Catalytic Enzymes and cleaning up Venus' atmosphere?

[HopDavid]

In many ways Venus is a much better candidate for earth-like development.

I am an asteroid guy. More in J. S. Lewis' camp than Zubrins. Asteroids can be more accessible because of their shallow gravity wells.

However my jihad against planetary chauvinism was softened when I learned small bodies orbiting a planet are even easier to reach in terms of delta V. This is because of the Oberth effect. Phobos and Deimos are two of the most accessible bodies in the solar system. If the planet's atmosphere can be used for aerobraking, this helps even more.

Because of the Oberth effect and atmospheric drag, it becomes easier to capture asteroids in a planetary orbit. It might be doable to add more moons to Mars in addition to Phobos and Deimos. Likewise, some of the asteroids with close approaches to Venus might be made into Venusian moons.

Not only would 10 Venusian moons be easier to reach in terms of delta V, but it would simplify supply logistics. Sending supply ships to 10 small bodies in the same planetary neighborhood would be much easier than sending supply ships to 10 bodies each with a different solar orbit.

I especially like Venus because her orbit has a pretty geometry.

Earth-Venus synodic period is very close to 8/5 years. So the Hohmann launch windows from earth to Venus lie on the points of a cosmic 5 pointed star.

The period of an earth-Venus Hohmann orbit is very close to 4/5 years. So a Hohmann cycler launched at a window would return to an earth window to Venus on a regular basis.

I did a Flash animation of this at this page: The Case For Venus.

 

[NicknamedBob]

In many ways Venus is a much better candidate for earth-like development.

I am an asteroid guy. More in J. S. Lewis' camp than Zubrins. Asteroids can be more accessible because of their shallow gravity wells.

However my jihad against planetary chauvinism was softened when I learned small bodies orbiting a planet are even easier to reach in terms of delta V. This is because of the Oberth effect. Phobos and Deimos are two of the most accessible bodies in the solar system. If the planet's atmosphere can be used for aerobraking, this helps even more.

Because of the Oberth effect and atmospheric drag, it becomes easier to capture asteroids in a planetary orbit. It might be doable to add more moons to Mars in addition to Phobos and Deimos. Likewise, some of the asteroids with close approaches to Venus might be made into Venusian moons.

Not only would 10 Venusian moons be easier to reach in terms of delta V, but it would simplify supply logistics. Sending supply ships to 10 small bodies in the same planetary neighborhood would be much easier than sending supply ships to 10 bodies each with a different solar orbit.

I especially like Venus because her orbit has a pretty geometry.

Earth-Venus synodic period is very close to 8/5 years. So the Hohmann launch windows from earth to Venus lie on the points of a cosmic 5 pointed star.

The period of an earth-Venus Hohmann orbit is very close to 4/5 years. So a Hohmann cycler launched at a window would return to an earth window to Venus on a regular basis.

I did a Flash animation of this at this page: The Case For Venus.

This notion of moving asteroids around to make moons of them is a bit ambitious.

I'm not opposed to it, but it is ... ambitious. Additionally, while the orbital delta vees may be as even and regular as a well-managed train service, you're still talking about rocketry; using fuel of some nature to propel spacecraft on Hohmann orbits.

Much simpler in the initial stages would be a rotating orbiting vessel, one that extended its tentacles into the highest, most rarified atmosphere that atmospheric craft could hope to navigate. By grappling those aircraft, the orbiting construct turns them into interplanetary craft, because if they are later released at the top of the rotation, they could be flung toward the next planet.

Obviously, momentum losses would have to be made up, but that's easier than moving asteroids.

Also, these orbiting transfer devices would have to be built, and they would have to mass a great deal more than the loads they are to move. That's ambitious too.

However, once built, like the beanstalk on Mars or Earth's moon, (Both are possible with today's materials. Mars works because it has a high rotation rate and low gravity. The moon works because you build it at the Earth-moon L1 point, and anchor it on the moon's Nearside. Gravity does the rest. It's not a "sling" operation like other beanstalks.), a rotating orbiter needs very little in continuing maintenance. It's mainly a dance of angular momentum exchanges, which save considerably on rocket fuel.

Speaking of rocket fuel, I'd like to use Venus' abundant carbon dioxide. Stored in insulated holds as dry ice, and heated to incandescence by nuclear engines, carbon dioxide would make a wonderful rocket fuel. And Venus would never miss it.

Yes, it's true that all of this effort is unnecessary, but traveling to the New World was unnecessary a few centuries ago.

If man is to have a destiny, he must colonize the solar system. Not just one location, or two, but as many places as possible. Venus, Mars, Earth's moon, Mars' moons, large and small asteroids, the Trojan Asteroids, the moons of the gas giants, and the dark, hidden worlds of the Oort Cloud.

And then we can expand.

 

[HopDavid]

This notion of moving asteroids around to make moons of them is a bit ambitious.

I'm not opposed to it, but it is ... ambitious. Additionally, while the orbital delta vees may be as even and regular as a well-managed train service, you're still talking about rocketry; using fuel of some nature to propel spacecraft on Hohmann orbits.

If you nudge a near approach asteroid early enough you can alter the near approach into an atmosphere grazing orbit. Then the atmosphere could provide most the delta V for planetary capture.

For a vessel coming from earth, .4 km/sec suffices for Venus capture. This capture orbit has a high periapsis, but it's still an elliptical orbit about Venus.

There are likely Venus approaching asteroids with aphelions less than 1 A.U. For these capture orbit delta V would be even less.

Much simpler in the initial stages would be a rotating orbiting vessel, one that extended its tentacles into the highest, most rarified atmosphere that atmospheric craft could hope to navigate. By grappling those aircraft, the orbiting construct turns them into interplanetary craft, because if they are later released at the top of the rotation, they could be flung toward the next planet.

You seem to be advocating a momentum exchange tether.

On earth momentum exchange tethers can restore lost momentum by using solar panels to run a current through it's length while passing through earth's magnetic field.

For Mars orbit, Phobos or Deimos can act as tether anchors. With these large momentum banks, momentum loss isn't a big worry.

Venus has neither a strong magnetic field nor a moon. But perhaps it's doable to balance suborbital catches with superorbital catches. Super orbital catches might include receiving taxis from an earth-Venus cycler. That might be a way to preserve the tether orbit you want. Another way to restore Venus tether momentum might be with solar sails. This could be more workable near Venus given that insolation is nearly double what we get from earth.

Obviously, momentum losses would have to be made up, but that's easier than moving asteroids.

Also, these orbiting transfer devices would have to be built, and they would have to mass a great deal more than the loads they are to move. That's ambitious too.

As I mentioned, minute delta V can change a near approach asteroid into an atmosphere grazing. And aerobraking can provide much of the delta V to capture. Successive drag passes can circularize the orbit.

For a kilometer sized asteroid, even this scheme is very ambitious. But for a 50 meter asteroid, perhaps doable.

a 50 meter asteroid would make a nice start as a momentum bank for a Venusian tether.

However, once built, like the beanstalk on Mars or Earth's moon, (Both are possible with today's materials. Mars works because it has a high rotation rate and low gravity. The moon works because you build it at the Earth-moon L1 point, and anchor it on the moon's Nearside.

Here is my critique of a lunar beanstalk to EML1: Problems with mega engineering projects at quasi stable orbits

Mars has simular angular velocity to earth, nearly a 24 hour day. This plus its lower gravity make a Martian beanstalk more doable than an earth beanstalk, as you say.

However a Mars bean stalk would cross the orbit of Phobos. If you wanted the stalk to extend beyond Mars synchronous orbit so it could fling payloads earthward, it would also cross Deimos.

And this is an ambitious project. Mars synchronous orbit is 17000 kilometers. If you wanted the beanstalk to have enough momentum to support its own weight, it would have to extend well beyond 17000 kilometers. You would also want it extend beyond 17000 kilometers if you wanted to fling payloads away from Mars.

Far more doable is a beanstalk anchored on Phobos.

This beanstalk's marsward end touches Mars atmosphere at a 300 km altitude. At this point it's moving about .6 km/sec with regard to Mars surface, easily reached with a suborbital hop. At 14660 kilometers, this tether is shorter than even the distance to Mars synchronous orbit. But it suffices to hurl payloads towards Ceres as well as earth.

Yes, it's true that all of this effort is unnecessary, but traveling to the New World was unnecessary a few centuries ago.

If man is to have a destiny, he must colonize the solar system. Not just one location, or two, but as many places as possible. Venus, Mars, Earth's moon, Mars' moons, large and small asteroids, the Trojan Asteroids, the moons of the gas giants, and the dark, hidden worlds of the Oort Cloud.

And then we can expand.

Amen!

In terms of available surface area and resources, the small bodies are where it's at. The big moons and planets may have more volume and mass, but most of this is inaccessible. When you tunnel to increasing depth, heat and/or stress present formidable engineering obstacles. So when talking about planets, we're considering the planetary surface. In contrast, the entire volume of an asteroid is reachable, you can tunnel clear through the center. I believe this true even of Ceres.

But as I mentioned earlier, big gravity wells are an important resource that can actually reduce delta V needed to reach various objects.

And, to bring this post back on topic, Venus can be an important resource to make those asteroids closest to the sun more accessible.