Sorry, I didn’t realize ISS-RAD was inside the ISS, or that the Martian atmosphere was that thick in aggregate… Was the research warning about the riskiness of interplanetary travel based on dose rates like the ones in the figure you just
sent, or under less shielding, or over a longer time than LEO astronauts are exposed, or what? Or was the extra risk due to the different composition of the GCRs, or the likelihood of SEPs (largely shielded out in the ISS orbit)? I’m trying to understand
what the differences are between exposure of astronauts in LEO and that of astronauts on a trans-Mars trip, which is what needs to be pointed out to address this apparent contradiction of the two papers.
Mark D. Looper
Space Sciences Department
The Aerospace Corporation
M/S M2-260
P.O. Box 92957
Los Angeles, CA 90009-2957
Mobile: 310-529-3406
Voicemail: 310-336-6302
From: "Zeitlin, Cary J (JSC-SD2)[WYLE LABORATORIES, INC.]" <cary.j.zeitlin@nasa.gov>
Date: Wednesday, January 9, 2019 at 10:11 AM
To: Mark D Looper <mark.d.looper@aero.org>, Harlan Spence <spence@guero.sr.unh.edu>
Cc: "crater-team@lists.sr.unh.edu" <crater-team@lists.sr.unh.edu>
Subject: Re: [Crater-team] Link to paper - requires a subscription :-(
Yes, absolutely, shielding matters and is especially important for the SAA. ISS-RAD was moved around Station every few months during 2018, which explains part of the variation. And MSL-RAD is under ~ 23 g cm^-2 of CO2, so of course the
comparison is not apples to apples. But it’s interesting how it seems to be working out, even if the “agreement” is the product of numerous factors that are sort of conspiring to give such similar results.
From: Mark D Looper <mark.d.looper@aero.org>
Date: Wednesday, January 9, 2019 at 12:03 PM
To: "Zeitlin, Cary J (JSC-SD2)[WYLE LABORATORIES, INC.]" <cary.j.zeitlin@nasa.gov>, Harlan Spence <spence@guero.sr.unh.edu>
Cc: "crater-team@lists.sr.unh.edu" <crater-team@lists.sr.unh.edu>
Subject: Re: [Crater-team] Link to paper - requires a subscription :-(
Is it not also a matter of shielding, in that the LEO SAA spectrum is falling with energy and thus is comparatively easy to shield against, whereas the interplanetary GCR spectrum rises up to very deeply penetrating energies? What were
the assumptions in the paper(s) warning about interplanetary radiation exposure? The plot you sent is for detectors relatively open to space, right?
Mark D. Looper
Space Sciences Department
The Aerospace Corporation
M/S M2-260
P.O. Box 92957
Los Angeles, CA 90009-2957
Mobile: 310-529-3406
Voicemail: 310-336-6302
From: Crater-team <crater-team-bounces@lists.sr.unh.edu> on behalf of "Zeitlin, Cary J (JSC-SD2)[WYLE LABORATORIES, INC.]" <cary.j.zeitlin@nasa.gov>
Date: Wednesday, January 9, 2019 at 9:51 AM
To: Harlan Spence <spence@guero.sr.unh.edu>
Cc: "crater-team@lists.sr.unh.edu" <crater-team@lists.sr.unh.edu>
Subject: Re: [Crater-team] Link to paper - requires a subscription :-(
Good point! Nuance is completely lost in these things.
OTOH, the exposure isn’t all that different in LEO, as I’ve been learning since we started getting ISS-RAD data. The geomagnetic field is protective, but in terms of dose, the SAA passes more or less undo the protection. So the difference
is mostly that the LEO spectrum is more populated at low-LET than deep space, which is an even greater degree of nuance.
☺
From: Harlan Spence <spence@guero.sr.unh.edu>
Date: Wednesday, January 9, 2019 at 11:44 AM
To: "Zeitlin, Cary J (JSC-SD2)[WYLE LABORATORIES, INC.]" <cary.j.zeitlin@nasa.gov>
Cc: "crater-team@lists.sr.unh.edu" <crater-team@lists.sr.unh.edu>
Subject: Re: [Crater-team] Link to paper - requires a subscription :-(
Hi Cary,
One issue is that the press picked up on this and said that all the prior studies showing that space radiation is a problem is now called into question. So there’s a bit of damage control for those who didn’t understand the nuances
between LEO and deep space exposure.
= Harlan
________________________________
Harlan E. Spence
Director, Institute for the Study of Earth,
Oceans, & Space and Prof. of Physics
Morse Hall, Room 306
University of New Hampshire
8 College Road
Durham, NH 03824-3525
Phone: 603-862-0322
Fax: 603-862-1915
http://www.eos.unh.edu/Faculty/Spence
________________________________
On Jan 9, 2019, at 2:37 PM, Zeitlin, Cary J (JSC-SD2)[WYLE LABORATORIES, INC.] <cary.j.zeitlin@nasa.gov> wrote:
Thanks for the links – I’m glad they did this, even with all the caveats about sample size, etc.
From: Crater-team <crater-team-bounces@lists.sr.unh.edu> on behalf of Harlan Spence <spence@guero.sr.unh.edu>
Date: Wednesday, January 9, 2019 at 11:32 AM
To: "crater-team@lists.sr.unh.edu" <crater-team@lists.sr.unh.edu>
Subject: [Crater-team] Link to paper - requires a subscription :-(
________________________________
Harlan E. Spence
Director, Institute for the Study of Earth,
Oceans, & Space and Prof. of Physics
Morse Hall, Room 306
University of New Hampshire
8 College Road
Durham, NH 03824-3525
Phone: 603-862-0322
Fax: 603-862-1915
http://www.eos.unh.edu/Faculty/Spence
________________________________