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Anomalous Long Term Effects in Astronauts' - Dosimetry (ALTEA_Dosi)
Principal Investigators
Research Area:
Radiation biology
Species Studied
Scientific Name: Homo sapiens Species: Human

Outside the protection of Earth's atmosphere ISS crewmembers are exposed to increased radiation, but the radiation environment is even more severe as exploration crews leave Earth's geomagnetic field and transit to other planets. The measurements made by the ALTEA hardware will help scientists characterize the heavy ion radiation spectrum inside the ISS, and the measurements while the ISS is at high geomagnetic latitudes will give insight to the radiation environment outside the Earth's magnetosphere.

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.

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Di Fino L, Casolino M, De Santis C, Larosa M, La Tessa C, Narici L, Picozza P, Zaconte V. Heavy-Ion Anisotropy Measured by ALTEA in the International Space Station. Radiation Research. 2011; 176(3): 397-406. []

Radiation tolerance

Data Information
Data Availability
Archive is complete. No data sets are available for this experiment. Please Contact LSDA if you know of available data for this investigation.

Galactic cosmic rays
Radiation measurement

Mission/Study Information
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

Additional Information
Managing NASA Center
Johnson Space Center (JSC)
Responsible NASA Representative
Johnson Space Center LSDA Office
Project Manager: Jessica Keune
Institutional Support
National Aeronautics and Space Administration (NASA)
Italian Space Agency (ASI)