Sorry, people. I forgot about this thread, it seems. xD
Rugoz wrote:- Minimal?? Not compared to robotic exploration.
- $8bn a year is not for building the base, its for sending humans there on a regular basis, keeping them alive and bringing them back to Earth. The "base" is rather trivial.
Where are you getting this $8bn a year estimate from? It sounds like a bit too much for just sending a crew there.
Unless you think I'm claiming we should start sending missions to Mars right away, which would be crazy.
- No actually it requires a lot more than current technology to be feasible.
Actually, no... We do have technology to build a ship and send a manned mission to Mars. The main obstacle right now is cost.
For example in-space cryogenic propulsion, solar electric propulsion with 100s of kw
There are other forms of propulsion which would be more expensive and less efficient, but would still be usable.
life support systems that can independently operate for years
That is feasible with current technology.
Also, keep in mind that by "currently technology", I mean that we would start now. Special spacecraft would be needed, and it could take a few years to design, build and test a prototype.
Mars EDL for large payloads
That's the one thing you might have a point. I really don't know. But I would be surprised if NASA scientists hadn't been developing such a system for years now.
ISRU
Completely unnecessary for early missions. It will probably be needed later on once we build a permanent base and need to stay there for lengthier periods of time.
What a great response! Rolling your eyes is always a great scientific counter-argument to scientifically valid projects like space elevators and solar power! (My turn:
)
Space elevators are the best solution to overcoming gravity wells. And solar energy is not only the one that is more available to us in the solar system, it is the most wasted form of energy on Earth as well.
But Mars isn't "naturally there". It depends on the target Asteroid and its orbit. There's no reason why Mars should be chosen as a staging point.
Mars will always be close to a section of the asteroid belt. It obviously wouldn't be used as a unique storehouse for space resources.
In fact its a pretty shitty choice because of its high gravity unless you need it for a swing by.
Again, you are assuming we would have to go down the gravity well. There is no reason why we can't use Mars gravity on our side and establish all sorts of fueling stations and storage sites on its orbit.
And once space elevators become feasible, we will be able to use the gravity well in our favor and use it as a storage site as well.
That's why people talk about Asteroid mining. Asteroids have almost no gravity so you can easily "land" on them and use low thrust high ISP systems like nuclear/solar electric propulsion. Mining anything in space using chemical propulsion is hopeless and will never happen.
No objections from me here. The only problem is that you are forgetting why we need asteroid mining in the first place: to build structures in space. Mining from asteroids and keeping everything there would be a huge waste of effort.
The future (and I'm not talking about the near future, this could easily take centuries) will probably see all sorts of man-made structures orbiting not only the sun (which is something more difficult to accomplish), but also planets, dwarf planets, moons...
Harmattan wrote:Mars for colonization is pointless. It would be too cruel even for death row prisoners (guaranteed claustrophobia, severe health problems because of the long-term low gravity, and isolation because of communication latency). No colonization without genetically modified humans. But we are not there and this may require us to engineer babies for this purpose (ethics !). Until then space is for explorers who want to leave their mark and only stay a few months, or poor souls you will pay a hell lot for 2 years contracts.
I have a feeling you quoted the wrong person there, because I clearly stated that:
Smertios wrote:Well, I have to agree. There is little reason to colonize Mars. Just like there is little reason to colonize Antarctica. The environment is simply too inhospitable. That doesn't mean we shouldn't get there and establish scientific bases, though. Mars can even be a hopping station for ships transporting minerals from the asteroid belt.
Mars as a mining base is pointless. There are just better alternatives.
Not as a mining base. As a storage base.
Mars will always be close to one section of the Asteroid Belt, but not always close to the Earth (or other points in the Inner Solar System). As such, it is a great choice for a storage base for mined metals from the asteroids.
Mars as a refueling station is absurd. In space you don't slow down if you stop the engines. So you burn everything early and by the time you reached Mars you already spent two thirds of your travel time and you do not have to spend a single additional Joule to reach the asteroid belt.
Precisely why you will eventually need refueling stations in the future. You can't really slow down or stop the spacecraft without burning fuel. In the future, it's possible we won't even need any fuel to reach other places of the solar system, as we can always use a solar sail to do so. But you can't stop your ship without burning fuel. If you stop whatever engine you might have, you'll simply continue traveling in the same speed.
Placing fueling stations in the orbits of other planets would make space exploration of other parts of the solar system much easier, as it could help diminishing the payload you need to carry in your ship, bringing its inertia down. It's similar to the reason why we have so many fueling stations in highways across the world. That way, you don't need to carry a lot of fuel all the time you want to travel.
Space mining involves catapults, not spaceships. You pack the resources like a ball, form a thermal shield around it, strap a device to slow it down once it approaches/enters Earth, and you catapult that to Earth's oceans with a big railgun. That's the basic idea at least.
That's a terrible idea. Once we have multiple companies investing in asteroid mining, the last thing they will want is to have another company wait in the middle of the way stealing the minerals they catapult to the Earth...
We will eventually have sealed spacecraft to deliver valuable resources to other destinations in the solar system, pretty much like we do with other goods on Earth already. You don't see many mining companies who just build a conveyor belt system to send their minerals to the other side of the continent unsupervised, for example.
Humans in space always make things a lot more expensive. They need food, water, atmosphere, faster travel times but lower accelerations (no railgun), plenty of room and equipments (fitness/hygiene/distraction/sleep), gravity, communications, training, monitoring, garbage disposal, redundant systems, etc. For every kg of passenger you have a hundreds times heavier overhead. And you can't even sacrifice them and replace them with spare ones. Transporting humans is too complex and expensive, and no colony would be autonomous before more than a century even after you set up a base (our industrial processes are just too complex).
But needed, nevertheless. If we are not gonna send humans to outer space, space exploration itself is completely useless and a huge waste of time.
Humans may not be needed. Lil' Mars explorer did a hell of a job alone, and maybe we can also invent slower mining techniques that do not need humans. It's true that not having humans make things complicated, but having humans in space is complicated in the first place. Besides it will only take a few decades before robots are more autonomous than humans.
Again, that is a common misconception to how automation systems work. There isn't and there will probably never be an unsupervised automation system on Earth. Computers can't make decisions as well as humans yet, after all...
Spatial elevators are so far impossible to build. It has nothing to do with energy, it is a matter of materials. Steel will not bring us further than 2-4km tall, after that it will break under its own weight (or tension if you strap a counterweight in space). Maybe carbon nanotubes but it's a big maybe.
Definitely carbon nanotubes.
That's a technology we already have. In the next few years, it will probably start being manufactured on large scale.
Photovoltaic energy is more expensive because it needs more labor. This is as simple as that: between its short lifespan, rare earth materials (labor), slow and careful crystal growing (labor) that takes a lot of water (labor) and energy (labor), it is simply easier to just pump oil from Earth.
Wait, what? What is the labor cost to produce 1 kWh of electrical energy using solar power? Exactly zero.
Also, who said anything about photovoltaics? There are plenty of ways to gather the energy of the sun, including solar thermal plants, for instance.
Photovoltaic cells are still a bit inefficient, but that will change in the future.
Solar energy is not wasted without PV. It heats your house, the soil and the atmosphere, and it grows carbon storage devices (plants). Only a small fraction is actually wasted (< 30%) and a PV panel does not change it much.
Again, you are the only one talking about photovoltaics here...
And also, yes, it is wasted. The Earth reflects back to space ~35% of all the solar radiation it gets from the sun. 35% is a huge waste.
And that is only taking into consideration only the Earth's energy budget — that is, how much of the energy the Earth receives and sends back untransformed. I'm not talking only about the Earth here. The whole reason why Dyson spheres and other similar megastructures were designed was precisely because we waste more than 90% the power the sun irradiates to the rest of the universe.
We have more than enough deuterium on Earth. It is abundant in oceans, easily extracted, and we would need ridiculous amounts. You could easily power the world for thousands of years, provided you can make controlled fusion work (that's a "maybe").
If by "the world" you means "Earth", sure. But we are talking about long-term space exploration here.
Harmattan wrote:I do believe in space colonization but only once we will have terraformed those planets and genetically modified ourselves. Before that colonization amounts to sending detainees colonize the Antarctic. Worse actually. This is pointless, we will not achieve anything that way.
You cannot rush things.
Colonization is the not only reason why you send people to space, though.
And the actual feasibility of terraforming is yet to be proven. Space colonization is much more likely to involve space habitats like the O'Neill Cylinder or the Stanford Torus at first.