ion drive as a tunnel boring device?

So, from deep within the peanut gallery come a couple
questions/comments and such that will perhaps sound absurd but if
nothing else I suspect the responses it might trigger will be good
learning.

Just how well might an ion drive work to bore a hole in the ice on say
Europa? Would it even be able to get to the bottom of the ice? I
suppose that if it could one would have to worry about a blow-out... I
was just wondering if after landing something useful could be done
with the powerplant that got one to Europa in the first place.

Getting more general, is one better-off trying to dig mechanically
through the ice?

If one were to try to melt through it - say not with the ion drive,
but with a probe that is simply sufficiently warmer than the ice and
just let gravity pull you in (wouldn't think you need to go very fast)
I guess you wouldn't need to worry about the blowout because the ice
would reform behind/above the probe as it went.

But comms back to the lander and thence Earth might be dodgy through
the ice (?) so I guess the probe needs to trail some wires beind it?
Say four of them for (supplemental?) power and comms?

Pointers to URLs would be great,

rick jones
--
a wide gulf separates "what if" from "if only"
these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to raj in cup.hp.com but NOT BOTH...

Rick Jones wrote in news:_Vs_b.954$1h5.93
@news.cpqcorp.net:


Just how well might an ion drive work to bore a hole in the ice on say
Europa?

An ion drive can only work in a vacuum.

Europan ice might contain materials other than water, and may not be
free of solid debris; otherwise a resistive heater from a very ample
power supply (nuclear) might work. Perhaps even an RTG, which has
ample waste heat.

--Damon

Damon Hill wrote:
Rick Jones wrote in news:_Vs_b.954$1h5.93
@news.cpqcorp.net:
Just how well might an ion drive work to bore a hole in the ice on
say Europa?

An ion drive can only work in a vacuum.

Is there an atmosphere on Europa? I figured that any ice
melted/vaporized by the drive exhaust would simply vent into space. I
see now with a bit of web searching that there is indeed atmosphere on
Europa. So much for that...

Europan ice might contain materials other than water, and may not be
free of solid debris; otherwise a resistive heater from a very ample
power supply (nuclear) might work. Perhaps even an RTG, which has
ample waste heat.

I'd not considered non-meltable debris in the ice. That is a good
point. That would indeed do a number on just melt and drop. I wonder
what the chances are of there being such stuff in the ice?

rick jones
--
Wisdom Teeth are impacted, people are affected by the effects of events.
these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to raj in cup.hp.com but NOT BOTH...

Rick Jones wrote in message ...
Just how well might an ion drive work to bore a hole in the ice on say
Europa?

Not well. The exhaust doesn't involve a lot of mass. Arguably,
Jupiter's radiation belts give an example of the effects of ion drives
on the Galilean moons.

Getting more general, is one better-off trying to dig mechanically
through the ice?

Yes, I strongly suspect so. If you've got the kilowatts to operate an
ion drive in Jovian space, you've probably got a lot of heat and
electricity from a nuclear power supply, which can power a reasonable
drill or hot melting surface.

Mike Miller, MatE

In article ,
Rick Jones wrote:
An ion drive can only work in a vacuum.

Is there an atmosphere on Europa? I figured that any ice
melted/vaporized by the drive exhaust would simply vent into space. I
see now with a bit of web searching that there is indeed atmosphere on
Europa. So much for that...

Europa's atmosphere is much too thin to be a significant issue, actually.
But the water vapor boiling off from the bottom of the hole will be coming
straight up into the ion engine; it doesn't dissipate into space instantly.

Europan ice might contain materials other than water, and may not be
free of solid debris...

I'd not considered non-meltable debris in the ice. That is a good
point. That would indeed do a number on just melt and drop. I wonder
what the chances are of there being such stuff in the ice?

Probability pretty high, considering things like the assorted colors
seen on the surface.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

Unfortunately, if the ice shifts -- which it may -- those wires are very
likely to break. Communication through that ice is just a really
difficult problem no matter how you tackle it.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |



Nawwww..... ultrasonic sound waves should propogate very nicely through
Ice......IMHO

take care

Blll

How to keep the drill warm? Friction or ..
Lubrication? At the temps I believe we are talking it will be very cold?

Mike



Rick Jones wrote:

So, from deep within the peanut gallery come a couple
questions/comments and such that will perhaps sound absurd but if
nothing else I suspect the responses it might trigger will be good
learning.

Just how well might an ion drive work to bore a hole in the ice on say
Europa? Would it even be able to get to the bottom of the ice? I
suppose that if it could one would have to worry about a blow-out... I
was just wondering if after landing something useful could be done
with the powerplant that got one to Europa in the first place.

Getting more general, is one better-off trying to dig mechanically
through the ice?

If one were to try to melt through it - say not with the ion drive,
but with a probe that is simply sufficiently warmer than the ice and
just let gravity pull you in (wouldn't think you need to go very fast)
I guess you wouldn't need to worry about the blowout because the ice
would reform behind/above the probe as it went.

But comms back to the lander and thence Earth might be dodgy through
the ice (?) so I guess the probe needs to trail some wires beind it?
Say four of them for (supplemental?) power and comms?

Pointers to URLs would be great,

rick jones
--
a wide gulf separates "what if" from "if only"
these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to raj in cup.hp.com but NOT BOTH...