PB666

Wasn't that from a movie with chevy chase in it? I wonder why the vehicle has an alarm bell going off, within about 30 minutes everything within 3000 miles would be dead anyway.

Its not possibly massive enough to compress to 9.93. 1.6 times the radius of earth is 7.4 earth masses, its not massive enough to produce exotic materials at its core.

Unlikely, I think WIMPs are now pretty much excluded.

Geeze, must be radioactive as hell. d = 9.93 . . . . . . .

I think something like 3 of the 4 major candidates have now been ruled out. Higgs is massless, but it could be a type of Boson that increases gravity in empty space. IOW its rest energy is much greater than higgs.

http://www.sussex.ac.uk/newsandevents/index?id=42599 The matter part of dark gravity may not exist, I think that dark gravity is probably defined by energetic fields and not particles that have a rest mast.

So my attempted landing on Mercury went well until I landed, lol . . . . . . . Couple of problems now in the virtual journey. First we need to map (flag/satellite) a landing site. The lander ran out of fuel meters above landing site, survived the landing but then fell over on the steep terrain. Broke off the solar panel (which was useless because site was sunblocked) and broke off one of four engines (useless because there is no fuel). Poor Val. Here is the basic problem, the great place to land and get water (I nailed it) is actually a terrible place to land (you can't see . . . .) and its far from the source of power. So this informs our mercurian travel. We need to take down a rover, filled with wire and some solar panels that can be layed out. And the rover needs to be positioned before. This means our mercurial colony needs a robot. The craft lands at a great spot for harvesting the sun all the (weird) mercurial year, once he establishes an energy site the robot needs carry/unwind the cable back to the where the future landing site is going to be. See other thread. We want to use high tension wire and a step-up transformer to generate the voltage we need to because P = I^2*R and since the power may need to travel a couple of kilometers and we are not going to be using superconductors we need the amperage to be as low as possible. Thus in the colonization area we need a step-down transformer. So our mercurial landing needs to be the following. 1st a remote controlled lander that can flag a good solar collection site (and prepare that site if necessary but can also find a good colony site. 2 a remote controlled builder that can establish a solar array and take the wire down to base. We do not need Megawatts of power, 10 to 50 kW should meet all the needs of the colony. Also need to start thinking about a Mercurial launch vehicle for buildings. My lander at LMercO was 60T (40 times that of my satellite).[The apollo 11 lander was 20 ish) To get a 60T vehicle to mercury means I need a launch vehicle of 27.24 K tons. Thats not the bad part (see your favorite launch vehicle), I have no way of building an end Transfer ION powered spacecraft that inserts a 60T payload into Mercurial orbit.

If only things would grow in space and make solar panels. But at least this design is modular enough the side pieces could be assembled in a space factory, drawn into space, inflated and attached. The problem is that the design is surface inefficient.

Not sure where you got the number from. The balls do not have to be a km, they could be on a tether as to reduce the internal volume.

Not everything is about you.

The inflatable version would work if it was filled with aerogel that way if there was a micrometeorite collision it would hold its form. You could drag them safely behind the ship via a long stand-out and a tether. But you are not going to be able to conduct megawatts of power that easily. You could locally feed current to the center of the sphere, but once you collect it you are now talking about 10,000s of volts traveling down two conductors and they are still going to be very hot. The largest number of spheres per cross-sectional area would be 3, this means our 10 to 100 MW is traveling down a maximum of 3 wires for 3 to 30 Megawatts per wire. I have done some calculations. The wire I have choose is Grosbeak (26/7), its1.3 kg/meter and has an electrical resistance of 8.97E-5 per meter, a flow limit of 798 A at STP it has a strength of <1211 kN. The power output of a wire is given by Amps2*Ohms. The Temperature of the wire is given as Qemitted = P/A = sT4 where Q is the rate of emission, P/A is power over area, E is the emissivity constant of a metal (aluminum = 0.11), s is the Stefan's constant (5.97E-8 m2/K4 and T is the temperature in kelvin. The outside of Grosbeak is 10 aluminum wires of approximate AWG 6.5 and has a emission area (one half the surface of each strand) of 0.1 m2 per meter of length. As a consequence we can determine the temperature of the surface of the wire in cold dark space. Aluminum wire in normal operation is not suppose to exceed 333'K and the maximum tolerance of 363'K, with a prefered operating temperature below 293'C. For a 10 MW feed (where plus and minus strand are separated) in unlit space, the preferred voltage on grosbeak is 62 kV, the nominal minimum voltage is 51 kV and brief minimum voltage of 45 kv. Power loss along the conductor is not substantial even over a kilometer (0.005%) at 62 kV. The greatest risk is overheating of the wire. You can give the wire a coating that allows greater emission, aluminum being a great reflector is also a poor emitter. It should be noted that the highest amperage in atmosphere is higher than it is in space, this is because air can flow between strands cooling them, in space there is no air for to cool. This is something to keep in mind as we are thinking about electric powered space craft. The two cables themselves suffice as the tether, the problem is that there needs to be a high voltage transformer (and its thermal radiator) somewhere near the power source, probably embedded in the power source itself. For example in an inflated sphere, power is traveling from the outside of the sphere to the center, presumably the tether travels to several spheres.The voltage is best converted on the surface where the heat can be released as small as possible amperage load going to the transmission cable/tether. I should point out that if you needed less force to hold the wire you could use a hollow carbon fiber core with a single large diameter shell of aluminum wire, in this case transmission only occurs at the surface of the cable where heat is generated over large areas. This would give structural rigidity of the wire and prevent the wire from twisting (+ and - making contact, a very bad thing, linemen may take a month to reach Puerto Rico, they don't make calls in deep space).

Start with 30 kT, light match, 2 kT in orbit. Pick a desert Island to launch from, not very neighbor friendly.

The joke was kind of missed, I noticed the illustration was from 2017, so I was curious why there was the plate stamp of an empire that ceased to exist in 1989 and that never really had a serious moon program in the 15 years before that.

yeah that was it

Nice strut connectors, are they using a reverse spoiler as a decoupling separation enhancer. I think I designed this rocket about two years back Edit: The CCCP must stand for something, for the life of me I can't remember what.

Chinese aren't exactly promoting their space science on a global basis the way other nations do: Their claim to fame is the blew up on satellite with another satellite causing a great increase in space debris. They landed a robot on the moon that made a p in the lunar sand and then died. They could certainly work on the Public relations. For example Space Center Nanking or something like that.

The framing and wiring are big issues in my mind. If these cannot be deal with then there is going to have to be an increase in weight per unit area to provide in-panel electronics dedicated for power transmission issues. The framing issues are equally problematic. The plumbing site I was reading said that for any length of pipe there is a limit in length you cannot go beyond because any momentum (internal or external) suffices to catastrophically bend the pipe there has to be support or bracing along the length. Even in space that could become problematic. Bigger still, MatterBeam wants to use Low ISP engines. What happens to those 100 meter long panels or panels out on a long pole when you start throwing 0.1g+ acceleration at them. The poles will bend and you will lose directional control. Every aspect of a solar-powered ship is designed for low accelerations. Edit. A parachute in space does not work. Imagine a space ship traveling at 32000 m/s and a solar wind traveling out at 750,000 m/s. Which way will the parachute go?

how easy is it to start that building process at 17km up where the temperature can carbonize an egg (if the acid does not dissolve it first). Easier, build a giant space film 50,000km in diameter, go place it at venusian L1. As the temperature drops the SO4 will begin to fall out leaving mostly CO2 and nitrogen, on the night side of the planet the air will cool and CO2 will sublimate and fall out. Of course if you have done all that you can use the same film at L1 to allow you to live on the surface . . . lol. These are dreams of future futurism, at current these are all space fantasies, nothing more.

And that is the problem, there first of anything is more or less a prototype, and prototypes are quickly abandoned for production. Minimally they need to replace the engines every few cycles, and docking clamps and other parts need to be examined for wear and tear. If we are just looking at the F9s non-expendables the suffer quite a bit of wear upon landing, eventually they are going to have inflight failures as a consequence of that wear. There is a marginal utility of gain on recycling, if you recycle something 2 or 3 times you actually get most of the gain. No recycle save 0 recycle once (save <50% per flight) dS/df = 50% recycle twice (save <66% per flight) dS/df = 16.6% recycle three (save <75% per flight) dS/df = 8.33% recycle four times (save <80% per flight) dS/df = 5% recycle five times (save <83.3% per flight) dS/df = 3.333% If the total other cost of the vehicle is high then you may not want to recycle more than 5 times if the risk incurred by increased recycling exceeds the added savings for one more recycling. And there are other concerns, for instance the original engines on the B707 and B727 had to be replaced because they failed to meet pollution and noise standards that evolved. DC6 and DC7 where state of the art commercial airliners when completed, their production practically came to a full stop when the B707 was introduced. Most but not all of the original engines on the B747 have been replaced . . . . . . . .

Sure, why not just bring a trillion tons of carbon into venusian atmosphere to build the tower of babel, how well will that all go down.

OK so the next part. The inclination node for Mercury occurs about 48 days after the vernal equinox and on this day one can launch from cape canaveral at about AtP77 and circularize orbit at 145 km. A burn to a velocity at AtP296 centered to about 14800 m/s can create an elliptical that peaks approximate to Mercury's apoapsis and is approximately the same plane. The total amount of DV required is about 16000 to 16500 m/s from launch to first part of Hohmann transfer. As mentioned in the previous post above there are craters with water near the two poles of mercury, as well as water that accumulates transiently. Already we have determined and ION drive system 6500 capable of insertion into Mercury. This creates a required 23000 m/s dV required to reach Mercury. We have not yet considered the lander and its dV required, this will be part of the orbital payload weight.

Humans generate their own fertilizer. Yes you can aerobrake but you cannot land. Venus has less gravity than Earth. In addition your airship, when exposed to unpredictable venusian winds and invert, inverted gravity is not to good on the head.

You must consider the engineering problems at some point. For films in space for them to be effective they must stretch over wide areas. If the efficiency is 50% (higher efficiency will eventually be self-defeating) then you know that you have 700 kw per meter. So your average home is around couple thousand kilowatts at peak usage on two bands. These are generally double or triple zero wires and thats at 120 volts. Go to the hardware store and ask to see and weight triple zero wires. The are very heavy an very stiff. The electrical supply to your house is 4160v AC take a look at the size of the conductor, this is for groups of 16 houses. So now we are looking at MW sized panels. The current flow for a Megawatt at 120 v is 8333 Amps. What kind of wire are you going to put that on. 4160, the wire that serves electricity to your transformer is not insulated by any thing but air and distance, although there are insulators for high voltage wire (we used to use 100,000 volt electron microscope and the insulation was about an inch thick). The current flow at 4160 is 240.64. Oh and I forgot to point air is an insulator, space is not. What happens in space is that at high voltages the gas ionizes (glows at its emission spectrum) and conducts electricity through the plasma (this is how we used to carbonized EM grids); not much but enough to cause problems with electronics around your ship. The wire an its insulation create structural rigidity and add to weight. This particular problem I have thinking about for a couple of years now. These are some of my prototype solar ships. This ships panels are1 kg/square meter (much lower than the ISS's). The solar panels are 100 meters by 10 meters (1000 meters). The wattage at the base of the panel I considered as a problem. With the newer lighter weight films the problem goes up many fold. BTW this is KSP you may note the two storage compartments, just about everything else I modeled. (Although the solar panels don't work in the current unity version). For any system in which it is possible to create plasma it is also possible to create electromagnetic responsiveness to radiofrequencies. Because of the spin it is possible to use electromagnetic radiation to accelerate them. Although you cannot get the particle as hot as the sun, it is possible to move it in a laminar stream once it is ionized. You have to remember that thermal heat is about average collision speed. If the electromagnetism is directed at the center of the stream away from the walls it can be accelerated to well above the limit speed (that is the whole principle of VASIMR. For example if the outlet is in line with an RF generator and the heated stream is fed from a 30' angle into that line it could be accelerated even further. See the thread on Mercury. With thrusts in the 0.1 or 0.01 range it is still possible to use ION drive without spiraling by carefully timed kicks. How you do this is quite simple. On the day that you are supposed to depart determine where the optimal burn (assume you have infinite acceleration). Track that point backwards say 2 or 3 days, it will be at a different angle to prograde (about 0.985 higher angle to prograde) this means the launch window needs to be offset backwards 3 minutes 55 seconds each day. Once launched begin your kicks over a span of -5 to +5 angle to prograde every orbit, keeping the periapsis at constant altitude by a small correcting burn each apoapsis. As the velocity reaches escape velocity for that orbit a single final burn needs to be done. This will place the craft on a hyperbolic trajectory where it has all the time it needs to burn. For transit to Mars this works well because the ship will be optimal burn at an AtP180 to 90, and at 160 degrees on the prograde motion it will be behind the sun (termination) and all the ISP in the world will not help you. Therefore doing multiple burns at higher angle to prograde days before allows better solar and after requires more battery (AtP270 has the highest power production). All the TWR in the world wont help you between AtP130 and Atp20. The problem with solar electric (see image above) there is no good way to get sun at high density in planetary exits because its always hitting at oblique angles. In the case above the angle is fixed (this is good for Interplanetary) but not so good for Oberth burns. If I rotate the angle then the first side mounted panel blocks the other two side mounted. So the best thing is to battery up and kick. Once you get an orbit that is hyperbolic you can move to ATP20 on the Prograde outbound motion and then start using what is left of the oberth effect (once you create a hyperbolic you thrust applies oberth logic, and energy you gain in low orbit past the escape energy you must keep on system exit). If you are power burning on a round trip you definitely want that ISP, you will burn alot. First your outbound vector is going to pass ATP20 much later because it will have substantial radial component relative to the earths motion around the sun. Your burn will be earlier but once you pass ATP160 you will loose most of the rest of the Oberth effect.

As you are limited by 3.25E25 W/m2*r. There is no limit to the ISP to solar thermal since at high temperatures gas becomes ionized. At such temperatures uv lasers and rf can be used to accelerated the heated gas. The issue is stabilizing the mess before it glows white hot. Its nice to see the theory, but the reality currently for application solar panels is about 40% efficiency, this I don't see as the major concern. I can simplify the problem like this. 1. We need light weight frames that can be deployed that are huge. I don't mean 10x bigger than current, but 100x or 1000x bigger than current frames (such as ISS). I was thinking for example a device that is 40 meter long or more (2, 1 on boths sides of ship). IN reaching orbit it unfolds like pocket knife. The end the travel to the center on piece grabbing the second, then the pieces move away as the center brace telescopes outward in both direction to 200 or 300 meters and pulling a then solar film that is 400 x 40 meters = 16000 sq. meters. Getting efficiency over 50% is not necessary if the weight can be reduced to 0.1 kg per m2 2. In the example above panels are producing 50% eff x 16000 x 1400 w = 11.2 MW of power, the power density at the ends 280 kilowatts per meter. if the voltage is 12 then the amperage is 20,000 amp per meter on the pickup bar. This is way too high for the conductors to efficiently conduct. The voltage needs to be raised to around 600 volts this drops the amperage on the pickup bar to around 500 amps, this amounts to several bulky wires. And alternative is a pickup wire on the side. But again this has to step up the voltage to 5000V range in order to get the amperage down. 3. In the above example there is a ship with 32000 sq. meter of panel at 22.4 MW of power and at 0.1 kg per sq. meter. the panels weigh 3.2 tons. This is not too bad for a ship that weight 20 to 50 tons but lets see how bad. Suppose a 10 kg ION thruster produce a maximum of 35 kw but we can use them most efficiently at 20 kw and have an ISP of 9000 (exhaust velocity of 89,000 m/s). 22.4 mw/0.02 Mw per thruster is 1120 drives. Each drive occupies a quarter of a meter, the ION drive foot print is gong to be 250 m2 (a 9 meter radius, this would be between factor 12 and 16 KSP rocket in diameter). The drives themselves would add 11.2 tons. Not to bad. But for all of that what are we going to get in terms of thrust. N= 2 * 22.4 * 0.8/9000 = 3982 N. If the weight is 50 to 60 tons then the acceleration is 0.0724 a with a maximum TWR of 0.1297 inside the orbit of venus. Not adequate for oberth maneuvers but lets look at total performance. Lets say 1/3 of the ship was devoted to fuel, what types of dV are we looking at. A 55 ton ion driven solar electric would loose 16.5 Ton and gain 31,500 m/s of dV. Such a ship has 11.2 tons of thrusters 3.2 tons of panel, 16.5 tons of fuel, a few tons of electrical (converting 22.4 MW of power safely into thruster usable form). At 80 percent efficiency those thrusters total will generate 4.48 MW of heat (which we wave our hands and pretend we have dealt with all the while knowing the ship melted), We need another 3.2 tons of ultralight radiator. Oh and BTW the waste heat is 500 times more power than the fission based reactors! This leaves a payload of 17.9 tons. However, outside planetary systems, this amount of thrust and dV is more than enough to do anything you want to do in our solar system. If you kick heliocentric retro down to mercury and perform an oberth around mercury you can be leaving the solar system at 50,000 or more m/s with 17.9 tons of payload. Fat chance stopping at pluto though, its still too little sunlight. 17.9 Tons is still to small to transfer colony ships or earth return landers. 17.9 ton payload, however is an excellent size for an interplanetary tug than can cycle back and forth to mars several times on a single load of fuel, or increase payload for one round trip. Films need to be pulled from both ends, this is why I mentioned framing. The frames need to stretch from two opposing sides of a rectangular film. What MB is not considering however is that with very large film solar panels there is a large wattage flowing over the ends, unless the voltage has been stepped up into the kV range there is going to be alot of heat at the interface.

I thought that memes were banned Send a message to the aliens of 128b and tell them to upload pictures of their planet to face-book.