NASA Found A Cheaper Way To Reach Mars Safely

NASA has come up with a cheaper and safer way to reach Mars? Well what are we waiting for? Let's start shooting stuff into space!

Now new research lays out a smoother, safer way to achieve Martian orbit without being restricted by launch windows or busting the bank. Called ballistic capture, it could help open the Martian frontier for more robotic missions, future manned expeditions and even colonization efforts. "It's an eye-opener," says James Green, director of NASA's Planetary Science Division.

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Sounds cool, although the article seems to be a bit confusing, seems to be comparing the brute force method with this ballistic trajectory approach, not the ideal window approach vs. ballistic approach.

Just imagine if they missed target and had human passengers . . .

The cost increase of the life support since it takes months longer probably cancel out the fuel savings. I suspect thats why all missions that use it are unmanned.

Why not just find a wormhole? The worst that could happen is ending up behind someone's bookcase.

Getting to Mars is not "hard"-hard. It just takes a long time.

Landing on mars is a bit tough, on account of the low atmospheric density.
Parachutes are almost useless, so you need a powered landing.

Getting back from the surface of Mars is IMMENSELY difficult. Gravity is substantial, and you need a lot of power to get back into space. Which means a lot of fuel. SO you have to land with a lot of fuel - which means you had to make the trip to mars with a lot of fuel - which means you had to get a lot of fuel up into space.

-scheherazade

Megalith said:

Why not just find a wormhole? The worst that could happen is ending up behind someone's bookcase.

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economy mars trip

scheherazade said:

Getting to Mars is not "hard"-hard. It just takes a long time.

Landing on mars is a bit tough, on account of the low atmospheric density.
Parachutes are almost useless, so you need a powered landing.

Getting back from the surface of Mars is IMMENSELY difficult. Gravity is substantial, and you need a lot of power to get back into space. Which means a lot of fuel. SO you have to land with a lot of fuel - which means you had to make the trip to mars with a lot of fuel - which means you had to get a lot of fuel up into space.

-scheherazade

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or you just don't come back

all of this is moot without an established lunar presence

all talk manned space travel and colonization is pointless without reliable fusion energy.

Uvaman said:

all talk manned space travel and colonization is pointless without reliable fusion energy.

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Well you also have the issue of protection from harmful rays coming from the sun. I think even the IIS as it is wouldn't be suitable for a deep space environment.

But I suppose if you have "unlimited" energy from a reliable fusion reactor that could be miniaturized enough and fit into a spacecraft that would be a non-issue?

Other than obvious reasons (cost, time) I don't see why we or someone hasn't built a large electromagnetic projectile launcher (rail gun) big enough to launch payloads into "space" instead of the traditional rocket method.

We have the technology to build a large (miles long) rail gun capable of launching large payloads so why haven't we or anyone else built one other than the cost to do so?

Most of the fuel used in rocket launches are used to carry the fuel to launch the rocket. Imagine launching an "empty" rocket using a railgun to the moon. Then using the same rail gun to launch fuel to the moon, followed by other supplies and the people to man it.

Most of the cost of "wasting" fuel to get large payloads out of Earth's gravitational pull would pay for itself very, very quickly.

Heck one could be built on the Moon to launch objects further into our solar system. Imagine not having to use any non-renewable fuel with getting payloads to Mars. You could in theory launch small payloads daily with this type of system to resupply a colony on Mars. Build one on Mars to launch stuff back.

Send old people, they won't last long here anyway. He11, I'll volunteer in a few years just for fun.

Skillz said:

Other than obvious reasons (cost, time) I don't see why we or someone hasn't built a large electromagnetic projectile launcher (rail gun) big enough to launch payloads into "space" instead of the traditional rocket method.

We have the technology to build a large (miles long) rail gun capable of launching large payloads so why haven't we or anyone else built one other than the cost to do so?

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The speed something has to travel in order to orbit at say 200km (space shuttleish distance) is about 17,500 mph, now that's the speed required in a direction parallel to the Earth's surface to stay in orbit. Now there are a few things at issue here.
1) Once it leaves the launcher it can't get any faster, no more energy is going into the system,
2) We can't launch at a direction parallel to Earth's surface since we already are moving in that direction and we want to get 200km higher, so that requires a steeper angle to fling it up which requires a bit more speed
3) All that speed is at Earth's surface, as it climbs up it's fighting against gravity, which slows it down, which requires even MORE speed
4a) The atmosphere would definitely slow things down since friction is a function of velocity squared.
4b) Lets ignore 1 through 3 though and assume we can launch at 17,500 mph and we don't need to go much faster, that's like Mach 28... I don't know of any aircraft that can survive that speed in the atmosphere, up in space with no air it's fine, but in air? You're basically going to create a huge fireball.
5) Going from 0 to 17,500 over a couple miles of track, would be about 950Gs on whatever object is being launched.

So while a rail gun launcher sounds good in theory, you need to make it really long, and use it on places with limited atmosphere (the Moon could work... but there's nothing on the Moon, if you already got something to the Moon you spent the energy to get there, now you need to spend more energy to leave the Moon)

sfsuphysics said:

The speed something has to travel in order to orbit at say 200km (space shuttleish distance) is about 17,500 mph, now that's the speed required in a direction parallel to the Earth's surface to stay in orbit. Now there are a few things at issue here.
1) Once it leaves the launcher it can't get any faster, no more energy is going into the system,

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The speed to escape Earth's gravity (escape velocity) is 11.2 km/s which is 25,053.7 MPH. Launching the cargo East will get help from Earth's rotation going the opposite direction. (It's how the shuttle gets into LEO at ~17.5k MPH, because they launch it East)

sfsuphysics said:

2) We can't launch at a direction parallel to Earth's surface since we already are moving in that direction and we want to get 200km higher, so that requires a steeper angle to fling it up which requires a bit more speed

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Launch the cargo East. You'll also want to shoot at an angle. Not directly up nor directly parallel to Earth's surface. Think launching it up the side of a mountain.

sfsuphysics said:

3) All that speed is at Earth's surface, as it climbs up it's fighting against gravity, which slows it down, which requires even MORE speed

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That's correct, to maintain the average speed of 11.2km/s you'll need to launch it faster than that. Do note that at 11.2km/s you'll reach 200km in about 18 seconds.

sfsuphysics said:

4a) The atmosphere would definitely slow things down since friction is a function of velocity squared.

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This is why I mentioned a mountain previously. Where the atmosphere is already thinner than a place closer to sea level. Also

sfsuphysics said:

4b) Lets ignore 1 through 3 though and assume we can launch at 17,500 mph and we don't need to go much faster, that's like Mach 28... I don't know of any aircraft that can survive that speed in the atmosphere, up in space with no air it's fine, but in air? You're basically going to create a huge fireball.

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The Space Shuttle's launch speed is 17.5k MPH. While it does look like a huge fireball blasting across the sky it's not actually a fireball.

sfsuphysics said:

5) Going from 0 to 17,500 over a couple miles of track, would be about 950Gs on whatever object is being launched.

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I'm not talking a couple miles. I'm thinking something in the 100 or more mile range.

sfsuphysics said:

So while a rail gun launcher sounds good in theory, you need to make it really long, and use it on places with limited atmosphere (the Moon could work... but there's nothing on the Moon, if you already got something to the Moon you spent the energy to get there, now you need to spend more energy to leave the Moon)

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The closer to the poles you get the better this system would work.

FLECOM said:

or you just don't come back

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I've heard about this proposal. What happens to your mission if a passenger decides he doesn't want to die there. Will play great with the public to have some dude out of his mind with the realization he just did something stupid.

Cerulean said:

Well you also have the issue of protection from harmful rays coming from the sun. I think even the IIS as it is wouldn't be suitable for a deep space environment.

But I suppose if you have "unlimited" energy from a reliable fusion reactor that could be miniaturized enough and fit into a spacecraft that would be a non-issue?

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In honesty, I am hoping evolution would take care of that.
If the place we end up gives us sufficient life expectancy, its possible I think.. we would always be controlling for exposure anyhow.
I do hope for a future with humans in Mars, Jupiter's moons things like that.
I think it can happen, even with our seemingly primitive rockets.. but in my eyes, more than water, energy needs to arrive first.. if water is there, frozen, even contaminated, we can melt it and clean it, but it takes lots of energy.. we can get metals from the soil of other planets, but again, energy, heat=energy, light=energy, pretty much any and all industrial process take lots of power.. and I think the first humans to colonize would basically need to built massive energy sources while ensuring some level of survival (of course the choice to colonize a particular place is a whole separate process).

scheherazade said:

Getting to Mars is not "hard"-hard. It just takes a long time.

1. Landing on mars is a bit tough, on account of the low atmospheric density. Parachutes are almost useless, so you need a powered landing.

2. Getting back from the surface of Mars is IMMENSELY difficult. Gravity is substantial, and you need a lot of power to get back into space. Which means a lot of fuel. SO you have to land with a lot of fuel - which means you had to make the trip to mars with a lot of fuel - which means you had to get a lot of fuel up into space.

-scheherazade

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1. Yep...it's about 100 times thinner than Earth, which means one (or both) of two things are needed for a safe and soft landing:
2. Not really, as the gravity is only about 1/3 of what it is on Earth.

Skillz said:

The speed to escape Earth's gravity (escape velocity) is 11.2 km/s which is 25,053.7 MPH. Launching the cargo East will get help from Earth's rotation going the opposite direction. (It's how the shuttle gets into LEO at ~17.5k MPH, because they launch it East)

Launch the cargo East. You'll also want to shoot at an angle. Not directly up nor directly parallel to Earth's surface. Think launching it up the side of a mountain.

That's correct, to maintain the average speed of 11.2km/s you'll need to launch it faster than that. Do note that at 11.2km/s you'll reach 200km in about 18 seconds.

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First points were simply to set up the situation on how fast something needs to move at the speeds needed for such an orbit.
.

This is why I mentioned a mountain previously. Where the atmosphere is already thinner than a place closer to sea level. Also

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Mountains might be thinner, but they certainly aren't that thin, tallest one in the continental US is a bit over 14,000 ft to the peak, that's less than half the distance that commercial airplanes fly, and they definitely still feel wind resistance at a measly 500mph they travel. Plus you'd initially be moving at ground level, so unless your system was in a vacuum tube the atmosphere issues still would be persistent

The Space Shuttle's launch speed is 17.5k MPH. While it does look like a huge fireball blasting across the sky it's not actually a fireball.

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The Space Shuttle's launch speed most definitely is not 17.5k MPH, it gets up to that speed eventually, but only when it's actually out of the atmosphere. To put it better, it's re-entry speed initially starts out at that speed, now as soon as it touches the thinnest part of the atmosphere when the hell up, those specially made heat tiles under the shuttle start glowing white hot. So if you had something traveling that fast even at a mountain top, it definitely is going to be roasting. The thing with rockets is the downside is they carry their fuel with them, but they also slowly speed up, so they're traveling the slowest when they're in the thickest parts of the atmosphere, and really gain speed when the atmosphere no longer is of concern, with a rail gun launching system you'd be moving the fastest when you're in the thickest part of the atmosphere which translates to tons of lost energy.

I'm not talking a couple miles. I'm thinking something in the 100 or more mile range.

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100 mile track that's for the most part straight? Good luck getting that thing built. And you reduce the G force to 19Gs which probably could fine for equipment, for people that'd still be dangerous for any prolong period of time. Space Shuttle would max out at about 3gs on the astronauts. The upside if you go from 0 to 17.5k MPH, you'd only experience those G forces for about 40 seconds or so. However even the best test pilots would black out in 40 seconds.