Hi all, In cooperation with ISISpace in Delft, who built the satellite, I made a rather unique observation last night (27 August): the LED beacon of a 6U cubesat, NAPA-2 (2021-059CN)! NAPA-2, launched as part of the Transporter 2 rideshare mission on 30 June, is a 6U cubesat in a 520 x 540 km orbit sun-synchronous orbit, built for the Royal Thai Air Force. It carries two Earth observation cameras. It also carries an experimental LED beacon (consisting of 12 bright LED's). It is an experiment to see whether such a beacon can aid in optical tracking of cubesats. Over the past week I made 3 attempts to image the beacon, in coordination with ISISpace who provided me with information on which passes the beacon was active. They also adjusted the beacon's blink rate to facilitate it being "on" at least once while passing through the FOV of my camera, and made sure that the satellite's attitude was such that the beacon pointed into the direction of Delft and Leiden. The first attempt was negative, the second marginally positive only, the third attempt (with a larger lens) 100% positive. The beacon was imaged for two seconds last night and the moment it temporarily switched off was captured (the beacon was in a "3-seconds-on, 1-second-off" mode). The beacon was faint (fainter than expected), with an R magnitude of about +10.2. It was faintly but unambiguously visible in the imagery, taken at 25 fr/s with a WATEC 902H2 Supreme fitted with a Samyang 2.0/135 mm lens. Video: https://vimeo.com/593285105 More imagery (framestacks) and a more elaborate report: https://sattrackcam.blogspot.com/2021/08/first-positive-observations-of-led.html You can see the LED's switch off when the satellite is about in the center of the FOV. Astrometry: 48963 21 059CN 4353 G 20210827005238401 56 75 0235083+485754 16 S 48963 21 059CN 4353 G 20210827005238441 56 75 0235104+485902 16 S 48963 21 059CN 4353 G 20210827005238600 56 75 0235245+487058 16 S 48963 21 059CN 4353 G 20210827005238920 56 75 0235548+489288 16 S 48963 21 059CN 4353 G 20210827005238960 56 75 0235559+489369 16 S 48963 21 059CN 4353 G 20210827005239241 56 75 0236219+491484 16 S 48963 21 059CN 4353 G 20210827005239561 56 75 0236505+493724 16 S 48963 21 059CN 4353 G 20210827005239600 56 75 0236520+493851 16 S 48963 21 059CN 4353 G 20210827005239761 56 75 0237107+495137 16 S 48963 21 059CN 4353 G 20210827005239801 56 75 0237095+495331 16 S ----------------------------------------------------------------------------- WATEC 902H2 Supreme + Samyang 2.0/135 mm + GPS time-inserter + TANGRA What these numbers mean: http://www.satobs.org/position/IODformat.html ----------------------------------------------------------------------------- Residuals w.r.t. elset 21239.30175625: STA YYday HH:MM:SS.sss AZ EL XTRK deltaT Perr ( 1) 4353 21239 00:52:38.401 78.0 60.9 -0.02 0.02 0.023 ( 2) 4353 21239 00:52:38.441 77.9 60.9 -0.02 0.04 0.033 ( 3) 4353 21239 00:52:38.600 77.7 60.9 -0.02 0.03 0.030 ( 4) 4353 21239 00:52:38.920 77.2 61.0 -0.02 0.03 0.025 ( 5) 4353 21239 00:52:38.960 77.2 61.0 -0.02 0.06 0.044 ( 6) 4353 21239 00:52:39.241 76.7 61.0 -0.02 0.03 0.031 ( 7) 4353 21239 00:52:39.561 76.2 61.0 -0.02 0.03 0.031 ( 8) 4353 21239 00:52:39.600 76.2 61.0 -0.02 0.05 0.044 ( 9) 4353 21239 00:52:39.761 75.9 61.0 -0.02 0.03 0.025 (10) 4353 21239 00:52:39.801 75.9 61.0 -0.03 0.04 0.041 rms 0.03367 At the time of my observation, the satellite was at a range of 598 km, at a sky elevation of 62 degrees. It was still in earth shadow at that time, so all the light visible in the video came from the 12 LED's! Amazing that LED's on a cubesat at almost 600 km can be imaged! The LED beacon is not continuously operational: it will only occasionally be switched on for a few minutes on certain passes, while in reach of a tracking station. - Marco ----- Dr Marco Langbroek - SatTrackCam Leiden, the Netherlands. e-mail: sattrackcam_at_langbroek.org Cospar 4353 (Leiden): 52.15412 N, 4.49081 E (WGS84), +0 m ASL Cospar 4355 (Cronesteyn): 52.13878 N, 4.49937 E (WGS84), -2 m ASL Station (b)log: http://sattrackcam.blogspot.com Twitter: _at_Marco_Langbroek ----- _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-lReceived on Fri Aug 27 2021 - 17:59:16 UTC
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