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India launched its Chandrayaan-3 spacecraft this morning on a rather long journey to the Moon. It should arrive towards the end of August and place a rover on the lunar surface. The spacecraft is taking a low energy route to lunar orbit starting from a transfer orbit with a perigee of 170 km and an apogee of 35,000 km and raising the apogee at selected perigees until it gets enough energy to get to the Moon. The ephemeris is on JPL Horizons and the attached plot is derived from that and shows the spacecraft altitude from now until August 26. This is another opportunity to have a go at imaging a spacecraft on the way to the Moon.
ISRO will be tracking the spacecraft and lander from its main facility in India but ESA will also be providing support using its ground station at Kourou and the 32-m deep space antenna at Goonhilly in Cornwall.
https://ssd.jpl.nasa.gov/horizons/app.html#/
https://www.youtube.com/watch?v=q2ueCg9bvvQ
https://www.esa.int/Enabling_Support/Operations/ESA_ground_stations_support_Chandrayaan-3_Moon_mission
https://www.goonhilly.org/ghy-6-32m-x/s-bandAttachments:
Its clear tonight so, after 90mins on Gyulbudaghian’s, I had a bash with the 300mm Newtonian. Hadn’t noticed how fast Chandrayaan-3 was predicted to be moving. 4 arc secs per second…
Got it in 1 sec exposures. Will work out a magnitude tomorrow.First observations were through a hedge which really did not help.
I processed last nights data and got magnitudes of between 13.8-14.0 (Gaia g unfiltered) with a 0.12 mag spread – which is okay given it was initially viewed through a hedge and very low. Position errors were within the seeing disk.
Give it was moving at ~300 arc secs/min I used either 1s or 0.6s exposures. I think that was near perigee. It looks rather slower tonight.
I got it at twilight this morning after a night of comet imaging. It was on its way out to apogee at a range of 120,000 km or so.
According to Horizons it should have been at 00 10 42.42 -04 00 27.0. The attached shows it a bit northeast of that but it looks as if the Horizons ephemeris is pretty good. This is a 60s exposure so the magnitude is meaningless since the image was trailed.
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I measured it at mag 15.0 and a couple of arc minutes out of position. Think it was doing 47 arc secs / minute. Had not realised it would be so bright.
It will get harder once they stop the orbits and head for the Moon.
as seen here https://britastro.org/observations/observation.php?id=20230727_171727_a83c82388a61d48e
But this does raise an interesting question. Can/have spacecraft in lunar orbit been photographed/seen from the Earth? I recall that Lunar Orbiter (5?) was recorded, but the solar panels were tilted specifically for the occasion.
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