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

 

[Questioner]

A payload/plane probably weighs 20,000 pounds.
One could possibly disconnect the wings and tail & parachute them back to Earth with a transponder.

The other option is a dead lift capsule right from the ground [a virtual elevator] which would require perfect geosynchronity. The cable could have some excess on the ground that was hooked up with the payload on a cushioned raised platform to guard against major shocks/bumps as it got picked up.

The other thought is the raised platform could descend from under the payload leaving it dangling.

The hook assembly to altitude is orbiting the Earth.
In geosynch there is no air friction from the orbit, but hanging through 60-70 miles of atmosphere means wind/air friction of some amount which will likely mean some expenditure of rocket fuel for that.

For passengers a self contained space ready pressurized cabin is needed. For most freight only a structurally sound containment is needed.

I think the main technical hurdle is the cable itself.

It has to hold 60 or 70 miles of its own weight as well as 20,000 pounds of payload.

Carbon fiber will weigh less, but producing that quantity in a structurally sound form is a question.

On lift it is acceleration that requires more [most?] fuel. A minimally accelerated lift puts less additional stress on the cable.

Getting out of the unpredictable atmosphere/weather sooner has advantages.

 

[Questioner]

I suppose the passengers could wear space suits then one wouldn't need a pressurized lift module.

 

[Questioner]

[Utilization]
Trying to figure out how much fuel is needed to lift something into orbit.

If the skyhook assembly is essentially already in orbit then one is adding 20,000 lbs to it,
so i think that lowers the center of mass of the total combination,
so one needs to raise the totality of mass to a point where the orbital speed is sufficient to put it back into equilibrium.

Obviously initially vertical elevation is needed to avoid various Earth surface stuff.

One could increase the speed of orbit forward or vertically elevate the mass or some combination thereof.

The whole purpose is to achieve elevation, but increased lateral speed will also do that but more slowly.

I'm not sure if either method is more fuel economic but also possibly more time consuming.

If it's more fuel efficient to raise payloads slowly that might be used for freight & maybe more expedited lifting might be done for passengers.

Lifting slowly is easier on the cable.

Space traffic & avoiding junk may come into play/consideration.

Getting out of weather hazards sooner is advisable, especially depending on [near-]current conditions.

It might be possible to have a parachute on the payload capsule for low elevation mishaps.

At very high orbital altitudes perhaps a backup skyhook with a catchnet could be available for any orbital decay if a payload got dislodged.

In between, high atmosphere problems might be harder to address.

 

[Questioner]

[Utilization]

It could be once the payload was above most of the atmosphere [70 miles] it might be passed to a shuttle carrier.
That means the top of the skyhook would be about 140 miles high and the bottom would be at 70 miles.

Having the cumbersome dangling cable only at a limited range of altitudes would make it easier for all considered to manage/avoid.

A shuttle/carrier trying to dock with something without that extensive cable would be much easier, more agile.

 

[Questioner]

[Utilization]

Lighting.
It might be necessary to have a thin grounding wire that was 30(?) miles long that dangles below the 70 miles of actual lift cable.

The grounding wire could be uniform and spoolable. Maybe even ground based at the pick up location and dropped at its full extension.

It would entail additional weight, but could probably be lighter carbon fiber.

The Hindenberg likely would not have blown up if its built up charge imbalance from weather had been properly grounded.

Hmm, balloon payload pick up?
With a compressor to save and reuse any lighter than air gasses?
Hot air wouldn’t need to be salvaged.
Tracking the somewhat unpredictable balloon path to link up could be somewhat tricky.

Ready to try anything for efficient lift technology

 

[Classical Motion]

A conductor moving thru an M field produces current. And the earth can source or sink lots of current. And we have several charge fields or shells around the earth. With these potentials, even insulators can become conductors.

What’s gonna happen if we discharge those shells? Or provide a path for neutralization?

This might be one of our ideas we need to be protected from.

What would happen if earth gained a net charge? Or lost our charge? Or locked up our ground charge?

It might be destructive both high and low. Earth’s E fields function are still a mystery.

We have ozone holes. An electric hole might be fatal. And quick.

Any disturbance in the ionosphere could change the light spectrum that gets to the surface.

A radiation modification.

As for cheaper lift, a balloon is all we have for now. But lot’s of acceleration is still needed.

And maybe we could find a method of ionic flotation, after we run out of molecular density.

Maybe a charged/magnetic balloon might continue to rise.

 

[Classical Motion]

Maybe we could sling bulk into space. Don't use a counterweight. Sling two at once. From the equator. Acceleration will still be needed for orbit. We also need an orbital intersection, to switch from equatorial to polar orbits.

 

[Questioner]

I think i have the physics all wrong.
The lower the orbit the faster or more massive the vector inerta needs to be.

Geosynch generally only happens at very high altitude.

The space station is 250 miles up & orbits every 90 minutes.

So the only way to have a lower and much slower orbit is to have incedible mass with vector inertia.

Which gets back to a space elevator
only now with correctly supplied with orbiting rocket fuel.

Chasing my own tail.

The Chicxulub caution comes back into play unless one uses an incredibly long cable.