-----------------------------------------------------------------------
  **MSFC PRACA : 2003-02-12 08:41**

  -----------------------------------------------------------------------

  -----------------------------------------------------------------------
  MSFC Problem Reporting and Corrective Action (PRACA) System

  WHOLE RECORD REPORT( + ADDENDUM)
  -----------------------------------------------------------------------

+--------------+---------------+-----------+---------+------+--------+
| **MSFC       | **In-Flight   | **C       | **      | *    |        |
| Record \#**\ | Anomaly       | ontractor | JSC#**\ | *KSC |        |
| A15773       | Number**\     | Report    | \--     | #**\ |        |
|              | \--           | Number**\ |         | \--  |        |
|              |               | E-156     |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Problem    |               |           |         |      |        |
| Title**\     |               |           |         |      |        |
| LIQUID LEVEL |               |           |         |      |        |
| SENSOR       |               |           |         |      |        |
| FAILED ATP   |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **EICN#**\   | **ELEMENT**\  | **Cont    | **F     | **   |        |
| \--          | ET            | ractor**\ | SCM#**\ | FCRI |        |
|              |               | MMMSS     | \--     | T**\ |        |
|              |               |           |         | 1R   |        |
+--------------+---------------+-----------+---------+------+--------+
| **HCRIT**\   | **Sys_Lvl**\  | **Misc    |         |      |        |
| \--          | N             | Codes**\  |         |      |        |
|              |               | A B C D E |         |      |        |
|              |               | F G H I J |         |      |        |
|              |               | K L M N O |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| *            | **NO          | *         | **SER/  | *    |        |
| *HARDWARE**\ | MENCLATURE**\ | *PART#**\ | LOT#**\ | *MAN |        |
| EIM          | \--           | \--       | \--     | UFAC |        |
|              |               |           |         | TURE |        |
|              |               |           |         | R**\ |        |
|              |               |           |         | \--  |        |
+--------------+---------------+-----------+---------+------+--------+
| *            | **NO          | *         | **SER/  | *    |        |
| *HARDWARE**\ | MENCLATURE**\ | *PART#**\ | LOT#**\ | *MAN |        |
| LRU          | \--           | \--       | \--     | UFAC |        |
|              |               |           |         | TURE |        |
|              |               |           |         | R**\ |        |
|              |               |           |         | \--  |        |
+--------------+---------------+-----------+---------+------+--------+
| *            | **NO          | *         | **SER/  | *    |        |
| *HARDWARE**\ | MENCLATURE**\ | *PART#**\ | LOT#**\ | *MAN |        |
| NCA          | LOX LEVEL     | 74L4-1    | 1649    | UFAC |        |
|              | SENSOR        |           |         | TURE |        |
|              |               |           |         | R**\ |        |
|              |               |           |         | SIMM |        |
|              |               |           |         | ONDS |        |
+--------------+---------------+-----------+---------+------+--------+
| **Test/      | **Prevailing  | **F /     | **Fail  | **   |        |
| Operation**\ | Condtion**\   | U**\      | Mode**\ | Caus |        |
| A - ATP      | F -           | F         | EN -    | e**\ |        |
|              | FUNCTIONAL    |           | OPEN    | U -  |        |
|              |               |           |         | UNK  |        |
|              |               |           |         | NOWN |        |
+--------------+---------------+-----------+---------+------+--------+
| **System**\  | **Defect**\   | **Ma      | **Work  | **   |        |
| ELECTRICAL   | DC - BROKEN   | terial**\ | Con     | Fail |        |
|              |               | C - EEE   | tact**\ | Dat  |        |
|              |               |           | JOHN    | e**\ |        |
|              |               |           | ADAMS   | 01   |        |
|              |               |           |         | /10/ |        |
|              |               |           |         | 1994 |        |
+--------------+---------------+-----------+---------+------+--------+
| **Received   | **Date        | **FMEA    | **IFA:  | *    |        |
| at MSFC**\   | Isolated**\   | Ref       | Mission | *Mis |        |
| 01/12/1994   | 01/10/1994    | erence**\ | P       | sion |        |
|              |               | 3.6.1.1   | hase**\ | Ela  |        |
|              |               |           | \--     | psed |        |
|              |               |           |         | Tim  |        |
|              |               |           |         | e**\ |        |
|              |               |           |         | \--  |        |
+--------------+---------------+-----------+---------+------+--------+
| *            |               | **S       |         | **   |        |
| *Location**\ |               | ymptom**\ |         | Time |        |
| SIMMONDS     |               | EN - OPEN |         | Cycl |        |
|              |               |           |         | e**\ |        |
|              |               |           |         | \--  |        |
+--------------+---------------+-----------+---------+------+--------+
| *            |               |           |         |      |        |
| *Effectivity |               |           |         |      |        |
| Text**\      |               |           |         |      |        |
| \--          |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Vehicle    |               |           |         |      |        |
| Effectivity  |               |           |         |      |        |
| Codes**      |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Vehicle    | **Vehicle     | **Vehicle | **      | *    |        |
| 1**\         | 2**\          | 3**\      | Vehicle | *Veh |        |
| \--          | \--           | \--       | 4**\    | icle |        |
|              |               |           | \--     | 5**\ |        |
|              |               |           |         | \--  |        |
+--------------+---------------+-----------+---------+------+--------+
| **Mission    |               |           |         |      |        |
| Effectivity  |               |           |         |      |        |
| Codes**      |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Mssn 1**\  | **Mssn 2**\   | **Mssn    | **Mssn  | **   |        |
| \--          | \--           | 3**\      | 4**\    | Mssn |        |
|              |               | \--       | \--     | 5**\ |        |
|              |               |           |         | \--  |        |
+--------------+---------------+-----------+---------+------+--------+
| **Estimated  |               |           |         |      |        |
| Completion   |               |           |         |      |        |
| Dates**      |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **MSFC       | **Contractor  | **LVL 3   | *       |      |        |
| Approved     | Req Defer     | Close**\  | *Remark |      |        |
| Defer Until  | Until Date**\ | \--       | /       |      |        |
| Date**\      | 01/31/1994    |           | Ac      |      |        |
| 01/21/1994   |               |           | tion**\ |      |        |
|              |               |           | 01/     |      |        |
|              |               |           | 31/1994 |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **I          |               |           |         |      |        |
| nvestigation |               |           |         |      |        |
| / Resolution |               |           |         |      |        |
| Summary**    |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Last MSFC  | **CN RSLV     | **Defer   | **Add   | *    |        |
| Update**\    | SBMT**\       | Date**\   | Date**\ | *R/C |        |
| 04/12/1994   | 01/31/1994    | 0         | 01/     | Code |        |
|              |               | 1/20/1994 | 12/1994 | s**\ |        |
|              |               |           |         | 0 -  |        |
|              |               |           |         | EXPL |        |
|              |               |           |         | \--  |        |
|              |               |           |         | \--  |        |
+--------------+---------------+-----------+---------+------+--------+
| **Assignee** |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Design**\  | **Chief       | **S &     | **Pro   | *    |        |
| R. MOYE      | Engineer**\   | MA**\     | ject**\ | *Pro |        |
|              | M. PESSIN     | R.        | \--     | ject |        |
|              |               | JACKSON   |         | MG   |        |
|              |               |           |         | R**\ |        |
|              |               |           |         | P.   |        |
|              |               |           |         | CO   |        |
|              |               |           |         | UNTS |        |
+--------------+---------------+-----------+---------+------+--------+
| **Approval** |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Design**\  | **Chief       | **S &     | **Pro   | *    |        |
| R. MOYE      | Engineer**\   | MA**\     | ject**\ | *Pro |        |
|              | M. PESSIN     | R.        | \--     | ject |        |
|              |               | JACKSON   |         | MG   |        |
|              |               |           |         | R**\ |        |
|              |               |           |         | P.   |        |
|              |               |           |         | CO   |        |
|              |               |           |         | UNTS |        |
+--------------+---------------+-----------+---------+------+--------+
| **PAC        | **PAC Review  | **MSFC    | **St    | *    |        |
| Assignee**\  | Complete**\   | Closure   | atus**\ | *F/A |        |
| B. HURST     | BH            | Date**\   | C -     | C    |        |
|              |               | 0         | CLOSED  | ompl |        |
|              |               | 2/10/1994 |         | etio |        |
|              |               |           |         | n**\ |        |
|              |               |           |         | 01   |        |
|              |               |           |         | /10/ |        |
|              |               |           |         | 1994 |        |
+--------------+---------------+-----------+---------+------+--------+
| **Problem    | **SEV**\      | **Program | **      | **O  |        |
| Type**\      | \--           | Name**\   | REVL**\ | PRIN |        |
| \--          |               | \--       | \--     | C**\ |        |
|              |               |           |         | \--  |        |
+--------------+---------------+-----------+---------+------+--------+
| **FUNC       | **Software    | *         |         | **SU | **So   |
| MOD**\       | E             | *Software |         | BTYP | ftware |
| \--          | ffectivity**\ | Fail      |         | E**\ | C      |
|              | \-- \-- \--   | CD**\     |         | \--  | losure |
|              | \-- \--       | \--       |         |      | CD**\  |
|              |               |           |         |      | \--    |
+--------------+---------------+-----------+---------+------+--------+
| **RES PERSON | **Approval    |           |         |      |        |
| L2**\        | Signature     |           |         |      |        |
| \--          | L3**\         |           |         |      |        |
|              | \--           |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Related    | **Related     |           |         |      |        |
| Document     | Document      |           |         |      |        |
| Type**\      | ID**\         |           |         |      |        |
| \--          | T-121356      |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Related    |               |           |         |      |        |
| Document     |               |           |         |      |        |
| Title**\     |               |           |         |      |        |
| \--          |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Related    | **Related     |           |         |      |        |
| Document     | Document      |           |         |      |        |
| Type**\      | ID**\         |           |         |      |        |
| \--          | \--           |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Related    |               |           |         |      |        |
| Document     |               |           |         |      |        |
| Title**\     |               |           |         |      |        |
| \--          |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Related    | **Related     |           |         |      |        |
| Document     | Document      |           |         |      |        |
| Type**\      | ID**\         |           |         |      |        |
| \--          | \--           |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Related    |               |           |         |      |        |
| Document     |               |           |         |      |        |
| Title**\     |               |           |         |      |        |
| \--          |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Contractor |               |           |         |      |        |
| Status       |               |           |         |      |        |
| Summary**    |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Reliabi    |               |           |         |      |        |
| lity/Quality |               |           |         |      |        |
| Assurance    |               |           |         |      |        |
| Concerns,    |               |           |         |      |        |
| Recomm       |               |           |         |      |        |
| endations:** |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Problem    |               |           |         |      |        |
| D            |               |           |         |      |        |
| escription** |               |           |         |      |        |
|              |               |           |         |      |        |
| A LOX LEVEL  |               |           |         |      |        |
| SENSOR       |               |           |         |      |        |
| FAILED THE   |               |           |         |      |        |
| SUPPLIER     |               |           |         |      |        |
| ACCEPTANCE   |               |           |         |      |        |
| TEST. THE    |               |           |         |      |        |
|              |               |           |         |      |        |
| SENSING      |               |           |         |      |        |
| ELEMENT      |               |           |         |      |        |
| DEVELOPED AN |               |           |         |      |        |
| OPEN CIRCUIT |               |           |         |      |        |
| UPON         |               |           |         |      |        |
| IMMERSION IN |               |           |         |      |        |
| CRYOGENIC    |               |           |         |      |        |
|              |               |           |         |      |        |
| FLUID DURING |               |           |         |      |        |
| THE FIRST    |               |           |         |      |        |
| THERMAL      |               |           |         |      |        |
| SHOCK TEST   |               |           |         |      |        |
|              |               |           |         |      |        |
| CRITICALITY: |               |           |         |      |        |
| THE 74L4-1   |               |           |         |      |        |
| LOX LEVEL    |               |           |         |      |        |
| SENSOR IS    |               |           |         |      |        |
| CRIT. 3 IN   |               |           |         |      |        |
| ALL          |               |           |         |      |        |
| POSITIONS    |               |           |         |      |        |
|              |               |           |         |      |        |
| ON THE ET    |               |           |         |      |        |
| FOR THE      |               |           |         |      |        |
| SENSING      |               |           |         |      |        |
| ELEMENT OPEN |               |           |         |      |        |
| CIRCUIT.     |               |           |         |      |        |
| HOWEVER, THE |               |           |         |      |        |
| 74L4-1       |               |           |         |      |        |
|              |               |           |         |      |        |
| SENSOR IS    |               |           |         |      |        |
| VIRTUALLY    |               |           |         |      |        |
| IDENTICAL TO |               |           |         |      |        |
| THE 74L4-2   |               |           |         |      |        |
| LH2 LEVEL    |               |           |         |      |        |
| SENSOR. THE  |               |           |         |      |        |
|              |               |           |         |      |        |
| 74L4-2 LEVEL |               |           |         |      |        |
| SENSOR IS    |               |           |         |      |        |
| CRIT. 1R;    |               |           |         |      |        |
| FMEA ITEM    |               |           |         |      |        |
| CODE         |               |           |         |      |        |
| 3.6.1.1; \"  |               |           |         |      |        |
| FAILS WITH   |               |           |         |      |        |
|              |               |           |         |      |        |
| FALSE WET    |               |           |         |      |        |
| SIGNAL.\"    |               |           |         |      |        |
|              |               |           |         |      |        |
| NOTE: THE    |               |           |         |      |        |
| SENSOR IS    |               |           |         |      |        |
| LIMITED LIFE |               |           |         |      |        |
| CONTROLLED   |               |           |         |      |        |
|              |               |           |         |      |        |
| \* REVISION  |               |           |         |      |        |
| \"A\" CLOSES |               |           |         |      |        |
| ALL TASKS.   |               |           |         |      |        |
| SEE          |               |           |         |      |        |
| ASTERISKS    |               |           |         |      |        |
| FOR CHANGES  |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **Contractor |               |           |         |      |        |
| In           |               |           |         |      |        |
| vestigation/ |               |           |         |      |        |
| Resolution** |               |           |         |      |        |
|              |               |           |         |      |        |
| GENERAL:     |               |           |         |      |        |
|              |               |           |         |      |        |
| THE 74L4-1   |               |           |         |      |        |
| LOX LEVEL    |               |           |         |      |        |
| SENSOR WAS   |               |           |         |      |        |
| UNDERGOING   |               |           |         |      |        |
| THE          |               |           |         |      |        |
| ACCEPTANCE   |               |           |         |      |        |
| TEST AT      |               |           |         |      |        |
|              |               |           |         |      |        |
| THE          |               |           |         |      |        |
| SUPPLIER,    |               |           |         |      |        |
| B.F.         |               |           |         |      |        |
| GOODRICH     |               |           |         |      |        |
| AEROSPACE,   |               |           |         |      |        |
| SIMMONDS     |               |           |         |      |        |
| PRECISION    |               |           |         |      |        |
| DIVISION,    |               |           |         |      |        |
|              |               |           |         |      |        |
| VERGENNES,   |               |           |         |      |        |
| VERMONT. THE |               |           |         |      |        |
| TESTING IS   |               |           |         |      |        |
| CONTROLLED   |               |           |         |      |        |
| BY           |               |           |         |      |        |
| ACCEPTANCE   |               |           |         |      |        |
| TEST         |               |           |         |      |        |
|              |               |           |         |      |        |
| PLAN 946,    |               |           |         |      |        |
| REVISION S.  |               |           |         |      |        |
| THE          |               |           |         |      |        |
| TRANSDUCER   |               |           |         |      |        |
| DEVELOPED AN |               |           |         |      |        |
| OPEN CIRCUIT |               |           |         |      |        |
| WHEN         |               |           |         |      |        |
|              |               |           |         |      |        |
| IMMERSED IN  |               |           |         |      |        |
| LN2 FOR THE  |               |           |         |      |        |
| FIRST OF THE |               |           |         |      |        |
| SEVEN        |               |           |         |      |        |
| THERMAL      |               |           |         |      |        |
| SHOCK CYCLES |               |           |         |      |        |
| PER          |               |           |         |      |        |
|              |               |           |         |      |        |
| PARAGRAPH    |               |           |         |      |        |
| 6.4.10 OF    |               |           |         |      |        |
| THE ATP. THE |               |           |         |      |        |
| SENSOR WAS   |               |           |         |      |        |
| REMOVED FROM |               |           |         |      |        |
| THE LN2      |               |           |         |      |        |
|              |               |           |         |      |        |
| AND          |               |           |         |      |        |
| EXAMINED;    |               |           |         |      |        |
| THE BROKEN   |               |           |         |      |        |
| SENSING      |               |           |         |      |        |
| ELEMENT      |               |           |         |      |        |
| COULD BE     |               |           |         |      |        |
| SEEN WITHIN  |               |           |         |      |        |
| THE          |               |           |         |      |        |
|              |               |           |         |      |        |
| SENSOR       |               |           |         |      |        |
| HOUSING. THE |               |           |         |      |        |
| FAILURE WAS  |               |           |         |      |        |
| DOCUMENTED   |               |           |         |      |        |
| ON MARS      |               |           |         |      |        |
| T121356      |               |           |         |      |        |
|              |               |           |         |      |        |
| THE LEVEL    |               |           |         |      |        |
| SENSOR       |               |           |         |      |        |
| UTILIZES THE |               |           |         |      |        |
| DECREASE IN  |               |           |         |      |        |
| THE          |               |           |         |      |        |
| ELECTRICAL   |               |           |         |      |        |
| RESISTANCE   |               |           |         |      |        |
|              |               |           |         |      |        |
| OF A METAL   |               |           |         |      |        |
| WHEN COOLED  |               |           |         |      |        |
| TO DETECT    |               |           |         |      |        |
| THE PRESENCE |               |           |         |      |        |
| OF A         |               |           |         |      |        |
| CRYOGENIC    |               |           |         |      |        |
| FLUID        |               |           |         |      |        |
|              |               |           |         |      |        |
| THE SENSOR   |               |           |         |      |        |
| USES A GOLD  |               |           |         |      |        |
| FLASHED      |               |           |         |      |        |
| PLATINUM     |               |           |         |      |        |
| WIRE, .0005  |               |           |         |      |        |
| INCH IN      |               |           |         |      |        |
| DIAMETER,    |               |           |         |      |        |
|              |               |           |         |      |        |
| AS THE       |               |           |         |      |        |
| SENSING      |               |           |         |      |        |
| ELEMENT. THE |               |           |         |      |        |
| LEVEL SENSOR |               |           |         |      |        |
| SIGNAL       |               |           |         |      |        |
| CONDITIONER, |               |           |         |      |        |
| WHICH        |               |           |         |      |        |
|              |               |           |         |      |        |
| IS MOUNTED   |               |           |         |      |        |
| IN THE       |               |           |         |      |        |
| ORBITER,     |               |           |         |      |        |
| PROVIDES A   |               |           |         |      |        |
| CONSTANT     |               |           |         |      |        |
| CURRENT TO   |               |           |         |      |        |
| THE SENSING  |               |           |         |      |        |
|              |               |           |         |      |        |
| ELEMENT      |               |           |         |      |        |
| WHICH CAUSES |               |           |         |      |        |
| IT TO RISE   |               |           |         |      |        |
| IN           |               |           |         |      |        |
| TEMPERATURE. |               |           |         |      |        |
| THE          |               |           |         |      |        |
| TEMPERATURE  |               |           |         |      |        |
| AND          |               |           |         |      |        |
|              |               |           |         |      |        |
| RESISTANCE   |               |           |         |      |        |
| OF THE       |               |           |         |      |        |
| ELEMENT      |               |           |         |      |        |
| DECREASE     |               |           |         |      |        |
| RADICALLY    |               |           |         |      |        |
| WHEN         |               |           |         |      |        |
| IMMERSED IN  |               |           |         |      |        |
| A            |               |           |         |      |        |
|              |               |           |         |      |        |
| CRYOGENIC    |               |           |         |      |        |
| LIQUID. THE  |               |           |         |      |        |
| SIGNAL       |               |           |         |      |        |
| CONDITIONER  |               |           |         |      |        |
| DETECTS THE  |               |           |         |      |        |
| DECREASE IN  |               |           |         |      |        |
|              |               |           |         |      |        |
| RESISTANCE   |               |           |         |      |        |
| AND CONVERTS |               |           |         |      |        |
| IT TO A      |               |           |         |      |        |
| \"WET\"      |               |           |         |      |        |
| OUTPUT       |               |           |         |      |        |
| SIGNAL. THE  |               |           |         |      |        |
| SIGNAL       |               |           |         |      |        |
|              |               |           |         |      |        |
| CONDITIONER  |               |           |         |      |        |
| IS ALSO      |               |           |         |      |        |
| DESIGNED TO  |               |           |         |      |        |
| GIVE A       |               |           |         |      |        |
| \"WET\"      |               |           |         |      |        |
| SIGNAL IN    |               |           |         |      |        |
| THE EVENT OF |               |           |         |      |        |
|              |               |           |         |      |        |
| AN OPEN      |               |           |         |      |        |
| CIRCUIT IN   |               |           |         |      |        |
| THE LEVEL    |               |           |         |      |        |
| SENSOR       |               |           |         |      |        |
|              |               |           |         |      |        |
| THE SENSOR   |               |           |         |      |        |
| HAS AN       |               |           |         |      |        |
| ALUMINUM     |               |           |         |      |        |
| CASE WHICH   |               |           |         |      |        |
| IS PRODUCED  |               |           |         |      |        |
| BY           |               |           |         |      |        |
| INVESTMENT   |               |           |         |      |        |
|              |               |           |         |      |        |
| CASTING.     |               |           |         |      |        |
| VERY FEW OF  |               |           |         |      |        |
| THE INTERNAL |               |           |         |      |        |
| SURFACES,    |               |           |         |      |        |
| AND NONE OF  |               |           |         |      |        |
| THE EXTERNAL |               |           |         |      |        |
|              |               |           |         |      |        |
| SURFACES,    |               |           |         |      |        |
| ARE FINISH   |               |           |         |      |        |
| MACHINED FOR |               |           |         |      |        |
| DIMENSIONAL  |               |           |         |      |        |
| CONTROL. THE |               |           |         |      |        |
| INTERNAL     |               |           |         |      |        |
|              |               |           |         |      |        |
| SURFACES OF  |               |           |         |      |        |
| THE CASE AND |               |           |         |      |        |
| THE COVER    |               |           |         |      |        |
| ARE PAINTED  |               |           |         |      |        |
| WITH A       |               |           |         |      |        |
| SPRAYED-ON,  |               |           |         |      |        |
|              |               |           |         |      |        |
| BAKED,       |               |           |         |      |        |
| TEFLON       |               |           |         |      |        |
| PAINT. THE   |               |           |         |      |        |
| PAINT        |               |           |         |      |        |
| PREVENTS     |               |           |         |      |        |
| WETTING OF   |               |           |         |      |        |
| THE CASE,    |               |           |         |      |        |
| I.E          |               |           |         |      |        |
|              |               |           |         |      |        |
| RETENTION OF |               |           |         |      |        |
| CRYOGENICS,  |               |           |         |      |        |
| AND ALSO     |               |           |         |      |        |
| PROVIDES     |               |           |         |      |        |
| SOME         |               |           |         |      |        |
| ELECTRICAL   |               |           |         |      |        |
| INSULATION   |               |           |         |      |        |
|              |               |           |         |      |        |
| BETWEEN THE  |               |           |         |      |        |
| CASE AND THE |               |           |         |      |        |
| SENSOR       |               |           |         |      |        |
| ELEMENT. THE |               |           |         |      |        |
| ELEMENT IS   |               |           |         |      |        |
| SUPPORTED BY |               |           |         |      |        |
|              |               |           |         |      |        |
| A CERAMIC    |               |           |         |      |        |
| SUBSTRATE.   |               |           |         |      |        |
| THE          |               |           |         |      |        |
| SUBSTRATE    |               |           |         |      |        |
| HAS FIRED-ON |               |           |         |      |        |
| GOLD CIRCUIT |               |           |         |      |        |
| PATHS        |               |           |         |      |        |
|              |               |           |         |      |        |
| WHICH        |               |           |         |      |        |
| PROVIDE A    |               |           |         |      |        |
| MEANS TO     |               |           |         |      |        |
| TERMINATE    |               |           |         |      |        |
| THE ELEMENT  |               |           |         |      |        |
| WIRE BY      |               |           |         |      |        |
| WELDING. THE |               |           |         |      |        |
|              |               |           |         |      |        |
| SENSOR       |               |           |         |      |        |
| OUTPUT WIRES |               |           |         |      |        |
| ARE ATTACHED |               |           |         |      |        |
| TO THE       |               |           |         |      |        |
| SUBSTRATE BY |               |           |         |      |        |
| STEEL        |               |           |         |      |        |
| TERMINALS    |               |           |         |      |        |
|              |               |           |         |      |        |
| HELD IN      |               |           |         |      |        |
| PLACE WITH   |               |           |         |      |        |
| RIVETS AND   |               |           |         |      |        |
| SPRING       |               |           |         |      |        |
| WASHERS      |               |           |         |      |        |
|              |               |           |         |      |        |
| TASK I.      |               |           |         |      |        |
| FAILURE      |               |           |         |      |        |
| I            |               |           |         |      |        |
| NVESTIGATION |               |           |         |      |        |
|              |               |           |         |      |        |
| THE FAILED   |               |           |         |      |        |
| SENSOR WAS   |               |           |         |      |        |
| DOCUMENTED   |               |           |         |      |        |
| ON MARS      |               |           |         |      |        |
| T121356. THE |               |           |         |      |        |
| MARS WAS     |               |           |         |      |        |
|              |               |           |         |      |        |
| D            |               |           |         |      |        |
| ISPOSITIONED |               |           |         |      |        |
| FOR FAILURE  |               |           |         |      |        |
| ANALYSIS, TO |               |           |         |      |        |
| BE PERFORMED |               |           |         |      |        |
| AT MAF       |               |           |         |      |        |
|              |               |           |         |      |        |
| RES          |               |           |         |      |        |
| PONSIBILITY: |               |           |         |      |        |
| R.           |               |           |         |      |        |
| RAMSEY/3830  |               |           |         |      |        |
| \-- M.       |               |           |         |      |        |
| COMBS/3830   |               |           |         |      |        |
|              |               |           |         |      |        |
| J.           |               |           |         |      |        |
| ADA          |               |           |         |      |        |
| MS/3741\--D, |               |           |         |      |        |
| W            |               |           |         |      |        |
| ESTPHAL/3840 |               |           |         |      |        |
|              |               |           |         |      |        |
| \*           |               |           |         |      |        |
| COMPLETED:   |               |           |         |      |        |
| JANUARY 21,  |               |           |         |      |        |
| 1994         |               |           |         |      |        |
|              |               |           |         |      |        |
| \* CLOSURE   |               |           |         |      |        |
| STATEMENT    |               |           |         |      |        |
|              |               |           |         |      |        |
| THE SENSOR   |               |           |         |      |        |
| WAS RECEIVED |               |           |         |      |        |
| FROM         |               |           |         |      |        |
| SIMMONDS     |               |           |         |      |        |
| PRECISION IN |               |           |         |      |        |
| GOOD         |               |           |         |      |        |
| CONDITION    |               |           |         |      |        |
|              |               |           |         |      |        |
| VISUAL       |               |           |         |      |        |
| EXAMINATION  |               |           |         |      |        |
| OF THE       |               |           |         |      |        |
| SENSOR       |               |           |         |      |        |
| CONFIRMED    |               |           |         |      |        |
| THAT ONE END |               |           |         |      |        |
| OF THE       |               |           |         |      |        |
|              |               |           |         |      |        |
| FRACTURED    |               |           |         |      |        |
| ELEMENT WIRE |               |           |         |      |        |
| COULD BE     |               |           |         |      |        |
| SEEN WITHIN  |               |           |         |      |        |
| THE SENSOR.  |               |           |         |      |        |
| WHEN THE     |               |           |         |      |        |
|              |               |           |         |      |        |
| CASE WAS     |               |           |         |      |        |
| OPENED IT    |               |           |         |      |        |
| WAS          |               |           |         |      |        |
| DETERMINED   |               |           |         |      |        |
| THAT THE     |               |           |         |      |        |
| FRACTURE HAD |               |           |         |      |        |
| OCCURRED     |               |           |         |      |        |
|              |               |           |         |      |        |
| NEAR THE     |               |           |         |      |        |
| CENTER OF    |               |           |         |      |        |
| THE ELEMENT. |               |           |         |      |        |
| THE TWO ENDS |               |           |         |      |        |
| OF THE WIRE  |               |           |         |      |        |
| AT THE       |               |           |         |      |        |
|              |               |           |         |      |        |
| FRACTURE     |               |           |         |      |        |
| WERE REMOVED |               |           |         |      |        |
| FROM THE     |               |           |         |      |        |
| ELEMENT      |               |           |         |      |        |
| ASSEMBLY AND |               |           |         |      |        |
| MOUNTED ON A |               |           |         |      |        |
|              |               |           |         |      |        |
| SAMPLE       |               |           |         |      |        |
| CARRIER FOR  |               |           |         |      |        |
| EXAMINATION  |               |           |         |      |        |
| IN A         |               |           |         |      |        |
| SCANNING     |               |           |         |      |        |
| ELECTRON     |               |           |         |      |        |
| MICROSCOPE   |               |           |         |      |        |
|              |               |           |         |      |        |
| (SEM). THE   |               |           |         |      |        |
| FRACTURE     |               |           |         |      |        |
| FACES OF THE |               |           |         |      |        |
| WIRE WERE    |               |           |         |      |        |
| INDICATIVE   |               |           |         |      |        |
| OF A TENSILE |               |           |         |      |        |
|              |               |           |         |      |        |
| OVERLOAD IN  |               |           |         |      |        |
| A DUCTILE    |               |           |         |      |        |
| MATERIAL.    |               |           |         |      |        |
| THE EXTREME  |               |           |         |      |        |
| DELICACY OF  |               |           |         |      |        |
| THE SENSING  |               |           |         |      |        |
|              |               |           |         |      |        |
| ELEMENT      |               |           |         |      |        |
| MAKES IT     |               |           |         |      |        |
| SUSCEPTIBLE  |               |           |         |      |        |
| TO IMPACT    |               |           |         |      |        |
| DAMAGE FROM  |               |           |         |      |        |
| FOREIGN      |               |           |         |      |        |
| MATERIALS    |               |           |         |      |        |
|              |               |           |         |      |        |
| IN THE       |               |           |         |      |        |
| LIQUID       |               |           |         |      |        |
| NITROGEN     |               |           |         |      |        |
| USED DURING  |               |           |         |      |        |
| ACCEPTANCE   |               |           |         |      |        |
| TESTING AND  |               |           |         |      |        |
| TO           |               |           |         |      |        |
|              |               |           |         |      |        |
| INSUFFICIENT |               |           |         |      |        |
| SLACK IN THE |               |           |         |      |        |
| ELEMENT.     |               |           |         |      |        |
| THERE WERE   |               |           |         |      |        |
| NO           |               |           |         |      |        |
| INDICATIONS  |               |           |         |      |        |
| AS TO        |               |           |         |      |        |
|              |               |           |         |      |        |
| WHICH OF THE |               |           |         |      |        |
| TWO LIKELY   |               |           |         |      |        |
| P            |               |           |         |      |        |
| OSSIBILITIES |               |           |         |      |        |
| WAS THE      |               |           |         |      |        |
| CAUSE        |               |           |         |      |        |
|              |               |           |         |      |        |
| TASK CLOSED  |               |           |         |      |        |
|              |               |           |         |      |        |
| \* CAUSE     |               |           |         |      |        |
|              |               |           |         |      |        |
| THE ROOT     |               |           |         |      |        |
| CAUSE IS     |               |           |         |      |        |
| UNKNOWN. THE |               |           |         |      |        |
| MOST         |               |           |         |      |        |
| PROBABLE     |               |           |         |      |        |
| CAUSE WAS    |               |           |         |      |        |
| EITHER:      |               |           |         |      |        |
|              |               |           |         |      |        |
| 1\) IMPACT   |               |           |         |      |        |
| DAMAGE FROM  |               |           |         |      |        |
| A FOREIGN    |               |           |         |      |        |
| OBJECT IN    |               |           |         |      |        |
| THE LN2; OR  |               |           |         |      |        |
|              |               |           |         |      |        |
| 2\)          |               |           |         |      |        |
| PERSONNEL    |               |           |         |      |        |
| ERROR DURING |               |           |         |      |        |
| SENSING      |               |           |         |      |        |
| ELEMENT      |               |           |         |      |        |
| MANUFACTURE  |               |           |         |      |        |
| WHICH        |               |           |         |      |        |
|              |               |           |         |      |        |
| RESULTED IN  |               |           |         |      |        |
| EXCESSIVE    |               |           |         |      |        |
| TENSION IN   |               |           |         |      |        |
| THE ELEMENT  |               |           |         |      |        |
|              |               |           |         |      |        |
| TASK II.     |               |           |         |      |        |
| CORRECTIVE   |               |           |         |      |        |
| ACTION       |               |           |         |      |        |
|              |               |           |         |      |        |
| \* NO        |               |           |         |      |        |
| CORRECTIVE   |               |           |         |      |        |
| ACTION FOR   |               |           |         |      |        |
| THE FAILURE  |               |           |         |      |        |
| IS POSSIBLE. |               |           |         |      |        |
| THE CAUSE OF |               |           |         |      |        |
| THE          |               |           |         |      |        |
|              |               |           |         |      |        |
| FAILURE      |               |           |         |      |        |
| COULD NOT BE |               |           |         |      |        |
| DETERMINED.  |               |           |         |      |        |
| REVIEW OF    |               |           |         |      |        |
| THE          |               |           |         |      |        |
| ASSOCIATED   |               |           |         |      |        |
| TEST AND     |               |           |         |      |        |
|              |               |           |         |      |        |
| M            |               |           |         |      |        |
| ANUFACTURING |               |           |         |      |        |
| STEPS FOUND  |               |           |         |      |        |
| NO           |               |           |         |      |        |
| INDICATIONS  |               |           |         |      |        |
| THAT THE     |               |           |         |      |        |
| EXISTING     |               |           |         |      |        |
| CONTROLS     |               |           |         |      |        |
|              |               |           |         |      |        |
| HAD BEEN     |               |           |         |      |        |
| DEVIATED     |               |           |         |      |        |
| FROM OR THAT |               |           |         |      |        |
| THE CONTROLS |               |           |         |      |        |
| WERE         |               |           |         |      |        |
| INADEQUATE.  |               |           |         |      |        |
| THERE        |               |           |         |      |        |
|              |               |           |         |      |        |
| HAS BEEN A   |               |           |         |      |        |
| SINGLE       |               |           |         |      |        |
| PREVIOUS     |               |           |         |      |        |
| SUPPLIER ATP |               |           |         |      |        |
| FAILURE OF A |               |           |         |      |        |
| 74L4 SENSOR  |               |           |         |      |        |
|              |               |           |         |      |        |
| DUE TO       |               |           |         |      |        |
| IMPACT       |               |           |         |      |        |
| DAMAGE       |               |           |         |      |        |
| CAUSING      |               |           |         |      |        |
| FRACTURE OF  |               |           |         |      |        |
| THE ELEMENT. |               |           |         |      |        |
| THERE HAS    |               |           |         |      |        |
| BEEN         |               |           |         |      |        |
|              |               |           |         |      |        |
| NO SUPPLIER  |               |           |         |      |        |
| ATP FAILURE  |               |           |         |      |        |
| OF A 74L4    |               |           |         |      |        |
| SENSOR DUE   |               |           |         |      |        |
| TO INCORRECT |               |           |         |      |        |
| TENSION      |               |           |         |      |        |
|              |               |           |         |      |        |
| CAUSING      |               |           |         |      |        |
| FRACTURE OF  |               |           |         |      |        |
| THE ELEMENT  |               |           |         |      |        |
|              |               |           |         |      |        |
| TASK CLOSED  |               |           |         |      |        |
|              |               |           |         |      |        |
| TASK III.    |               |           |         |      |        |
| CLEARANCE OF |               |           |         |      |        |
| E            |               |           |         |      |        |
| FFECTIVITIES |               |           |         |      |        |
|              |               |           |         |      |        |
| \* THIS IS   |               |           |         |      |        |
| AN EXPLAINED |               |           |         |      |        |
| CLOSURE OF   |               |           |         |      |        |
| THE CAPS     |               |           |         |      |        |
|              |               |           |         |      |        |
| \* ALL ETS   |               |           |         |      |        |
| CLEARED. THE |               |           |         |      |        |
| SENSOR       |               |           |         |      |        |
| FAILED       |               |           |         |      |        |
| DURING       |               |           |         |      |        |
| VENDOR       |               |           |         |      |        |
| ACCEPTANCE   |               |           |         |      |        |
| TESTING      |               |           |         |      |        |
|              |               |           |         |      |        |
| AND ALL      |               |           |         |      |        |
| INSTALLED    |               |           |         |      |        |
| SENSORS HAVE |               |           |         |      |        |
| PASSED THE   |               |           |         |      |        |
| VENDOR       |               |           |         |      |        |
| TESTS. THERE |               |           |         |      |        |
| ARE          |               |           |         |      |        |
|              |               |           |         |      |        |
| TESTS OF     |               |           |         |      |        |
| SENSOR       |               |           |         |      |        |
| RESISTANCE   |               |           |         |      |        |
| AFTER        |               |           |         |      |        |
| INSTALLATION |               |           |         |      |        |
| ON THE ET    |               |           |         |      |        |
| THAT WOULD   |               |           |         |      |        |
|              |               |           |         |      |        |
| DETECT THE   |               |           |         |      |        |
| FAILURE      |               |           |         |      |        |
|              |               |           |         |      |        |
| NOTE: THIS   |               |           |         |      |        |
| IS ALSO THE  |               |           |         |      |        |
| DEFERRAL     |               |           |         |      |        |
| RATIONALE    |               |           |         |      |        |
|              |               |           |         |      |        |
| TASK CLOSED  |               |           |         |      |        |
|              |               |           |         |      |        |
| TASK IV.     |               |           |         |      |        |
| CAPS CLOSURE |               |           |         |      |        |
| SUMMARY      |               |           |         |      |        |
|              |               |           |         |      |        |
| \* THIS IS   |               |           |         |      |        |
| AN EXPLAINED |               |           |         |      |        |
| CLOSURE OF   |               |           |         |      |        |
| THE CAPS     |               |           |         |      |        |
|              |               |           |         |      |        |
| \* THE CAUSE |               |           |         |      |        |
| OF THE       |               |           |         |      |        |
| FAILURE OF   |               |           |         |      |        |
| THE LEVEL    |               |           |         |      |        |
| SENSOR       |               |           |         |      |        |
| DURING       |               |           |         |      |        |
| SUPPLIER ATP |               |           |         |      |        |
|              |               |           |         |      |        |
| COULD NOT BE |               |           |         |      |        |
| DETERMINED.  |               |           |         |      |        |
| NO           |               |           |         |      |        |
| CORRECTIVE   |               |           |         |      |        |
| ACTION WAS   |               |           |         |      |        |
| POSSIBLE.    |               |           |         |      |        |
| REVIEW       |               |           |         |      |        |
|              |               |           |         |      |        |
| OF THE       |               |           |         |      |        |
| SUPPLIERS    |               |           |         |      |        |
| TEST AND     |               |           |         |      |        |
| MANUFACTURE  |               |           |         |      |        |
| CONTROLS     |               |           |         |      |        |
| FOUND NO     |               |           |         |      |        |
|              |               |           |         |      |        |
| D            |               |           |         |      |        |
| EFICIENCIES. |               |           |         |      |        |
| THERE ARE    |               |           |         |      |        |
| SUFFICIENT   |               |           |         |      |        |
| TESTS OF     |               |           |         |      |        |
| SENSOR       |               |           |         |      |        |
| PERFORMANCE  |               |           |         |      |        |
| IN           |               |           |         |      |        |
|              |               |           |         |      |        |
| THE ET BUILD |               |           |         |      |        |
| CYCLE TO     |               |           |         |      |        |
| ASSURE       |               |           |         |      |        |
| PERFORMANCE  |               |           |         |      |        |
| ON THE       |               |           |         |      |        |
| FLIGHT       |               |           |         |      |        |
| VEHICLE      |               |           |         |      |        |
|              |               |           |         |      |        |
| TASK CLOSED  |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+
| **MSFC       |               |           |         |      |        |
| Response/C   |               |           |         |      |        |
| oncurrence** |               |           |         |      |        |
|              |               |           |         |      |        |
| 1/12/94 -    |               |           |         |      |        |
| DEFERRAL     |               |           |         |      |        |
| RATIONALE:   |               |           |         |      |        |
|              |               |           |         |      |        |
| BASED ON THE |               |           |         |      |        |
| INFORMATION  |               |           |         |      |        |
| IN \"TASK    |               |           |         |      |        |
| III.         |               |           |         |      |        |
| CLEARANCE OF |               |           |         |      |        |
| EFF          |               |           |         |      |        |
| ECTIVITIES\" |               |           |         |      |        |
|              |               |           |         |      |        |
| (ABOVE),     |               |           |         |      |        |
| THIS PROBLEM |               |           |         |      |        |
| HAS BEEN     |               |           |         |      |        |
| DEFERRED FOR |               |           |         |      |        |
| THE NEXT SIX |               |           |         |      |        |
| (6) MONTHS   |               |           |         |      |        |
| PER          |               |           |         |      |        |
|              |               |           |         |      |        |
| NSTS 08126,  |               |           |         |      |        |
| REVISION E,  |               |           |         |      |        |
| PARAGRAPH    |               |           |         |      |        |
| 3.3.10.1,    |               |           |         |      |        |
| ITEM D WHICH |               |           |         |      |        |
| STATES \"THE |               |           |         |      |        |
|              |               |           |         |      |        |
| PROBLEM      |               |           |         |      |        |
| CONDITION IS |               |           |         |      |        |
| CLEARLY      |               |           |         |      |        |
| SCREENED BY  |               |           |         |      |        |
| PREFLIGHT    |               |           |         |      |        |
| CHECKOUT OR  |               |           |         |      |        |
| SPECIAL      |               |           |         |      |        |
|              |               |           |         |      |        |
| TESTS (I.E., |               |           |         |      |        |
| FAILURE MODE |               |           |         |      |        |
| SHOULD NOT   |               |           |         |      |        |
| OCCUR        |               |           |         |      |        |
| FOLLOWING    |               |           |         |      |        |
| THE TEST).\" |               |           |         |      |        |
|              |               |           |         |      |        |
| APPROVED:    |               |           |         |      |        |
| \_           |               |           |         |      |        |
| \_\_\_PARKER |               |           |         |      |        |
| V.           |               |           |         |      |        |
| COUNTS(SIG   |               |           |         |      |        |
| NED)\_\_\_\_ |               |           |         |      |        |
| DATE:\_\     |               |           |         |      |        |
| _\_\_1/20/94 |               |           |         |      |        |
| \_\_\_\_\_\_ |               |           |         |      |        |
|              |               |           |         |      |        |
| PARKER V.    |               |           |         |      |        |
| COUNTS       |               |           |         |      |        |
|              |               |           |         |      |        |
| ET PROJECT   |               |           |         |      |        |
| MANAGER      |               |           |         |      |        |
+--------------+---------------+-----------+---------+------+--------+

  -----------------------------------------------------------------------
  MSFC Problem Reporting and Corrective Action (PRACA) System

  ASSESSMENT ADDENDUM REPORT
  -----------------------------------------------------------------------

  ---------------- ------------------- ---------------- ----------- ----------- ------------
  **MSFC           **IFA#**\           **Contractor     **JSC#**\   **KSC#**\   **EICN#**\
  Report#**\       \--                 RPT#**\          \--         \--         \--
  A15773                               E-156                                    

  **Asmnt Part#**\ **Asmnt Part        **Asmnt                                  
  74L4-1           Name**\             Serial/Lot#**\                           
                   L02 LEVEL SENSOR    1649                                     

  **HCRIT CD**\    **FCRIT CD**\       **CAUSE CD**\    **FAIL                  
  \--              1R                  U - UNKNOWN      MODE**\                 
                                                        EN - OPEN               

  **Asmnt FMEA**\  **Asmnt FM**\       **FMEA CSE**\    **FMEA                  
  3.6.1.1          1                   A                SCSE**\                 
                                                        2                       

  **Asmnt FMEA**\  **Asmnt FM**\       **FMEA CSE**\    **FMEA                  
  \--              \--                 \--              SCSE**\                 
                                                        \--                     

  **Asmnt FMEA**\  **Asmnt FM**\       **FMEA CSE**\    **FMEA                  
  \--              \--                 \--              SCSE**\                 
                                                        \--                     

  **Correlated     **Correlated        **Correlated                             
  Part#**\         Part#**\            Part#**\                                 
  \--              \--                 \--                                      

  **Associated     **Associated        **Associated                             
  LRU#**\          LRU#**\             LRU#**\                                  
  \--              \--                 \--                                      

  **MAJOR DESIGN                                                                
  CHANGES**                                                                     

  **APRV DATE**\   **DESCRIPTION OF                                             
  \--              CHANGES**\                                                   
                   \--                                                          

  **ASSESSMENT                                                                  
  TEXT**                                                                        
  ---------------- ------------------- ---------------- ----------- ----------- ------------