New Mars Forums

Just fun, lets check how far you would travel if you accelerated at 1-G for 1 days, and decelerated at 1-G for the next day.
There are 86400 seconds in a say, if you were to accelerate at 10 meters per second for 1 day you would achieve a velocity of 864 km/sec, your average velocity for that day would be 432 km/sec, now over 86400 seconds you would travel 37,324,800 km and over the next day while decelerating you would cover the same distance for a total of 74,649,600 km The average distance of Mars from the Sun is 228,000,000 km, subtract 150,000,000 km from that and you get 78,000,000 km. These are average orbital distances of the two planets, and the planets would have to be lined up in order to make this journey in 2 days, even is we accelerated and decelerated at 1-G the entire time. If we were willing to make our passengers uncomfortable and strap them into acceleration couches, we could probably have consistent travel times of 2 days between the planets, I don't know how a Solar Express would do this. I wonder what it was she was writing about, I assume there was something she was reporting on, what was its real capabilities? I know you could have an interplanetary space elevator, for instance you could deploy one at Earth's L2 point and another one at Mars' L1 point, and when the planets are lined up right, you can ascend the L2 space elevator and release at the right spot and be on course for Mars, an you could do the opposite for the Mars L1 Space Elevator. If we build a ring around the Sun at 189,000,000 km, such a ring would orbit the Sun every 1.41981 years. What if we deployed a series of rotavators on that ring, it would rotate backwards in relation to its orbit, that means it would rotate clockwise while it orbits around he Sun counterclockwise, the Sunward end would move at Earth's average orbital velocity, while the Marsward end would move at MArs's orbital velocity. If you could get enough of these rotovators, there would always be on conveniently located. You travel up the elevator to the ring, then you travel along the ring until you are in the right position in relation to Mars, then you travel up the space elevator towards Mars and you let go, you just need to spend a little rocket fuel to land on Mars from there, and you will have arrived.

How do you know its not long enough? We have never froze anything for 212.5 years! The thing is, freezing them is just a means of storing information in molecules. Interstellar space is colder than liquid nitrogen, one need look no further than the planet Pluto to see that!

The bloat comes from having to keep people alive through the journey, I would say it would make more sense to have the ship operated by AIs, and when it arrives it can gestate frozen human embryos and raise actual humans to settle the planet. The main problem with generation ships is that the population tends to expand during the journey so you have to plan to population expansion or enforce strict population controls so that the resources of the ship are no used up! Now remember when I said, for a Generation ship, I'd pick a Bernal Sphere that was a mile wide? The standard Bernal Sphere is 500 meters wide, a mile wide Bernal Sphere is 3 times larger! so it has 10 times the living space.

The standard Bernal can house a population of 10,000 people, mine has living space for 100,000 people, but I would send only 10,000 people in it to make allowances for population growth over two and a half centuries, during that journey there is no additional material to build stuff out of except what you brought with you. Once we arrive in the system, there is material we could build new habitats out of an we can accommodate population growth once we are there. That is why I would suggest a starship that is crewed by AIs, they could be built like the Terminator robot, artificial parts on the inside and human organs on the outside, including a womb. If fact the exterior human body parts could have the DNA of the future humans to be born, We might not even have to freeze them. Just have the robots wear one human body after another until they get there, then they can mate and produce real human children or they can clone themselves to produce humans. Basically you have human bodies minus the brain - a computer with resident AI takes over the functions of the human brain, the electronic brain does not age, new parts for it can be fabricated if necessary, and the software can be downloaded into a new computer if necessary, so the AIs can survive the long journey through space, and they can hibernate, go into automatic mode and do whatever to avoid getting bored. The starship need not be that big.

The robots human bodies would need food, they would age, the robots then get new human bodies to replace them as needed and they go on. The food gets recycle, the air and the water too. The AIs can live in a virtual world when they are not moving their organic bodies about or performing bodily functions. This can all be automatic as opposed to involving higher brain functions. Once there, humans are raised and they populate the planet.

It is much closer to its primary than Venus, a closer approximation would be to one of the larger moons of Jupiter, such as Ganymede for example. Ganymede is tidally locked to Jupiter. Ganymede has a very circular orbit, the only reason its not completely circular is that other moons tug on it.

If you look at that video, he has a point. I think nuclear propulsion is closer than laser arrays thousands of miles wide. We do have frozen embyos, all we need is nuclear fusion propulsion and artificial intelligence, and as he said we have real examples in the Universe to go by, stars, and us! Anyway a laser array requires sustained effort on the home front, and more importantly, it needs the laser array to slow it down, beam power across light years, hit a reflector and then hit the ship to slow it down, that sounds like mighty fancy shooting if you ask me, hitting a target you can't even see, a target who's light would be 4.25 years out of date, such an unprecedented degrees of precision and anticipation, it is much easier to build a fusion powered starship. AI is around the corner, we already have frozen embryos, we just need someone to raise them to adulthood upon reaching the destination.

Tidally locked planet. You know if the orbit is not circular, there will still be places on the planet where the Sun will rise and set. The planet orbits faster as it pulls closer to the star but orbits slower as it pulls farther away, but the rate at which the planet rotates remains constant, there will be places where the planet is rotating faster than its orbiting the sun, and other places where is it rotating at an angular speed that is slower. The Sun will appear to rise, and then set at the same place, so that way you can have a local day and night. The red sun will dip below the horizon and them pop up again, giving us about 4 days of night and 4 days of daylight. A star that is already red will give off a "bloody sunset." The sky will appear to be a very dark blue. Probably leaves in native plants if there are any will be black.

A swarm of micro sails that can communicate across light years with power beamed across light years is a big assumption! At 20% of the speed of light it would take 21 years plus 4.25 years for the signal to get back to us, and how many pictures would we get? The swarm would be in and out of the Proxima system very quickly as it passes through at 20% of the speed of light.

https://en.wikipedia.org/wiki/Proxima_Centauri
A planet as warm as Earth of the same size and characteristics could be 0.041 AU from Proxima, which is about 6.2 million kilometers or 3.8 million miles. Proxima is 0.141 times the size of our Sun. Proxima would appear 3.4 times the size of our Sun in the sky of this hypothetical planet, its disk would be 1.82 degrees wide. Humans living on this planet would need to have a flare shelter handy if they live on the lit side of this planet. The orbit period I get using the orbit calculator,
http://orbitsimulator.com/gravity/artic … ator2.html
is 8.8 days.
An interesting question is if we sent humans to this planet, what would they do once they got there? Maybe we could colonize the dark side. If there is plant life on the planet, it would create molecular oxygen, doesn't matter what type of biology it is, or whether it is compatible with humans, just so long as it creates oxygen so that humans could breathe it. Now this planet is likely to be tidally locked, on the dark side there is likely to be an ice cap, and temperatures would be quite cold, but not enough to freeze or liquefy oxygen, if we warmed that air, we could breathe it, we could melt some water ice. A Proxima Power Satellite could provide us with energy, beaming microwaves down to the planet's surface. Conditions would be like Antarctica during the winter or worse!

I suppose we would need to go through a technological singularity first, some people are predicting that one will occur within 20 years, which basically means we build machines that are smarter than we are. When we build such machines, we need to set goals for them. One possibility is what planets to terraform. I am not sure we will ever need to break up Mercury, and use it to build millions of free floating space habitats, I figure we might as well terraform Mercury, as we will probably be able to travel outside of our solar system long before we use up all the material within it. I think Mercury is easier to terraform than the Moon because of its stronger gravity. As a society, we need to decide what we want to do with Mercury, Venus, the Moon, and Mars, and the asteroid belt.

Sunlight even intense sunlight at Mercury's distance is relatively easy to block. Only a small proportion of Mercury's materials would need to be used to construct the wrap-around Sunshade I diagrammed. the shade need not be thick to block all the sunlight from reaching Mercury. This particular sunshade is 7 times the radius of Mercury itself. the only conflict is whether to use Mercury as building materials for an artificial world or terraform its surface. If we go for terraforming, the first step would be to block all sunlight, then use solar collectors on the outside to power artificial sunlight to provide a 24-hour day on the surface of Mercury, then we have to add atmosphere. It seems easier to bring the atmosphere from Titan than to terraform Titan by adding the energy that it lacks. Mercury has too much energy, it can sell the surplus energy to finance the terraforming of Mercury and people can live on its surface. Mercury has the same surface gravity as Mars, the escape velocity for Mercury is 4.25 km/sec compared to 5.02 km/sec for Mars. I think a terraformed atmosphere of Mercury would be much as proposed for Mars, once we shade the entire planet and provide artificial sunlight for it! the landscape on Mercury is much different from Mars, it is older and consists largely of craters and upthrust mountains caused by impact craters. I think terraforming Mercury would be harder than terraforming Mars, but easier than terraforming Venus, as you basically just have to add atmosphere to it, and get rid of all that excess sunlight!

All you have to do is block the Sunlight and add some atmosphere. You don't have to get rid of an atmosphere, because its already gotten rid of. As for it being deep within a gravity well, that is important for taking something off Mercury and moving it to another part of the Solar System, but what about transporting an atmosphere from Titan to Mercury, Titan and Mercury are about the same size. You just basically have to lift atmosphere off Titan, reach the escape velocity of Titan, and the local escape velocity from orbit around Saturn, and then lose most of Saturn's 9.67 km/sec orbital velocity, and aim it just right to hit Mercury. Make sure Mercury is completely shaded when this collision occurs. Lets say we drop a series of balloons full of nitrogen, water, and carbon dioxide onto the planet. Will all of it escape into space? I think a lot of it will cool upon contact with Mercury's cold surface. We could build up this atmosphere over time, as we drop more and more atmospheric balloons on top of Mercury. No need to slow them down, Mercury will do that, all you need to do is hit Mercury with them.