Kelly O. Humphries
Jonhson Space Center, Houston                                                                     
February 14, 1991                      
(Phone:  703/483-5111)

RELEASE:  91-26

NASA INVENTOR OF THE YEAR ANNOUNCED  

     Johnson Space Center's Leo Monford, NASA's Inventor of the 
Year, is determined to make the Space Shuttle's robot arm even 
more useful than it is, and his inventions could revolutionize 
orbital docking and robotics use.

     The invention that earned him the award is a "Docking 
Alignment System,  Monford calls it the Targeting and Reflective 
Alignment Concept, or TRAC.

     By itself, the new precision alignment system is a 
significant improvement. But used in concert with another of 
Monford's inventions, a Magnetic End Effector, it could change 
the shape of future robot arms, satellites and space stations.

     Monford, who works in the New Initiatives Office's Space 
Servicing Systems Project Office, is the first JSC employee to 
receive the Inventor of the Year award since its inception in 
1980. The award will be presented March 28 at a NASA Headquarters 
ceremony,  according to NASA General Counsel Edward Frankle, who 
announced Monford's selection Feb. 5.

     "My job is to come up with innovative thoughts and 
technologies and stimulate others into producing those products," 
Monford said. "I honestly can't think of an award I would desire 
more than this one."

     TRAC utilizes a television camera mounted inside the arm's 
end effector and a monitor on the Shuttle's aft flight deck, both 
with alignment marks and a flat, mirrored target marked with 
cross hairs on the target object. It has been tested extensively 
at the manipulator development facility and is able to routinely 
insert square pegs into square holes with only  0.03 of an inch 
clearance.

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   Here's how it works. An astronaut operating the remote 
manipulator system from the aft flight deck moves the arm to 
within range of the fixed-focus television camera inside the arm. 
The operator makes translational corrections with the arm until 
the cross hairs on the target and the monitor line up. 

     Then, the operator uses rotational controls until the camera 
is able to see its own image. Since the camera can see only 
directly in front of itself, it will not see its own image until 
the end effector and the target are perpendicular to each other. 
When the camera can see itself and the cross hairs are lined up, 
alignment is complete.

     "It's like looking through a rifle scope," Monford said.  
"Once you understand the idea of aligning the cross hairs, it 
just comes naturally to you."

     The existing alignment system uses a target with a 
protruding post. The main advantage of Monford's system is that 
the target is flat. Many proposed space operations for the 
Shuttle's arm or a space station arm involve stacking and 
unstacking objects for construction purposes.

     "When you try to make things stack up, a protruding target 
gets in the way," Monford said. The beautiful thing about the 
TRAC system, he added, is that it works perfectly with the 
operator's hand controllers, which maneuver the arm through 
separate rotational and translational controls.
                                     
    The first practical application of TRAC will be on STS-37, as 
a part of Development Test Objective 1205, "TRAC Application for 
RMS Alignment/Deflection Measurements." TRAC will be used to 
provide precise data on the amount of "play" in the remote 
manipulator system when a space walking astronaut applies force 
to the oustretched arm. The targeting system will gather data 
that would be difficult or impossible to gather otherwise.

     Monford said researchers at Texas A&M, his alma mater, are 
working on automating TRAC. Instead of cross hairs, the automat 
system uses corner cubes on the target that reflect light back 
only in the direction of its origin, similar to bicycle 
reflectors and a light-emitting diode on the camera lens. A 
computer lines up the flood-lit corner cubes to determine when 
the arm is perpendicular to its target. When the camera can see 
the reflection of the LED on its lens, the computer will know the 
alignment is exact.

     "It's really a generic concept. It has very broad 
application," he said, explaining that it can provide a precise 
reference point for intelligent robots that need to perform 
exacting tasks on three-dimensional surfaces.   Put the TRAC 
system together with Monford's Magnetic End Effector, patent 
pending, and the possibilities grow.

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     The MEE is a potential replacement for the Standard End 
Effector, which grapples payloads through electro-mechanical 
means, using cables to snare a protruding grapple fixture. The 
MEE, with no moving parts, uses electro-magnetic force to "clomp 
onto" a plate made of ferrous metal  attached to the payload. The 
metal plate shares the advantage of flatness with the alignment 
target, and the MEE's centerline camera would allow the docking 
plate to double as the target plate for the TRAC system.

     Monford's smaller, lighter MEE is two-fault tolerant both in 
grappling and releasing payloads and requires no regularly 
scheduled maintenance or pyrotechnic safety release devices.

    Proposed MEEs would give different sized arms the capability 
to grapple common target plates, add the ability to transfer both 
power and data to payloads and provide a method of attaching a 
variety of power tools that could help alleviate the need for 
some extravehicular activity space walks by astronauts. "I think 
in the space station era, this type of an end effector will be 
baselined," Monford said.

     The TRAC, MEE, a JPL Force Torque Sensor that provides a 
representation of forces and moment on the arm, and a Carrier 
Latch Assembly that uses electromagnetic force to help hold 
satellites in the payload bay, are scheduled to fly as part of  
the Dexterous End Effector Flight Demonstration on STS-58.   "I'm 
looking forward to some other exciting flight experiments that 
would leapfrog from this one."
     
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     Photos to illustrate this story are available to media 
representatives by calling the JSC Photo Library at 713/483-8603.  
Photo numbers are:  S91-28033 and S91-28080 thru 82.