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NASA Launches Sun Observatory; Spacewalk Planned

   The U.S. space agency has launched a new solar observatory into space,
   as  crews from the space shuttle Endeavour and the International Space
   Station  get  set for a spacewalk. An unmanned rocket propelled NASA's
   Solar  Dynamics  Observatory into space early Thursday. Later Thursday
   is the first of three scheduled spacewalks on the 13-day mission. NASA
   says  astronauts  will  use  the  three spacewalks to install a module
   known as "Tranquility" -- the final major piece of the space station.

   Suzanne Presto | Washington 11 February 2010

Photo: Courtesy of United Launch Alliance

   A   United   Launch  Alliance  Atlas  V  with  NASA's  Solar  Dynamics
   Observatory  satellite rolls out to the Space Launch Complex 41 launch
   pad on Cape Canaveral Air Force Station

   The  sun  is the driving force behind the Earth's climate, but changes
   in  the  sun  affect  more  than  just the weather on this planet. VOA
   reports  on NASA's plans to launch its Solar Dynamics Observatory this
   week.  The  observatory  is expected to deliver unparalleled images of
   the  sun, allowing scientists to study "space weather" that can affect
   satellite communications, navigation systems and even electrical power
   lines here on Earth.
   We  experience  the  sun's  warmth  and  light  firsthand, but we also
   experience  the  effects  of the sun's changing magnetic field here on
   Earth, perhaps without even realizing it.
   Scientist  Dean Pesnell says changes in the sun's magnetic field cause
   what  scientists  call "large particle events" - and such an event was
   even behind a blackout in southern Sweden seven years ago.
   "When  the  sun  has  a  large  particle  event,  those particles come
   through, interact with our magnetic field and can actually take down a
   power  system," Pesnell said. "The most recent example was the town of
   Malmo in Sweden, which lost its power in 2003."
   Pesnell  works  at  NASA's  Goddard  Spaceflight  Center  just outside
   Washington. He explains that the sun is dynamic. Its changing magnetic
   field  sends  electrically charged particles into the solar system, or
   it  converts  to  explosions in the sun's atmosphere or eruptions that
   release billions of tons of solar material into space.
   Such  activities alter the levels of energy and radiation in our solar
   system and can affect technology, such as satellite communications and
   navigation systems.
   But  Pesnell  explains we do not always feel the direct impact here on
   Earth.
   "It is kind of like standing there with a water hose spraying and then
   you  spin  around  on  a  turntable," Pesnell said. "If your friend is
   standing  somewhere,  you only hit them every once in a while when the
   water hose happens to pass by them."
   The  sun  is  the  source  of space weather, such as solar wind, solar
   flares  and  eruptions.  It  is the sun's effect on space weather, and
   space  weather's  effect on us, that has NASA scientists excited about
   the new Solar Dynamics Observatory. The mission will determine how the
   sun's  magnetic  field  is generated and destroyed and give scientists
   insight into space weather.
   Pesnell  is  a  Solar  Dynamics  Observatory  project  scientist.  The
   observatory  is  expected  to  reveal  the  sun's  inner  workings  by
   constantly  taking  high-resolution  images  of  the  sun,  collecting
   readings  from  inside  the  sun  and  measuring  its  magnetic  field
   activity.
   The  observatory  will  provide  images unlike anything that have been
   recorded so far, providing details of the sun and its features.
   "We  estimate  it will be one image every three-quarters of a second,"
   Pesnell said.
   This  data  is  expected  to help researchers eventually predict solar
   storms and other solar activities that can affect spacecraft in orbit,
   as well as power, communications and navigation systems here on Earth.
   NASA   says   the  observatory's  images  will  have  10-times  better
   resolution than high-definition television.
   "We  hope  that  it  will  be  displayable as a near real-time movie,"
   Pesnell said. "The data should be available fairly soon after it comes
   down  for  making  movies  that people can look at to find interesting
   events."
   The  observatory's  prime mission is expected to last five years, with
   the  observatory  sending  down  about 1.5 terabytes of data daily. To
   compare,  NASA  says  that  is  about  the  equivalent  of downloading
   half-a-million songs each day.
   The solar observatory was supposed to be launched on an unmanned Atlas
   V  rocket Wednesday, but gusty winds forced a delay. NASA says it will
   try again Thursday.

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