What human equivalent decade would you want the Career game to start?

[Frozen_Heart]

LV-N is '60's tech.

Wasn't used in space in the 60s and still hasn't been though. It might be a long time its ever used.

[regex]

Wasn't used in space in the 60s and still hasn't been though. It might be a long time its ever used.

And yet it's still '60's tech.

E: I feel it's important to make this distinction as KSP's progression should not reflect human politics.

Edited April 19, 2015 by regex

[Eric S]

I think 30s or 40s makes sense. Starting unmanned is good because it makes your first manned flight seem more meaningful.

Starting manned makes your first unmanned flight seem more meaningful, at least if you're using RemoteTech. As a more straight answer, I'd be fine with starting unmanned if the game had kOS or something like it built in, but that's not the direction the game has gone. And yes, I've played alternate tech trees, and RemoteTech or kOS is the only thing that makes starting unmanned interesting to me for more than one playthrough. I'll try the sounding rockets mod, but I don't see that as being that much different.

E: I feel it's important to make this distinction as KSP's progression should not reflect human politics.

I'll second that. Fear of the words atomic and nuclear are out of hand in the common populous, to the point that they had to jump through hoops to find a name for MRI that didn't scare people.

[Kibble]

2020-2030s. (Aka LV-N, Rapier)

Nuclear engines and SABRE might not fly ever - studies generally show that the extra ISP from solid-core nuclear-thermal rocket engines does not make up for the severely increased complexity, mass of the reactor and nuclear fuel, and the fact that the propellant is nasty liquid hydrogen. SABRE, on the other paw, probably just won't work.

Rocket technology is fairly old, and about as mature as jets! Space travel will almost certainly look very similar for hundreds of years to come.

[regex]

studies generally show that the extra ISP from solid-core nuclear-thermal rocket engines does not make up for the severely increased complexity, mass of the reactor and nuclear fuel, and the fact that the propellant is nasty liquid hydrogen.

Good one, I lol'd.

[Brotoro]

Good one, I lol'd.

regex is correct in being amused.

[uglyduckling81]

Nuclear engines and SABRE might not fly ever - studies generally show that the extra ISP from solid-core nuclear-thermal rocket engines does not make up for the severely increased complexity, mass of the reactor and nuclear fuel, and the fact that the propellant is nasty liquid hydrogen. SABRE, on the other paw, probably just won't work.

Rocket technology is fairly old, and about as mature as jets! Space travel will almost certainly look very similar for hundreds of years to come.

\

11 mins for explanation on how the engine works.

Actually nuclear propulsion is incredibly simple requiring almost no moving parts. The only moving part is in fact a pump which is driven by what is essentially exhaust gas the same turbo on a car works, The do need a basic electrical component to control the amount of heat the reactor uses also. It's a very simple and fairly fail safe engine. I have seen it explained in other videos but this one explains the concept very well in an easy to understand manner. They also get approximately twice the Isp as a chemical rocket.

[Kibble]

\

11 mins for explanation on how the engine works.

Actually nuclear propulsion is incredibly simple requiring almost no moving parts. The only moving part is in fact a pump which is driven by what is essentially exhaust gas the same turbo on a car works, The do need a basic electrical component to control the amount of heat the reactor uses also. It's a very simple and fairly fail safe engine. I have seen it explained in other videos but this one explains the concept very well in an easy to understand manner. They also get approximately twice the Isp as a chemical rocket.

I have seen that video. It does not address the very complex plumbing required to operate a nuclear reactor. It only gets twice the ISP when using all-hydrogen propellant. Also that's the theoretical - the actual Kiwi motors test-fired got lower ISP. The concept to use SIVB with a NERVA instead of J2 would actually have decreased its payload, because hydrogen is so nepid.

Also you ignored the complex set of mechanics driving the boron-plated neutron-deflectors.

[uglyduckling81]

It seems to me the deflectors are controlled by a simple electronic actuator found in every RC model in the world.

Clearly rocket engines are complex beasts but comparatively nuclear isn't overly complex. It has other issues though like radiation.

The other major factor to think about is liquid engines have been chosen as the standard and developed for so long it's not fair to compare them to a technology that was put away and effectively shelved. If it had another 50 years of serious investment and research who knows what it could now be capable of.

Liquid was cheaper and easier and safer at the time so it was clearly a winner. Plus we were only going to the Moon which liquid is clearly capable of achieving.

If you wan't to go further you start to run into a problem because the distance is so vast to leave the solar system you need much greater ratio's than even nuclear can provide sort of making it a redundant product.

You really have to move away from fuel based propulsion because there is just no way to carry enough fuel to travel so far.

You need to start to think about solar sails but then you have a problem of much lower light levels even at the edge of the solar system.

We need something that hasn't been invented yet to make a big impact.

Oh I started to ramble.....

[KSK]

I'd rather KSP wasn't based on historical accuracy. This is Kerbin and not Earth after all. I think the current tech tree progression is pretty fun, starting manned and all.

This. But if we are aligning to human equivalent decades, I'd say late 50s for game start. I'm sure there was a great deal of fascinating technical development in the 30s and 40s and I look forward to reading about them one day. In KSP terms though, I really don't see the point in having more than a single tier of sounding rockets since the vast bulk of that development is abstracted out.

Sounding rockets would be great for snagging the first couple of altitude achievements and maybe a biome hop or two to teach new players the basics of earning Science points. After that - let's move on please. Having to start each game by running through half a dozen variations of a basic sub-orbital rocket, each going slightly higher than the one before it would get old really really quickly. By all means mod it in if you like but I would strongly disagree with going that way for the stock game.

I think the technological limitation on making a big, complicated space program is NOT the rocket technology...it's the electronics/computer technologies. If you start too soon, your only option for complex control systems is kerbol brains onboard (such as they are).

And this. A lot of the earliest serious spaceflight proposals involved crewed craft because the current state-of-the-art in electronics was too primitive (think vacuum tubes) to imagine much else. Also human spaceflight and exploration of the stars was kind of the point of the exercise. Then there were the really outlandish proposals in the late 50s - again for crewed spacecraft.

Leaving aside gameplay considerations, I really don't have a problem with starting crewed, either on technical or historical grounds.

Edited April 20, 2015 by KSK

[tater]

It already starts in the 50s, and only a few elements available are as far as maybe the 1970s. The bulk of the tech tree is basically simultaneous.

[Kegereneku]

I want to vote for the Rocketpunk Era but its not on the list, so I didn't vote.

[tater]

And yet it's still '60's tech.

E: I feel it's important to make this distinction as KSP's progression should not reflect human politics.

While I agree regarding politics, I think that one element that IMHO, KSP could really use is the sense of competition/pressure that the Space Race added to the equation. It means (particularly in a Kerbal context) that some missions might be taken with more risk than they otherwise might have been. Not recklessness, but enhanced risk to achieve a particular goal.

Hard to add to KSP, mind you, but I think that the Cold War really pushed rapid progress in a way that would not have otherwise occurred.

[rcp27]

In terms of technology, I would put an appropriate start point to be around 1955. Rockets with minimal payload can just about reach the Karman line (70 km on Kerbin), and jet aircraft can reach supersonic speeds in limited circumstances.

I think the premise of KSP is different from the environment that gave rise to the development of rocketry in our history. To my mind, KSP has a role like that of NASA: a civilian, not military organisation, with the goal of science, not warfare. In our world, rockets were developed for military purposes. First the V2, then various cold war nuclear missiles. This favoured automatic, unmanned tech, because you don't want a pilot having to fly this kind of mission. Kerbals are motivated by the excitement of riding on fast and exciting rockets, and going places for science. Therefore I regard the KSP target as being much more motivated on doing it manned first. If you can't put a Kerbal on it, what's the point?

[regex]

While I agree regarding politics, I think that one element that IMHO, KSP could really use is the sense of competition/pressure that the Space Race added to the equation. It means (particularly in a Kerbal context) that some missions might be taken with more risk than they otherwise might have been. Not recklessness, but enhanced risk to achieve a particular goal.

A driving, competitive force would probably be pretty good for the career game, for sure. Cold War politics, eh... I don't think that really has a place in KSP and it's one of the reasons I object to characterizing Kerbal advancement in terms of human advancement, especially when it comes to things like nuclear engines whose usage for humans is largely dictated by the politics of nuclear weapons and their use in space, and the politics of humans in general (funding battles, etc...). Kerbals seem to be focused much more as a species on spaceflight than humans.

Kerbals are motivated by the excitement of riding on fast and exciting rockets, and going places for science. Therefore I regard the KSP target as being much more motivated on doing it manned first. If you can't put a Kerbal on it, what's the point?

Entire post well put, just quoting this to punctuate that Kerbal development should not follow human development except for logical constraints and advancements.

[panzer1b]

1945 please, during the creation of the german colony on the moon. Then we get space zeppelins, ufos with cannons on them, and kubelwagens on the moon .

/sarcasm!

[John FX]

A driving, competitive force would probably be pretty good for the career game, for sure. Cold War politics, eh... I don't think that really has a place in KSP and it's one of the reasons I object to characterizing Kerbal advancement in terms of human advancement, especially when it comes to things like nuclear engines whose usage for humans is largely dictated by the politics of nuclear weapons and their use in space, and the politics of humans in general (funding battles, etc...). Kerbals seem to be focused much more as a species on spaceflight than humans.

Entire post well put, just quoting this to punctuate that Kerbal development should not follow human development except for logical constraints and advancements.

I'm not trying to establish the development that happens after the game starts, just what the starting tech should be, I think the thread is derailing from the original question.

Another way of putting it would be "What tech should be in tier 0 on the tech tree" as opposed to "How should KSP tech develop"...

[Rath]

I have seen that video. It does not address the very complex plumbing required to operate a nuclear reactor. It only gets twice the ISP when using all-hydrogen propellant. Also that's the theoretical - the actual Kiwi motors test-fired got lower ISP. The concept to use SIVB with a NERVA instead of J2 would actually have decreased its payload, because hydrogen is so nepid.

Also you ignored the complex set of mechanics driving the boron-plated neutron-deflectors.

One thing though- Most devlopment stopped or slowed on NTRs when it became obvous that politicans that know nothing of space travel and parts of the public that say no to anything with the word nuclear wouldn't let them be launched. Maybe the kerbals didn't have this problem because they jeb is king or something so they wroked overtime to keep on devloping NTRs and made them good.

[Frozen_Heart]

I have seen that video. It does not address the very complex plumbing required to operate a nuclear reactor. It only gets twice the ISP when using all-hydrogen propellant. Also that's the theoretical - the actual Kiwi motors test-fired got lower ISP. The concept to use SIVB with a NERVA instead of J2 would actually have decreased its payload, because hydrogen is so nepid.

Also you ignored the complex set of mechanics driving the boron-plated neutron-deflectors.

I've seen the calculations for a Saturn V NERVA drop in replacement. The reason it gets much lower dV is due to hydrogens lower density. If the size of the stage is increased so it has the same mass as the original stage, then the dV is actually slightly improved compared to a chemical rocket.

Also these were reactor designs from the 60s. One designed today could benefit from many improvements and would be likely to be much lighter and have a greater TWR than a 60s era one.

Anyway can we continue this debate in the science labs section as its pretty off topic.

Edited April 21, 2015 by Frozen_Heart

[Kibble]

I've seen the calculations for a Saturn V NERVA drop in replacement. The reason it gets much lower dV is due to hydrogens lower density.

Right!

Anyway can we continue this debate in the science labs section as its pretty off topic.

I think the discussion is relevant to the topic - being, what future decade might a NERVA-like rocket engine bee flown?

politicans that know nothing of space travel and parts of the public that say no to anything with the word nuclear wouldn't let them be launched

SNAP and the Soviet RORSATs were launched, despite being nuclear fission reactors.

[tater]

Had the Space Race continued past Apollo (it functionally ended when the US reached the finish line), I think NTRs would have been at least tested in space. A friend's dad worked on Rover a little (I know many Los Alamos people, both my generation, and parents of friends) and he was confident that it was a good system. Classes I had (taught by a few LANL people) on lunar bases, and space infrastructure assumed some NTR use, of course they also talked about fuel depots, etc. H2 storage is certainly a problem with boiloff rates of ~0.1%/day.

Something to consider would be multiple fuels. Use H2 for Mars transfer insertion, and lower Isp propellants for the return (that are more easily stored). The outbound transfer burn involves higher dv than the return. I would assume there might be a point where the curves cross, and we could find the optimal balance of propellants---take vastly more H2 to deal with boiloff, or burn all the H2 right away, and use denser propellants for return.

If all the H2 was burned within a few days of launch, boiloff is not meaningful. Our craft will obviously be considerably more massive, but at least that portion can be built ahead of time (the denser fuel tanks).

Edited April 21, 2015 by tater

[Kibble]

It seems to me that future decades of advancement in space vehicle technology will bring maturity to IVF, reusing some vehicle components, and LNG fuel.

[tater]

That's why the current tech tree (and I fear the 1.0 tree) is so screwy. The extant 0.90 tree is almost coincident in terms of timing, but there are places where real advances in tech could be put into the tree to make it meaningful.

A simplified version of Real Fuels would be cool to see, for example (I'm talking stock, so something accessible to most players in terms of complexity). If some of the engines required fuels with meaningful boiloff, then you'd have cool trade offs… better Isp, vs long-term fuel loss (tracked the way Roverdude does out of focus resource mining (assuming I understand that correctly), look at the time since last focus, then delete time_in_days*0.001 fuel (or whatever the rate is). Then have the tree include upgrades. Use boiloff for power generation, or combine to make water (assuming some LS system in game), whatever.

Then you get NTRs when you should, but the rated Isp for for H2, which has pros and cons, or you bring a tank with alternate propellant, but get lower Isp using that. Later advances might have different capabilities (or perhaps at the end of the tree their are tanks with an order of magnitude lower boiloff rates).

[LethalDose]

TBH I would not say that it flatlined, just that a new direction was needed after going in a wrong direction ( I'm from the opinion that the Shuttles the USA and the USSR made in the 80's were a terrible idea that made the space exploration go sideways for a couple of decades ). It is good to see that people started to worry about making better rockets again, though

Well, technically, "sideways" is kind of a flat line

But I agree, in retrospect, the shuttle kind of stagnated the space program, but I largely blame the USAF's involvement/shenanigans for a large portion of why the shuttle never lived up to it's hype.

[Pigbear]

Well, technically, "sideways" is kind of a flat line

But I agree, in retrospect, the shuttle kind of stagnated the space program, but I largely blame the USAF's involvement/shenanigans for a large portion of why the shuttle never lived up to it's hype.

technically upwards is kind of a flat line