In the depths of space, the Mars Webcam is active. It was developed by Belgium-based Caeleste, a specialist in bespoke sensors. Bart Dierickx, CTO and founder of Caeleste and Dirk Uwaerts project manager and partner at Caeleste share their insight of the project with Caeleste sales and marketing officer Lotte De Kam.
Q: Bart, Dirk, it was recently brought to our attention that the VMC (visual monitoring camera) – the Mars Webcam – has become the most popular planetary orbiting instrument amongst amateur astronomers, students and teachers. I believe that you were the designers of this instrument.
Dirk: The objective was to design, develop and test a novel micro camera chip, to be used as a miniature monitoring camera for space applications. Compact and with as few components as possible.
Bart: The design was fully CMOS technology and allowed for an easy combination of control logic, ADC, interfaces and image compression circuitry. The “Mars Webcam” is based on the IRIS-1 image sensor (Integrated Radiation-tolerant Imaging System).
Q: What was the origin of this camera? Why was it created?
Bart: It all started in 1997 with its predecessor the “VTS” – the Visual Telemetry System. After the debacle of the Ariane 501 launch in 1996, ESA commissioned a “little” monitoring camera for the on-board observation of spacecraft activities.
Dirk: We were part of the project as project supervisor and designer and had to create in a few months the first CMOS camera ever used in space missions. The VTS was based on the logarithmic Fuga15d and mounted on the ESA launch vehicle Ariane 502.
Q: Hence the successor of this project was the Visual Monitoring Camera (VCM) IRIS-1?
Bart: After the VTS, the successor was developed, the “VMC”. It uses the IRIS-1 colour or black and white camera chip and has direct interfacing to the spacecraft’s telemetry system, not requiring a bulky camera master unit.
Dirk: VMC cameras have been used successfully on the XMM and Cluster II (space missions by ESA), to verify spacecraft separation and solar panel deployment.
Bart: The VCM on the actual Mars Express that took off in June 2003 during Europe’s first Mars expedition, was used to monitor the separation of the Beagle 2 lander. The Beagle dramatically failed, but the Mars Express with the IRIS-1 VCM is still in orbit and alive and is re-baptised the “Mars Webcam”.
Q: For this reason, the VMC is not just an ordinary camera in an extraordinary place? What are the unique features of the design?
Bart: The IRIS Pixel used the “high fill factor patent”. It allowed for extraordinary high light sensitivity.
Dirk: The challenges were particularly interesting for this project. CMOS imagers were immature and there was sparse knowledge on radiation tolerance of CMOS imagers in space. It is still operational today – not really bad…
Bart: We are most challenged by projects that have never been done before and to see how far we can go.
Q: As far as Mars apparently?
Dirk: To create a Mars “Webcam” was never the intention, but it is nice the know that our baby is space legacy today.
*Bart and Dirk started the development of the VMC with Imec and FillFactory. Also involved in the realisation of the VMC were Werner Ogiers (now at AMS) and Guy Meynants (now KULeuven) and the company OIP in Oudenaarde.
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