How to ship, process, manage & utilize rocket fuel around the Solar system

[Questioner]

How to ship, process, manage & utilize rocket fuel around the Solar system

This is an open discussion about space [freefall] based fuels that will unlock cheaper, safer, easier space travel off of [& back on to] this planet & beyond.


My thought is having frozen blocks of water, ammonia, methane, CO2, etc. wrapped, sealed in some kind of reflective thermal barrier.

One could use little bits of the block as thrust by heating up the appropriate places.

It could be industrially crude, but would need sophisticated enough guidance controls.

If one is patient and time is not a immediate consideration then very little thrust is needed to launch and then brake it at its destination.

Slower transport takes longer but its safer & more efficient.

I suppose questions about accumulating/creating the ice block in the first place comes to mind.
Also where the best places are to aquire the ice in the first place is something to think about.


I'm thinking if some of those small [<1km] moons of Jupiter are mostly ices one might be able to propell & guide one into a 28 day orbit around the Moon that kept it always in the Moon's shadow.
Then one could mine portions of it and probably use a solar energy farm in space [or on the Moon] to process for maximum chemical energy storage.

If NASA and anyone else is serious about us becoming a space faring species they should get on board with space/freefall based fuels.

It could initially be a public-private initiative to get the first load of space based fuels and then test & try out technological means to utilize it.

Once the space economy gets going commercial interests will drive it on its own.

[Utilization] My guess is mobile orbiting skyhook assemblies & their partner hookplanes/hookjets are the way to go, but even there the best particulars have yet to be determined.

 

[Questioner]

[Utilization]
I am wondering if a graduated cable makes best sense.
It could be thicker at the top where it holds the most weight tension, but weighs less,
& thinner at the bottom where it holds less weight tension, but weighs more.

For a static hanging that would work but for a spooling cable it could be problematic.

 

[Questioner]

(In case you haven't guessed this sky fuel methodology has me pretty darn excited.)

[Utilization]
Using freefall fueled cabled platforms makes getting out of any significant gravity well a nearly nominal task rather than climbing an impenetrable stone wall.

If they ever go to Mars they will be best off leaving/acquiring a fuel supply in orbit.
Maybe they go raid a comet or ice moon/asteroid first and leave their fuel supply in orbit with their skyhook platform and then land on & explore Mars's surface.
The base matter can be solar processed for maximum chemical thrust while they run around on Mars.

It might make getting off the Moon borderline trivial.

Lifting production products out of a gravity well is a minor additional shipping cost rather than a choking overriding barrier.

It opens up the entire Solar system to us,
which as an adult I know is potentially a can of worms.

So be smart and get a fat juicy worm early while the pickings are still good.

I suspect nothing will be quite the same once this takes social & economic hold.

 

[Questioner]

[Utilization]
Pragmatic Considerations

One needs a region on the planet with very calm weather to link the cable bottom & the hookplane.

Having a cable dangling low in the sky is a real invitation to be a lightning conductor.

The orbiting path of the fuel, rocket frame & dangling cable i believe will support [keep suspended] all that & it's only as the cable begins to lift the payload, the hookplane that the high altitude rockets will need to start firing.

If one is using a static/non-spooling cable the whole works, the fuel the rocket frame and cable along with the hookplane will be lifted at the same time,
even though the hookplane is hanging probably a couple hundred miles below the rocket frame et al.

So my current thought on the major hurdles are
1) The ribbon/cable [matterial, engineering & production
2) acquiring [& processing] the load of rocket fuel
3) weather [& avoiding space junk & meteors]

 

[Questioner]

Antarctica is a possibly good location weatherwise.

 

[billslugg]

"Maybe they go raid a comet or ice moon/asteroid first and leave their fuel supply in orbit with their skyhook platform and then land on & explore Mars's surface." - Questioner

I have a "Delta V" chart of the solar system. It shows the delta V it takes to go from one solar system location to another. The delta V's include the acceleration to get there and the deceleration to come to a stop.
For example:
Earth surface to LEO takes 9,256 m/s of velocity change.
Then another 5,661 m/s to get to the Moon and land.
To go from Earth straight to Mars takes 18,534 m/s.
From Mars to Vesta in the asteroid belt takes 10,974 m/s.

Conclusion: If you have a base on Mars, and if you can find fuel on Vesta, you can save 41% on your rocket fuel bill. Conditions apply.

 

[Questioner]

[Utilization]
One will probably only get a few miles off the ground with the hookplane, maybe 8 miles & the cable will need a radar transponder(s) [lights?] on the low end so other aircraft can know to avoid it.

My question is how fast can one lift the payload/hookplane.
The sooner it gets out of air traffic the better, but i don't know if that would demand more or less rocket fuel consumption overall for faster or slower lifts.

Having a cable dangling 250 miles vertically in orbit means that will have be managed for satellites and major space junk.
One needs spotting [radar?] all the way up & down for possible problems.

Once the skyhook assembly and dangling hookplane achieve mass orbiting equilibrium then a small amount of additional thrust will move it all slowly away from Earth.

I'm not sure where or what one does with assemblies not currently in use.

One probably keeps them in some kind of orbit, but the speed & distance/radius from Earth I'm not sure about what makes best sense.

One might keep unused skyhooks together in an orbiting cluster so other space activities can more easily avoid them.
Could also be a maintenance & inspection location.

It might be possible even with a graduated cable to fold it up somewhat, but one wouldn't want to degrade their condition.

It might be that there was an assigned altitude for parking skyhooks.
Maybe from 1000 miles to 1500 miles.
Or it could be an assigned orbit at some range of altitudes.

Having fuel in orbit means satellites can be refueled so they could have more active avoidance/steering capabilities.

 

[Questioner]

[Utilization]

Basically the fuel & rocket frame assembly needs to be above any significant atmosphere so it is in a frictionless orbit where its forward momentum counters gravitational influence.

This could probably easily done 100 miles up.
The problem with that is it will probably be traveling much much faster than the/a hookplane can travel.

I suppose some geosynchronity could cover that, but that knocks out Antarctica & may mean contending with tropical/equatorial weather.

At a minimum the cable probably needs to be 70 miles long.

 

[Questioner]

Probably a shock absorber or bungee section on the bottom of the cable for when the hookplane first connects it will still be flying.

Then maybe that gets winched up to hard cable as the atmosphere gets thin & virtually all the altitude incease is from cable lift.

That will be a delicate coordination between the two operators.

 

[Questioner]

It does look like Vesta does have water ice.
So they could pause there & load with water then go to Mars and solar power could be splitting water to H & O while they explored.

Then they would have ready rocket fuel.

Mars probably requires a much shorter cable because of less mass/gravity and barely any atmosphere.

On Mars it would need to be a geosynchronous orbit, but they could be picked up virtually right off the surface.

Scheduling a mission that coordinates all three orbits of Earth, Vesta & Mars needs to be done.

I suppose they could revisit Vesta & haul fuel/water back to Earth on return to 'pay for their keep'.

I suppose they could just mine excess water in the first place from Vesta since it will just be in orbit around Mars.

Sign me up, lol.

Well, not me personally, untested space tech still scares me.

On Earth for near geosynch maybe the Sahara has better/calmer weather conditions since Antarctica is pretty much not geosynchronizable.

 

[Questioner]

What could be done is have a working/commercial enterprise to Vesta where it gets mined for water,
then a bulk load of fuel could be slow lauched back to Earth manned or unmanned,
& then with a necessary amount of fuel the science & engineer team could go and explore equitorial Mars.

One could set up automated mining, at Vesta but it almost certainly will encounter unforseen problems at some point.

The Mars mission would be primarily limited to the equitorial region, but they could land & explore one location then lift up and then explore a different location.

Being cooped up tin cans for long periods would be psychologically stressful, but they could have large inflatable recreational bubbles.

I wonder if freefall has any inherent general effects on human psychology.

It's scary to think of angry resentful people with easy ability to nudge big rocks in the Earth's, Moon's or Mars's directions.

This will inevitably be a can of worms.

Up sides can't help but come with down sides.

And this is pretty much the definition of up side.

Let's do it! Lol