Where would we build a base first?

[More Boosters]

Hey.

Let's just that say that, in this day and age, we have the means and technology to go to any major celestial body in our solar system and set up a base that would construct rockets mostly from mined materials from the body. These rockets would then be used to explore other bodies within or without the Solar System. A lot would still come from Earth, so the travel time back also would matter, but the base would be mostly self sufficient.

Where should such a base be and what would spacecraft built to be launched from that planet look like? Please don't just jump to Moon; the base is mostly self sufficient.

[regex]

Let's just that say that, in this day and age, we have the means and technology to go to any major celestial body in our solar system and set up a base that would construct rockets mostly from mined materials from the body.

[Citation Needed]

Now, if you're talking a refueling station, Deimos and Ceres have a lot of water, i'd say those are good candidates for a permanent "starter" base.

[smjjames]

Well, the obvious place to start first is somewhere that is the easiest to reach (relatively speaking), least amount of time, etc, and where would that be? Mars.

The Moon is a good place to get some practice under our wings.

Mercury: Takes a while to get to, also hot.

Venus: As uninhabitable as you can get.

One of the big asteroids/dwarf planets such as Ceres or Vesta: Definetly enticing candidates and not that much further out from Mars, but we'd probably want better interplanetary rockets than the chemical ones we have now.

The Gas Giants and Ice Giants: Transit time is years to decades, you'd need to eiher have cryostasis or send astronauts while they are young, you've also got Jupiters radiation to deal with, Saturns is probably similar, I don't know much about the radiation belts of Uranus and Neptune.

Pluto: With the deltaV required to get there quickly and then stop, you would need a much better engine than we use now. Either that or send a generation ship that can last 4 generations maybe.

[Kibble]

we have the means and technology to go to any major celestial body in our solar system

What about minor celestial bodies? The minor planets have alot to offer, in convenient bite-size packages!

[More Boosters]

What about minor celestial bodies? The minor planets have alot to offer, in convenient bite-size packages!

Feel free to make a case.

[_Augustus_]

Well, the obvious place to start first is somewhere that is the easiest to reach (relatively speaking), least amount of time, etc, and where would that be? Mars.

The Moon is a good place to get some practice under our wings.

Mercury: Takes a while to get to, also hot.

Venus: As uninhabitable as you can get.

One of the big asteroids/dwarf planets such as Ceres or Vesta: Definetly enticing candidates and not that much further out from Mars, but we'd probably want better interplanetary rockets than the chemical ones we have now.

The Gas Giants and Ice Giants: Transit time is years to decades, you'd need to eiher have cryostasis or send astronauts while they are young, you've also got Jupiters radiation to deal with, Saturns is probably similar, I don't know much about the radiation belts of Uranus and Neptune.

Pluto: With the deltaV required to get there quickly and then stop, you would need a much better engine than we use now. Either that or send a generation ship that can last 4 generations maybe.

Venus' upper atmosphere is quite hospitable, you could walk outside in scuba gear.

[SuperFastJellyfish]

Venus' upper atmosphere is quite hospitable, you could walk outside in scuba gear.

It's closer in terms of transfer time, as well.

[Kibble]

Feel free to make a case.

With simple* observations from Earth we can determine the general physical and orbital characteristics of minor planets, and sort out the ones that are close-by and that have useful compositions (metal or carbon-rich, or whatever). And unlike Mars or Moon, countless minor planets are small enough to tug onto more favourable, easy-to-reach orbits - easing the delta vee load on interplanetary infrastructure. This smallness also makes them easy to launch from and land on, both delta vee- and TWR-wise.

AFAIK, while minor planets in the inner Solar System are drier than the driest slab of concrete baking in the Gobi desert, you can still find volatiles on them (in the form of hydrated clays and such). With water and ammonia, you can make hydrazine and nitrogen tetroxide, tasty** rocket fuel! Alternatively if the minor planets are just too dry, a good backup is a base near the Lunar poles.

*complex, math-heavy

**deadly poisonous

[regex]

AFAIK, while minor planets in the inner Solar System are drier than the driest slab of concrete baking in the Gobi desert

I've heard the opposite, water is very common, especially in the outer solar system.

[Kibble]

I've heard the opposite, water is very common, especially in the outer solar system.

Oh yeah in the outer Solar System water is cheap as dirt! In fact, out there water literally is ​dirt!

Edited for a complete thought: But the delta vee, travel time, low data rate communications, and limited solar power mean its (probably) not a good idea to go back and forth from like Jupiter to Earth.

Edited August 8, 2015 by Kibble

[peadar1987]

The Gas Giants and Ice Giants: Transit time is years to decades, you'd need to eiher have cryostasis or send astronauts while they are young, you've also got Jupiters radiation to deal with, Saturns is probably similar, I don't know much about the radiation belts of Uranus and Neptune.

Far smaller and less intense than that of Jupiter. They are less massive, so have smaller cores of metallic hydrogen, and lack a volcanic moon like Io, which injects massive numbers of particles into the van Allen belts, which are then energised by the magnetic field.

[regex]

But the delta vee, travel time, low data rate communications, and limited solar power mean its (probably) not a good idea to go back and forth from like Jupiter to Earth.

If the objective is to make a "base" where one could build and refuel rockets, implying self-sufficiency, why not go somewhere with an abundance of one of the most vital elements of life, that also doubles for fuel?

[Pixel of Life]

Moon. It's close and easy to get to, and you've got a near-unlimited amount of regolith that can be reprocessed or used to shield the base from radiation.

[Nibb31]

If the goal, as stated by the OP is to serve as a base to "explore the Solar System", then surely you would be better off launching a few dozens of rockets from Earth that using hundreds of launches to build a base to launch the original dozens of rockets from somewhere else. It is far easier to launch an SLS from Cape Canaveral than it is to build the infrastructure that would allow you to source and build locally an SLS on Mars.

If you want to benefit from space construction, then your primary requirements are a low gravity well and proximity to Earth. So either you build an orbital factory that you supply by mining NEOs, or you build a base on the Moon. Both of which are science fiction at this point. Anything beyond that silly Star-Trek-induced wishful thinking.

[Scotius]

Moon. Easy to reach, land and return from. Contains all elements needed to get space industry going.

[WestAir]

Orbit. Starting with a larger-than-ISS modular colony. Imagine if you will a self sufficient, ever expanding modular station. As its population grows we add to it. It would have no upper limit of size and its modular structure allows quick repair and replacement of aging infrastructure. If done right any moon colony might seem underwhelming in comparison.

Edit: The idea here being that running a lunar mining expedition via away team from a station is easier than starting one from Earth.

Edited August 8, 2015 by WestAir

[Rakaydos]

Lunar Lagrange. Can be repurposed as a counterweight when upgrading the station with a lunar elevator.

[Thomassino]

Titan. Mainly because its icy surface is soaked in hydrocarbons, which means great ISRU possibilities, thus potential self-sufficiency from Earth (which is good considering dV budget and time to get to Saturn) It would be kinda hard to launch rockets from considering thick atmosphere, but open-cycle thermal turbojets would have been great there.

[TrooperCooper]

Laythe of course!

[o Atomsk]

Even if it would be impractical, I would love to have a base on Callisto, or at least an orbiting station by Callisto.

It's such a beautiful moon.

[mellojoe]

I like the idea of the Mars-cycler base. The Aldrin-cyle is a little over 2 years, which means basically every two years, for major launches with massive savings. Hop onboard the base at the Earth intercept, do the refuelling and refining over the 5 month trip to Mars. Drop off any crews or changes at the Mars intercept. Then launch the major mission from outside of Mars' orbit. Meanwhile, any remaining tooling or crew transfers or resupplies can return to Earth.

For practical purposes, though, the Moon is probably the best bet for a mining base operation.

[SciMan]

The Moon, but only because we haven't towed a suitable NEO into earth orbit yet.

[cryogen]

One of the lunar Lagrange points, perhaps EML1.

• Zero-g
  
• High solar constant
  
• One of the cheapest destinations from earth, after LEO
  
• (In particular, no delta-v penalty for landing on a surface. This also allows low-thrust (SEP) cargo shipments from LEO)
  
• Reasonably fast evacuation to earth possible (~1-3 days)
  
• Very cheap to near-earth heliocentric, to bring in NEO asteroid material (minimum of just 140 m/s to C3=0!)
  
• Very cheap to SEL2, to bring in space telescopes for upgrades
  
• Very cheap to low lunar orbit, and the lunar surface
  
• Reasonably cheap to bring in satellites from GEO (probably low-thrust / SEP)
  
• Cheap to high-C3 interplanetary (descent to low earth altitude + Oberth burn)
  
• Generally strikes good delta-v balance between a lot of places
  

Compared against similar locations,

• Solar Lagrange points need more delta-v from earth
  
• Near-earth asteroids need more delta-v, and have very long transit times
  
• Lunar orbit needs more delta-v, and has high station-keeping costs
  
• Various tradeoffs between EML1/EML2 (unstable) and EML4/EML5 (stable halo orbits)
  
• LEO is cheaper from earth, but very expensive from heliocentric. If you want to use lots of asteroid material (water ice, shielding mass), you want to assemble things in a high orbit like EML or SEL
  
• GEO is more expensive from both earth and heliocentric (VERY suboptimal)
  
• Lunar surface is in a deep gravity well, has day/night cycle, and is covered in dust
  

(Of course, this isn't an original idea at all!)

edit:

Should emphasize how surprisingly cheap EML could be.

The low-thrust delta-v for LEO -> EML1 is 7 km/s. With a solar-electric tug, you could probably get 1.2 : 1 mass ratios or better (e.g. for a 1-year spiral, at 8,000s Isp and with 200 W/kg solar panels).

I.e., take 10 Falcon Heavy launches to LEO (500 tons). With a 4 MW solar array (~50 tons), and 50 tons of xenon propellant, you could lift 400 tons of payload to EML1 (on paper). That's <$2 billion of launch vehicles, for the entire mass of the ISS. (The ion engines would probably cost more).

For bringing in mass from a low-C3 NEO, you could get LEO multipliers as high as 100:1. I.e. one Falcon Heavy launch (50 tons) gets 40 tons of SEP propulsion to a NEO, which then pushes 4,000 tons of NEO mass by 300 m/s, into EML1. For bulk shielding, that's insanely cheap! 4,000 tons of iron-nickel, for example, would surround a 10-meter TransHab with >1 meter thickness.

This is just silly back-of-the-envelope stuff, but it's provocative.

Edited August 15, 2015 by cryogen