Mir mission to Mars?

Thread View: sci.space

2 messages

[T] Back to Threads [V] Tree View [G] Group Articles

2 total messages Started by Paul Shawcross Wed, 27 Jan 1993 14:55

#7119

Author: Paul Shawcross
Date: Wed, 27 Jan 1993 14:55

28 lines
1998 bytes

The major problem with using Mir for a manned Mars mission
is that Mir is not designed to protect its crew from the
interplanetary radiation environment.

At most times in the solar cycle, there would be a near
certainty that any unshielded astronauts on a two
year mission to Mars would be killed by solar flares. (At
the minimum of the cycle, the astronauts might make it
--some years have no major flares)

Adding a shielded "storm cellar" to Mir could greatly
reduce the danger.  Probably about 25 gm/cm^2 of shielding
would be needed to allow the crew to survive a major flare
in fairly good shape - extra mass would be roughly:
25 gm/cm^2 * 2*pi*200cm * 200 cm = somewhere around 6,500
kg for a 2meter long, 4 meter diameter "cellar".

Of course, there's also the cosmic ray radiation dose,
which is much more difficult to shield against and is
about 20-40 REM/yr depending on the time in the solar
cycle (more or less inverse to the flare probability)
This is below, but close to, the annual limit allowed for
shuttle astronauts (50 Rem/yr last I heard)

For more details I recommend looking at the AIAA's report
on assessment of technologies for the SEI -- it has a
lengthy section on the need for shielding and the effect
on total mission mass.

Re: Mir mission to Mars?

#7265

Author: gawne
Date: Thu, 28 Jan 1993 00:43

14 lines
1087 bytes

In article <1993Jan27.212245.20024@stsci.edu>, rdouglas@stsci.edu 
(Rob Douglas) asks:

> So what is it that keeps Mir astronauts alive in Earth orbit?
> Are you saying that some of the Earth's atmosphere protects them
> to an extent that those in interplanetary travel would notice the 
> difference?

The Earth has an extensive magnetic field that deflects charged particles.
Since cosmic rays are charged particles then Mir is protected from them.
Not to say there is no cosmic ray flux at Mir, just a lot less than 
it would experience in interplanetary flight.

-Bill Gawne,  Space Telescope Science Institute

Thread Navigation

This is a paginated view of messages in the thread with full content displayed inline.

Messages are displayed in chronological order, with the original post highlighted in green.

Use pagination controls to navigate through all messages in large threads.

Back to All Threads