Caldwell Internet Express
  Caldwell Internet Express
     4307 Vergie Avenue
 Beltsville, MD 20705-1511		  Voice:(301) 937-1891
    Fax:(301) 937-1934
EMAIL jody@calix.com

Please support these pages by visiting our sponsor!

[Prev][Next][Index]

Two Studies Will Refine and Expand Solar Monitoring Task

Douglas Isbell
Headquarters, Washington, DC                   March 19, 1998
(Phone: 202/358-1753)

RELEASE: 98-47

TWO STUDIES WILL REFINE AND EXPAND SOLAR MONITORING TASK

    The Naval Research Laboratory, Washington, DC, and the 
University of Colorado's Laboratory for Atmospheric and Space 
Physics in Boulder have been selected by NASA's Office of Earth 
Science to conduct parallel six-month definition studies of a 
new small satellite to monitor variations in the amount of 
radiant solar energy that reaches Earth.

    The precise measurements to be obtained by the Total Solar 
Irradiance Mission (TSIM) will help scientists better 
understand the relationship between the Sun's variable energy 
output and its effects on Earth's climate.  The six-month 
feasibility studies will focus on the development of a 
preliminary system design and operations concept for the cost-
capped $23 million mission.

    NASA has been measuring the total radiative output of the 
Sun from the unique perspective of space since the late 1970s.  
The current sensor being used is called the Active Cavity 
Radiometer Irradiance Monitor (ACRIM).  NASA has flown two 
ACRIM instruments, including the ACRIM-II instrument onboard 
NASA's Upper Atmosphere Research Satellite.  A third ACRIM 
instrument is scheduled for launch aboard a dedicated small 
satellite in October 1999.

    TSIM will extend the broad data set gathered by the ACRIM 
series while exploring a new capability to measure solar 
irradiance in two discreet spectral bands.  Once proven, this 
operationally oriented capability is a candidate for flight 
aboard future National Polar Orbiting Environmental Satellite 
System missions being planned by a tri-agency partnership among 
NASA, the Department of Defense and the National Oceanic and 
Atmospheric Administration.

    "TSIM will be developed in 36 months or less using the same 
key principles of 'faster, better, cheaper' spacecraft 
demonstrated by the agency's Discovery Program," said Dr. 
Ghassem Asrar, NASA Associate Administrator for Earth Science.  
"We hope to obtain an instrument payload that is lighter and 
more technologically advanced, yet provides an exciting 
additional capability that will give us new knowledge about our 
climate and why it varies."

    TSIM is part of NASA's Earth Observing System, a series of 
advanced remote-sensing satellites designed to provide 
simultaneous measurements of a broad range of physical, 
chemical and biological processes to enable researchers to 
study the Earth's land, oceans, air, ice and life as a total 
system.  TSIM also will serve as NASAÕs contribution to the 
joint small Science Satellite (SciSat) program with the 
Canadian Space Agency.  NASA and Canada have committed to 
developing independent science research missions to be launched 
on a NASA-funded launch vehicle in December 2001, with shared 
data after launch.

    The two selected teams will document their analyses for 
NASA  review by the end of 1998, with one team being selected 
to proceed with development.  TSIM program management will be 
provided by NASA's Goddard Space Flight Center in Greenbelt, MD.

                        -end-