SwissCube: The First Entirely-Built Swiss Student Satellite with an Earth Observation Payload

This paper presents a novel low-power imaging system for nanosatellite proximity operations. A robust independent camera module with on-board image processing, based on the ARM Cortex-M3 microcontroller and fast static random access memory, has been developed and characterized for the requirements of the ESTCube-1 mission. The imaging system, optimized for use in a single unit CubeSat, utilizes commercial off-the-shelf components and standard interfaces for a cost-effective reusable design. The resulting 43.3 mm × 22 mm × 44.2 mm (W × H × D) aluminium camera module weighs 30 g and consumes on the average of 118 mW of power, with peaks of 280 mW during image capture. Space qualification and stress tests have been performed. A detailed case study for the ESTCube-1 10 m tether deployment monitoring and Earth imaging mission is presented. For this purpose a 4.4 mm telecentric lens, 10 bit 640 × 480 pixel CMOS image sensor, 700 nm infrared cut-off filter and a 25% neutral density filter are used. The resolution of the assembled system is 12.7 mm and 1 km per pixel at distances of 10 m and 700 km, respectively. Custom on-board image evaluation and high dynamic range imaging algorithms for ESTCube-1 have been implemented and tested. Optical calibration of the assembled system has been performed.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Imaging system for nanosatellite proximity operations

Kuuste¹,

Eenmäe²,

Allik³

et al. 2014

“…Attitude Determination and Control Systems (ADCS) of CubeSats and nanosatellites have emerged from simple, mostly passive ones, to active systems that are often critical to mission success. Examples of such ADCSs are experimental sailing and de-orbiting satellites NanoSail-D [8], LightSail-1 [9], CubeSail [10], and DeorbitSail [6]; observation satellites RAX [11], UniBRITE (CanX-3A) [12], TUGSAT-1/BRITE-Austria [13], SwissCube [14], AAUSAT-II [15], Firefly [16], Aalto-1 [17], MicroMAS [18], and CHIME [19]; formation flying satellites CanX-2 [20], CanX-4, and CanX-5 [21]; and experimental attitude control satellites COMPASS-1 [22] and STRaND-1 [23]. In addition to Earth observation, Aalto-1 plans to perform high spin rate control for tether deployment and a de-orbiting experiment [24].…”

Section: Introductionmentioning

confidence: 99%

Attitude determination and control for centrifugal tether deployment on the ESTCube-1 nanosatellite

Slavinskis¹,

Kulu²,

Viru³

et al. 2014

This paper presents the design, development, and pre-launch characterization of the ESTCube-1 Attitude Determination and Control System (ADCS). The design driver for the ADCS has been the mission requirement to spin up the satellite to 360 deg·s −1 with controlled orientation of the spin axis and to acquire the angular velocity and the attitude during the scientific experiment. ESTCube-1 is a one-unit CubeSat launched on 7 May 2013, 2:06 UTC on board the Vega VV02 rocket. Its primary mission is to measure the Coulomb drag force exerted by a natural plasma stream on a charged tether and, therefore, to perform the basic proof of concept measurement and technology demonstration of electric solar wind sail technology. The attitude determination system uses three-axis magnetometers, three-axis gyroscopic sensors, and two-axis Sun sensors, a Sun sensor on each side of the satellite. While commercial off-the-shelf components are used for magnetometers and gyroscopic sensors, Sun sensors are custombuilt based on analogue one-dimensional position sensitive detectors. The attitude of the satellite is estimated on board using an Unscented Kalman Filter. An ARM 32-bit processor is used for ADCS calculations. Three electromagnetic coils are used for attitude control. The system is characterized through tests and simulations. Results include mass and power budgets, estimated uncertainties as well as attitude determination and control performance. The system fulfils all mission requirements.

“…Advances in miniaturized integrated circuit technologies have improved environmental tolerances, stability, and functionality while decreasing the size and reducing power consumption of satellites. Such satellites as RAX [3], BRITE [4], SwissCube [5], CanX-2 [6], Delfi-C3 [7], AAUSAT-II [8], AAUSAT-3 [9], and COMPASS-1 [10] have demonstrated the versatility of CubeSats for fulfilling a variety of missions. With the increasing scientific importance of CubeSat missions fault tolerance is now becoming critical.…”

Section: Introductionmentioning

confidence: 99%

Design of the fault tolerant command and data handling subsystem for ESTCube-1

Laizans¹,

Sünter²,

Zalite³

et al. 2014

This paper presents the design, implementation, and pre-launch test results of the Command and Data Handling Subsystem (CDHS) for ESTCube-1. ESTCube-1 is a one-unit CubeSat, which will perform an electric solar wind sail experiment. The development process of the CDHS for ESTCube-1 was focused on robustness and fault tolerance. A combination of hot and cold hardware redundancy was implemented. Software, including a custom-written internal communications protocol, was designed to increase the system's fault tolerance further by providing fault detection and fall-back procedures. Tests were carried out to validate the implementation's performance and physical endurance. The final CDHS design is operational within the set requirements. Tests that verify fault tolerance of the system in orbit are suggested.