Solutions

Miniature Camera Development

Several missions in the past, notably TeamSat (1997), XMM (1999), and Cluster II (2000) have demonstrated on-board cameras for visual feedback of spacecraft-launcher separation or antenna deployment. Each of these camera examples were ad-hoc designs, using off-the-shelf components, typically industrial vision CMOS active pixel sensors and fairly small rad-tolerant FPGAs. In addition to their one-off nature, these cameras were somewhat restrained in operation by the S/C’s OBDH (On Board Data Handling) system or the interface thereto.

The VTS camera on TeamSat lacked image memory and thus the S/C computer had to directly read out the pixel array. Even with a tailored RS422 serial data interface of 3.125Mb/s this limited the system frame rate to just one image per second.

The VMC cameras on XMM and Cluster II offered spacecraft interface compatibility through their TTCB-01 serial links running at 100kb/s or less. The XMM cameras had internal storage for one image, the Cluster camera had an external add-on memory box, the XMXU, offering in-line storage for about 10 images. In both cases the acquisition time for one image was 200ms.The IRIS3 single-chip camera, aimed to overcome some of the limitations of older systems, offering more functionality and portability, higher electro-optical performance and yet lower impact on existing S/C architectures.

The IRIS1 chip VMC cameras were based on a “linear” concept, the IRIS3 chips allowed to have limited number of PCBs, which could be fitted in “flat” concept.

Flat VMC Design

The IRIS3 is a single-chip camera for visual monitoring from spacecraft in flight. This 1024 x 768 pixel imager has all interface and control logic on chip, and is capable of directly addressing up to 64 megawords of off-chip memory for image storage.

Main features:

• 10-bit ADC
• On-chip interface & control logic
• On-chip SDRAM controller
• Radiation tolerant

The objective is composed of 4 lenses, all with antireflection coating and made of radiation resistant glass. Dedicated aluminum mechanical housing design by OIP to fit the power supply module and Main camera module.

Keywords

Solution: Camera

Type: Monitoring (flat configuration)

Application field: Monitoring

Mission: Demonstrator

Life: Demonstrator delivered. Project completed.