[bearnard1212 (OP)]

What is the most advanced space technology you ever heard about? Today, when we are close to the crewed journey to Mars it`s rather interesting to know, what was for you the real breakthrough in the space tech world?

[Halc]

There seems to be no single technological breakthrough that move the state of the art forward from its otherwise steady pace of small, careful increments.
The largest breakthrough I've seen is probably privatization of the industry. An environment where the space group (NASA say) is not using its own money just doesn't have as much drive to find more efficient ways of doing things.

[bearnard1212 (OP)]

There seems to be no single technological breakthrough that move the state of the art forward from its otherwise steady pace of small, careful increments.
The largest breakthrough I've seen is probably privatization of the industry. An environment where the space group (NASA say) is not using its own money just doesn't have as much drive to find more efficient ways of doing things.

How it`s useful for space explorations? I only see the benefit for NASA. Do you think that it influences on the development of particular space missions?

[charles1948]

What is the most advanced space technology you ever heard about? Today, when we are close to the crewed journey to Mars it`s rather interesting to know, what was for you the real breakthrough in the space tech world?

Surely it has to be: "Project Orion", in the 1960s.  Orion space-vehicles were to be propelled by nuclear energy, generated by many hundreds of small fission-bombs.  These would be detonated in sequence, at intervals of a few seconds, under the base of the vehicle.  The base would be protected from blast-erosion by films of oil.

The result would be a really gargantuan spacecraft, weighing thousands of tons and the size of an old ocean-liner, capable of travelling to Mars in a few weeks or months . And to the outer planets within a similarly short time.

The motto of the Orion ship designers was "Saturn by 1970!"

Why it never came to fruition, is something of a mystery.  You can read about it on Google.

[Kryptid]

Why it never came to fruition, is something of a mystery.

It would, no doubt, have been extraordinarily expensive. Then there is the issue of people worrying about a nuclear-powered spacecraft crashing during lift-off. Those two challenges would have been formidable to overcome.

[charles1948]

Why it never came to fruition, is something of a mystery.

It would, no doubt, have been extraordinarily expensive. Then there is the issue of people worrying about a nuclear-powered spacecraft crashing during lift-off. Those two challenges would have been formidable to overcome.

As for the expense, it wouldn't have been more than building 1,000 Minuteman ICBM's  each equipped with nuclear warheads.  The US government did that in the 1960s, when "Orion" was being considered.

As for the worry about the radioactive consequences of "Orion" crashing during lift-off,  the US government used to conduct tests of nuclear weapons, in the megaton range, on its own territory, in Nevada..

That didn't seem to cause any worry, except to Howard Hughes.

So I think there must be another reason for the termination of the revolutionary "Project Orion". What that is, you guess.

[Bored chemist]

Taxpayers / voters may have been more concerned about a Russian invasion than about not getting to Saturn.

[charles1948]

US taxpayers seem more concerned about chewing gum, the right to buy AK-47s in Walmart, and electing Presidents like Trump.

So their views on the peaceful exploration of the Solar System by atomic spaceships such as "Orion", may I think, be disregarded.

[Bored chemist]

It seems that, by the simple trick of owning the media, you can get the US population to vote for damned near anything. (Or anyone)

[charles1948]

It seems that, by the simple trick of owning the media, you can get the US population to vote for damned near anything. (Or anyone)

Are there any limits - you thinking of running?

[Bored chemist]

It seems that, by the simple trick of owning the media, you can get the US population to vote for damned near anything. (Or anyone)

Are there any limits - you thinking of running?

I'm not American.
I'm also not nearly rich enough.

[alancalverd]

I think the most significant technical advance was implementing the decision to use liquid hydrogen fuel.

Rocket science is very simple Newtonian physics and elementary chemistry. Rocket engineering is a whole lot more complicated.

[vhfpmr]

Voyager 1 is the space technology that has advanced furthest from earth so far.

[Hayseed]

What advances?  We've been in space for decades now, and still at the same velocities.  With those pitiful velocities, we have to have a gravity craft(spinning) and a whole lot of shielding......before we go anywhere.  The idea of Mars now.......is foolish.   A station or base on the far side of moon is much more valuable.  We need to learn how to move, before we go anywhere.

[alancalverd]

What's so interesting about the far side of the moon?

[Hayseed]

It's a black-out area for measurement.  Much blacker area than the black-out area around Green Bank. And it will allow reception of all frequencies.  No atmospheric filter.  10,000 Hz to 100 MHz or so might be very interesting.  1 to 30 MHz would interest me.  And without that filter, THz would be of great interest to many.  With all the chatter from earth, and earth orbits, blocked out.  We could use almost the whole dark side as a giant ear/eye for unexplored spectrums.  And solar flux studies as well.

[evan_au]

(The far side of the Moon is) a black-out area for measurement

I'm afraid that as soon as we go someplace, we take sources of interference with us.

The Chinese have a rover on the far side of the Moon. So they have a relay satellite orbiting the Lunar L2 point (but with a radius big enough so that it can always be seen from Earth, around the sides of the Moon).

See: https://en.wikipedia.org/wiki/List_of_objects_at_Lagrange_points#Earth%E2%80%93Moon_Lagrange_points

[charles1948]

I think the most significant technical advance was implementing the decision to use liquid hydrogen fuel.

Rocket science is very simple Newtonian physics and elementary chemistry. Rocket engineering is a whole lot more complicated.

Yes.  If rockets are going to be propelled by chemical energy, the liquid hydrogen/ liquid oxygen mix generates the most thrust.  (Except if fluorine was used, but that element is so reactive it eats away its own metal fuel-pipes -unless the pipes were made of fluorite)

The use of liquid hydrogen in the first-stage of the US Saturn 5 booster, was possibly why it beat the Soviet rockets to the Moon.  The Soviet boosters, I think, always used kerosene, or some other chemical compound less energy-productive than pure hydrogen.  Also the Soviets were never able to engineer really big rocket-engines, so had to use complicated clusters of small ones.  Over 40 in their N-1 equivalent  of the Saturn-5.  The N-1 was launched 4 times and blew up  every time.

As you say, there's a big difference between Rocket Science and Rocket Engineering!

[evan_au]

Except if fluorine was used, but that element is so reactive it eats away its own metal fuel-pipes -unless the pipes were made of fluorite

You can also make them out of Nickel. Fluorine reacts with Nickel to produce a protective layer.
For the pipes, start at 4:30.
Watch the lot for video of Fluorine reacting with various chemicals...

[Bored chemist]

The big problem with fluorine is when it's hot (and a rocket implies that it will be).
The hot fluorine will make its way through the nickel fluoride layer. If you are unlucky, the metal pipe actually catches fire.
If you don't shut off the flow, the metal burns back until it reaches the cylinder.
This is not good news.

The problem is less likely if you use heavy wall pipes (because they can heat-sink the reaction.
Heavy isn't a thing that rocket makers usually like.

But they gave it a go...
https://apps.dtic.mil/dtic/tr/fulltext/u2/a307841.pdf