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ESA’s Euclid Observatory is currently scheduled for launch at 1511 UTC on 2023 July 1. The spacecraft will take around 30 days to get to its operating orbit so this is another opportunity to image a spacecraft on its way to L2. Unfortunately, at this time of year, L2 is low down since it is opposite the Sun in the sky and I don’t have any details of the transfer orbit so I can’t currently provide an ephemeris. The last time I looked it is not on JPL Horizons. I’m hoping that this information will become available shortly after launch. The final Lissajous orbit around L2 has a radius of a million km so, from Earth, that corresponds to maximum apparent separation of 40 degrees from the anti-solar point.
Launch is on a SpaceX Falcon 9 from Cape Canaveral. It was originally planned to be on a Russian Soyuz. Unlike JWST there is only one deployable structure (the high-gain antenna) so the magnitude evolution should be relatively smooth. I would expect it to have a similar brightness to Gaia, so around mag 12 immediately after launch fading to 19 or so on station.
Euclid’s main payload is a 1.2-m aperture telescope with a 600 megapixel focal-plane array consisting of 36 CCD273-84 4Kx4K sensors made by Te2V here in Chelmsford. It will be in contact with a ground station once per day for a period of 4 hours with a downlink which supports a data rate of 75 Mbps over the 1.5 million km range. That will allow it to download around 120 GB of image data per day via ESA’s 35-m aperture deep space antennas.
More info:
https://www.euclid-ec.org/
https://arxiv.org/ftp/arxiv/papers/1610/1610.05508.pdf
https://arxiv.org/abs/2108.01201Launch on Falcon 9 looked to be perfect and acquisition of signal happened on time at the New Norcia ground station in Australia. As I write this the spacecraft is being tracked and commanded by the 35-m antenna at Cebreros, just outside of Madrid. I haven’t managed to find an ephemeris but it must be pretty close to the Moon in the sky since the shadow of the subreflector (equivalent to the Cassegrain secondary) is almost on top of the beam waveguide entrance aperture (the hole in the main dish). A live image of the antenna is here:
https://tethys.ejr-quartz.com/cebreros/cebreros.jpg
Attachments:
CelesTrak says it is lost.
https://celestrak.org/satcat/table-satcat.php?NAME=euclid&PAYLOAD=1&MAX=500NORAD ID 57209. Hopefully TLE will be available soon.
Thanks for that. ESA are tracking it and it is a shame that they haven’t publicly released any trajectory information. I’m not aware of any optical observations yet but it has been close to the Moon in the sky and it is at a far south declination. Once the Moon is out of the way I expect it will be picked up. I’ve been keeping an eye on NEOCP to see if any of the surveys get it.
ESA Ops did a small (2.1 m/s) trajectory correction the day after launch which implies that the Falcon 9 upper stage injection was very good. As far as I can tell everything is fine with the spacecraft.
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