Just spoke with ATV ground segment engineer Fabio Sintoni: today, teams at ATV-CC and Kourou will conduct the first live test of the vessel’s space-to-ground radio link.
He says the test is interesting as it involves rotating and pointing the 15m dish antenna of ESA’s Kourou tracking station at the vertical assembly building (BAF) at Kourou, which currently houses ATV on top of Ariane 5. The antenna and BAF are separated by just a few kilometres (as you can see in this image from the 2009 launch of Herschel/Planck), so engineers will be able to conduct a real, ‘over-the-air’ test of the radio link between the two.
Once in orbit, the link is used as a backup and enables ATV to communicate directly to ESA ground stations located at Maspalomas and Villafrance, Spain, and Redu, Belgium. Today’s test gets underway at 16:00 CET.
More info on Kourou station via ESA’s ESTRACK pages
Discussion: 3 comments
This is not only a backup to the space-to-ground link, but primarily the nominal link for proximity communications betwenn the ATV and the ISS !!
Nicfit, you are right. The primary use of the proximity link is communication with the ISS service module (SM) during docking. However the transponder on board and the ESA ground stations have been reconfigured to enable commanding ATV JK from ground. This is a new feature offered by ATV JK and by the ATV ground segment now includes several ESA ground stations (Maspalomas, Villafranca and Redu).
This is why this test is called ‘back-up’. Later on, you will be able to read more technical details on this new use of the Proximity Transponder. Cheers!
Hi Nicfit: You are correct – the main use of the transponder – the transmitter/receiver on board ATV – is for direct ISS<-->ATV ‘proximity’ communications. As Fabio mentioned, we will post an update in the blog as soon as we can on how the proximity link was redeveloped into a ‘back-up’ space-to-ground link. Thanks for visiting the blog! — Daniel