[ RadSafe ] SwRI-led RAD measures radiation from solar storm

[ROY HERREN]

Friday, January 27, 2012
http://www.swri.org/9what/releases/2012/rad-solarstorm.htm
SwRI-led RAD measures radiation from solar storm
For immediate release
The largest solar particle event since 2005 hit the Earth, Mars and the Mars 
Science Laboratory spacecraft travelling in-between, allowing the onboard 
Radiation Assessment Detector to measure the radiation a human astronaut could 
be exposed to en route to the Red Planet. 

 
On Sunday, a huge coronal mass ejection erupted from the surface of the sun, 
spewing a cloud of charged particles in our direction, causing a strong "S3" 
solar storm. A NASA Goddard Space Weather Lab animation of the CME illustrates 
how the disturbance impacts Earth, Mars and several spacecraft. Solar storms can 
affect the Earth's aurorae, satellites, air travel and GPS systems; no harmful 
effects to the Mars Science Laboratory have been detected from this solar event.
 
"We only have a few hours of data downloaded from the RAD so far, but we clearly 
see the event, said RAD Principal Investigator Don Hassler, science program 
director in the Space Studies Department at Southwest Research Institute. The 
Mars Science Laboratory, launched Nov. 26, will land a sophisticated car-sized 
rover called Curiosity on the surface of the planet in August. Loaded with 10 
instruments including RAD, Curiosity will traverse the landing site looking for 
the building blocks of life and characterizing factors that may influence life, 
such as the harsh radiation environment expected on Mars. "This SPE encounter is 
particularly exciting in light of the alignment between the Earth, MSL and Mars 
right now and for the next few months. It will be very interesting to compare 
the RAD data, collected from inside the capsule, with the data from other 
spacecraft."
 
This event has also been seen by the Solar Dynamics Observatory, Geostationary 
Operational Environment Satellites, the Advanced Composition Explorer, and the 
twin Solar Terrestrial Relations Observatory spacecraft in Earth orbit as well 
as the Solar Heliospheric Observatory flying between Earth and the sun.
 
"RAD was designed to characterize radiation levels on the surface of Mars, but 
an important secondary objective is measuring the radiation during the almost 
nine-month journey through interplanetary space to prepare for future human 
exploration," said Hassler. "RAD is an important bridge between the science and 
exploration sides of NASA.
 
"Not only will this give us insight into the physics of these giant clouds, but 
like an astronaut, RAD is tucked inside the MSL 'spacecraft,'" Hassler 
continued. "Measurements from RAD will give us insight about the shielding 
provided by spacecraft for future manned missions in deep space."
 
RAD will collect data nearly continuously during cruise and will downlink data 
every 24 hours. Positioned in the front-left corner of the rover, the instrument 
is about the size of a coffee can and weighs about three pounds, but has 
capabilities of an Earth-bound instrument nearly 10 times its size. When MSL 
arrives at Mars, RAD will detect charged particles arriving from space and will 
measure neutrons and gamma rays coming from Mars' atmosphere above, or the 
surface material below, the rover. 

 
SwRI, together with Christian Albrechts University in Kiel, Germany, built RAD 
with funding from the NASA Human Exploration and Operations Mission Directorate 
and Germany's national aerospace research center, Deutsches Zentrum für Luft- 
und Raumfahrt.
 
The Mars Science Laboratory is a project of NASA's Science Mission Directorate. 
The mission is managed by NASA's Jet Propulsion Laboratory, a division of 
Caltech. The mission's rover was designed, developed and assembled at JPL. 

 
Movie/Measuring radiation on Mars: http://youtu.be/2x99mFg_Jyc
 
Movie/Measuring radiation en route to Mars: http://youtu.be/v5WSnxyjvJk

 
For more information, contact Deb Schmid, (210) 522-2254, Communications 
Department, Southwest Research Institute, PO Drawer 28510, San Antonio, TX 
78228-0510.