Ion propulsion question.

Chaotic42

Lifer
This site says that the acceleration of a craft with an ion drive is very slow. It literally does 0-60 in 345600 seconds.

If we could accelerate it, with a huge burst of energy, to say 30,000 mi/h, couldn't the ion drive take over and cut a few weeks off of it's trip time? At 33,000 mi/h, it could travel to Mars (as the space crow flies) in about 65 days (144 million miles - 93 million miles). I realize this isn't an accurate way to determine distance, but you get the picture.

Being able to travel to Mars in 3 months would be amazing. They are currently saying 2-3 years for a round trip, it could be something like 7-8 months if this ion drive can really do 33,000 mi/h.

Very cool.

iwearnosox

Lifer
Your theory is akin to strapping a jet engine to a hyundai, it just doesn't work that way.

KidViciou\$

Diamond Member
How does it stop?

btw, if they use that for cargo, what about space pirates? how will it be guarded if it takes soo long for it to be useless for people?

Freejack2

Diamond Member
From what it says, it looks like these things would be good to maintain a speed but it would still require some other propulsion to get it up to speed. I think they'll be using it quite a bit in the future though.

Savij

Diamond Member
Well, I'm guessing that the 3 months travel time is if mars and earth are at the exact same spot in their orbits as possible. Considering how large the orbital radii are, it's not very likely that they are very close to each other for very long and could in fact be at opposite sides of the solar system for long periods of time.

iwearnosox

Lifer
Originally posted by: KidViciou\$
How does it stop?

btw, if they use that for cargo, what about space pirates? how will it be guarded if it takes soo long for it to be useless for people?
It uses the gravity of an infinitely dense object to decelerate. Ergo, they will be putting you in orbit with mars before they launch.

KidViciou\$

Diamond Member
yea, basically hehe

AaronB

Golden Member
Zero to 60 in four days......

Think I had one of those the Ford Escort I used to own...

Gravity

Diamond Member
Interesting theory but flawed calculations on speed. Mars is doable but very, very expensive and the potential for human casualties is still high. We've got enough on right now without worrying about the women we'll strand on another planet.

Chaotic42

Lifer
Originally posted by: iwearnosox
Your theory is akin to strapping a jet engine to a hyundai, it just doesn't work that way.

JoeKing

Lifer
Originally posted by: iwearnosox
Your theory is akin to strapping a jet engine to a hyundai, it just doesn't work that way.

little friciton in space however. I don't see why not. Get the craft up to speed using regular propellant, cut engines at peak velocity, then let the ion drive take over.

KidViciou\$

Diamond Member
or you could run both engines simultaneously until the ion engine exceeds the combustion engine

DurocShark

Lifer
The whole point of the ion engine is its long life, low fuel requirements, and high top speed. Anything that uses it, unless time was not a factor, would almost certainly have a little rocket to give it the initial boost. Decelleration would need to be done by the ion engine unless a much larger rocket was carried as cargo.

I'm still waiting for matter/antimatter reaction engines so I can go visit my friends at Alpha Centauri. They don't call anymore.

Jeff7181

Lifer
Originally posted by: DurocShark
The whole point of the ion engine is its long life, low fuel requirements, and high top speed. Anything that uses it, unless time was not a factor, would almost certainly have a little rocket to give it the initial boost. Decelleration would need to be done by the ion engine unless a much larger rocket was carried as cargo.

I'm still waiting for matter/antimatter reaction engines so I can go visit my friends at Alpha Centauri. They don't call anymore.

She's shackin up with me now, stop calling!

Snapster

Diamond Member
That'd break the current ATOT booty call record!

matt426malm

Golden Member
Originally posted by: Jeff7181
Originally posted by: DurocShark
The whole point of the ion engine is its long life, low fuel requirements, and high top speed. Anything that uses it, unless time was not a factor, would almost certainly have a little rocket to give it the initial boost. Decelleration would need to be done by the ion engine unless a much larger rocket was carried as cargo.

I'm still waiting for matter/antimatter reaction engines so I can go visit my friends at Alpha Centauri. They don't call anymore.

She's shackin up with me now, stop calling!

Mars Tracectory Info
There are 3 ways to get to Mars

Hoffman Transfer- Pros- safe, cheap little fuel , long mars stay, you can take a bigger ship Cons- long trip

Direct Shot- Pros- very fast, long mars stay cons- very dangerous, going to fast to aero-break in atmosphere, to much fuel cost, almost certainly must be launched from space.

Oposition- Pros- realtively fast getting there cons- slow return, small window of oportunity, 30 days on mars!

Radiation is not the problem it is made out to be 52-58 rems for each of the three. Thats less rems per year then an xray tech. The risk is in one big solar flare, storing the water in the walls and a lead-lined safety shelter fix this.

Hoffamn Transfer is perfect to send the return vechile, but it take a little to long. Idealy you would have a little bit of the direct and hoffman for the crew. This article talks a lot about the disadvantages of zero-g. That is stupid because you just tie your ship to the upper booster and swing them in a circle for artificail gravity.

matt426malm

Golden Member
But Ion propulsion is a good system for a trip to say saturn or jupiter.