New Mars Forums

Actually Woerner is the CEO of the DLR, that's the German space agency, so more like Griffin than just some politician.
According to that link from gaetanomarano's post he just asked for a new vehicle launched on top of the Ariane 5, then he added "but best would be a space glider that takes off and lands horizontally".

The first suggestion seems to be realistic, Europe is long overdue developing its own manned spacecraft. I hope they will finally come up with something that is developed until it works and not stop at half way again.

As for more advanced, fully reusable launchers, that should be developed on relatively low budgets, until we have something that can be built with moderate development costs. If the shuttle shows anything, then that you can waste a lot of money by betting on the wrong horse.
My personal favorites for accomplishing something in that sector are the altspacers, they have more freedom to experiment since they're using their own money.

Yes, it's similar, only this one would be in GEO, always pointing at the same spot as long as it's needed.

How predictable, that environmentalists are also against this idea, it's something technically new and challenging after all.

Even in LEO it should be possible to only focus the beam to a spot when it's above a city, so that the wildlife wouldn't be disturbed.
But we'll need to improve our knowledge of extreme lightweight space structures first, no-one has ever tried to do anything of that kind on Earth, gravity and weather would make it impossible to build and keep structures that light on the ground.

Yes, at the moment the discussion is about pushing that date further out, but there are a lot of people even against that. By the way do you know how they will replace the lost power?

Either by importing energy from neighboring countries like France (who make some 90% of theirs by nuclear plants), or sadly more likely with gas though that new pipeline, for which our former chancellor Schroeder signed an agreement before becoming one of the chief managers of the consortium building it, after he lost the election.
That consortium mainly consists of the Russian corporation Gazprom, the one that Putin is using to limit the independence of former Soviet states. The pipeline is being built in the Baltic Sea, directly connecting Russia with Germany, bypassing the Baltic States and Poland.

You know, sometimes I think I'm in the wrong movie here.

I agree that we should only use lasers if it turns out there is now other way to keep the reflected light focused over a long distance.
But actually my idea was to use a structure that rotates about an axis that always keeps it reflecting the sunlight to the same spot on Earth, completing one rotation every 24 hours, while moving along its geostationary orbit.

Peak performance would be when the Sun is almost behind the Earth, so at the mid of the night, then we would have a short "mirror eclipse" until the Sun "comes out" on the other side of the Earth. At noon, when the Sun is at it's highest point as seen from the target area, reflection area would be about zero (without multiple reflection), then increasing again and so on.

This means that those Earth-based solar power generators would simply have to be pointed towards the mirror at dawn, then stay in this position until sunrise.
But it would also be easy to build structures specifically for these mirrors, because you wouldn't have to follow the movement of the light source as is the case with the Sun.

Clouds would be no problem for this system because of its flexibility, you could have several possible locations to point the mirrors at and could simply redirect the light on an alternative target if weather conditions became bad.

I don't know if there are online references for mirrors, maybe try to search for the Moon distance measurement by using the mirrors on the Moon.
I write this because I searched up the presentation I've seen from one of the guys who developed the laser altimeter for Mars Global Surveyor (it's called MOLA).
There they say that at 400km distance the laser spot had a diameter of 160 metres, the beam had a divergence of 420 µrad, that should be an angle of 0.024°. By the way they measure the altitude by pointing a telescope with a view area of optimally also 160m at the same spot where the laser hits and send pulses and measure the time for the light to travel to the surface and back to the telescope.

Then in this presentation there is an interesting part about the Moon distance measurement. This is done with the mirrors left on the Moon by Apollo. In the document they state they used a laser in an Earth observatory with a beam divergence of 50µrad, leading to a spot diameter of 20km on the Moon surface, where the mirrors are.
Then say say the reflected beam had a diameter of 40km back on Earth. This can only be the case if the mirror reflected the beam very accurately, not adding to the divergence, which means it is far superior to that wall mirror I used this afternoon to see how much it spreads the light from the Sun, that can be assumed as parallel here (it was still fun lighting up all the neighbors walls and roofs    ).
Anyway, if it would turn out it's still not possible to reflect Sunlight from GEO without significant divergence, we could probably directly convert the light to laser light with a set of central tubes (see wikipedia http://en.wikipedia.org/wiki/Laser)

Definitely, if we can make that happen the possible uses are endless.

I would place them in GEO because that way anything you would have at Earth would only need to be pointed towards the same spot all the time. LEO is a no go because you would have to move the mirrors very rapidly, could only light a spot for a few minutes at a time and the gravity gradient forces would probably just rip apart such a flimsy structure. And it would cause a lot of drag because of the huge surface area.

It could be made very lightweight, I remember reading a post somewhere on this forum about some sort of plastic mirrors (I think it was mylar) with a coat thickness of just 1 or 2 micrometers, which would mean a few gramms of weight per square meter, so a few tons for a square kilometer.

Since we get 1300W/m² from the Sun here at Earth, this would mean over a gigawatt reflected per square kilometer. It would need some supporting structure, just look up solar sails on that issue, they thought about a lot of possible ways to make their sails stable and were thinking about even bigger surface areas if memory serves. Also look for solar sails for methods to steer it.

Anyway we could even cope with degradation by micrometeorites by changing the mirror surface while keeping the supporting structure underneath. One possible way would probably also be to use some liquid that doesn't vaporize at a high rate in vacuum, but I don't know if there is anything in the range we would need.

I would start different projects at the same time.
First, we would need reliable and cheap launchers in the range from one ton to 100 tons, we could use existing ones, so I would just buy these.
Then we need a capsule for manned missions and a cargo transport. Once these are all together we can start on the more interesting part.
We need to do some development and testing on assembling very large, very lightweight structures in orbit. This will be the basis for space mirrors, solar cell arrays and tethers.
One of the first priorities will be developing a tug, mainly an orbital garbage truck really with a tether and some sort of a net. It would be equipped with electrical propulsion, some sort of plasma engines in the 10 to 20 km/sec exhaust velocity range would be ok. This tug (or several of them) I would use to collect space debris in similar orbits, then getting it to a processing plant in orbit, another early priority project.
This would enable us to clean EO of all the scrap while providing metals for simple orbital structures.

Let's assume this would take up the first 10 to 15 years.
By the end of that period we could start looking for the Moon.
While continuing the buildup of the Earth orbit infrastructure, we would send out early manned limited time missions to the surface of the Moon. Beyond testing the equipment designed to survive on the surface, priorities would be to start mining for any useful resources, from oxygen to metals and Helium3 of course, if there is any power plant on Earth we could sell it to. Most of the resources would be used on the Moon or sent back to Earth orbit, preferably using an increasing network of momentum exchange tethers, which would reduce the cost of two way cargo transfers along the Earth-Moon route.

If this infrastructure is set up, we will be ready to build our first Mars ship, it will be a large scale project with extensive in orbit construction and designed for settlement. Since we need to stay on the surface of Mars for about 2 years as a minimum, we could use parts of the spaceship to set up an initial base. The mission of the people (volunteers) would be to stay for this minimum of two years, then decide if they are still in a shape to stay for another two year period and so on. At every low energy route opportunity, we would send at least supplies for the colonists, or even better more of those Mars ships. While we have people on the surface, they should try to expand/improve the Base with in situ materials, radiation hardening the base would be a high priority and could be done by pouring Martian rocks on top of the base or digging an underground facility. Another important task would be setting up a greenhouse for oxygen/food production and mining water.

At this point the 15 Billion budget would get too tight to support all operations at the same time, so the space mirror/moon mining projects should better start bringing in some cash. This would also be the right time to start looking seriously for some Asteroid mining, since our knowledge of zero g construction would be advanced enough after all those years of EO assemblies.

This is basically one possible way to do it, though you can never know if someone will come up with a radically new type of propulsion for example. In that case, better Isp launchers would tend to reduce the importance of the Earth-Moon connection in this scheme.

Hmm that's the problem there are a lot of theories and every one says something different. I heard about this ice age thing first in a scientific tv-show on the Bavarian channel called Alpha Centauri. Luckily all their shows are on the net and I reviewed it, the guy really did say that we probably prevented an ice age, it was not just the voices that usually talk in my head.

Anyway I searched up that theory and found it on the same wikipedia page you reffered to. Here it is:

As I said all this seems too controversial to me to make some major changes to the way we are doing things based on it, although that rapid cooling you talk about can be potentially dangerous, we should definitely take a look into what we could do to stop it if we saw something like that beginning to happen.

What kind of shuttle are you talking about, one that would slow down and return to Earth after delivering the passengers?
In this case I agree, but if you make a two way capsule that goes on to the destination (Mars for example) lands there and waits for the next cycler to arrive, then rides along that one back to Earth, I guess it should have enough time to dock between the planets, same way capsules do the docking game in LEO, only on a heliocentric scale.
But I agree with you cyclers are very impractical for a lot of reasons. No minimum energy trajectory to make it periodic, no easy way to maintain it and by the time we need them we will have advanced nuclear propulsion/plasma engines or for the cheaper alternative one way modular spaceships that can serve as a space station in Mars orbit or even be ferried down to the surface in parts.

But then it also has advantages to start small and quiet. I remember reading the biography of Theodore von Karman, who emigrated to the US prior to ww2.
It's interesting what he had to tell about the people interested in rocketry in the 50'ies. He said they were a bunch of amateurs who were not taken seriously by the established aeronautical branch of people. Yet they became the key people in the Apollo program, one of them actually had to go back to China because he was accused of being a communist by McCarthy. He became the father of the Long March rockets then.
These people pretty much built the space industry up to a Moon landing within a decade and began from nothing.
The similarity between them and todays Altspacers is striking. I think they are our best bet for some completely new concepts being tried out and some really big advances to what space business is about today.

Hi Josh, yes it's also more difficult to keep the pieces together, you know, all the stuff around you. Uhmm where is my pen now again?

Cohen I hope you got the private message, anyway my email is thfledrich@gmx.de if you want to talk privately.
All others you can spam my address now but you will make me angry.  :shock:

Thanks for the compliment Marsman, but as for the need for professionals from the gaming industry, I think that at least in the specific sector of strategy games there is a trend towards very small groups or just one person designing a complete game. If you look at titles like the Europa Universalis series for example, I believe I can create a space game of a similar size within a year or two if I mainly work just on that project. (ok without the music but I have a friend who is a musician)
This is because of the advent of freely available graphics platforms like OpenGL which enable us to do things more quickly without having to bother about graphics too much.
The problem with larger companies in this arena is that they also have very high running costs (by the way most of these now large companies started out with doing small games in the '80ies and '90ies), which forces them to design their products for the mainstream market to get more costumers and stops them from trying out new things because of the risks. That's why these companies are having an increasingly difficult time to keep the public interested in their products.

Now for the film industry I am not that familiar with that field, but YouTube is certainly a chance to do something with a smaller budget even though the likes of Discovery Channel are doing a great job now in bringing tech stuff to a wider public.

I agree with you, noosfractal, that the environmentalists are driving away a lot of dreamers who could help mankind get into space otherwise.
But on the other side I can't even understand why they think the way they do.
I mean in the end their ideology comes down to establishing total control over everyone. That's the only way they can limit growth indefinitely, while we space people only need a relatively small place on Earth where we can do what we want undisturbed. We don't need to force our way of life upon them, if they like to live like they say that's fine with me.
But of course we can never go to orbit if everyone is forced to spend less than 3000W on average instead of improving the way we create energy.
Somehow they remind me of the people who forced Chinese sailors to scrap their own fleet and never go out to the sea again during the Ming Dynasty.
But luckily there are still different cultures on Earth today so even if they manage to turn over the west someone else (Chinese, Indians) will still do the job.

I think the space community/industry has all the money they can get. Noosfractal is right in that we are competing against other advocates who are only begging for enough food or basic education for the many millions of people living in absolute poverty.
It is a wonder that we get as much resources as we do against these odds and personally I think it would be quite immoral to ask for a lot more.
What we really need is to lower the cost of spaceflight, this would often mean taking less expensive options that mostly are only slightly less capable than the high-end stuff we are using today.
Let's take heat shields for example, why waste money on reusable materials when you could have a simple and cheap ablator that can be refurbished and reattached to a reusable capsule?
Or take upper stage engines, there are variants that have a nozzle throat made of a platinum alloy where platinum is the cheapest ingredient, while it only improves isp by a few sec compared to cheaper alternatives.
At the same time, there are new materials like carbon/aramid fibers (kevlar and that sort of stuff) that could make fuel tank materials much lighter than metal ones at no significant price increase to the whole system.
But I'm digressing into the tech stuff too much....
Anyway my point is to contribute to the overall technical development to lower the costs, it might be a slow process or there could be unexpected leaps any time, but consider what proportion of the world's economy former explorers had at hands and you will see that we are quite well off compared to them.