It has been over half a century since the Saturn V flew. In terms of modern technology, a half a century is a long time. And while we begin to slowly return to the idea of there being best solutions, most of what was learned with that monumental machine is still not appreciated. What is even more unfortunate is that the mistakes made after Apollo were not considered and those wrong turns have gone uncorrected. All constructs follow their purpose. Perhaps 50 centuries ago there were four wheeled wagons and that design can be seen in the modern car. The ME-262 jet fighter is the same configuration used for most large passenger jets. The Saturn V embodies several fundamental design concepts that are almost impossible to improve upon.
The first fundamental is the 3 stages, with the first carrying the payload clear of the lower atmosphere and through the maximum stresses of the launch, then the second placing the third stage into a Low Earth Orbit, and finally the third stage carrying the payload out of Earths gravity well into outer space. The first stage using the largest and thus the fewest number of engines possible.
The second fundamental is the escape tower/capsule combination with the tower able to blast the minimum mass capsule at extreme velocity away from a launch failure off the pad and during the most dangerous parts of the ascent. The self-stabilizing capsule shape parachuting into the ocean represents far less risk than any other possible method of returning human beings from space.
The third fundamental is the Moon as the primary destination for Human Space Flight and indeed after Apollo 8 in 1968 the very definition of Human Space Flight should have been changed and Earth orbit not defined as HSF but rather Earth Orbit or Orbital Flight. Using this measure the space age lasted less than 4 years.
In the half century since Saturn V reusability has become a recent issue with the question of whether expending single use hardware is still desirable and to what degree reusability will replace this paradigm.
One lesson seems clear; the spaceplane is a failed concept. The penalty for wings and landing gear and all that goes with it is not worth the trouble. In regard to reusing stages, Vertical Take-off/ Vertical Landing (VTVL), which was proposed long before Apollo, now appears to be a new fundamental.
Russia detonating a nuclear weapon would activate multiple systems in the U.S., China, England, France, and the five lesser nuclear powers and set several hair triggers. The critical problem here is that M.A.D. is based on destroying the adversary completely with massive nuclear retaliation as THE way to keep these weapons from being used. It is all or nothing. The only way to be sure you have enough weapons to do that is to launch them before the enemy destroys them with a “first strike.” This is why satellites and communications are so important because it requires very little degradation of those warning and control systems before the button to launch everything is pushed. And that turns into the end of the world. With the tens of thousands of weapons that existed in the 80’s this meant almost the entire human race would die from the effects. Not that bad now but it would still be horrific beyond what anyone could imagine with likely half or more of humankind dying from starvation. Billions would die. What people do not get, and which is more terrifying than anything else about this, is that there are powerful people who would not have a problem with making it happen. It can happen though most of us do not think so.
I am sitting out in the middle of nowhere in the Midwest and this town has broadband. Ironically I lived in Florida close to some pretty big cities and had to use satellite internet and had no problem with it except during thunderstorms. Starlink is a field of dreams waiting for video gamers in Alaska to pay for a fleet of shiny starships to Mars. It is like Enron, Theranos, and Delorean all rolled into one.
It does not “seem” to have been, it was. The Space Shuttle concept was a Saturn V class launch vehicle that expended one tank on the altar of the rocket equation and reused everything else. It was and is an excellent concept. The Falcon does not do this and is not in the same league.
The reason the Shuttle always did this so poorly was that it was designed and run on the cheap and that can be traced back to three things;
1. The Vietnam War which made a fortune for defense contractors but pushed government spending over edge, leaving little left for NASA.
2. The rise of Neoliberalism which demanded “the market” decide all things, and the Space Shuttle “make space pay for itself.”
3. The Reagan Revolution which insured no improvements would be made on the STS and that pressure to launch would kill two crews.
“In orbit refueling” is the white elephant in my opinion. It became part of NewSpace dogma because the Falcon 9 could not and cannot lift enough to support any worthwhile lunar return missions. I remember well ten years ago when small cheap rockets and depots could do it all and anything not made by their favorite company was endlessly trashed by fanboys.
Of course that never stopped and the same philosophy, modified, continues with the shiny.
A Super Heavy Lift Vehicle can send whatever needs to be sent to the Moon directly. A very large payload can be sent by a dual SHLV launch with an Earth Departure Stage docking with the payload in orbit. This is the most efficient architecture for cislunar space and sending humans Beyond Earth and Lunar Orbit (BELO) requires nuclear energy. Due to the requirement for shielding and artificial gravity, chemical propulsion is useless for human missions beyond the Moon. No magic depots needed.
What is “unforgiveable” to me is what NewSpace fans consider the solution to everything.
Actually Vlad, I started saying LEO was not space as a reaction to NewSpace dogma that proclaimed LEO as the place where propellent depots and tourist space stations would be and only the favorite hobby rocket was needed to make it all happen if only all the NASA money was just handed over to Elon. Remember?
I think what pushed me over the edge is when HLV tonnage was redefined. I remember when the Saturn V was the benchmark and that magic 100 tons was considered heavy lift and anything less was not. That changed because of NewSpace nonsense. The goalposts were moved as they say. I can move them also, or at least try to.
It was not about me, it was about fanboys, and I am sticking with it as long as the other nonsense continues. It makes sense to limit how much hyperbole and misinformation can be pushed on the public by defining what is and what is not. Now that you know what I am doing we can have an intelligent conversation about it.
Call me odd but I do not consider 62 miles up to be “outer space.” Sorry.
Ten…or hundred people can tell me 62 miles up is space but I do not have to agree since there is more than one definition of where space begins. It is arbitrary and subject to change because there is really no clear demarcation. The one I suggest using is the altitude where an object in orbit remains over one spot on Earth. That is 22,236 miles up. Anything hovering over a spot on the Earth, or in a different orbit that more than half of is above this altitude- I would call both Earth orbit and “Space”. I might go even farther and say outside of the Earth’s magnetosphere is “Outer Space.” Since the magnetosphere is largely absent above the poles then some orbits might be categorized as outer space I guess. Then there are the limits of Cislunar Space to consider. What would you suggest for that Vlad?
Because NewSpace fanboyism has tainted ALL discourse about space I really cannot tell you what I “believe” about SLS. I can tell you that America’s enemies love the NASA-bashing. I will not add to that trashing of the U.S. and it’s interests. In my view it falls under giving aid and comfort and is treasonous. While it is claimed it is all in the interest of making sure tax dollars are not wasted, I consider that a wink wink nudge nudge simply because these same people screaming at the top of their lungs about cost plus have zero to say about the ISS or the DOD or the recent Space Force budget. It is plain to me it is about an ideology, and the fanboys are ideologues I often refer to as “Ayn Rand in Space libertarian whackjobs.” It is anti-government, anti-taxation, and promotes the profit motive and “entrepreneurs” as the only way to expand humankind into space. In my view it is cult-like and bizarre to work against national space programs so viciously in the interest of promoting a private company. I do believe it is the worst thing that has ever happened to space exploration. Those fanboys that comment here, most of which I now have blocked, are well aware of my worldview and downvote me regularly.
“In general LOX\Kerosene and LOX\Methane give more thrust than hydrogen.“
Yeah….rocket science is not “in general.” Hydrogen has more energy per kilo.
You are wrong.
“Also in terms of ISRU making Oxygen is what gives the most bang for the buck not hydrogen and there are ways to make Oxygen out of lunar soil-“
And in terms of ISRU it is ICE that is, by far, by ANY MEASURE, the most useful resource.
You are wrong again!
If you are going to insert yourself into a conversation with this obviously fanboy-biased stuff, do it with someone else please.
As for the Atlas/Delta comparison, using the charts on the wiki pages, for 155,000 more pounds of lift-off thrust the Atlas lifts 210 more kilos (463 more pounds) to GTO.
Atlas
4,750 kg to GTO Maximum thrust (860,000 lbf) (sea level)
Specific impulse
311.3 s (3.053 km/s) (sea level)
337.8 s (3.313 km/s) (vacuum)
Delta
4,540 kg to GTO Maximum thrust (705,000 lbf) (sea level)
Specific impulse Sea level: 360 s (3.5 km/s)
Vacuum: 412 s (4.04 km/s)
The second stage of the Saturn V was actually of much lighter construction than the third stage which is contrary to what you stated, even though what you stated does make sense. If you have never read the story of the second stage it is epic. As for the Delta vs Atlas, I used to know some stats on those birds about 10 years ago but can’t recall much- and I don’t feel like studying up. If I am recalling correctly though, the Delta lifts more than the Atlas. It is just more expensive due to the engine (mostly). That is not what you are inferring if I am reading you correctly.
I do recall that hydrogen was thrice-damned by a certain fan club because their company of choice did not use it. I remember that vividly and the less-tankage-is-better-than-more-Isp argument rages on to this day it seems. The reality is that thrust being equal, a 450 Isp engine Lander is going to land and lift a lot more than a 350 Isp Lander…no matter what. Methane is interesting in that it is right between kerosene and hydrogen. Higher Isp than Kerosene but much less dense- like hydrogen. The worst of both worlds, but also the best for now because it is easier to store than hydrogen. While Hydrogen Peroxide is not nearly as toxic as NTO, it is still far more nasty than LOX.
In my view it all depends on cryo-cooler technology making hydrogen practical. If cryo-coolers can be made to work efficiently then ice on the Moon makes hydrogen the way to go. If a way to brew methane out of lunar resources can be found then that is plan B.
“Nothing like Apollo LM would ever be approved today,-“
It would absolutely be approved today. The design was nearly perfect if you want to put two people on the surface of the Moon from lunar orbit and then bring them back up. The pressure-fed hypergolic ablative thrust chamber engines, one variable and the other one not variable and even simpler for abort or ascent, were and are as good as it gets even now, over half a century later. What really surprises me is they have not simply taken that design and reproduced it with better materials. That is essentially what SpaceX did with the Falcon 9, which closely follows the design of the original Saturn 1B. Unfortunately SpaceX did not follow it closely enough and use an escape tower.
Hydrogen has the most energy- the highest Isp’s, well over 400. Because it requires more tankage this works against it in some ways but for upper stages it cannot be beat because of that number. Despite being extremely difficult to store and other problems- it is what took America to the Moon and von Braun, though initially being against hydrogen, eventually admitted the two hydrogen upper stages were the main reason Apollo succeeded.
Another reason hydrogen is desirable is the expander cycle rocket engine- the RL10 with an Isp of 460 seconds (!) which is a fairly simple engine and thus very reliable is the prime example. Hydrogen is so troublesome to maintain if these highest Isp numbers were not important then it would not be used. It is as simple as that. The ice on the Moon makes hydrogen desirable because propellants can be made from that ice. The trick is keeping it from boiling off. A high-powered efficient cryo-cooler would make all things possible in cislunar space by way of the lunar ice. But I have yet to see or hear anything about that hardware yet.
“Hydrogen is especially suited for heavy duty transport applications in buses, trucks, trains, ships, aircraft, and applications in stationary power.”
Only the last two really…ammonia works better in piston engines and ships with the caveat that nitrous oxide is filtered out of the exhaust. Ammonia transports far more easily that hydrogen. But you can’t filter jet exhaust so for commercial jets it is the go-to in the future.
I like the Stratolaunch as a candidate to use liquid hydrogen, carrying it in the two fuselages. A passenger pod equipped to detach and safely land with parachutes would make it a revolutionary commercial passenger jet.
“-for both a sustainable human presence on the moon and also future human missions to Mars,-“
Whenever Mars is mentioned it is a flag that what is being discussed is total B.S.
A “sustainable human presence on the moon” first of all requires a radiation sanctuary of some kind. I have seen nothing about that anywhere. Nothing.
There are three ways to do it in my opinion:
1. Find a lava tube we can move into, which would be great, but there are zero missions I know of to find one.
2. Have a plan to erect some kind of structure over a small crater and then an excavator to pile regolith on top.
3. Use robot landers to take ice-derived water up to lunar orbit to fill a wet workshop or workshops with water for radiation shields.
I would suggest work on flying around the Moon with people on a very limited number of missions to perfect that, while landing robots on ice deposits to perfect ISRU, and place some workshops in lunar orbit. And while we are doing that we can look for lava tubes AND perhaps do some robot construction on the surface.
Landing humans on the Moon just for bootprints is nothing more than a repeat of Apollo and will accomplish very little. Some kind of permanent presence is the goal, either in lunar orbit, in a crater, or in a lava tube.
Ice on the Moon 