Over the past week the station has been dedicated to an S-band scan looking for new targets and refreshing the frequency list, triggered by the recent launch of the mysterious ZUMA mission. This tends to be a semi-annual activity as it can eat up a lot of observing resources even with much of the data gathering automated the data reviewing is tedious.
Upon reviewing the data from January 20, 2018, I noticed a curve consistent with an satellite in High Earth Orbit (HEO) on 2275.905MHz, darn not ZUMA… This is not uncommon during these searches. So I set to work to identify the source.
A quick identity scan using ‘strf’ (sat tools rf) revealed the signal to come from 2000-017A, 26113, called IMAGE.
A Delta IV rocket launched the classified NROL-47 satellite from Vandenberg in California on January 12, 2018. The satellite is believed to be the 5th member of the Topaz (FIA Radar) project, radar satellites operating in 1100km altitude, 123 degree inclined retrograde orbits. Broadcast warnings for the NROL-47 launch placed the impact areas of the solid rocket motors, the first stage and the de-orbit area of the second stage at markedly different locations than with previous Topaz launches, indicating an orbital inclination around 108 degrees. Hence, it was not clear if NROL-47 is a Topaz satellite. Continue reading “NROL-47 transmits at S-band”