Manned astroid mission?

In article ,
Hop David wrote:

3 arguments are often used against asteroids:
They're too far.
When they're in the neighborhood, they're moving too fast.
If they come near, they only do so once in a great while.

I'm not sure if Nicoll was using the "too far" argument in an oblique
way.

No. Just pointing out the sun exists, is very big and
needs to be taken into account when talking about orbits, which
I hadn't actually thought would be controversial in any way.

James Nicoll
--
It's amazing how the waterdrops form: a ball of water with an air bubble
inside it and inside of that one more bubble of water. It looks so beautiful
[...]. I realized something: the world is interesting for the man who can
be surprised. -Valentin Lebedev-

On 17 Oct 2003 14:18:02 -0400, in a place far, far away,
(James Nicoll) made the phosphor on my monitor glow
in such a way as to indicate that:

Just pointing out the sun exists, is very big and
needs to be taken into account when talking about orbits, which
I hadn't actually thought would be controversial in any way.

That statement is not controversial in any way. As I said, it was
simply an issue of nomenclature.

--
simberg.interglobal.org * 310 372-7963 (CA) 307 739-1296 (Jackson Hole)
interglobal space lines * 307 733-1715 (Fax) http://www.interglobal.org

"Extraordinary launch vehicles require extraordinary markets..."
Swap the first . and @ and throw out the ".trash" to email me.
Here's my email address for autospammers:

In article ,
Rand Simberg wrote:
On 17 Oct 2003 14:18:02 -0400, in a place far, far away,
(James Nicoll) made the phosphor on my monitor glow
in such a way as to indicate that:

Just pointing out the sun exists, is very big and
needs to be taken into account when talking about orbits, which
I hadn't actually thought would be controversial in any way.

That statement is not controversial in any way. As I said, it was
simply an issue of nomenclature.

It's bad nomenclature if it ignores a major gravity well.
In many cases, the dominant one.

--
It's amazing how the waterdrops form: a ball of water with an air bubble
inside it and inside of that one more bubble of water. It looks so beautiful
[...]. I realized something: the world is interesting for the man who can
be surprised. -Valentin Lebedev-

On 17 Oct 2003 14:30:58 -0400, in a place far, far away,
(James Nicoll) made the phosphor on my monitor glow
in such a way as to indicate that:

In article ,
Rand Simberg wrote:
On 17 Oct 2003 14:18:02 -0400, in a place far, far away,
(James Nicoll) made the phosphor on my monitor glow
in such a way as to indicate that:

Just pointing out the sun exists, is very big and
needs to be taken into account when talking about orbits, which
I hadn't actually thought would be controversial in any way.

That statement is not controversial in any way. As I said, it was
simply an issue of nomenclature.

It's bad nomenclature if it ignores a major gravity well.
In many cases, the dominant one.

It doesn't ignore that "gravity well." It just doesn't call it a
"gravity well" (unless one is talking about solar escape missions).

Everyone who does planetary trajectories is well aware of the
influence of the solar gravity field, just as everyone is well aware
that there is gravity in space in general, even when they say "zero
gravity". As I said, be careful--you're starting to sound like
Stuffie..

--
simberg.interglobal.org * 310 372-7963 (CA) 307 739-1296 (Jackson Hole)
interglobal space lines * 307 733-1715 (Fax) http://www.interglobal.org

"Extraordinary launch vehicles require extraordinary markets..."
Swap the first . and @ and throw out the ".trash" to email me.
Here's my email address for autospammers:

James Nicoll wrote:
In article ,
Hop David wrote:

snip


As I mentioned elsewhere in this thread, some asteroids have orbits
nearly tangent to earth's. Dv can be low and even less if lunar assists
are used. On the asteroid's return the homecoming astronauts can use
aerobraking to help match velocities with the earth. Also by the time
they reach earth, they might have mined some fuel and reaction mass from
the asteroid that would help them get home.


For the non-flesh payloads some form of asteroid mounted
projector (A cannon, linear accelerator or such) could be used.
Looking at the table for round trip opportunities that shows up
in several UofA publications, I see that on 01/07/98 a payload
could have been sent to Earth with a delta vee of 0.083 km/s,
which I think is within the abilities of a paintball gun. Of course,
the payload would have to have some way of matching velocities with
the Earth once it gets there (For small payload, aerobraking should
do).

Something capable of firing material out at 1ish km/s could
be used on a number of asteroids to put material in the vicinity of
Earth. For mining purposes, I think to think of this as the high
velocity interplanetary lawn dart method of returning commercial
payloads to Earth. Note: accurate terminal guidance will reduce law
suits as well as the number of payloads lost in the ocean.


In my fantasy asteroid miners dig underground tunnels (The dust and
debris from an open pit mine would make problems approaching and leaving
the asteroid). The ore carts are modified mag lev trains.

After time, tunnels pierce the asteroid clear through. When a mag lev
train tunnel pierces the asteroid clean through, it can double as a rail
gun to send payloads on their way.

A net work of asteroid piercing tunnels would also facilitate travel to
different points on its surface. You could jump in a tunnel entrance and
reach it's exit on the asteroid's antipode with zero energy expenditure,
if you're in no hurry. Here is a gif:
http://clowder.net/hop/railroad/tunnel.gif
The trip time through an asteroid's diameter would be the same as the
period of a circular orbit just above the asteroid's surface.

Hop
http://clowder.net/hop/index.html






--
Hop David
http://clowder.net/hop/index.html

In article ,
Rand Simberg wrote:
On 17 Oct 2003 14:30:58 -0400, in a place far, far away,
(James Nicoll) made the phosphor on my monitor glow
in such a way as to indicate that:

In article ,
Rand Simberg wrote:
On 17 Oct 2003 14:18:02 -0400, in a place far, far away,
(James Nicoll) made the phosphor on my monitor glow
in such a way as to indicate that:

Just pointing out the sun exists, is very big and
needs to be taken into account when talking about orbits, which
I hadn't actually thought would be controversial in any way.

That statement is not controversial in any way. As I said, it was
simply an issue of nomenclature.

It's bad nomenclature if it ignores a major gravity well.
In many cases, the dominant one.

It doesn't ignore that "gravity well." It just doesn't call it a
"gravity well" (unless one is talking about solar escape missions).

Everyone who does planetary trajectories is well aware of the
influence of the solar gravity field, just as everyone is well aware
that there is gravity in space in general, even when they say "zero
gravity". As I said, be careful--you're starting to sound like
Stuffie..

I have no idea who "Stuffie" is but I wouldn't use "zero
gravity" either. I'd use "free fall" or maybe "microgravity",
depending on circumstances. You use sloppy terms like "zero gravity"
and you end up with people who think the moon is beyond gravity and
so the astronauts need lead boots to stay down.

Anyway it would be a shame if at some future point a more
accurate use for the phrase "zero gravity" came up and the phrase
was already being misused to mean "free fall".
--
It's amazing how the waterdrops form: a ball of water with an air bubble
inside it and inside of that one more bubble of water. It looks so beautiful
[...]. I realized something: the world is interesting for the man who can
be surprised. -Valentin Lebedev-

In article ,
Hop David wrote:


James Nicoll wrote:
In article ,
Hop David wrote:

snip


Cosmic Lawn Dart material deleted but it led to

In my fantasy asteroid miners dig underground tunnels (The dust and
debris from an open pit mine would make problems approaching and leaving
the asteroid).

Really? I'd have assumed, if I ever thought about it, that
the dust would be cleared away like the coma on a comet. Does this not
happen fast enough?



--
It's amazing how the waterdrops form: a ball of water with an air bubble
inside it and inside of that one more bubble of water. It looks so beautiful
[...]. I realized something: the world is interesting for the man who can
be surprised. -Valentin Lebedev-

JRS: In article , seen in
news:sci.space.policy, Rand Simberg
posted at Fri, 17 Oct 2003 18:26:17 :-

Just pointing out the sun exists, is very big and
needs to be taken into account when talking about orbits, which
I hadn't actually thought would be controversial in any way.

That statement is not controversial in any way. As I said, it was
simply an issue of nomenclature.

Two things are important in technical journalism.

* The author should understand what he is writing about.
* The reader should understand what the author has written.

--
© John Stockton, Surrey, UK. Turnpike v4.00 MIME. ©
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
some Astro stuff via astro.htm, gravity0.htm; quotes.htm; pascal.htm; &c, &c.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.

Hop David wrote in message ...
James Nicoll wrote:
In article ,
Hop David wrote:

snip


As I mentioned elsewhere in this thread, some asteroids have orbits
nearly tangent to earth's. Dv can be low and even less if lunar assists
are used. On the asteroid's return the homecoming astronauts can use
aerobraking to help match velocities with the earth. Also by the time
they reach earth, they might have mined some fuel and reaction mass from
the asteroid that would help them get home.


For the non-flesh payloads some form of asteroid mounted
projector (A cannon, linear accelerator or such) could be used.
Looking at the table for round trip opportunities that shows up
in several UofA publications, I see that on 01/07/98 a payload
could have been sent to Earth with a delta vee of 0.083 km/s,
which I think is within the abilities of a paintball gun. Of course,
the payload would have to have some way of matching velocities with
the Earth once it gets there (For small payload, aerobraking should
do).

Something capable of firing material out at 1ish km/s could
be used on a number of asteroids to put material in the vicinity of
Earth. For mining purposes, I think to think of this as the high
velocity interplanetary lawn dart method of returning commercial
payloads to Earth. Note: accurate terminal guidance will reduce law
suits as well as the number of payloads lost in the ocean.


In my fantasy asteroid miners dig underground tunnels (The dust and
debris from an open pit mine would make problems approaching and leaving
the asteroid). The ore carts are modified mag lev trains.

After time, tunnels pierce the asteroid clear through. When a mag lev
train tunnel pierces the asteroid clean through, it can double as a rail
gun to send payloads on their way.

A net work of asteroid piercing tunnels would also facilitate travel to
different points on its surface. You could jump in a tunnel entrance and
reach it's exit on the asteroid's antipode with zero energy expenditure,
if you're in no hurry. Here is a gif:
http://clowder.net/hop/railroad/tunnel.gif
The trip time through an asteroid's diameter would be the same as the
period of a circular orbit just above the asteroid's surface.

Hop
http://clowder.net/hop/index.html

What possible point could there be in this?

In article ,
John Ordover wrote:
Hop David wrote in message ...
James Nicoll wrote:

snippity snip snip material return to Earth as well
as moving around in asteroids.

What possible point could there be in this?

What, a nearly content free one-line reply to a sixty plus line
article? I've never really been sure. Is it some form of self-commentary,
a concrete example of why trimming is a good idea or perhaps to show
why a more detailed question might be called for? Only the author knows,
I fear.

James Nicoll
--
It's amazing how the waterdrops form: a ball of water with an air bubble
inside it and inside of that one more bubble of water. It looks so beautiful
[...]. I realized something: the world is interesting for the man who can
be surprised. -Valentin Lebedev-