From NASANews@luna.osf.hq.nasa.govFri Oct 27 16:04:04 1995
Date: Fri, 27 Oct 1995 15:51:51 -0400
From: NASA HQ Public Affairs Office <NASANews@luna.osf.hq.nasa.gov>
To: press-release-com@mercury.hq.nasa.gov
Subject: Revolutionary New Miniature Sensor System Developed

Douglas Isbell
Headquarters, Washington, DC           October 27, 1995
(Phone:  202/358-1753)

Mary Beth Murrill
Jet Propulsion Laboratory, Pasadena, CA 
(Phone:  818/354-5011)

RELEASE:  95-195

REVOLUTIONARY NEW MINIATURE SENSOR SYSTEM DEVELOPED

         A team led by NASA researchers has devised a 
miniaturized sensor system that could be a catalyst for a 
revolutionary new generation of small, low-cost spacecraft 
to explore the solar system.
        
        The Planetary Integrated Camera-Spectrometer, or 
PICS, is expected eventually to replace whole suites of 
individual spacecraft instruments that, on some NASA 
missions, can weigh more than 400 pounds and take up as 
much room as a four-drawer filing cabinet. Literally 
smaller than a breadbox, PICS combines some of the most 
productive and often-used space sensors into an 11-pound package. 

     Its development represents a crucial step toward 
enabling future NASA missions that will have to use smaller 
launch vehicles and, hence, smaller spacecraft to travel to 
distant planets and other bodies in the solar system. 

        In addition to being much smaller, the PICS system 
offers high performance and improved instrument sensitivity 
over previous spacecraft instruments of the same type at 
lower overall cost, according to PICS Program Manager Gregg 
Vane of NASA's Jet Propulsion Laboratory (JPL), Pasadena, 
CA.  "Many people assume that low cost implies low 
capability," he said, "but PICS proves you can have very 
high capability at low cost."

        The PICS prototype, developed through a 
collaboration between researchers at JPL, industry, 
universities and the U.S. Geological Survey, recently 
completed successful science and engineering tests that 
qualify the instrument system for development as flight 
hardware.  PICS is a candidate for flight on several future 
planetary spacecraft missions.  

        PICS is one of the first successful efforts to 
squeeze down multiple instrument optics,  functions and 
electronics into a small, efficient unit that requires 
dramatically less power and mass than was previously 
achieved.  It brings together in one integrated sensor 
system an ultraviolet imaging spectrometer, an infrared 
imaging spectrometer and two visible-light cameras --
instruments that can characterize the chemical makeup,
thermal properties, weather, atmospheric physics and 
geophysics of bodies in the solar system. 

        In the past, each of these spacecraft instruments 
has been built with its own separate, dedicated optical 
system and electronics. In PICS, the instruments share 
common telescope optics and extremely low-power, 
miniaturized instrument electronics. The result is one 
highly-capable integrated instrument system that requires 
less than five watts of power and is so small it can be 
tucked under an arm.  In comparison, similar instruments on 
the Voyager spacecraft required 75 watts to operate four 
large, entirely separate optical sensors, in addition to a 
sophisticated pointable scan platform for aiming.
        
        "PICS will be able to achieve Voyager-class science 
at 10 cents on the dollar," said geologist Dr. Larry 
Soderblom of the U.S. Geological Survey in Flagstaff, AZ.  
"PICS will allow the science return we are accustomed to 
from our flagship missions like Voyager, but at the cost of 
a Discovery mission -- about 1/10th to 1/20th of the cost."

         PICS' initial development was triggered by a 
challenge from designers of  NASA's Pluto Express mission, 
a proposed exploration of the only known planet in the 
solar system that still awaits close reconnaissance by a 
spacecraft.  The Pluto mission's requirements called for an 
instrument incorporating two spectrometers -- one far 
ultraviolet and one infrared -- in addition to two visible-
light cameras, all weighing in at less than about 15 
pounds.  Space instrument specialists say no previously 
existing instrument met these constraints or even came 
close to matching those specifications.

        From the outset, the PICS team's approach was to 
simplify the system and to minimize the mass and power of 
the instruments by maximizing the extent to which 
components can be shared.  To further reduce mass and power 
consumption, PICS was designed to eliminate items such as 
focusing mechanisms and filter wheels found on traditional 
spacecraft imaging systems.

        Another critical innovation in the PICS design was 
the decision to construct all the optical and structural 
components of silicon carbide. The material is inexpensive, 
highly dimensionally stable, chemically non-reactive and 
possesses excellent structural capabilities and 
manufacturability, according to Vane.  

        Beyond the innovations in materials and 
miniaturization that made PICS work is a new management 
approach calling for concurrent engineering and science planning. 

        
        "This contrasts with the more traditional approach 
taken in past missions where the scientists defined the 
requirements and the engineers developed the design, often 
with little interaction between the two groups," Vane said.  
Individual instruments were developed in this way, 
independent of each other and delivered to the spacecraft 
engineers as a fait accompli, he said.  "We've reengineered 
the process of how to design a sensor system.  Simply 
working together as an integrated team of scientists and 
engineers from the start has made the difference." 
 
        "With PICS instrument technology now in hand, JPL 
mission planners can reasonably conceive of missions to any 
planet in the solar system with a Delta or similar launch 
vehicle," said Dr. Patricia Beauchamp, PICS instrument 
manager.  One concept on the drawing board would send a 
PICS-equipped spacecraft beyond Pluto to the so-called 
Kuiper Belt of comets.  Another would put a spacecraft in 
orbit around Neptune's moon, Triton.  

	Fully prototyped and tested, PICS has been designed 
for ease of manufacture, integration and test.  A flight 
model for a candidate mission could be produced in 18 
months.   "We're ready to roll,"  Beauchamp said. "We're 
just waiting for a ride."

        The Planetary Integrated Camera-Spectrometer is 
being developed at the JPL for the Research Program 
Management Division of NASA's Office of Space Science, 
Washington, DC.
                        -end-

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