Manned Mission to Mercury

Well, when you are out of low earth orbit, you are about halfway to
anywhere in the solar system. I think a Mercury mission, down near
the Sun, could be a valuable research project. However, I don't think
you'd have to be hasty, setting down and lifting off near sunrise. If
you picked a real good place and landed near a pole, then you could
set up a partially reflective shield and stay for a while. As would
be appropriate for the long trip to get there and back. You settle
near but not on a pole so you see (part of) the sun above the horizon
always on the same side from your base.

Cheers -- Martha Adams

On Wed, 29 Oct 2003 17:00:03 +0000 (UTC), in a place far, far away,
(Martha H Adams) made the phosphor on my monitor glow
in such a way as to indicate that:

Well, when you are out of low earth orbit, you are about halfway to
anywhere in the solar system. I think a Mercury mission, down near
the Sun, could be a valuable research project. However, I don't think
you'd have to be hasty, setting down and lifting off near sunrise. If
you picked a real good place and landed near a pole, then you could
set up a partially reflective shield and stay for a while. As would
be appropriate for the long trip to get there and back.

The trip wouldn't be that long. It could be done in about half a
year, each way. In fact, it's impossible to take much longer than
that with impulsive maneuvers.

--
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..."
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Rand Simberg wrote:
On Wed, 29 Oct 2003 17:00:03 +0000 (UTC), in a place far, far away,
(Martha H Adams) made the phosphor on my monitor glow
in such a way as to indicate that:


Well, when you are out of low earth orbit, you are about halfway to
anywhere in the solar system. I think a Mercury mission, down near
the Sun, could be a valuable research project. However, I don't think
you'd have to be hasty, setting down and lifting off near sunrise. If
you picked a real good place and landed near a pole, then you could
set up a partially reflective shield and stay for a while. As would
be appropriate for the long trip to get there and back.


The trip wouldn't be that long. It could be done in about half a
year, each way. In fact, it's impossible to take much longer than
that with impulsive maneuvers.


A Hohmann to Mercury is about 3 and half months?

Say you left Earth mid January, 2005 and arrived at Mercury towards the
end of April. I believe the next Hohmann launch window for Earth would
be in July. So the mission would take longer than 7 months as you'd be
stuck on Mercury 2 months.

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

On Wed, 29 Oct 2003 11:56:35 -0700, in a place far, far away, Hop
David made the phosphor
on my monitor glow in such a way as to indicate that:

The trip wouldn't be that long. It could be done in about half a
year, each way. In fact, it's impossible to take much longer than
that with impulsive maneuvers.


A Hohmann to Mercury is about 3 and half months?

Say you left Earth mid January, 2005 and arrived at Mercury towards the
end of April. I believe the next Hohmann launch window for Earth would
be in July. So the mission would take longer than 7 months as you'd be
stuck on Mercury 2 months.

I said each way, not total duration.

--
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:
The trip wouldn't be that long. It could be done in about half a
year, each way. In fact, it's impossible to take much longer than
that with impulsive maneuvers.

For Mercury, you might want to use electric propulsion. The delta-V gets
unpleasantly large for doing it impulsively, because Mercury is so very
deep in the Sun's gravity well.
--
MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer
pointing, 10 Sept; first science, early Oct; all well. |

In article ,
John Savard wrote:
Not that it is a particularly _practical_ idea, but if we are able to
keep an astronaut supported in space long enough to mount a
personelled expedition to Mars, it would actually be possible to land
a man on Mercury... and return him safely to Earth.

The propulsion problems are rather worse than for Mars, unfortunately.
There is no atmosphere to help with arrival and descent, and the delta-V
needed for reaching Mercury is distinctly large.

...Land on a site on Mercury just as the Sun peeps
over the horizon, and then after a short mission, lift off to return
to Earth as enough of the Sun shows over the horizon to make things
warm.

Or, as others have suggested, land at a high latitude, where the Sun never
gets very high in the sky and hence the temperatures stay moderate. (In
fact, there is radar evidence suggesting ice at Mercury's poles. Its
origins are presumably similar to those of the lunar polar volatiles.)
--
MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer
pointing, 10 Sept; first science, early Oct; all well. |

Good suggestion -- especially since it's likely there's water ice in the
never-sunlit polar craters.



"Martha H Adams" wrote in message
...
Well, when you are out of low earth orbit, you are about halfway to
anywhere in the solar system. I think a Mercury mission, down near
the Sun, could be a valuable research project. However, I don't think
you'd have to be hasty, setting down and lifting off near sunrise. If
you picked a real good place and landed near a pole, then you could
set up a partially reflective shield and stay for a while. As would
be appropriate for the long trip to get there and back. You settle
near but not on a pole so you see (part of) the sun above the horizon
always on the same side from your base.

Cheers -- Martha Adams

Henry Spencer wrote:
In article ,
Rand Simberg wrote:

The trip wouldn't be that long. It could be done in about half a
year, each way. In fact, it's impossible to take much longer than
that with impulsive maneuvers.


For Mercury, you might want to use electric propulsion. The delta-V gets
unpleasantly large for doing it impulsively, because Mercury is so very
deep in the Sun's gravity well.

Maybe Venusian gravity assists could save some delta-v.

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

On Wed, 29 Oct 2003 19:58:46 GMT, in a place far, far away,
(Henry Spencer) made the phosphor on my monitor
glow in such a way as to indicate that:

In article ,
Rand Simberg wrote:
The trip wouldn't be that long. It could be done in about half a
year, each way. In fact, it's impossible to take much longer than
that with impulsive maneuvers.

For Mercury, you might want to use electric propulsion. The delta-V gets
unpleasantly large for doing it impulsively, because Mercury is so very
deep in the Sun's gravity well.

Well, I didn't say it would be *cheap*--just fast. ;-)

--
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:

Henry Spencer wrote:
In article ,
John Savard wrote:

Not that it is a particularly _practical_ idea, but if we are able to
keep an astronaut supported in space long enough to mount a
personelled expedition to Mars, it would actually be possible to land
a man on Mercury... and return him safely to Earth.


The propulsion problems are rather worse than for Mars, unfortunately.
There is no atmosphere to help with arrival and descent, and the delta-V
needed for reaching Mercury is distinctly large.

Mercury Mission
insertion at Hohmann aphelion 7.5 km/sec
exit at Hohmann perihelion 9.6 km/sec
Total 17.1 km/sec
Mars Mission
Insertion at Hohmann perihelion 2.9 km/sec
exit at Hohmann aphelion 2.7 km/sec
Total 5.6 km/sec

Assuming an exhaust velocity of 4 km/sec
e^(17.1 / 4)= 72.7
e^(5.6 / 4) = 4.04

So for a 10 ton payload you'd need 727 tons of fuel for the Mercury trip
and 40 tons of fuel for the Mars trip? (Not considering escape velocity
from planets though. Doesn't look like Mars escape velocity is much
different from Mercury's)

Hope I did that right.





...Land on a site on Mercury just as the Sun peeps
over the horizon, and then after a short mission, lift off to return
to Earth as enough of the Sun shows over the horizon to make things
warm.


Or, as others have suggested, land at a high latitude, where the Sun never
gets very high in the sky and hence the temperatures stay moderate. (In
fact, there is radar evidence suggesting ice at Mercury's poles. Its
origins are presumably similar to those of the lunar polar volatiles.)

ISTR several science fiction stories where anti-matter is manufactured
at Mercury. Presumably because solar energy is abundant.



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