6th Huygens checkout on 28 July
27 July 2000
The 6th Huygens in-flight checkout will be executed on Friday 28 July from 16:00 GMT to 20:00 GMT.The Huygens activities will be carried out while Cassini will be in view of the Goldstone Deep Space Antenna.The Huygens telemetry data will be routed via the Jet Propulsion Laboratory, Pasadena, California, to the Huygens Probe Operations Centre (HPOC) at ESOC, Darmstadt, Germany. Arrival of the first data in HPOC is expected at around 17:00 GMT (19:00 Local Time).Like the previous checkout, this one will also be performed while Cassini's High Gain Antenna (HGA) is pointed at Earth. The Sun will be at about 10 deg. away from the axis of the HGA, well outside its main lobe. This is illustrated by the image provided by JPL Solar System Simulator, accessible at http://www.jpl.nasa.gov/cassini/today. The attached image shows the position of 25 July 2000, which will not be very different on 28 July 2000.
Only a small amount of radio noise is expected to be picked up from the Sun, therefore the radio environment should be excellent for another calibration point of the Huygens receivers.
Since Cassini's HGA is nominally pointed at the Earth, Huygens large heatshield helps the HGA to shadow the rest of the spacecraft. The probe temperatures are continuously monitored by the Orbiter when the Probe is sleeping. A summary of the Probe temperature since early February is shown in the second figure.
The temperature of the batteries is currently about 12 °C, which is well within the range acceptable before executing a checkout. The battery temperatures are expected to increase by about 20-22 °C during a checkout, which will bring them to < 35 °C, well within the acceptable upper limit of 45 °C.
