NTSB · Safety Recommendation
Safety Recommendation A-93-101
Recommendation
THE NTSB RECOMMENDS THAT THE ORBITAL SCIENCES CORPORATION: REQUIRE, AS PART OF ELV LAUNCH PLANNING DOCUMENTATION: A COMMUNICATIONS PLAN THAT WOULD INCLUDE, AT A MINIMUM: A PROVISION THAT INTERPHONE OR OTHER COMMUNICATION ASSIGNMENTS BE APPORTIONED TO ALLOW DECISION MAKERS FROM EACH PARTY DIRECT ACCESS TO THE DECISION MAKERS OF OTHER PARTIES AND THE PROPER RADIO-TELEPHONE COMMUNICATION PHRASEOLOGY ARE USED, AND A PROVISION THAT KEY PARTICIPANTS IN THE LAUNCH MONITOR A COMMON INTERCOM CHANNEL AT AN ESTABLISHED POINT IN THE COUNTDOWN AND THAT THESE PARTICIPANTS CONTINUE TO MONITOR THIS CHANNEL DURING THE FINAL COUNTDOWN SEQUENCE AND AFTER LAUNCH.
Safety Issue and Context
ON FEBRUARY 9, 1993, ABOUT 0930 EASTERN STANDARD TIME, THE LAUNCH SEQUENCE FOR AN ORBITAL SCIENCES CORPORATION (OSC) PEGASUS EXPENDABLE LAUNCH VEHICLE (ELV) WAS ABORTED BY THE NATIONAL AERONAUTICS AND SPACE ADMINISTRATION (NASA) RANGE SAFETY OFFICERS, IN ACCORDANCE WITH A PREVIOUSLY ESTABLISHED LAUNCH CONSTRAINT. SEVERAL SECONDS LATER, THE LAUNCH SEQUENCE WAS REINITIATED BY THE OSC TEST CONDUCTOR, AND THE MISSILE SEPARATED UNEVENTFULLY FROM ITS CARRIER AIRCRAFT. THE IGNITION AND STAGING OF THE PEGASUS AND ITS SUBSEQUENT DEPLOYMENT OF TWO SATELLITES INTO LOW EARTH ORBIT WERE ALSO UNEVENTFUL. THERE WERE NO INJURIES TO PERSONNEL INVOLVED IN THE MISSION AND NO DAMAGE TO MISSION ASSETS.
Response History
May 9, 1994 · NTSB Correspondence · Orbital Sciences Corporation
THE BOARD NOTES THAT THE OSC HAS REVISED THE MCD TO REQUIRE APPROPRIATE COMMUNICATIONS PROTOCOL. ADDITIONALLY, IT IMPLEMENTED A DIRECT UHF VOICE LINK BETWEEN THE B-52 CARRIER AIRCRAFT PILOT & THE WESTERN RANGE CONTROL OFFICER & RANGE SAFETY OFFICER THAT PERMITS A VERY RAPID RESPONSE CAPABILITY TO CONVEY INSTRUCTIONS TO THE CARRIER AIRCRAFT. THE OSC HAS CLARIFIED & DOCUMENTED IN THE MCD THE VARIOUS COMMUNICATIONS NET ASSIGNMENTS TO INDICATE FUNCTION & USERS FOR EACH OF THE LAUNCH OPERATION NETS. THE TEST CONDUCTOR NET WAS DESIGNATED THE "LAUNCH NET" FOR COMMUNICATIONS & MONITORING AMONG ALL KEY PARTICIPANTS.
THE BOARD FURTHER NOTES THAT THE OSC HAS REVISED THE COMMUNICATIONS PROTOCOL & PHRASEOLOGY USED TO CALL A NO-GO CONDITION. SPECIFIC TERMINOLOGY WAS DEFINED TO ADDRESS A NO-GO CONDITION BEFORE THE "TERMINAL COUNT" (BEGINNING AT L-7 MINUTES) & MADE DISTINCT FROM AN ABORT CALL AFTER THE START OF THE "TERMINAL COUNT." BASED ON THIS INFO, THE BOARD CLASSIFIES A-93-101 "CLOSED--ACCEPTABLE ACTION."