{"id":2330,"date":"2020-08-01T01:01:00","date_gmt":"2020-08-01T01:01:00","guid":{"rendered":"https:\/\/library.iiap.res.in\/collaborate\/?p=2330"},"modified":"2025-06-09T07:15:03","modified_gmt":"2025-06-09T07:15:03","slug":"first-light-with-uvit-payload-on-astrosat","status":"publish","type":"post","link":"https:\/\/library.iiap.res.in\/collaborate\/?p=2330","title":{"rendered":"First Light with UVIT Payload on ASTROSAT"},"content":{"rendered":"\n

Amit Kumar<\/strong><\/p>\n\n\n

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Image credit: Indian Space Research Organisation (ISRO)<\/em><\/figcaption><\/figure><\/div>\n\n\n

I would like to share the heart holding experience of my first Space Project, UVIT on ASTROSAT. It was 30th November 2015. We had finished all the major checks on UVIT payload when its doors were closed. Just to remind the readers, ASTROSAT was launched on 29th September 2015 from ISRO space centre in Sriharikota(SHAR). Since then, the UVIT team had been engaged with the on-board checks of the payload, along with the Mission Operation team at ISTRAC-ISRO. It was quite tiring and full-of-patience work to check an instrument on-board and it becomes more critical when it comes in line-of-sight connection with the ground station only for 10 minutes in an orbit of 90 minutes. We used to prepare commands during the Spacecraft invisible period, verify it 2-3 times; and then clear it for upload in the next visible period of the spacecraft and verify the operation in the next orbit when we receive the data. This process was continued for 2 months. Generally, the UVIT operations used to happen in the eclipse part of the orbit and it used to be in the evening at Bangalore with the line-of-sight of connectivity. <\/p>\n\n\n\n

During the daytime on 30th<\/sup> November, the FUV and NUV doors opened in orbit numbers 935 and 936 respectively. Now, the UVIT and the team was ready to do its first ever on-board observation. The spacecraft was maneuvered to the source NGC 188 and all the command codes with required filter position were made ready. It was evening around 6:30 PM and the spacecraft was in orbit 938. As soon as the spacecraft came into visibility, the commands were uploaded, as it was visible only for 10-15 mins. Only a short observation was planned only for the VIS channel of UVIT (UVIT has 3 imaging channels; FUV, NUV and VIS).<\/p>\n\n\n\n

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\u201c…it was a moment of satisfaction and self-pride. My eyes were filled with tears…\u201d<\/strong><\/p>\n<\/blockquote>\n\n\n\n

Even if all the care was taken in command verification, the filter wheel of the VIS channel was positioned at the wrong place during the first observation. I was sitting on a terminal to verify the telemetry of the VIS channel and I noticed this wrong filter position and in excitement, I had commanded the operation team at MOX-ISRO for the movement of the filter wheel to the required position.\u00a0 In this process, the FW started rotating and because of a bright source in the Field of View, the on-board Bright Object Detector (BOD) logic of UVIT got triggered and it went to Power OFF state immediately. It was a big setback for the team and the problem identification started immediately. We narrowed down that filter wheel position and the image parameter set for VIS, to be changed, and we could start again in the next orbit.<\/p>\n\n\n\n

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With all precautions in place, we started with the same excitement again, but with little fear in heart. It was in orbit 939 of the spacecraft and all the commands were uploaded again. This time around, all the things went alright. Filter was positioned correctly and observation continued as planned. In this orbit, we were able to download the science data of the previous orbit 938. After having a quick look at the image of VIS, a big bright patch on the screen confirmed a BOD.\u00a0<\/p>\n\n\n\n

Now, everyone was waiting for the next orbit 940 to download the science data of the previous orbit 939, so that we could complete the first observation of UVIT. It was around 11:00 pm and the team was very curious and waiting for a quick look at the image with fingers crossed. As soon as the data download started and a quick look image appeared on the big screen at MOX, the whole team entered a big moment of joy and happiness after seeing the NGC 188 observed with UVIT. For me, as I was involved more in electronics hardware integration and testing till its on-board operation, it was a moment of satisfaction and self-pride. My eyes were filled with tears after seeing the first image. I was sitting on the console and wishes started pouring from all around. Then ISRO Chairman Dr Kiran Kumar also called the UVIT PM Prof. S N Tandon and congratulated the whole team.<\/p>\n<\/div>\n\n\n\n

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Image credit: Indian Space
Research Organisation (ISRO)<\/em><\/figcaption><\/figure><\/div><\/div>\n<\/div>\n\n\n\n

About the author<\/strong>
Amit Kumar<\/strong> is an engineer-E at IIA, who was associated with the ASTROSAT project.<\/p>\n\n\n\n

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<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Amit Kumar I would like to share the heart holding experience of my first Space Project, UVIT on ASTROSAT. It was 30th November 2015. We had finished all the major checks on UVIT payload when its doors were closed. Just to remind the readers, ASTROSAT was launched on 29th September 2015 from ISRO space centre…<\/p>\n","protected":false},"author":5,"featured_media":2339,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false},"categories":[24,18],"tags":[95],"_links":{"self":[{"href":"https:\/\/library.iiap.res.in\/collaborate\/index.php?rest_route=\/wp\/v2\/posts\/2330"}],"collection":[{"href":"https:\/\/library.iiap.res.in\/collaborate\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/library.iiap.res.in\/collaborate\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/library.iiap.res.in\/collaborate\/index.php?rest_route=\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/library.iiap.res.in\/collaborate\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2330"}],"version-history":[{"count":8,"href":"https:\/\/library.iiap.res.in\/collaborate\/index.php?rest_route=\/wp\/v2\/posts\/2330\/revisions"}],"predecessor-version":[{"id":3207,"href":"https:\/\/library.iiap.res.in\/collaborate\/index.php?rest_route=\/wp\/v2\/posts\/2330\/revisions\/3207"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/library.iiap.res.in\/collaborate\/index.php?rest_route=\/wp\/v2\/media\/2339"}],"wp:attachment":[{"href":"https:\/\/library.iiap.res.in\/collaborate\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2330"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/library.iiap.res.in\/collaborate\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2330"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/library.iiap.res.in\/collaborate\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2330"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}