baalke@mars.jpl.nasa.gov (Ron Baalke) (10/14/89)
GALILEO DAILY REPORT 13 OCTOBER 1989 General Spacecraft The spacecraft still remains in its launch ready state. A "no ops" command was sent today to reinitialize the command lost timer. Only one additional CDU (Command Detector Unit) subcarrier lock indication was obtained since the transmittal to the current time of 5:45 p.m. LCET Status remains the same; there are no problems. STS IUS: The IUS continues to make open circuit voltage checks on their flight batteries. It should be noted that they have to power up in order to perform their battery checks and in the process they check their telemetry. No problems have been reported. Atlantis: "A decision on an official launch date for Atlantis or the STS-34 mission is expected on Saturday, Oct. 14." KSC Public Affairs Office, 13 October 1989 Details Spacecraft The CDU (Command Detector Unit) subcarrier lock phenomenon is being monitored and analyzed both at JPL and KSC. At KSC, RFI (radio frequency interference) monitoring has been established for the 2115 Mhz signal emanating from a commercial carrier. Measurements have been made at the launch pad of this signal for purposes of adjusting the comparable measurements being made by the EMC/RFI KSC group in the O&C Building. The hopes are that during the occurrence of CDU lock, there would be a corresponding change in amplitude or shift in frequency of the 2115 signal that is constantly being radiated. However, the probability of such a corrolation is considered small. A preliminary search of the records for CDU subcarrier lock indications has been made for the RPM thermal conditioning test conducted at the pad on 27 September through 1 October. There have been no lock indications found to date. In addition, it must be recognized that the configuration at the pad has changed between then and now; the carry-on umbilicals have been disconnected, the payload bay doors closed, and GSE removed. Again, it must be emphasized that these tests are being performed for completeness and understanding and that there has not been a violation of the launch commit criteria. Schedule Discussion and Assessment The current schedule is still for 17 October at 12:57 p.m. EDT. There will be a mission status meeting on L-2 days on 15 October and on L-1 day on 16 October when the launch date will be firmed. Ron Baalke (818) 541-2341 Jet Propulsion Lab M/S 301-355 4800 Oak Grove Dr. Pasadena, CA 91109