Huygens Probe wake-up call tonight at 21:00 UTC
21 March 2001The 7th regular in-flight Huygens Probe checkout is scheduled to take place tonight at 21:00 UTC. The purpose of these regular in-flight checkouts is to verify the good health of the Probe and of its scientific payload.
Checkouts are not affected by the radio receiver problem that was discovered last year, and which is currently under investigation. In early April, the Huygens Recovery Task Force will identify the various recovery scenarios that will be studied in detail in the time frame April-June 2001.
Two weeks ago, the sequence of commands to execute the checkout was loaded into the Cassini Orbiter computer memory. It is programmed to be activated precisely at 21:00 UTC. The checkout data (about 300 Mbits) will be transmitted in real time by Cassini to NASA's Deep Space Network Goldstone station. Cassini/Huygens is now 875 million kilometers away from Earth. Radio signals travelling at 300 000 km/s, will take about 48 minutes to reach Earth! From Goldstone, the signals are routed to NASA's Jet Propulsion Laboratory, where the Probe data are extracted and then transmitted to the Huygens Probe Control Centre at ESOC, Darmstadt. Once all data are received at ESOC, the Huygens team will split the data into various subsets and distribute them to each instrument team for a quick analysis. For the Surface Science Package (SSP) team it is a significant moment as it is the first time it will receive and process the SSP data in their new home institute, the Open University in Milton Keynes, UK, where they recently moved to from the University of Kent.