PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011

Contact: Diane Ainsworth

FOR IMMEDIATE RELEASE                                May 6, 1996

SIERRA COLLEGE STUDENTS DELIVER PATHFINDER SUN SENSOR TO JPL

     Students from Sierra College in Rocklin, Calif., have 
delivered their very own creation -- "Mr. SunSensor" -- an 
engineering model of a sun sensor to be used this week in a Mars 
Pathfinder spacecraft operations simulation at NASA's Jet 
Propulsion Laboratory. 

     The students are part of a special student-industry-
government team which has spent the last two years building their 
own miniature spacecraft.  In a unique collaborative arrangement, 
JPL and industry representatives have been providing technical 
assistance to the team effort, while NASA and the Advanced 
Research Projects Agency (ARPA) furnished the funding.   
     
     "We met recently with the team for a technical review and 
learned that they were designing a sun sensor for their own 
spacecraft that could also be used for a specific Pathfinder 
test," said Dr. Dankai Liu, a lead engineer on the Pathfinder 
attitude and information management subsystem team at JPL.  "So 
we suggested integrating their sensor on the Pathfinder 
spacecraft and inviting them to watch the simulation."

     Ordinarily, a sun sensor would have been purchased or built 
by JPL to perform the test, Liu said.  JPL's partnership with 
Sierra College, industry and ARPA made the hardware delivery 
possible at no cost to the Laboratory.

     The students' project managers, Mike Dobeck and Stan 
Spencer, both instructors at the Northern California community 
college, jumped at the opportunity to get students involved in 
the Mars Pathfinder mission.  JPL representatives Dave Woerner, 
manager of the Pathfinder attitude and information management 
subsystem team, and Brian Muirhead, flight system manager, agreed 
whole-heartedly to the collaborative arrangement.  Dobeck also 
enlisted the participation of a group of high school students 
enrolled in a spacecraft design class at Colfax High School, near 
the Rocklin-based college. 

     "This antenna-pointing test is a critical step in the final 
months of Pathfinder testing and we're very glad to be able to 
use the students' sensor," Liu said.   "One of the first tasks 
the Pathfinder spacecraft will have to perform after it lands on 
the surface of Mars is find Earth and point its high-gain antenna 
toward us so we can communicate with the craft." 

     To demonstrate Pathfinder's pointing capability, engineers 
will mount the sensor on the spacecraft, then ask the spacecraft 
to find the sun and track it as it moves across the sky.  Liu's 
attitude subsystem team will measure errors in the lander's 
guidance system to determine Pathfinder's "marksmanship," or how 
accurately the spacecraft is pointing its antenna.     

     Attitude testing will take place during a two-day spacecraft 
operations simulation to be held at JPL on May 7 and 8. Other 
testing, including electrical, acoustic and thermal vacuum 
testing, will continue at the Laboratory through the summer.  
Pathfinder is scheduled to be shipped to Cape Canaveral, Florida, 
on Sept. 1, where it will be integrated on a Delta 2 launch 
vehicle and prepared for a Dec. 2 launch.
     
     The Mars Pathfinder mission is the first in NASA's Discovery 
program of low-cost planetary spacecraft with highly focused 
science goals.  The mission is managed by the Jet Propulsion 
Laboratory for NASA's Office of Space Science, Washington, D.C.

#####     

4/30/96 DEA
#9627      

      

2