Radiation exposure represents one of the greatest risks to humans traveling on exploration missions beyond low Earth orbit (LEO). Anomalous Long Term Effects in Astronauts' - Dosimetry (ALTEA-Dosi) will measure the particle flux in the U.S. Laboratory Destiny on the International Space Station (ISS), being able to discriminate particle type and measure particle trajectory and deposited energy. Comparison between data collected by ALTEA-Dosi, Intravehicular Charged Particle Directional Spectrometer (IVCPDS), and Extravehicular Charged Particle Directional Spectrometer (EVCPDS) will aid space agencies in understanding the radiation spectrum and radiation shielding characteristics of the Destiny.
Anomalous Long Term Effects in Astronauts' - Dosimetry will utilize the ALTEA hardware: a helmet-shaped device holding 6 silicon particle detectors designed to measure cosmic radiation passing through the detectors. The six identical silicon detector units (SDU) contain three sets of x-y plane silicon strip detectors. Each plane detector is 300 micrometers thick and divided into 64 strips. An event is recorded if at least all 3 x-plane detectors have signals above threshold, and these signals are the sum of the energy deposited in four adjacent strips. The geometry factor of each SDU is 250 cm-sr and is capable of measuring particle trajectory with an angular accuracy of 1.8 degrees and can resolve individual ionizing particles of charge 4 to 28 for energies above 25 MeV/n. In previous research, an electroencephalograph (EEG) measured the brain activity of the crewmember to determine if radiation strikes caused changes in the electrophysiology of the brain in real time. A Visual Stimulator performed tests of the crewmembers' overall visual system.
ALTEA-Dosi will continuously measure the cosmic radiation, without crewmember aid or wearing of the helmet, in the International Space Station (ISS) U.S. Laboratory, Destiny. The ALTEA-Dosi data will also be compared with data collected by Intravehicular Charged Particle Directional Spectrometer (IVCPDS), and Extravhicular Charged Particle Directional Spectrometer (EVCPDS) instruments. The IVCPDS and EVCPDS instruments measure the energy and species of individual ionizing particles of charge 1 to 10, where ALTEA-Dosi measures charge of 4 to 28; therefore, these data sets complement one another allowing for the measurement of the abundances of all ions that contribute significantly to crew radiation exposure.
Mission | Launch/Start Date | Landing/End Date | Duration |
---|---|---|---|
Expedition 17 | 04/08/2008 | 10/23/2008 | 198 days |
Expedition 18 | 10/12/2008 | 04/17/2009 | 187 days |
Expedition 19 | 03/26/2009 | 10/11/2009 | 199 days |
Expedition 20 | 05/27/2009 | 10/11/2009 | 137 days |
Expedition 21 | 10/11/2009 | 12/01/2009 | 51 days |
Expedition 22 | 11/30/2009 | 03/18/2010 | 109 days |
Expedition 23 | 03/18/2010 | 06/01/2010 | 75 days |
Expedition 24 | 06/01/2010 | 09/25/2010 | 117 days |
Expedition 25 | 09/24/2010 | 11/25/2010 | 31 days |
Expedition 26 | 11/26/2010 | 03/16/2011 | 111 days |
Expedition 27 | 03/14/2011 | 05/23/2011 | 70 days |
Expedition 28 | 05/23/2011 | 09/15/2011 | 115 days |
Expedition 29 | 09/16/2011 | 11/21/2011 | 40 days |
Expedition 30 | 11/14/2011 | 04/27/2012 | 166 days |
Expedition 31 | 04/27/2012 | 07/01/2012 | 65 days |
Expedition 32 | 07/01/2012 | 09/16/2012 | 78 days |