A sad thought but perhaps a nessisary one

>> >If you see that a robot is about to make a move that will damage
>it,
>> >then teleoperation can help as long as the time lag is less than
>the
>> >time required for the robot to take that action; in the case of a
>> >rover on Mars or an asteroid though, with a time lag measured in
>> >minutes, your robot's toast.
>>
>> What situation could you think of, were a robot becomes toast on an
>> asteroid?
>
>I am thinking specifically about mining processes. If a robot is
>going to wander into the path of your solar concentrator, it's
>crispyfried. If it is drving around a "truck" of ore at the time,
>you lose the truck too.

Granted, IF a robot gets into the path of a concentrator. But why
should the operator send him near to it when it operates?

I would not close out this possibility but do think such situations
would rather be exceptional.

If we had tele operated equipment the tele operators would develop a
rather careful operating habit which takes the time lag into account.

All what moves on the asteroid would probably be tele operated so it
is just a question of separating different operations or coordinating
them.

>
>> The American Ion thruster powered probe NEAR did land on the
>> asteroid EROS even it was not engineered to do a landing.
>
>Good for them, nice landing. But NEAR is just a landed orbiter, not
>a rover. And it isn't doing heavy industrial processes. It isn't
>digging a mine or operating a foundry or fixing other equipment.
>
>> I think teleoperation would be possible, using ion thruster powered
>> robots on asteroids. The Ion thruster of SMART I for instance
>produces
>> about 75 milli Newton (7,5 grams).
>> So if you "crash" with such a tender power onto an asteroid, what
>> should happen?
>
>As you point out, landing isn't the problem. The problem is what
>happens after that. Whatever rover is used would be moving around
>in a nearly microgravity environment.

My proposal would be that the lander is the prospector robot at the
same time. A rover would be no good fit in micro gravity I guess. A
ion driven craft (the lander) could hover and move to any point on the
asteroid. If it has thrusters pointing downward it can even replace
gravitational weight through thruster pressure and press down when it
collects ore.

> Take Eros for example, it's
>gravity is about 1/1600 of earth's gravity. If a rover is moving
>too quickly over the wrong spot (the gravitational field varies
>widely since it has irregular shape and composition) it could find
>itself in a parabolic trajectory, soon to become the newest crater
>on Eros.

See. Therefore just skip the rover and send an prospecting lander
instead.

Eros is one of the biggest known NEAs.

If you take the asteroid where Muses C will land on next year youll
have only one 750 thousandth of earth gravity.
So a prospector with its ore loaded of say one ton earth weight will
have an asteroid weight of only 1 1/3 grams.

What would it change when those 1 1/3 grams became 3 grams?

>> It is like driving a fairground scooter, not even since the forces
>> involved are a lot weaker. And yet those forces are enough to get
>tons
>> of asteroid materials off the asteroid ground.
>
>Except that if you are teleoperating from earth, then there are
>several minutes of delay between the time you move your joystick and
>the time the scooter reacts.

I just cant see many dangerous situations for a - smoothly - flying
or hovering robot on an asteroid. Normally the robot is the only
object which moves.

The operator knows what move will come next and can adjust to it. All
other than the robot will stay in the same place until the robot does
his motion.

>> So tell me a real situation were an robot on an asteroid needs to
>act
>> in a hurry.
>>
>> Frank
>
>OK, say your robot is operating a "truck" full of ore. In its path
>is an obstacle which will damage the truck. In the fifteen minutes
>that it takes for the problem to be transmitted to earth and the
>fifteen minutes that it takes for a signal to get back, either the
>robot will have avoided the obstacle on its own, will have hit the
>obstacle, or will be moving so slowly that earth-bound operators
>were able to take over (too slowly to be viable economically).

In my imagination there wouldnt be a truck in the first place. Just a
lander/prospector able to fly were it has to go.
But I have problems to imagine the nature of such an obstacle. I
think there are none which dont come from the robots actions and that
is just what the operator has to steer.

Frank