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Unmanned Spaceflight.com _ ExoMars Program _ TGO in orbit

Posted by: Habukaz Nov 2 2016, 05:18 PM

The latest and greatest on the plans for the CaSSIS imaging instrument:

QUOTE

After ExoMars TGO has reached its Mars Capture Orbit, the intention is to switch on CaSSIS in the week from November 21 to 28 and acquire images of Mars for the first time. A media release is planned on 1 December 2016 when ESA’s Ministerial Council is being held in Lucerne.

[...]

The highly elliptical orbit is not ideal. When we approach Mars, the orbital speed is much higher than in our science orbit and the timing will be difficult to get right. Our aim is to get something – we do our best – and learn from what we get.

[...]

When should the image be acquired, do we have enough time to rotate the instrument to get the 2nd half of a stereo pair, do we have enough time to get the data out of the instrument before the next image should be acquired? That planning process costs a lot of time and we don’t have many people to help do it. The hard part in MCO is that the speed over the surface at periapsis is much quicker than in the circular orbit so there is a good chance to mess it up.

http://nccr-planets.ch/getting-ready-tricky-task/

Posted by: Habukaz Nov 18 2016, 12:22 PM

First images should be from the Noctis Labyrinthus region (western edge of Valles Marineris) and (ideally) form a stereo observation.

QUOTE

There are no specific imaging targets in mind, although near the closest approach of the first orbit the orbiter will be flying over the Noctis Labyrinthus region and it will attempt to obtain a stereo pair. In the second orbit, it has the opportunity to capture images of Phobos.

http://www.esa.int/Our_Activities/Space_Science/ExoMars/ESA_s_new_Mars_orbiter_prepares_for_first_science

Some details on what the other instruments will be doing in the link.

Posted by: mcaplinger Nov 29 2016, 02:24 PM

First images: http://www.esa.int/Our_Activities/Space_Science/ExoMars/First_views_of_Mars_show_potential_for_ESA_s_new_orbiter

Posted by: Habukaz Feb 21 2018, 10:31 AM

http://www.esa.int/Our_Activities/Operations/Surfing_complete

Instrument testing starts mid-March, routine science observations around 21 April.

QUOTE

The initial phases of science gathering, in mid-March, will be devoted to checking out the instruments and conducting preliminary observations for calibration and validation. The start of routine science observations should happen around 21 April.

“Then, the craft will be reoriented to keep its camera pointing downwards and its spectrometers towards the Sun, so as to observe the Mars atmosphere, and we can finally begin the long-awaited science phase of the mission,” says Håkan Svedhem, ESA’s project scientist.

Posted by: PaulH51 Apr 26 2018, 08:25 PM

QUOTE (Habukaz @ Feb 21 2018, 06:31 PM)

http://www.esa.int/Our_Activities/Operations/Surfing_complete

Instrument testing starts mid-March, routine science observations around 21 April.

TGO returns its first images from its new orbit: http://www.esa.int/Our_Activities/Space_Science/ExoMars/ExoMars_returns_first_images_from_new_orbit

Posted by: antipode Apr 26 2018, 11:56 PM

Wow! If that's anything like what we will see in future i cant wait.

P

Posted by: wildespace May 6 2018, 06:28 AM

QUOTE (PaulH51 @ Apr 26 2018, 09:25 PM)

TGO returns its first images from its new orbit: http://www.esa.int/Our_Activities/Space_Science/ExoMars/ExoMars_returns_first_images_from_new_orbit

Any information on what filters were used for this image? It looks similar to MRO's IRB images (with telltale blues and yellows).

Is there a HiRISE coverage of this area?

P.S. If the image is indeed IRB, here's my attempt at reshuffling colour channels to imitate RGB:

http://ibb.co/d3r1tn

I assigned the green channel to red, blue to blue, and the average between the two to green, with some hue balancing to move the resulting orange and cyan to red and blue respectively.

Posted by: Phil Stooke Jun 29 2018, 06:32 AM

Need a TGO-CASSIS image fix? There are 5 here:

http://www.esa.int/Our_Activities/Space_Science/ExoMars/Highlights/Postcards_from_Mars

Phil

Posted by: bobik Sep 13 2019, 09:28 AM

https://cassis.oapd.inaf.it/archive/

Posted by: bobik Oct 10 2019, 06:24 AM

At the Tenth Moscow Solar System Symposium project scientist Håkan Svedhem https://www.youtube.com/watch?v=RfQ6eAuUz5w&t=6h56m25s that CaSSIS had run into problems with its rotation mechanism. Higher than normal https://www.youtube.com/watch?v=RfQ6eAuUz5w&t=7h02m05s had led to a suspension of its operation with tests of a new rotation method are going to begin in mid-October. No direct indication in the talk if there are any lasting implications on the stereo imaging capability of the camera.

Posted by: Sean Oct 10 2019, 02:41 PM

QUOTE (bobik @ Sep 13 2019, 10:28 AM)

https://cassis.oapd.inaf.it/archive/

Everything except one item is locked until April 2020.

Posted by: bobik Apr 19 2020, 08:10 AM

During the last https://mepag.jpl.nasa.gov/meetings.cfm?expand=m38 it was said that there has been a recent malfunction of the ACS TIRVIM channel on ExoMars TGO. The cryocooler is no longer able to bring the https://mepag.jpl.nasa.gov/meeting/2020-04/Day3/02_ExoMars%20Status%2017apr20_post.pdf#page=2. There is no detailed treatment in the presentation materials what this actually means for the further operation of the TIRVIM channel in particular or the science operations in general; besides, that it was mainly used for a general characterization of the martian atmosphere, nor possible root causes of the technical problem are mentioned (A dedicated press release would be desirable). The https://mipt.ru/dasr/upload/ispavr/Korablev__Three_IR_spectrometrs_JARS_8_1_084983_2014.pdf#page=9 had two cooled detectors and one redundant pyroelectric detector working at ambient temperature. Because of mass constraints, https://link.springer.com/content/pdf/10.1007/s11214-017-0437-6.pdf#page=23, one of the two cooled detectors and the redundant pyroelectric detector had to be cancelled. That is unfortunate, indeed. The cryocooler is a https://www.ricor.com/products/k508/ Stirling cycle cryogenic refrigerator adapted for operation in space, similar cryocoolers were also used in the https://link.springer.com/content/pdf/10.1007/s11214-017-0437-6.pdf#page=18 and https://orbi.uliege.be/bitstream/2268/228584/1/Neefs_15.pdf#page=13 on ExoMars TGO, as well as highly successfully in https://www.ricor.com/overview-of-ricor-tactical-cryogenic-refrigerators-for-space-missions/.

Posted by: bobik Aug 26 2020, 07:15 AM

It is noticeable that https://cassis.oapd.inaf.it/archive/cassis/searchdtm.php?data_set_id=&dtmversion=&latitude=&longitude=&distance=&date_from=&date_to=&page=162 into the Cassis DTM Repository became very sporadic over the last year. If this is related to the problems with the CaSSIS rotation mechanism is impossible to say without any "official" acknowledgment of the problem, let alone its solution.

Posted by: MahFL Feb 11 2021, 04:27 PM

New gas found in Mars's atmosphere.

https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Exploration/ExoMars/ExoMars_discovers_new_gas_and_traces_water_loss_on_Mars

Posted by: bobik May 13 2022, 03:13 PM

An intriguing https://www.illustre.ch/magazine/cassis-lappareil-suisse-qui-photographie-la-planete-mars why so few CaSSIS stereo pairs are made (#13), not rotation mechanism bearing problems (#10) but rather the stereo-mode is relatively power-intensive, thus only used sparingly in order to save the batteries... True or not, this issue apparently did not exist before mid-March 2019.

Posted by: bobik May 10 2023, 04:58 PM

A recent https://www.sciencedirect.com/science/article/pii/S0032063323000661 (full text available) on CaSSIS science planning contains some info about the rotation mechanism problems (http://www.unmannedspaceflight.com/index.php?showtopic=8249&view=findpost&p=245826) and especially about the consequences for science operations:

QUOTE

Another important event that triggered software changes at all levels were the motor issues CaSSIS experienced at the start of 2019. Although CaSSIS did recover part of the motor movement, at the time of writing the first 100 degrees of the full 360° rotation are not being used. Also the motor is being moved less frequently, with the end result that more images are acquired with a fixed motor position. In order to minimize the impact on the science, the tools were updated to take into account this fixed motor position. The CaSSIS team then identifies on a weekly basis a motor position that allows acquisition of many targets with a maximum of 20° misalignment with the spacecraft ground track. This provides almost full overlap of the colours in the CaSSIS focal plane so that colour imaging is efficient.

The tools were also updated to allow for stereo images and aligned single images that use the motor on an individual basis. As the CaSSIS teams has gained confidence the number of images allowed with these methods has been slowly increased to the point that is almost indistinguishable from the operations before the motor issues.

Posted by: volcanopele May 10 2023, 07:41 PM

Yep, we are taking 5 stereo images per week to help reduce wear and tear on the motor mechanism. We are also taking up to 30 "aligned" images, where the motor is rotated to align with the image groundtrack. Otherwise a fixed motor position is used.