially with regards to human spaceflight. There are commercial alternatives that can already provide heavy lift capability, or at the very least are well positioned to take $1-3B and get one with even heavier capabilities flying. NASA is far too risk adverse these days to be building a rocket or a crew vehicle. They figured this out for commercial crew, why can't they figure it out for other architectures? Imagine NASA being able to cut the $2.5B/year line item that SLS has ballooned to and redirect that to other human spaceflight goals. Leaving commercial companies to build does not mean NASA is entirely removed from the process, for example ULA/SpaceX have been heavily reliant on knowledge transfer and oversight from NASA on their path towards commercial crew. Honestly, having just graduated from a top aerospace/electrical engineering school and having experience in the industry myself, this is why you see the top talent going to places like SpaceX, Blue Origin, and a whole host of other commercial companies. These companies have a clear vision that NASA lacks. The NASA centers recent graduates gravitate towards are Caltech/JPL and APL/Goddard because they operate (almost) entirely independently from the rest of bureaucratic monster with serious research and a get-it-done attitude. A lot of the work at other facilities is farmed out to commercial companies, leaving a lot of NASA people in oversight/paperwork heavy jobs. This is not a blanket statement, but there is certainly a lot of "one technician doing the work and 5 engineers watching him" going on. So if you follow the idea that NASA belongs at the forefront of research, what type of work do they do? Well, they are research heavy and build only the most advanced tech as a result. They research Mars and build rovers/architecture to further that research and get humans there. They conduct research on the ISS to further medicine for people back on Earth and learn about long term "0g" exposure. They research deepspace travel and build lunar gateways and architecture to support that. They build drones to go to Titan, build probes to fly by outer planets, etc. And then, they pay a commercial company to fly it for them (just because NASA did the bulk of the research that enables current rockets to be so successful does NOT mean they have to continue being the one making the rocket. Yes SLS has Boeing as a primary contractor, but the point is it's branded as a NASA rocket).

jpadkins 7y ago

I think one of the great potentials of commercial space exploration (and exploitation) is better long term focus (and stable leadership). Changing the mission every 4 or 8 years is not conducive with this stage of space exploration.

newintellectual 7y ago

NASA is a terrible idea. Shut it down.

LinuxBender 7y ago

Would building a lunar space station get us closer to being able to deflect mass extinction sized asteroids?

moate 7y ago
Of course it would. But the important question is "how much closer". That would be much harder to answer.
- LinuxBender 7y ago
  Is there anyone from NASA or SpaceX here that could offer some opinions on how much closer we could get to deflecting / mining mass extinction asteroids?

yellowapple 7y ago

One of the things the anti-station crowd misses is that giant rockets like Apollo are pretty expensive and wasteful. Apollo was great for getting us to the Moon first, but not necessarily for continuing to go there. An ideal would be at the very least a place for the lander to dock and refuel during the return trip. Then you don't have to haul a lander on every single mission, and thus can use a smaller/cheaper rocket with just the (reusable!) crew module.

quanticle 7y ago

This might be a radical idea, but after reading that article, my thought was, "At this point, the most merciful thing to do might be to put NASA out of its misery." Specifically, this would entail: - The US government getting out of the business of designing launchers: We'd acquire launchers the same way the Air Force gets airplanes: define requirements and solicit bids. This isn't perfect (see: F-35), but it's a darn sight better than the current SLS process. After all, in World War 2, it's not as if the US Army Air Corps (and later, the US Army Air Force) designed every plane that it acquired. It put out requirements and solicited designs from aircraft manufacturers like Boeing, Curtiss, Vought, Douglas, etc. Now that rocketry is no longer an unproven and speculative endeavor, we should do the same, and seek to build up multiple competing rocket manufacturers - Giving near-Earth science to NOAA: Right now, Earth-focused satellites are split between NASA and NOAA. Giving a single agency responsibility for Earth-focused scientific satellites will ensure that they have a single clear voice advocating on their behalf - Sending the astronaut program back to the Air Force (or maybe create the much ballyhooed "Space Force") - Creating a new, smaller, more focused organization for exploration of deep space (i.e. space beyond Earth's gravity well). While this organization could wear NASA's logos, I think it would be better if there were a clean break with the past and the organization got a new name and new branding

stcredzero 7y ago
define requirements and solicit bids. This isn't perfect (see: F-35) Isn't the F-35 program criticized for short-circuiting a major part of the traditional procurement process? I'm not so sure you can completely compare the traditional procurement process and what happened with the F-35.
cheeko1234 7y ago
This is a terrible idea. NASA is still the best agency in the world for moving humanity forward, even with bureaucratic inefficiencies. No other agency will have the funds to do what NASA does for non-military reasons. For every tax dollar spent, the U.S. still gets about 7 times the return.
- DataGata 7y ago

avmich 7y ago

For long time NASA announced a space program after space program only to be canceled at an unfortunate moment. We have to understand that our problems with advancing manned spaceflight are mainly organizational. And because of that, it's beneficial to focus efforts not on a grand goal, which may not survive the next budgetary fight in Congress, but instead on capabilities which can mostly be used for whatever goal we'll have in mind at any particular moment. We're well on the way along this idea already. Whatever payload can be used for on LEO, we already have means to get some 20 metric tons there reliably. This, as Heinlein put, is already half-way to anywhere in the Solar system. We also work on manned spacecrafts, which, while useful for getting to ISS and back, can also be used - mostly - for much more distant trips, to near-lunar space and more. We're growing a network of automatic stations, which can provide early reconnaissance for various sky bodies, navigational beacons and relays. A bunch of companies have growing experience with controlled landing and launching of one-stage rocket devices. Gateway has a good property in that it's another component on the way to the Moon - and elsewhere - which has higher chances to survive another organizational shakeup because it's easier to build Gateway than to mount a sizable manned program to the Moon surface. Gateway is an ISS on steroids - in terms of getting to a much higher point - but not much more in terms of complexity, and we became pretty good with building and maintaining ISS. A smaller ISS in Moon vicinity can be less risky and less expensive than many other projects. As for usefulness - given that Gateway is in place, it's much easier to manage risks for more bold manned and unmanned projects on the Moon. Here I disagree with Griffin - he doesn't seem to recognize organizational challenges which Gateway allows to solve. Gateway has benefits in easier construction (you don't need to land heavy modules on the Moon), better understanding of international cooperation (e.g., ESA will get experience launching modules towards the Moon), uses other than Moon (for later stages, when we might have some flow of materials from the Moo surface), easier return to Earth (so less risks), better coverage of Moon surface in terms of accessibility etc. IMO, not bad for something which actually has a better chance to get funded to completion than existing alternatives.

cheeko1234 7y ago
Finally, a sensical comment. You're exactly right. Given the constraints of politics/funding, NASA can't pull off long-term & ambitious goals like they used to in the 60s-70s, and the administrator of NASA, Jim Bridenstine, knows that. Using your term: ISS on steroids, the next stepping stone would be the Gateway on steroids: an orbiting station around Mars. Here's a cool pdf from NASA that goes into details: https://arstechnica.com/wp-content/uploads/2019/05/2019-Why-Gateway-v5.pdf https://arstechnica.com/wp-content/uploads/2019/05/2019-Why-...

jessriedel 7y ago

> Aware of such criticisms, NASA is defending the Gateway. In May, the agency quietly distributed a white paper titled “Why Gateway?” [PDF] that makes the case for the space station. Casey Handmer's take on that document, the best I know and strongly critical, is here: https://caseyhandmer.wordpress.com/2019/05/05/the-lunar-gateway-nasas-version/ https://caseyhandmer.wordpress.com/2019/05/05/the-lunar-gate...

DuskStar 7y ago
> The SLS is derived from the shuttle core propulsion system, but despite adding a stage and 30% more fuel somehow lost 40% of its lift capacity. If you know how this happened, please let me know. That is a massively sick burn right there.

PaulHoule 7y ago

Polls show that ordinary people don't care about the Moon and Mars. There is actually more support for planetary protection from asteroids, space-based observation of both Earth and Sky (people love the Hubble), resource utilization in space, etc... That is, the real Gerard K. O'Neil stuff. If it were me I would set a goal of building a sunscreen at the Earth-Sun L1 point (e.g. planetary protection) using lunar or asteroid materials -- something like the lunar gateway would be an ideal crossing point for that. Space-solar power could be a byproduct of these efforts. This should have the urgency of Space Battleship Yamato (aka Star Blazers.) The lunar gateway is also essential to long-term deep space exploration. One place where Obama was totally wrong was going to Mars without going to the Moon first. Since a Mars mission is going to be isolated from Earth for so long, we need to know that all of the technology is completely reliable and the best way to do that is get it to the point where going to the Moon is like riding the bus. Radiation exposure in deep space is a known problem with the known solution of using space resources to build a radiation shield. This could be lunar or asteroidal rock and ought to be an early goal. I am also very curious about Lunar geology and also the possibility that the moon has hidden sources of volatiles. People talk about the water, but you also need Carbon and Nitrogen as well as Phosphorous and Potassium to grow plants and run an economy. (Also you can't breath pure oxygen unless you want to end up like the Apollo 1 astronauts)

LoSboccacc 7y ago

on one hand I agree that a lunar base would be a cheaper option for a wealth of reasons including not having to refuel orbit keeping rockets, however, landing supply is far more risky than docking supply, which compound with the mission's distance and scope: failing a shipment is always an eventuality, but losing it at launch is far worse than losing it on arrival, in the first case you know immediately, in the other you know 2-3 weeks later, and that influences how large your stockpile needs to be. what I'd say would be useful is if this station was the stepping stone for a lunar space elevator. then it would be a great investment and a true stepping stone for a permanent lunar presence, but a stationary orbit around the moon is impossible (too far, you'd fall on earth), so the tether would actually have to anchor the station.

whatshisface 7y ago

The genius of LOP-G is that it can be converted back to an asteroid intercept platform (its original purpose) should the next president decide to change NASA's mission yet again.

jbattle 7y ago

Given the exponential nature of Tsiolkovsky's rocket equation, I don't understand why its not common to perform multiple launches from the ground to LEO, and then rendezvous in orbit and go to the moon, or mars, or whereever. If I'm understanding the mechanics properly (informed mostly by kerbal space program!) the biggest "expense" in traveling most places is getting into LEO. And every doubling of payload requires more than doubling of fuel. All of which requires significantly larger and more complex rockets. Either I'm misunderstanding the true costs of launches (I know the fuel itself is relatively cheap) or I'm underestimating the complexity of linking two spacecraft in a robust and rigid connection while in orbit.

jessaustin 7y ago
TNSTAAFL. I think you're misunderstanding that equation? You're trying to get to orbit, so hold v and delta-v constant. Then you have the ratio of "wet" to "dry" masses constant. So the more you're launching, the more fuel it takes, and that is linear. I don't see how physics would work otherwise?
- manicdee 7y ago
  The ratio of wet and dry masses for a launch vehicle also depends on ISP, thrust, and aerodynamics. You can have an extremely high ISP and thus a lot of theoretical delta-v but you waste it all because your thrust ratio is below 1 and the vehicle can’t leave the ground. Over a certain size you can’t build up anymore and have to make the vehicle flat. This is because a certain surface area of exhaust nozzle can only provide so much thrust. So you get to about 100m and then your rocket can’t leave the ground because the mass of propellant is higher than the available thrust. Then there’s thrust to weight, meaning that to get off the ground and about two minutes into your launch it is far more important to have a lot of thrust than to have high efficiency. The rule of thumb for KSP players is 1.2 thrust to weight on the ground. You will fight gravity losses and end up with about 0.2g acceleration off the pad. This increases gradually as the mass of the vessel is burnt off. Later in flight the major force to overcome is atmospheric drag. The faster you go, the worse it gets. Fat rockets will have a harder time. So you can’t go too wide, you can’t go too tall, and there are many trade offs to be made along the way. But the short version is no, you don’t hold v and delta-v constant. There are many more variables to consider when launching a rocket from a standing start where gravity and an atmosphere are involved. Rockets do not scale linearly.

bushdid911 7y ago

Wow. Not even nuclear powering it.....

philwelch 7y ago

Out of curiosity, why isn't the gateway being planned for the Earth/Moon L1 point?

Animats 7y ago

The earth-orbiting ISS is only marginally useful. Who needs another money drain around around Luna? Moon Direct probably makes the most sense. It needs only the Falcon Heavy (about $150 million per launch) as a booster. That's a real rocket that's flown. No need for NASA's vaporware Space Lanch System ($14 billion spent so far over 8 years, still unfinished, zero launches.) Apollo did it with one giant launch, but now that assembling systems in orbit has been done many times, there's no real reason to build something the size of the Saturn V again.