Dave (imported) wrote: Tue Jun 23, 2009 2:48 pm The transmission loses are too large to make it economical. You know the answer even though you might not know the science... Think about it.

What has less resistance-- ground with worms, dirt and rocks or a continuous copper wire?

Not to mention harmful for the worms. --FLO--

This thread can still go all over the place.

The super gun idea sounds very Jules Verne. It might be doable if you needed to put solid shot in orbit, any more delicate payload might be a little problematical.

Another thing to consider when thinking of using a super gun or a rail gun to launch things from ground level is noise. The shock waves generated by firing something sizable to orbital or escape velocity, at ground level, might be heard around the world. It would be destructive, not to mention defining, for some distance around the launch point. Where are you going to put this thing? If you have ever witnessed a large booster launch from five to ten miles away you know that the rumbling of a rocket launch is bad enough.

I suspect that the bird strike question, would be a non issue for such a launch system. With a large object moving 27000 to 37000 feet per second I suspect that the shock wave would simply vaporize the birds.

All this searching for alternative launching systems would not be an issue if we had a real space program since Apollo. The nice thing about the Apollo program was that results were all that mattered. When the Space Shuttle came along, pork barrel politics had taken over. The people at NASA were so frightened that members of Congress would dump the entire Space Shuttle budget down their personal pork barrel rat holes after we beat the Russians to the moon (Probably, not an unreasonable fear.) that they destroyed the Saturn V production tooling and "lost" some of the key drawings so that the shuttle would be the only heavy lift launch system available. (BIG mistake!) The follow on SSTO (Single Stage to Orbit) launch systems that were to replace the shuttles were canceled for "budgetary reasons" as soon as any difficulties appeared in the development programs. (Politicians seem to forget that developing complex systems is called engineering not divination.)

Now, to attempt to meet the goal of getting back to the moon by 2019 (i.e. Beating the Indians, Chinese, and Japanese to commercial exploitation of the moon.) we see NASA engineers scouring old archives and taking pieces of the Saturn V booster, and other Apollo program equipment, out of museums and trying to reverse engineer them to find out how to former generation of engineers did it. (This is not an exaggeration.) The US had an incredible lead in space exploration and squandered it. Today, the only heavy lift launch systems the US has, despite having names from the glory days of US rocketry, are powered by engines either made in Russia or from licensed Russian designs. (Since the 1970s both the Russians and the French have put more commercial payload in orbit than the US.)

There is a bright spot on the horizon. There are several privately developed and financed launch systems, in the small to medium category, about to become operational. One of these, developed by a US startup, has already achieved orbit and another is scheduled for this year.

fhunter wrote: Tue Jun 23, 2009 3:17 am So you suggest to put attenuators on orbit around sun? A big controllable reflector in L1 (Lagrange point 1 - between earth and sun)? at least this position is gravitationally stable as far as I can remember. And this would be better for future space exploration - no need to avoid the fleet of satellites on launch .

On microwaves and generation of power on satellite - it is a dual use thing if it goes on receiving antennas - it's first use.

Just change orbit a bit and direct it on enemy country - it's second use.

That concerns me is that microwaves are harmful.

Well, it has been a long while since this thread was active, it was one of my favorite threads and I often think of it. Yesterday evening, my friend Dr. Evil and I were discussing the best and most practical methods of attaching "fricking" laser beams to the heads of sharks, and the subject of my massive solar reflectors and attenuators came up...

I very much like the idea of a solar attenuator at that "Lagrange point 1" that Fhunter mentions, but I got to thinking, COULD anything that big be stabilized in that orbit? There is something commonly called "solar wind," the continuous stream of energy and particles radiating from the sun, with this think facing it almost like a giant sail in space, could it ever be stabilized there without using massive amounts of fuel to keep pushing it back against the solar wind?

We could greatly benefit from some ways of controlling the sun's radiation, as I pointed out in my previous posts here, with the right ammount of attenuation, global warming would not be a worry, and the current heat wave burning Arizona could be tamed down a bit. With the right reflectors in place to boost the sunlight daytime in some agricultural areas, we would not have to lose so much to "late frosts" and other natural disasters.

DeaconBlues (imported) wrote: Fri Aug 26, 2011 2:35 pm Well, it has been a long while since this thread was active, it was one of my favorite threads and I often think of it. Yesterday evening, my friend Dr. Evil and I were discussing the best and most practical methods of attaching "fricking" laser beams to the heads of sharks, and the subject of my massive solar reflectors and attenuators came up...

I very much like the idea of a solar attenuator at that "Lagrange point 1" that Fhunter mentions, but I got to thinking, COULD anything that big be stabilized in that orbit? There is something commonly called "solar wind," the continuous stream of energy and particles radiating from the sun, with this think facing it almost like a giant sail in space, could it ever be stabilized there without using massive amounts of fuel to keep pushing it back against the solar wind?

We could greatly benefit from some ways of controlling the sun's radiation, as I pointed out in my previous posts here, with the right ammount of attenuation, global warming would not be a worry, and the current heat wave burning Arizona could be tamed down a bit. With the right reflectors in place to boost the sunlight daytime in some agricultural areas, we would not have to lose so much to "late frosts" and other natural disasters.

I need to calculate the size of the reflector, and thus the force which is applied to the reflector by the solar wind. After that we can judge, if the reflector can be made stable.

Interesting timing this thread reappearing now. A few weeks ago I was flying from Colorado to LA. My seat mate was a senior Boeing engineer, whose father was a refugee Jewish scientist from Germany, who had gone to work for the Manhattan project at Los Alamos NM,during and after WW2. My seat mate had grown up in Los Alamos, with the cream of American science partying in his parents house. After the war, the nuclear research was in Los Alamos and the rocketry was at White Sands further South in NM. There was much interplay between the two locations, the first bomb, developed at Los Alamos was exploded at White Sands. The rocketry stuff was headed by captured German Nazi rocket scientists under Von Braun while the Nuclear was headed by American and refugee European Jewish scientists (think Oppenheimer and Einstein) Apparently, although they worked together often, there was no great love lost between the two groups. It was widely believed that, had the Americans (or the Russians) not grabbed Von Braun, he would have hung or spent major prison time as a war criminal. He admitted to choosing slave labor at the local concentration camp, for his V-2 factory, where tens of thousands died of starvation and abuse. He was also a decorated member of the SS.

My new friend talked of a young researcher from Harvard who had worked at Los Alamos and played piano at his parents parties who later gained some fame as a folk singer, by the name of Tom Leary. The name didn't ring a bell, but when he sung a few lines of Werner Von Braun I immediately realized he was talking about Tom Lehrer (all of whose albums I have on vinyl) (see following link)

FianceeUvBigGuy (imported) wrote: Sun Jun 14, 2009 5:40 am Yoli here,

I remembered that Dad got a kick out of this re W. v. Braun.

http://www.youtube.com/watch?v=kTKn1aSO ... feature=iv

Enjoy!

Vapor traaaaaaails to yoooouuuu, untilllll we meeeet againnnnnn.

Y.

So Lehrer (who was himself Jewish) had actually met Von Braun and had partied with people who worked with him.

It was one of the most fascinating flights I have ever been on.

Transward

My father worked with German Rocket Scientist.

When chided by Jewish friends he would ask what they did in the (Joe) McCarthy Era.

My father worked for Voice of America and use to get 1 AM phone calls from Roy Cohn. He hung up after a few explicative.

Life at Los Alamos must have been interesting. Too bad they don't make a historical fiction series. I understand a maternity hospital had to be added beyond the plans. These families became an instant neighborhood for several years. And none were really from such terrain. There must have been some interesting experiences.

Moi

Oh, Yoli :hearthrob, how could you?

fhunter wrote: Sat Aug 27, 2011 2:08 pm I need to calculate the size of the reflector, and thus the force which is applied to the reflector by the solar wind. After that we can judge, if the reflector can be made stable.

I approximately calculated required size of the "solar attenuator". L1 point lies some 1.5million km from earth, on the direction earth-sun. Earth-sun distance is 150 million km. So, if we consider the sun as a point, this reduces to simple proportion.

We get (150-1.5)*6371/150=6307.29 km radius. Almost the earth radius.

Now, let calculate light pressure force + solar wind pressure, working on this surface.

The surface we get is approximately 1.25*10^14 square meters.

We have two external forces working on it:

solar wind pressure, (3.4*10^-9 N/m^2 at earth orbit)

light pressure, (4.57*10^-6 N/m^2 at earth orbit, for ideal black surface, twice this amount for reflective surface).

I calculated the force of about 1.143 Giga Newtons, in case of fully reflective surface. The real amount of force would be few orders less (we don't want to cause global freezing, are we?)

Now, second thing - stability, L1 and L2 points are dynamically unstable, so there would be need to correct orbit. But on the other hand, we potentially have up to 1.1GN of thrust for this orbit correction.

Right now, Arizona is going through some very hot weather, the hottest August since records were started in 1895. So I think about this a lot. Really odd thing is that July was a lot colder than normal.

I have thought about real weather changing things, like when Krakatoa erupted, spewed tons of ash into the upper atmosphere and blocked the sunlight, caused a "year without summer." So, while global warming sure seems to be heating things up, if any one of several "caldera" volcanos were to erupt, we could be sent into a new ice age in no time. Dramatic changes in global climate are NOT impossible, they have occured in the past and I think that IF we give it some thought, we could alter earth's climate to better suit us, but anything we do we have to be able to control, and if need be reverse. As fhunter wisely points out, we do NOT want to start global freezing.

I have thought that something as simple as launching a few rockets loaded with sand, and dispersing that sand into a low earth orbit could very well reverse global warming. But what if we made it too shady, too cold and started a new ice age? How would we get the sand back? So sand or dust clouds in orbit around the earth could very well cool our planet down, but just how to control that? No way I can think of.

IF we instead were to use a fleet of "parasol" satellites, they could be controled, but oh what a headache to keep them all positioned, turning and piruouetting all the time to provide the right ammount of shading, and don't even think about the staggering cost.

So, maybe one or more space parasols at the L1 or L2 points might be the best course. And I think that we might even want to have a space solar reflector in the planning just incase we need to warm up a few spots on earth. But these parasols and reflectors would by necessity be BIG, and they would be very costly to get into space... still, they could provide amazing benefit if they were able to control earth's climate.

Mirror at L2 would not help with global warming. L2 point is located past earth orbit, on the way to asteroid belt, nothing to reflect from earth there.

As for the satellite fleet - you do not need to change orbits, you only need to rotate mirrors on them.

Or you could just sprinkle some minerals on the open ocean where the limiting factor on life is mineral poor water.

Create planktonic blooms that also trap CO2 in their iddy biddy skeletons. This will have the side effect of creating fisheries.

Cheap and Ghia Friendly. Makes food and Omega 3 fatty oils too.

Moi