Mission to Venus

Terraformer · 2014-12-25 10:01:46

Of course food can be grown in an Airship, especially when the air itself is your lifting gas. Granted, you'll have to use aero/aquaponics, because actual soil will be too heavy.

Tom Kalbfus · 2014-12-25 18:20:39

Terraformer wrote:

Of course food can be grown in an Airship, especially when the air itself is your lifting gas. Granted, you'll have to use aero/aquaponics, because actual soil will be too heavy.

Assuming balloons are used and not airplanes.

SpaceNut · 2014-12-25 18:25:16

Lets not forget that at the 50 k altitude the atmospher of venus is going to bathe the ship in acid every second there and that means no metals that can come in contact to the air....

Impaler · 2014-12-25 22:35:25

Yes the exterior will just be made on plastic rather then metal, it looks like regular old polypropylene plastic might be adequate for the air-ships balloon as it is highly resistant to acid, they transport industrial acids in polypropylene bottles. It would also coat the gondola which is probably aluminum framed. The acidity problem is not as hard as it has been made out to be because we are removing the temperature component of the surface which would weaken most plastics and require us to use a super-alloy, but if we remain in a temperature benign environment the acid can be countered with very mundane materials. UV degradation may actually end up being more of a factor then acid in the long term survivability of the balloon envelopes, a more UV resistant plastic might be needed for that.

Also I would target the blimps to ride at the 55km altitude which puts them just above the bulk of the cloud layer and the bulk of the acid. The pressure their is only a half atmosphere but the temperature is a pleasant 80 Fahrenheit. The interior living space should then get a modest +2 psi over the outside environment which is mechanically almost nothing, leaks can be plugged with your fingers if they occur.

When I spoke of food I was simply talking about the mass of stored food being a limiting factor on an exploration type mission, if I want to stay longer I need more of it, not that I though food was practical to grow for such a mission. In any kind of true settlement then food growth is mandatory and is why you need to be using buoyant structures with more volume rather then planes for colonization, but the plane concept certainly has appeal for an exploration mission that involves accessing the surface due to it's better ability to fly into the wind and archive zero relative ground speed.

The use of a sub-orbital return rocket and 'half-way' to orbit docking with a second vehicle dose not sound good to me. It would require that the manned ascending rocket and an orbital target rocket both begin PERFECTLY timed and synchronized burns that target the same point, any deviation on the part of either rocket results in failure to meetup. The initially on orbit rocket must shed something like half of it's orbital speed to reach zero relative velocity with the ascending craft, and then it must regain the same amount, every m/s that the manned launcher is made less then orbital requires the vehicle it's going to rendezvous with to do 2 m/s to compensate, so were looking at something like 8 km/s total for that second vehicle, it is now very nearly as big as the rocket I'm proposing be launched maned and directly to orbit, both will require multiple stages too. Also the idea of a mid-air mating between two vehicles that are essentially in early re-entry is quite terrifying, their would be a lot of time pressure and some some atmospheric drag effecting their motions, one or both vehicles may have to do significant tail-flips and other acrobatics, this is far from the gentle and serene docking on orbit that we are used too. If we had permanent Venus occupation then an aborted launch to orbit just means a crew capsule plopping down in the 'ocean' of air down range, much as on Earth the crew would be easily recovered. In an exploration mission in which are consumables are depleted and their is no second rocket to get on a launch abort (possibly even a launch scrub) is a death sentence. This is why I think we want to keep the launch to orbit as simple and as Earth-like as possible.

The rocket I'm proposing would indeed be quite large, maybe Soyuz if we keep the crew capsule small. To protect it from corrosion it should be kept wrapped in plastic while floating at Venus and slung under the blip. If propellent is brought from Earth then easily stored ones like Hydrazine/H202 would be good. If we are willing to go ISPP, then CO/O2, Metho-LoX, even Hydro-Lox may be viable using Hydrogen extracted from the cloud layers. Bringing a wet or a dry rocket through entry into the Venus atmosphere is much much less difficult then doing it on Mars, it is even less difficult then on Earth, the higher scale height of the atmosphere gives more time and distance to decelerate in meaning lower g force and lower heating. The fact that we don't 'LAND' but rather just 'float-down' is to splash-down what a splash-down is to touch-down, super easy, their is a nothing to reach zero velocity relative too and no impact at all, all the landing gear can be dispensed with which have traditionally consumed 5%-10% minimum of dry mass for any kind of lander meant for a rough unprepared planetary surface.

The peak density of Sulfuric acid droplets occurs at 45km, their 25 mt per Million m^3 of atmosphere, that is 5% the mass density of a cloud on Earth, so the Venus atmosphere though 'bone dry' when looked at in totality dose have a zone of enrichment that makes extraction of hydrogen practical. Dangling a cloud-processing machine from a blimp at 55km down to the 45km level is quite doable (a steel cable could almost do that but we will stick with Zylon as it's so much lighter). Depending on the power needs and scaling efficiency of the equipment we may be able to get in the range of 100's of kg a day of raw cloud acid if the atmosphere can be drawn in and processed at rates of ~40 m^3 a second, big industrial air-processors can do that easily. Only acid is extracted and the remaining acid free air is just dumped. The acid is only about 2% hydrogen by mass which means converting it to water would reduce the mass 80%, fortunately their will be some water in the raw cloud condensate too, best estimates are 25% (for a total efficiency of ~40%) so it looks to be about comparable to humidity extraction on Mars.

In a colonized Venus I see fleets of 'Cloud trawler' blimps that do just this, dangle a cloud processing machine in the densest wettest clouds that can be found. Power would be sent down the tether and the acid would just be stored right in the processing unit, when it's full the processor would be winched up and the acid transferred to a tanker/transport blimp for transport back to the larger living and industry blimps.

These larger blimps would be the ones that focus on processing the WHOLE atmosphere, they also reside at 55 km altitude, they just take in the atmosphere right at their level without dangling the processor far below. The first step is also to extract acid but the low levels of acidity their means they produce only 4% as much per volume processed as the cloud trawlers. Removal of the acid is just the first stage though, they go on to liquify and distill the CO2 cracking it to CO and O2 from it and taking off the 3.5% N2 components. The deliveries of raw acid would be processed here (you need to react the acid with CO to convert it to water so it makes sense to do it here). Splitting the atmospheric processing this way makes for maximum production of hydrogen and water while still producing large quantities of other gasses, also sulfur may be a useful ballast (solid block so you can just drop it out a hatch) and the acid mix will contain small amounts of Chlorine and Florine which may have industrial uses but need some additional processing equipment to get. Once water and CO2 are available any desired hydrocarbon is accessible and we are in a similar situation to any proposed Mars atmospheric ISRU scenario in our choice of what to employ for rocket propellent and the needs of supporting habitats and industry but without dependency on exterior hydrogen delivery.

Quaoar · 2014-12-26 05:45:28

If it works, this rocket will be very good for coming back from Venus atmosphere to orbit: http://www.newmars.com/forums/viewtopic.php?id=7168

GW Johnson · 2014-12-26 16:25:43

I guess what I don't understand is why anybody would ever want to send humans to the surface of Venus as it exists today.

I cannot see going there with men until we have blown that dense CO2 atmosphere completely off the planet, with nuclear weapons, and then terraformed something more benign "from scratch". Venus as it currently exists is one of the most difficult and dangerous places that men could possibly visit, anywhere in the entire solar system.

GW

Terraformer · 2014-12-26 16:57:57

Correction: the Venus *surface* is one of the worst places to visit in the solar system. But the cloudtops are one of the best.

Impaler · 2014-12-26 21:09:58

He said surface already.

Venus surface is just for science and glory, same reasons we go to the bottom of the Oceans on Earth. Even if we were to ultimately need or want some of the material their for use in a Venus colony it would be accessed roboticly, again the same way we would mine the ocean floor on Earth if we ever found it to be economical (it's getting close).

Also I'm thinking that the Venus cloud colony may have an actual viable economic base, it's something were already doing here on Earth, it consumes billions on dollars and results in the relocation of large populations, entire cities here on Earth exist because of it.

Wealthy retirement communities.

They are generally located in warm and sunny environments and very much like to be isolated from the rif-raf, all things that Venus can offer. The clouds look nice and by propelling the craft against the wind during the day and with it during the night it should be possible to create a lopsided day/night ratio. At 55km the wind speeds averages 100 m/s and ranges from 70-130. Going completely passive the equatorial circuit would take ~100 hours with equal day and night, but if 30 m/s (air-speed of the Hindenburg) is used to create asymmetry then day length can be in daylight 75 hours and 40 hours of darkness. If I can also exploit the natural variations in the wind to get an additional 30 m/s differential (split evenly between day time slowing and night-time acceleration) then you can get 96 hours sunlight and just 36 in the dark. Battery power to continue propulsion for the long night period may be too heavy so I'd lower thrust and aim for a night of no less then 48 hours. That comes out to exactly a 6 day cycle in which you get 1 day of 'dawn' and morning, 2 days of solid day light, one day of evening and 'dusk', then 2 days of solid night. This would be rather enjoyable as the night periods are not so long as to get oppressive and the sunrises and sunsets stay at predictable and 'normal' times (they occur 8 times slower then on Earth though) at the beginning and ends of normal 24 hour days. Applying 15 m/s more thrust during day time could stretch it to a full 7 day cycle and we can have the night and the week-end be one and the same.

Last edited by Impaler (2014-12-26 21:12:56)

Quaoar · 2014-12-27 05:09:13

Probably, from what we can build now, a LOX-RP1 SSTO Rotary Rocket will be the best suited vehicle for Venus atmosphere.
The first manned mission can be performed in this way:
1) atmospheric entry with the base
2) slow descend using free wheel rotor and hovering in the atmosphere collecting samples
3) fire tip rotor rockets and start ascent in high atmosphere
4) fire main rocket engines and rendez-vous with the ERV in low orbit.

If we want a more long stay in the atmosphere, we have to add a balloon on the nose of the Rotary Rocket:
1) atmospheric entry with the base and the rotor blades folded
2) inflate balloon and atmospheric floating in the currents and collecting samples
3) unfold rotor blades, detach balloon
4) fire main rocket engines and rendez-vous with the ERV in low orbit.

Last edited by Quaoar (2014-12-27 05:09:56)

Tom Kalbfus · 2014-12-27 18:58:44

One possibility is to use laser powered jets to propel an aircraft around the globe in 24 hours if it is close enough to one of the poles to make a circle in 24 hours for 12 hours of day and 12 hours of night. of course the laser would be provided by a Solar Power Satellite in an orbit synchronized with the laser jet plane.
Here is an article:

Laser-Powered Aircraft Are The Future of Flight. Maybe

Aerospace engineer Leik Myrabo is absolutely sure lasers are the future of flight, and he’s confident we’ll be flying at hypersonic speed using beam-powered propulsion within a generation.

But experts doubt that.

Myrabo has spent two decades developing laser propulsion technology, which he laid out during "Expanding the Vision of Sustainable Mobility," a conference sponsored by the Art Center College of Design, one of the nation’s premier transportation design colleges.

Although it sounds like something out of Star Trek, Myrabo says the technology exists now and the challenge has shifted from sorting out the science to actually building the aircraft. He’s confident that challenge will be met within 20 years, ushering in a new era of flight.

"The whole philosophy behind my work is about doing much more with much less," Myrabo, a professor at Rensselaer Polytechnic Institute in New York, told Wired.com. "It’s about hypersonic transport for the period beyond oil. It’s about mass transit for the future."

Myrabo first got the idea in 1988 while working on the "Star Wars" anti-missile shield. He calls it LightCraft, a funnel-shaped craft with a parabolic reflector. It channels the heat generated by a laser into its center, heating the air to about 30,000 degrees and causing the it to explode, generating thrust. Small jets of pressurized nitrogen spin the LightCraft at 6,000 RPM to maintain stability.

It was all just theoretical research – which the U.S. Air Force, NASA and the Strategic Defense Initiative provided $600,000 to help finance – until 1997. That’s when Myrabo, working with the U.S. Army at the White Sands Missile Range in New Mexico, propelled a small LightCraft prototype (pictured at right with Tregenna Myrabo, business manager of Lightcraft Technologies; it was 6 inches long and weighed 2 ounces) 50 feet into the air. Another test in 2000 using a 10-kilowatt pulsed-carbon-dioxide laser saw the LightCraft climb to 233 feet during a 12.7-second flight. That’s not very high or very long, but then Robert Goddard’s first liquid-fueled rocket climbed just 41 feet during a 2.5-second flight.

Myrabo reportedly has made more than 140 test flights using small prototypes. He isn’t the only one exploring this field, either. Five years ago, NASA joined Tim Blackwell, a researcher at the Center for Applied Optics at the University of Alabama in Huntsville, in using laser propulsion to power a small model airplane. Researchers at the University of Tokyo have used a laser to propel a tiny airplane and detailed their findings in the journal Applied Physics Letters in 2002. Myrabo says he’s especially excited about tests being conducted cooperatively between the U.S. and Brazilian air forces; those tests, he says, are being done at greater power than any before.

Lasers remain the sticking point; even the most powerful laser is capable of only a modest test flight. But Myrabo is confident we’ll have that problem licked before long.

"In one generation, the science and technology needed to build and fly full-size LightCraft has been developed to maturity, ripe for commercialization," he writes in his forthcoming book, The LightCraft Handbook, slated for publication in April. "All that’s needed now is to actually build them. The problem has evolved from a scientific one to an engineering one."

However, some experts say the technology will never work.

Phil Coyle of the Center for Defense Information, and the Pentagon’s former top technology tester, told Wired.com last year that researchers have been trying for years to scale up the technology, with little success. LightCraft are severely limited by the power of lasers, the small size of the craft and the tiny amounts of propellant they carry.

"The propellant runs out before the LightCraft gets very far," Coyle said. "It’s sort of like trying to blow a paper airplane across the room with you own breath. You can give it a push with your first puff, but then the paper airplane is too far away and you can’t blow enough air to keep it going."

Nonetheless, Myrabo’s book lays out a broader vision for the technology, which he says in his book will bring "fringe benefits beyond access to space resources, space exploration and environmental preservation will also appear. Energy beamed down from power stations in space can be used for electrical propulsion of cars, trucks and trains, and for heating and cooling. Fossil fuel consumption and carbon dioxide generation will plummet. A global power system infrastructure with many parallel components, highly resistant to failure and sabotage, will emerge. The world will be a cleaner, safer place …"

Myrabo is almost dumbfounded that more people aren’t excited by laser-propelled flight, and he’s dismissive of jet technology. "You have a huge plane that has to lift 100,000 pounds of jet fuel off the ground," he says. "If you were able to offload all that fuel you wouldn’t need the wings. They’re just an unnecessary weight burden."

But jets will remain the dominant form of air travel for some time. Given the constraints of the technology, Myrabo says laser propulsion will be limited to launching satellites into low orbit — and even that is at least five or 10 years away. Still, he says the technology could reduce the cost of orbital flight by a factor of 1,000.

"There is nothing in chemical rocketry that can compete with that," he says.

He foresees laser flight carrying people around the globe and into space by 2020. Ground-based lasers called LightPorts would provide the energy needed to propel the crafts. It won’t become viable, he says, until the cost of jet fuel becomes so prohibitive the aviation industry embraces an alternative. Myrabo bases his timeline on the fact costs are moving in the right direction, with oil going up as lasers come down.

"Things have gotten to the point where you can buy the beaming power for a few dollars a watt," he says. "That’s when the whole thing becomes viable as a commercial enterprise."

At that point, he says, we could fly from New York to Tokyo in 45 minutes.

UPDATED 5:45 p.m. Eastern Feb. 20.

Photos and images: Leik Myrabo. Used with permission.

Last edited by Tom Kalbfus (2014-12-27 19:01:16)

Impaler · 2014-12-27 22:34:28

Are rotor-rockets able to do anything for that mission profile that a regular one can't? I'm not really familiar with what the concept can offer, only that it was experimented with and their seems to have been no follow up.

Also I've looked at the NASA pictures from the 'HAVOC' mission concept, their return rocket looks to be just 25 m long and 4-5 m wide. This would give it a volume of between 315 and 490 m^3 depending on the diameter. Assuming propellent density of around 1 g/cm^3 (rough averaging the 1.1 of Lox and the 0.8 of Kerosene) that results in a mass of the same magnitude, which would be getting close to F9 on the high end of the estimate, the low estimate is larger then the Antares rocket.

But the listed payload of the blimp (which is supported by a total of 25mt of helium, balloon, frame, propellers etc) is only 70 mt which implies a density between 0.2 - 0.14 which sounds much more like a Hydro-Lox rocket. Even then the capsule this rocket would return to Venus orbit is probably no bigger then a Soyuz entry capsule, say 2-3 tons total, little to no service module probably. If you thought most Mars assent capsules were 'minimalistic' this takes the cake. The NASA videos look to show only a crew of 2, which may be how they can stretch this, the capsule and rocket are all clearly custom for this mission as we have no rockets that small that run Hydro-lox or capsules in this size class.

This is why I think ISPP can do a lot of this type of mission, you have the energy availability, you have the atmosphere which is denser and easier to process then Mars, the additional lifting gas to support the growing rocket mass can be brought relatively easily as well as the Nitrogen/Oxygen mix waste byproducts. You can bring hydrogen and make hydro-carbons as in the standard Mars-Semi-Direct scenario, think of it as Venus-Semi-Direct but with most of the biggest hurdles (dust intake, thin-air, low temperature, fluctuating temperature, hard-surface landing, crew-surface-rendezvous, radiation dosages). If you think ISPP and refueling schemes work for Mars then they are even stronger on Venus.

RobertDyck · 2014-12-28 02:13:37

Venus has a lot of potential. It has 90% gravity, and 90% of Earth's surface. It also has lots of atmosphere. Nitrogen may be a smaller percentage than Earth, but total mass is 6 times Earth. That is 6 times the mass of nitrogen in Earth's atmosphere; that doesn't count soil nitrates, or proteins and DNA/RNA in living things. Venus could be great if terraformed. However, Mars can be settled now, terraformed later. Venus must be terraformed first, before it can effectively be settled.

I've said before the best way to terraform Venus is seeding the clouds with genetically engineered micro-organisms. This builds on Carl Segan's idea. Unfortunately the problem is a lot more difficult that scientists thought when Carl Segan wrote that paper. So part of the plan is seed the clouds of Venus, then leave it and focus on settling Mars while waiting for Venus to "cook". I use the work "cook" as a metaphor; the micro-organisms will convert the bulk of CO2 into a solid that will precipitate out.

Why is this relevant? Venus needs hydrogen. It has lots of oxygen, it needs hydrogen to make water. It's losing hydrogen from water through solar wind. Because it lacks a magnetosphere. So build a magnetosphere. That's where landing on the surface comes in. A big magnet on the surface to build a planetary magnetic field. We've discussed this for Mars. I advocated using big magnets manipulate convection currents in the core of the planet to create a dynamo. Like Earth's. Leverage your assets. Don't try to create a planetary magnetic field by bruit force, instead manipulate convection currents in the core so you can use the energy of the core itself as the primary energy source. A strong enough magnetosphere will capture solar wind, pulling it in as aurora. The plasma sheets of aurora will burn the hydrogen with atmospheric oxygen creating water. Of course that requires oxygen. See second paragraph.

Convection currents normally counter-rotate. That means any magnetic field created by one convection cell will be cancelled by the next. But Earth has a Moon with enough gravity to create tides. Not only in the oceans, but the crust. As the Earth rotates, that bulge moves, but there's a delay because rock and magma move slowly. That positions the bulge slightly out of alignment with the Moon. The Moon's gravity pulls on the bulge, slowing the Earth's rotation. This is how the Moon's rotation became tide locked with its orbit about the Earth. The effect on Earth is more subtle, and the Moon is slowly receding, so Earth will never become tide locked. But this effect only slows the crust and mantle, not the inner core. So the inner core spins faster than the rest of the planet. Earth's outer core is liquid, acting as a fluid bearing. The core is hot, partially residual heat from planetary accretion that created our planet in the first place, but also because a lot of uranium sunk to the core creating a giant nuclear reactor. The outer core has convection cells transporting that heat to the mantle. But the outer core also acts like a fluid bearing. That coordinates the convection cells. With more cells rotating in the same direction than the other, they reinforce creating a planetary magnetic field. And currents with net rotation around the iron core create a dynamo. Hence, strong planetary magnetic field.

Mars and Venus don't have a large moon. That means currents in the core counter-rotate, and the inner core is synchronized with the rest of the planet. Or is it? Mars appears to have an iron sulphide outer core. Manipulating that be difficult, iron sulphide at Earth surface pressure is not magnetic. Current estimate is Mars core has 17% light elements. But that's the whole core, what is the outer core? Is the outer core liquid, and is it magnetic and conductive? Those would be necessary for a magnetic field.

Venus is practically the same size as Earth. It should have a similar core. Its crust is significantly thinner, due to all that surface heat and pressure. But its core should be similar to Earth. And rotation is slowly synchronising with its orbit about the Sun. Enough for the inner core to spin a different rate? Could we use that to create a dynamo? And if we succeed, changing currents in the outer core could take a lot of time. That could require starting the magnetic field project early, relative to micro-organism action on the atmosphere.

Building big magnets on Venus, building size or larger, will be a very big job. But doing anything on Venus is a big job. Now do you understand why I consider advanced technology like nuclear propulsion appropriate for Venus? Anything on Venus is very advanced and far in the future. Near term is Mars.

Quaoar · 2014-12-28 07:51:34

Impaler wrote:

Are rotor-rockets able to do anything for that mission profile that a regular one can't? I'm not really familiar with what the concept can offer, only that it was experimented with and their seems to have been no follow up.

rotor-rocket can fly in the atmosphere like a spaceplane with atmospheric engines, without the mass penalty of wings an engines (actually we have no jet engines able to burn fuel using CO2 as an oxidizer). Rotor blades with tip rockets are very light, can function in every kind of atmosphere and during ascent augment the rockets exhaust with atmospheric gasses, resulting less propellant consumption

Tom Kalbfus · 2014-12-28 08:17:08

Impaler wrote:

Are rotor-rockets able to do anything for that mission profile that a regular one can't? I'm not really familiar with what the concept can offer, only that it was experimented with and their seems to have been no follow up.
Also I've looked at the NASA pictures from the 'HAVOC' mission concept, their return rocket looks to be just 25 m long and 4-5 m wide. This would give it a volume of between 315 and 490 m^3 depending on the diameter. Assuming propellent density of around 1 g/cm^3 (rough averaging the 1.1 of Lox and the 0.8 of Kerosene) that results in a mass of the same magnitude, which would be getting close to F9 on the high end of the estimate, the low estimate is larger then the Antares rocket.
But the listed payload of the blimp (which is supported by a total of 25mt of helium, balloon, frame, propellers etc) is only 70 mt which implies a density between 0.2 - 0.14 which sounds much more like a Hydro-Lox rocket. Even then the capsule this rocket would return to Venus orbit is probably no bigger then a Soyuz entry capsule, say 2-3 tons total, little to no service module probably. If you thought most Mars assent capsules were 'minimalistic' this takes the cake. The NASA videos look to show only a crew of 2, which may be how they can stretch this, the capsule and rocket are all clearly custom for this mission as we have no rockets that small that run Hydro-lox or capsules in this size class.
This is why I think ISPP can do a lot of this type of mission, you have the energy availability, you have the atmosphere which is denser and easier to process then Mars, the additional lifting gas to support the growing rocket mass can be brought relatively easily as well as the Nitrogen/Oxygen mix waste byproducts. You can bring hydrogen and make hydro-carbons as in the standard Mars-Semi-Direct scenario, think of it as Venus-Semi-Direct but with most of the biggest hurdles (dust intake, thin-air, low temperature, fluctuating temperature, hard-surface landing, crew-surface-rendezvous, radiation dosages). If you think ISPP and refueling schemes work for Mars then they are even stronger on Venus.

The formula for sulfuric acid is H2SO4, it appears you can obtain hydrogen from Sulfuric acid, H2 is more easily available than it is on Mars. I don't see why you couldn't collect Sulfuric acid from the clouds, since they completely encircle the planet. I've heard if you distributed al the water evenly on the planet's surface you would get 2 inches of water, but the thing is, all of the water is in the sulfuric acid clouds, right where the blimp is going to be, the sulfuric acid rain never reaches the surface, it evaporates and reforms droplets in the clouds. Hydrogen is a useful buoyant gas, and some of that hydrogen can be oxidized to make water. I think we could also steer a few comets to hit Venus, thus adding to the water supply there. We got a comet probe already, how hard would it be to nudge a comet so that it hits Venus, there are some asteroids with a lot of water too, nudge one towards Jupiter, and that planet can swing it towards Venus for impact. I think dumping more water on Venus could be helpful, make the clouds wetter for instance. I think the return capsule would be designed to lift astronauts to orbit in space suits, mass would be kept to a minimal, with no allowances for life support, it would have to dock with the mothership immediately!

Tom Kalbfus · 2014-12-28 08:34:19

RobertDyck wrote:

Venus has a lot of potential. It has 90% gravity, and 90% of Earth's surface. It also has lots of atmosphere. Nitrogen may be a smaller percentage than Earth, but total mass is 6 times Earth. That is 6 times the mass of nitrogen in Earth's atmosphere; that doesn't count soil nitrates, or proteins and DNA/RNA in living things. Venus could be great if terraformed. However, Mars can be settled now, terraformed later. Venus must be terraformed first, before it can effectively be settled.
I've said before the best way to terraform Venus is seeding the clouds with genetically engineered micro-organisms. This builds on Carl Segan's idea. Unfortunately the problem is a lot more difficult that scientists thought when Carl Segan wrote that paper. So part of the plan is seed the clouds of Venus, then leave it and focus on settling Mars while waiting for Venus to "cook". I use the work "cook" as a metaphor; the micro-organisms will convert the bulk of CO2 into a solid that will precipitate out.
Why is this relevant? Venus needs hydrogen. It has lots of oxygen, it needs hydrogen to make water. It's losing hydrogen from water through solar wind. Because it lacks a magnetosphere. So build a magnetosphere. That's where landing on the surface comes in. A big magnet on the surface to build a planetary magnetic field. We've discussed this for Mars. I advocated using big magnets manipulate convection currents in the core of the planet to create a dynamo. Like Earth's. Leverage your assets. Don't try to create a planetary magnetic field by bruit force, instead manipulate convection currents in the core so you can use the energy of the core itself as the primary energy source. A strong enough magnetosphere will capture solar wind, pulling it in as aurora. The plasma sheets of aurora will burn the hydrogen with atmospheric oxygen creating water. Of course that requires oxygen. See second paragraph.
Convection currents normally counter-rotate. That means any magnetic field created by one convection cell will be cancelled by the next. But Earth has a Moon with enough gravity to create tides. Not only in the oceans, but the crust. As the Earth rotates, that bulge moves, but there's a delay because rock and magma move slowly. That positions the bulge slightly out of alignment with the Moon. The Moon's gravity pulls on the bulge, slowing the Earth's rotation. This is how the Moon's rotation became tide locked with its orbit about the Earth. The effect on Earth is more subtle, and the Moon is slowly receding, so Earth will never become tide locked. But this effect only slows the crust and mantle, not the inner core. So the inner core spins faster than the rest of the planet. Earth's outer core is liquid, acting as a fluid bearing. The core is hot, partially residual heat from planetary accretion that created our planet in the first place, but also because a lot of uranium sunk to the core creating a giant nuclear reactor. The outer core has convection cells transporting that heat to the mantle. But the outer core also acts like a fluid bearing. That coordinates the convection cells. With more cells rotating in the same direction than the other, they reinforce creating a planetary magnetic field. And currents with net rotation around the iron core create a dynamo. Hence, strong planetary magnetic field.
Mars and Venus don't have a large moon. That means currents in the core counter-rotate, and the inner core is synchronized with the rest of the planet. Or is it? Mars appears to have an iron sulphide outer core. Manipulating that be difficult, iron sulphide at Earth surface pressure is not magnetic. Current estimate is Mars core has 17% light elements. But that's the whole core, what is the outer core? Is the outer core liquid, and is it magnetic and conductive? Those would be necessary for a magnetic field.
Venus is practically the same size as Earth. It should have a similar core. Its crust is significantly thinner, due to all that surface heat and pressure. But its core should be similar to Earth. And rotation is slowly synchronising with its orbit about the Sun. Enough for the inner core to spin a different rate? Could we use that to create a dynamo? And if we succeed, changing currents in the outer core could take a lot of time. That could require starting the magnetic field project early, relative to micro-organism action on the atmosphere.
Building big magnets on Venus, building size or larger, will be a very big job. But doing anything on Venus is a big job. Now do you understand why I consider advanced technology like nuclear propulsion appropriate for Venus? Anything on Venus is very advanced and far in the future. Near term is Mars.

I think settling Venus's atmosphere is a lot easier that terraforming the entire planet, the scale is a lot bigger when you try to alter a planet than when you are just trying to adapt to local conditions. I think before something is done to Venus, somebody has got to own it, I think the first settlers will get first dibs on what's to be done with the planet. I think one can fly around the planet within its atmosphere to obtain a 24-hour day. Park a Solar Power Satellite in a synchronized orbit with the Venusian Air Base, and we can have a laser beam power its engines and keep it moving forward to obtain atmospheric lift. I figure its enough to circle the North Pole once every 24 hours, there is less distance to cover in that time, therefore an airplane would have to travel as fast. 747s fly at 550 to 600 mph, so in 24 hours it would travel 13,200 miles, the cruising altitude of a 747 is 30,000 feet, which is approximately 10 km. So we need to build something that flies like a 747 in the Venusian atmosphere, since that atmosphere doesn't contain enough oxygen to combust jet fuel, we need another power source. I figure a Solar Powered laser would do the trick. Have a Solar Collector in space aim at a receptor on the airplane's back, the SPS orbits Venus in a 24-hour orbit, and it fires a low powered laser at the airplane's back, if the low powered laser gets reflected back by a laser reflector, the high powered laser switches on, while the low powered laser continues. Should the beams go out of alignment, the low powered lasers do not get reflected back and the SPS upon not receiving that laser reflection switches off its high powered laser until the low powered beams are realigned, We have to allow for some drift as there will be a communications delay between the airplane and the Satellite. Probably since the airplane wil be flying in a circle around one of the poles, the laser beam from space will come in at an angle. I'd say make the roof of the airplane transparent, at 60 km altitude, there would likely be few clouds above the airplane to block the laser light, maybe a few cirrus clouds perhaps.

SpaceNut · 2014-12-28 13:28:44

We want the Hydrogen and Oxygen but do not need the Sulfur but to bring the sulfuricx acid into a chamber with dissimular metals in it will cause a voltage to appear accross the electrodes or plates that are in the tank for electrolysis so we will need to add in other reactents to stop the effect.
Sulphuric Acid with other reactance placed into the mix before electrolysis will give some other needed materials for later use at the end of the page. Some of the reactances can be quite usefull for the seeding of the lower atmosphere

Tom Kalbfus · 2014-12-28 17:50:58

For an early manned mission, I think platinum will be available for the electrodes, and I don't believe Sulfuric Acid can dissolve platinum, it is even less reactive than gold, I believe.

Void · 2014-12-28 21:30:15

Since this discussion appears to be a cross between terraforming, methods of dwelling in the atmosphere of Venus, and so justifying human presence and a mission to the atmosphere of Venus, I will post.

I have this information on a critical issue:

http://en.wikipedia.org/wiki/Sulfuric_acid

Extraterrestrial sulfuric acid
Venus
Sulfuric acid is produced in the upper atmosphere of Venus by the Sun's photochemical action on carbon dioxide, sulfur dioxide, and water vapor. Ultraviolet photons of wavelengths less than 169 nm can photodissociate carbon dioxide into carbon monoxide and atomic oxygen. Atomic oxygen is highly reactive. When it reacts with sulfur dioxide, a trace component of the Venusian atmosphere, the result is sulfur trioxide, which can combine with water vapor, another trace component of Venus's atmosphere, to yield sulfuric acid. In the upper, cooler portions of Venus's atmosphere, sulfuric acid exists as a liquid, and thick sulfuric acid clouds completely obscure the planet's surface when viewed from above. The main cloud layer extends from 45–70 km above the planet's surface, with thinner hazes extending as low as 30 km and as high as 90 km above the surface. The permanent Venusian clouds produce a concentrated acid rain, as the clouds in the atmosphere of Earth produce water rain.
The atmosphere exhibits a sulfuric acid cycle. As sulfuric acid rain droplets fall down through the hotter layers of the atmosphere's temperature gradient, they are heated up and release water vapor, becoming more and more concentrated. When they reach temperatures above 300 °C, sulfuric acid begins to decompose into sulfur trioxide and water, both in the gas phase. Sulfur trioxide is highly reactive and dissociates into sulfur dioxide and atomic oxygen, which oxidizes traces of carbon monoxide to form carbon dioxide. Sulfur dioxide and water vapor rise on convection currents from the mid-level atmospheric layers to higher altitudes, where they will be transformed again into sulfuric acid, and the cycle repeats.

So, I feel it would be great to disrupt the Sulfuric Acid production. An enhanced Ozone layer might help. To get rid of Chlorine, add Hydrogen or water vapor to the upper atmosphere. That will at least reduce the destruction of Ozone which is produced. If that can occur, then less Sulfuric Acid production.

If I understand what they have said, you can also create water for your habitat by heating Sulfuric Acid above 300 degrees C and adding Carbon Monoxide. That would yield the water you need for your habitat.

To further get rid of Sulfuric Acid, perhaps a cloud seeding effort could nucleate more of it to rain, and so drop it down to the hot layers below.

I am thinking that further isolating water from the atmosphere would be helpful. Some could be split, and the Hydrogen released to the upper atmosphere, to reduce Chlorine and Bromine, the rest should be put into enclosures.

If a useful Ozone layer were caused to happen, then transparent plastic envelopes might be of use. I am thinking of an interior atmosphere of Nitrogen, Oxygen, CO2, and saturated humidity.

Balloons floating within the balloon could be robots that spray nutrients onto the interior of the plastic which would be wet from the saturated humidity.

The robot balloons would perhaps float with Helium or maybe Hydrogen could be rendered safe enough if they are not so big as to make a damaging explosion.

As Algae matts grow on the interior of the balloon they will become too heavy to stick and will fall down to the bottom, where the organic matter could be collected for whatever value it may have.

So my objective would be to expand this process until hopefully there was a good Ozone layer, and far less water vapor clouds. Ideally none or almost none.

Then the atmosphere of Venus would be much more conducive to human habitation.

Void · 2014-12-28 21:49:09

Quaoar wrote:

Impaler wrote:
rotor-rocket can fly in the atmosphere like a spaceplane with atmospheric engines, without the mass penalty of wings an engines (actually we have no jet engines able to burn fuel using CO2 as an oxidizer). Rotor blades with tip rockets are very light, can function in every kind of atmosphere and during ascent augment the rockets exhaust with atmospheric gasses, resulting less propellant consumption

Because of your post, I have been thinking about steam powered rotor rockets for transit between the clouds (Where habits might be possible), and the surface. Rotor down with a full tank of water (Which is also a consumable coolant), heat up your tank, and then rotor up with steam power. Not for humans I would think, but robots.

And on the surface nuclear powered robots for mining.

On the subject of mining, I wonder how hard it is to have super critical CO2 on the surface of Venus to extract Magnesium from the rocks?

And Magnesium being able to burn in CO2, of course that is the reason. I have read of Powdered Magnesium rockets, but I am sure they are hard to run. I think in one case they used a slurry of oil and Magnesium powder, but then tried to use Nitrogen? and Magnesium powder. (But I don't think it was a jet engine).

SpaceNut · 2014-12-28 22:33:09

Another thought is to cool the air intake to liquify the vapor which is acidic but then to continue to cool after the acid is drawn off for other useable content such as the CO2 which can be used to create methane in a sabatier reactor that along with other chemical havesting would also make for other boiler freindly alternatives to steam generation for the robotic mission launch from the surface that would be reusuable....

Impaler · 2014-12-29 02:10:24

Terra-forming Venus is off-topic (These forums are very bad at staying on topic BTW) and frankly so purely speculative as to be a complete shot in the dark. And I think it is being mentioned just as a reason to not go to Venus by comparing it's relative terraforming difficulty to that of Mars. But which planet is easier to Terraform is not and should not be a justification for which planet to colonize first. A colony is going to need to exist on a virgin planet and needs to be assume that the planet will remain virgin FOREVER, because the time-scales are so long to do it that it might as well be forever for any reasonable planning purposes. Your not going to say "well I could put in a better air-lock seal but hey in X years the planet will be terraformed anyway and we won't need any air-locks" obviously every bit of daily living and infrastructure will have to be designed for the original environment until and likely well after terraforming is producing changes (cause we need to be able to survive some unexpected sudden back-slide of the terraforming process).

As for the process I've always though sun-shades freezing out the whole CO2 portion of the atmosphere onto the surface would be the simplest thing, then you can just scoop it up in a conventional surface strip-mining like operation (I'm guessing it would be a few thousand feed deep mostly dry-ice across the whole planet), and either bury it deep underground or using some kind of magnetic rail-gun, fire packets of it into space towards what ever destination we feel needs some Carbon. The old Sagan ideas are frankly baloney and would have been nothing more the science-fiction even in his day. Cloud based micro-organisms can't do anything to Venus because they can't create compounds which will survive decent into the lower atmosphere for any kind of reasonable time-scales, they would just become a part of the existing chemical and thermal cycle without altering it in any way. Their may already BE organisms in the clouds creating some of the small chemical imbalances we see now, but given the temperature levels on Venus their is no terraforming that can just attack the planet as is, lowering temperature will need to come first and blocking virtually all sunlight is the fastest way to do it.

Void: I've explained several times in the thread why rocket propulsion is a horrible idea through the lower Venus atmosphere, it's like trying to go through the Earths ocean in a rocket. And it is completely unnecessary when we could access the surface by lowering a cable from a floating platform (which is coincidentally how we get to the bottom of Earths Oceans most of the time). People need to stop being hung up on 'Flying' everywhere at high thrust simply because we left the Earth and are in 'Spaaaace'.

Tom: I talked about Sulfuric acid harvesting and conversion to water extensively earlier in the thread and how it could be conducted effectively, so it sounds like your preaching my own idea back too me without having read the thread. When I mentioned bringing Hydrogen it was in the context of comparing Venus exploration mission to Mars ones in which Hydrogen being brought to Mars is assumed to be necessary to make return propellent. IF such a thing is possible on Mars then it will be EASIER on Venus, not that I think this is the only option or the best option, the very first initial mission are more likely to bring hydrogen and as mission size increases or infrastructure is built up on Venus the needle moves towards collecting hydrogen and indeed everything else locally, where the dividing line is I don't know. Their have been lots more studies done on the Mars ISPP problem and they tend to come down 50/50 for bringing Hydrogen being worth it (monetarily remember this is low TRL now) for a one-off mission like Mars Direct, but are decisively on the side of local collection if anything remotely permanent or reusable is the goal.

Last edited by Impaler (2014-12-29 02:25:57)

Tom Kalbfus · 2014-12-29 09:04:08

I think the most effective sun shade may be suspended particles high in the Venusian atmosphere. The Venusian cloud layer effectively reflects most sunlight back into space, they only problem is that it does so at a very high equilibrium temperature on the surface, but if we can come up with artificial cloud particles that operate at lower temperatures, then we can shade the surface, reflect sunlight back into space before it gets absorbed by the ground and trapped as heat.

A first good step would be to park a comet at the L1 point between Venus and the Sun, this would create a lot of shade at least temporarily until the comet evaporates.

Last edited by Tom Kalbfus (2014-12-29 09:06:24)

Void · 2014-12-29 09:10:31

You are inconsistent.

Void: I've explained several times in the thread why rocket propulsion is a horrible idea through the lower Venus atmosphere, it's like trying to go through the Earths ocean in a rocket. And it is completely unnecessary when we could access the surface by lowering a cable from a floating platform (which is coincidentally how we get to the bottom of Earths Oceans most of the time). People need to stop being hung up on 'Flying' everywhere at high thrust simply because we left the Earth and are in 'Spaaaace'.

The phrase "Most of the time". Well, maybe there is a minority case for using a rotor rocket. And in any case finding out why it is a burden and not useful is valuable. And I was attempting to interact with another member.

Then you dismiss what I say with "Its terraforming, this is the wrong place." Then you go ahead and propose a terraforming scheme which will require an enormous amount of time, but you say that we have to adapt to Venus the way it is.

Just pointing it out.

Tom Kalbfus · 2014-12-29 10:40:47

Terraforming is a different scale of engineering than sending merely a manned mission, even a manned mission to Venus would require a lot less effort than terraforming a planet. One thing you have to keep in mind is planets are big! Maybe its easy to forget that, Venus is almost as big as the Earth. I think inhabiting it is valuable if you later want to claim ownership of the planet, and once you do that, you can Terraform it. Ownership is a prerequisite to terraforming a planet, there would be legal challenges otherwise.

By the way, how much is the planet Venus worth? If the UN could auction it off to the highest bidder in a sale everyone would recognize, how much money could be offered? If you were the US Congress, how much would you pay for the planet Venus?

Void · 2014-12-29 14:10:05

Tom,

At the start I concluded that there would be no point to sending a personed mission to the atmosphere of Venus, unless you planned to inhabit it. It would be better to send automation.

If you do plan to inhabit the atmosphere of Venus, true, you have to have methods compatible with what will be encountered. However, if you have to make processed materials to expand your habitation, I see nothing wrong with altering the environment, if you can find a pressure point, and it fits with your economic/process model.

Small alterations such as removing Chlorine and Bromine from the upper atmosphere by adding Hydrogen to it (Or water which will add hydrogen), may be of a reasonable cost effort to justify. If an Ozone layer does develop as a consequence, it then reduces the Sulfuric Acid production in the atmosphere. It also as a consequence reduces the rigors imposed on your equipment by reducing U.V. and reducing the acid nature of the atmosphere.

Further tweeks such as containerizing as much water as possible into expanding habitats will also reduce the production of Sulfuric Acid.

Seeding the Sulfuric Acid clouds to cause them to rain out more (And be heated and decompose to water and Sulfur Trioxide), are contingent on the economic value of such an action. If you prefer water to Sulfuric Acid then you might want to make the effort.

No idea how much Venus is worth. Who owns it? "B.S.ers" according to them.

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