SOHO Recovery Updates

With D24 send/receive and D27 receiving we got many more signal spikes, some of which lasted up to 60 sec. Data modulation on the telemetry subcarrier was confirmed. However, we still have not been able to lock on the subcarrier and demodulate the signal. Efforts are being made to validate the ground system.

A test was performed using Transmitter 1 (which is connected to the +z low gain antenna). No signal was received. (Commanding through Receiver 2)

A test with carrier ON only produced spikes of the expected signal strength (-135 dbm).

A test with the previously unsuccessful switch-on procedure now was successful.

Tom van Overbeek and colleagues from the simulation section of ESA/ESTEC (TOS-EMM) have produced an MPEG animation of the time period 100-260 sec of the MMS-UK simulation of ESR7 which matches the available telemetry the best way. You can find the MPEG and some other information about the last minutes before the loss of telemetry on June 25 at: http://sohowww.nascom.nasa.gov/operations/ESR7/ or, for our European colleagues, at our mirror site at the Solar Sytem Divsion at ESTEC (SCI-SO): http://sohowww.estec.esa.nl/operations/ESR7/