Star Trek

This article in New Scientist describes a new kind of "solar sail" technology being investigated that they hope could send a ship to Mars in a month.

Actually the sail wouldn't be powered by sunlight so much as by a very large microwave beam sent from the surface of the Earth.

The way it's supposed to work, the sail will be covered with a substance that will, when it gets very hot, exude a gas. Since the sail will be heated from one side, the gas particles will go off into space in one direction, and the ship will be pushed forward. They believe a microwave beam trained on the ship for an hour would propel the ship faster than any of our probes have gone so far. However, they don't yet know what the best formulation of this gas-exuding substance would be, nor does anyone have a microwave generator of sufficient power handy.

Also, though the article doesn't mention it, I would suppose they'd also want a similar microwave beam stationed on Mars to slow the craft down at the other end. Perhaps that could be built by robots, which could be shipped to Mars in slower ships.

It sounds to me like this propulsion method would probably be cheaper as well as faster. The concept of "leaving the engine on Earth" should reduce payload mass and hence make the thing more efficient.

I'm getting more and more convinced that Mars is going to become important, economically, this century. Some of you kids reading this will very likely take a cruise there and back with your spouses, the whole trip taking three or four months, when you're ready to celebrate your retirement.

Thats a very interesting discovery. I wonder how they are going to keep all of the gas from being burned up quickly, because they dont know how long it will last yet.

this isn't anything new. there have been test for many years using lasers to combust the air under a spinning disk (the laser heats the air past it's flash point).

what you have described would require the craft to carry fuel (the gas that is being ignited). if the sail itself is what is excreting the gas, you would have to insure even distribution and would make such a technology not much better than just carrying your own fuel.

have a microwave laser like that wouldn't be very useful if it is ground based. an orbital platform would be much better. you would be able to fire at the ship in a more continuous beam than having to compensate for the earth's rotation. it would be easier to tweak the orbit to get desired results. you also don't have to worry about frying any birds.

you wouldn't need a second laser on mars to slow down. like i've said before this type of technology has been researched for quite some time. all you need is a compound sail that will deploy once you get close.

this type of technology has been proposed for interstellar travel, but it doesn't use any sort of gas. it uses the force of light against the sail.

Well, I seriously believe that the U.S government is spending too much money for the Mars project. My physics teacher said that the amount of time to travel to Mars is too long, and how the hell would the astronauts come back without building a mobile Cape Canaveral on the Mars surface, which is next to impossible?

I mean, the distance from Earth to Mars is, what, hundreds of times the distance from the Earth to the moon?

Quote (vengeanceforzuljin @ Feb. 16 2005, 2:08 pm)

Well, I seriously believe that the U.S government is spending too much money for the Mars project. My physics teacher said that the amount of time to travel to Mars is too long, and how the hell would the astronauts come back without building a mobile Cape Canaveral on the Mars surface, which is next to impossible? I mean, the distance from Earth to Mars is, what, hundreds of times the distance from the Earth to the moon?

simple, they don't come back. i could get into this in more detail because i'm involved in a project researching this possibility, but i'm busy right now.

Quote (vengeanceforzuljin @ Feb. 16 2005, 11:08 am)

Well, I seriously believe that the U.S government is spending too much money for the Mars project. My physics teacher said that the amount of time to travel to Mars is too long, and how the hell would the astronauts come back without building a mobile Cape Canaveral on the Mars surface, which is next to impossible? I mean, the distance from Earth to Mars is, what, hundreds of times the distance from the Earth to the moon?

So some research, there are all kinds of ideas on how to bring them back.  And a lot of them could actually work.  One was to send a robotic set up first that would contain everything the people would need to live there for a short time.  Even the return capsul (much like the lunar lander but stronger).  The "factory" would make the fuel and air for the people while they were on their way.  When the ship gets there, they take a small lander, land do the research, then leave and dock with the mother ship and come home....
but they would also have to design it for a long term stay incase anything went wrong

I know nothing of this subject but the phrase uses light against the sail sounds nautical to me.

zo! first a lady, then a princess, and then you totally skipped Queen and Captain straight to Commodore. WHen you promote yourself to Supreme Ruler of the World, give me a heads up, k?

Quote (Ezrian_Bashirax @ Feb. 17 2005, 11:02 pm)

zo! first a lady, then a princess, and then you totally skipped Queen and Captain straight to Commodore. WHen you promote yourself to Supreme Ruler of the World, give me a heads up, k?

I got bored with supreme ruler of the world years ago and decided to answer someone elses question instead.

Quote

Well, I seriously believe that the U.S government is spending too much money for the Mars project. My physics teacher said that the amount of time to travel to Mars is too long, and how the hell would the astronauts come back without building a mobile Cape Canaveral on the Mars surface, which is next to impossible? I mean, the distance from Earth to Mars is, what, hundreds of times the distance from the Earth to the moon?

The distance to Mars varies a lot more than the distance to the Moon, but at its closest it's about 35 million miles as compared with a quarter million miles to the Moon. But there are lots of things they know today, and intend to find out more about before attempting to send people to Mars, that they didn't know in the early 1970s when they went to the Moon. One of these is the so-called interplanetary highway, which is a tricky system of using orbits around the Lagrange points (NOT the same thing as slingshotting) to get from Earth to someplace else using less energy than previously thought possible. It also takes much longer, so we could not send a manned mission that way; but we could send the heavy cargo on an unmanned ship, many years ahead of the human beings, so they might have fuel for the return voyage and life-support machinery waiting for them even before they leave Earth.

Another is Project Prometheus, a program to harness nuclear energy for propulsion in space. If this works, the trip to Mars could be cut to a couple months. And there are other kinds of advanced propulsion systems being investigated, including the new kind of solar sail that I linked to in the first post of this thread. (AquamonkeyEG seems to have confused this technology with conventional solar sails. This is a new and different kind of thing.  A conventional solar sail merely uses the pressure of the sunlight for propulsion, and I've never heard of one that could achieve rapid acceleration. It doesn't "outgas" like this kind would.)

As for having to build our own Cape Canaveral on Mars, I think that's an exaggeration. We didn't build such a facility on the Moon and we got there and back all in one trip. In Mars's case I think we're planning more unmanned preliminary trips that would actually take cargo to support the eventual human trip. We might, for instance, land a nuclear reactor to Mars, and use its energy to run robots that would prepare fuel by electrolyzing the groundwater; then our astronauts could refuel (at least for the boost from surface to Mars orbit) with native Martian H2 and O2 rather than hauling it all the way from Earth.

Quote (markthom @ Feb. 21 2005, 10:08 pm)

Quote Well, I seriously believe that the U.S government is spending too much money for the Mars project. My physics teacher said that the amount of time to travel to Mars is too long, and how the hell would the astronauts come back without building a mobile Cape Canaveral on the Mars surface, which is next to impossible? I mean, the distance from Earth to Mars is, what, hundreds of times the distance from the Earth to the moon? The distance to Mars varies a lot more than the distance to the Moon, but at its closest it's about 35 million miles as compared with a quarter million miles to the Moon. But there are lots of things they know today, and intend to find out more about before attempting to send people to Mars, that they didn't know in the early 1970s when they went to the Moon. One of these is the so-called interplanetary highway, which is a tricky system of using orbits around the Lagrange points (NOT the same thing as slingshotting) to get from Earth to someplace else using less energy than previously thought possible. It also takes much longer, so we could not send a manned mission that way; but we could send the heavy cargo on an unmanned ship, many years ahead of the human beings, so they might have fuel for the return voyage and life-support machinery waiting for them even before they leave Earth. Another is Project Prometheus, a program to harness nuclear energy for propulsion in space. If this works, the trip to Mars could be cut to a couple months. And there are other kinds of advanced propulsion systems being investigated, including the new kind of solar sail that I linked to in the first post of this thread. (AquamonkeyEG seems to have confused this technology with conventional solar sails. This is a new and different kind of thing.  A conventional solar sail merely uses the pressure of the sunlight for propulsion, and I've never heard of one that could achieve rapid acceleration. It doesn't "outgas" like this kind would.) As for having to build our own Cape Canaveral on Mars, I think that's an exaggeration. We didn't build such a facility on the Moon and we got there and back all in one trip. In Mars's case I think we're planning more unmanned preliminary trips that would actually take cargo to support the eventual human trip. We might, for instance, land a nuclear reactor to Mars, and use its energy to run robots that would prepare fuel by electrolyzing the groundwater; then our astronauts could refuel (at least for the boost from surface to Mars orbit) with native Martian H2 and O2 rather than hauling it all the way from Earth.

well... i didn't actually look at the link, but there has been conjecture of using multi-stage conventional solar sails in conjunction with high powered orbital lasers for interstellar travel at an acceleration of 1g.

while the mainstream thought is for a round-trip manned mission to mars, i've been involved in a program that is looking for a way to land permanent settlements on the surface. this includes living space, green houses, manufacturing facilities, power generation. the initial structures will be made from a plastic-like material based on elements in the mars soil that is compressed into useable shapes. later structures will be dug into hillsides and have dirt piled up on top to help keep in the pressure (mars atmosphere at lower pressure than on earth). the entire process would be done in a series of smaller missions, each 1 bringing different supplies (recreational media, additional construction hardware...). the goal is to have a self-sustaining facility on mars.

Quote (Vash066 @ Feb. 17 2005, 2:35 pm)

Quote (vengeanceforzuljin @ Feb. 16 2005, 11:08 am) Well, I seriously believe that the U.S government is spending too much money for the Mars project. My physics teacher said that the amount of time to travel to Mars is too long, and how the hell would the astronauts come back without building a mobile Cape Canaveral on the Mars surface, which is next to impossible? I mean, the distance from Earth to Mars is, what, hundreds of times the distance from the Earth to the moon? So some research, there are all kinds of ideas on how to bring them back. And a lot of them could actually work. One was to send a robotic set up first that would contain everything the people would need to live there for a short time. Even the return capsul (much like the lunar lander but stronger). The "factory" would make the fuel and air for the people while they were on their way. When the ship gets there, they take a small lander, land do the research, then leave and dock with the mother ship and come home.... but they would also have to design it for a long term stay incase anything went wrong

also astronauts could use resources on Mars itself to help "fund" a trip home, i think they have researched a lot into this idea allready and its simple 1960's chemistry...

I heard that they were working on an engine that would allow a craft to get all the way to Pluto in 9-15 weeks.

Of course, it's been several years since I've heard anything about it.

that would be interesting it would have to be pretty damn fast.  And I don't know if I'd want to be insomething that went that fast with out some sort of good sensor system to see what was up ahead....way up ahead.