13IF-107-50154-68 

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NRO APPROVED FOR 

RELEASE 1 JULY 2015 

To: W. C. Williams Date: 10 September 1968 

Subject: Guidance & Control Laboratory From: D. J. Griep 

Justification 

The purpose of the Guidance and Control Laboratory is to provide direct 

hardware support and hardware studies for Air Force satellite programs. 

This support involves the activities currently underway in support of the 

MOL Program. 

Approximately 80% of the lab activity is involved with MOL related support. 

The following brief summary of contributions to the MOL Program are 

listed below: 

1. Large Diameter Ball Bearing Study - A study of the torque noise 

in large diameter ball bearings for the Tracking Mirror (TM) drive 

on MOL has been conducted in the lab. Bearings procured and 

tested in the G&C Lab have to date provided the only bearings which 

will meet the overall drive performance for TM control. Bearings 

evaluated at Aerospace have been supplied to General Electric for 

the purpose of TM drive studies. The results of these General 

Electric tests provided the first instance of "in- spec " performance 

of the TM drive simulator. In addition, the Aerospace bearing 

test fixture has a greater capability for evaluating ball bearing 

torque noise. General Electric is currently redesigning their 

fixtures to copy the Aerospace configuration. Current plans in 

the G&C Lab involve the experimental investigation of the effects 

of installation cocking angle and the evaluation of nine-inch diameter 

bearings, for the roll axis of the TM drive servo. 

2. TM Drive Electronic Evaluation - An experimental investigation 

of the bias and bias stability in TM Drive electronics is underway. 

Current Image Velocity Sensor (IVS) limitations make it desirable 

to reduce the electronic biases in the TM Drive and determine 

its stability. Aerospace is in disagreement with G. E. on the level 

of bias and stability of bias. Experimental verification is mandatory 

to resolve this item. 

3. Air Bearing Table - A three axis air bearing table is being installed 

in the Lab. Using this table, initial experiments are planned to 

develop a single axis simulation of the TM Drive system on MOL. 

HANDLE VIA BYE AN 

'CONTROL: SYSTEM ONLY 

-SECRET- DORIAN 

-SECRET DORIAN 
BIF-107-50154-68 

NRO APPROVED FOR 

RELEASE 1 JULY 2015 -SECREf- DORIAN 

Guidance & Control Laboratory Justification Page -2- 

This simulator is necessary due to the problem of data correlation 

at General Electric. Current General Electric studies have 

been unable to correlate individual component data with overall 

TM Drive performance. General Electric does not possess the 

proposed simulation capability and would dilute their effort if 

required to develop this simulator. These experiments are necessary to develop the rationale for the TM Drive system evaluation 

before flight. Unless adequate correlation between component 

measurements and overall TM Drive performance can be made, 

a component/system buyoff criteria cannot be developed. This 

simulator will be used in the future for feasibility studies involving 

advanced MOL control system concepts such as CMG's (Control 

Moment Gyros). 

4. MOL ACTS Thruster Electrical Performance - At program office 

request, the low voltage performance of the ACTS thruster valves 

was experimentally determined. These data provided Aerospace 

with technical information to require the contractor to consider 

alternative solutions to an overall MOL system problem involving 

low voltage operation. 

5. Low Thrust Study - The determination of the thrust and total 

impulse imparted to the MOL vehicle by expelling water from the 

fuel cell/life support system is under study. A measurement 

apparatus capable of measuring 10-5 pounds of thrust for short 

duration pulses (.050 sec. ) is being developed in the lab. 

6. Low Frequency Instrumentation - A RMS meter capable of 

measurements at frequencies below 0.001 Hz was developed in 

the Lab during studies for another program. This meter configuration and associated techniques were supplied to General Electric 

at their request. This device is being used in the TM Drive 

data evaluation. 

7. TM Drive Gyro Noise - Initial estimates of the noise level 

present in the proposed TM drive gyros indicated that these units 

could possible be improved by redesign of the electronics. A brief 

study was conducted in the Laboratory and the results obtained 

indicated that an electronics redesign would not significantly 

reduce the noise level. This information was supplied to G. E. 

and eliminated any extensive studies by G. E. or the gyro 

manufacturer. 

DORIAN 
BIF-107-50154-68 

NRO APPROVED FOR 

RELEASE 1 JULY 2015 -Saha DORIAN 

Guidance & Control Laboratory Justification Page -3- 

8. Image Velocity Sensors - In support of the Image Velocity Sensor 

development, a laboratory breadboard simulation of the processing 

electronics will be constructed in the Lab. This breadboard will 

start when the selection of a final sensor is made and at the 

completion of current analytical studies associated with input scene 

characteristics. A major study has been underway during the past 

year to develop a model of input scene characteristics suitable 

for IVS design and evaluation. 

In addition to the MOL activity, the Lab supports other Air Force satellite 

programs in the areas of Guidance & Control Hardware. Programs being 

supported are: 467 Program, 110 Program, Low G accelerometer studies 

(LOGACS) and T-Ill Program. 

144 

David J. Griep 

SECRET DORIAN