On-Board Computer for Twin Nano Satellite Mission - STUDSAT-2A/2B

Paper number

IAC-13,D1,4,11,x19184

Author

Mr. Bheema Rajulu, N.M.I.T. Bangalore, India

Coauthor

Prof. Sankar Dasiga, N.M.I.T. Bangalore, India

Coauthor

Prof. Basavarajaiah s, SIT, Tumkur, India

Coauthor

Mr. Yathin S K, NMAMIT Mangalore, India

Coauthor

Mr. Shivaprasad Kamath, NMAMIT Mangalore, India

Coauthor

Mr. Vikhyath Kumar, NMAMIT Mangalore, India

Coauthor

Ms. Shruthi Nagabhushana, N.M.I.T. Bangalore, India

Coauthor

Mr. Nakul Rao, N.M.A.M.I.T, Nitte, India

Coauthor

Mr. Nischal Rao, N.M.A.M.I.T, Nitte, India

Year

2013

Abstract

STUDSAT-2 is a STUdent SATellite program which aims to build Nano Twin satellites each weighing approx. 10 kg with the dimensions of 30 x 30 x 20 cm3 with an objective of demonstrating Inter-Satellite Communication for the purpose of improving temporal resolution for remote sensing applications. Payload, Attitude determination and control systems, Electronic power system, Command and data handling, Inter Satellite link, Structure, Communication are the major subsystems involved in STUDSAT-2. OBC is the brain of satellite.
The On Board Computer (OBC) for STUDSAT-2 is ARM based Cortex –M4 microcontroller with DSP and FPU instructions combined to 168 MHz performance. This paper elaborates the performance and the features of the chosen processor with Functional, Operational and Interface Requirements & protocols. The overall system architecture and requirements of the subsystems is accomplished by the low cost real-time operating system (RTOS) which support various types of peripheral interfaces, telemetry storage and data processing. The various peripherals for the C&DH system consist of a set of memories, a microcontroller supervisor IC and temperature sensors at various locations of the satellite. Three different types of memories are used for different applications. For storing and retrieving the OS code in case of malfunction a radiation resistant Read Only Memory is used. A Read/Write Non-Volatile Radiation Resistant Memory is used for storing the telemetry data. And for storing the images from the CMOS image sensor a fast and lard read/write memory is used. The controller will be supervised by a watchdog timer to catch runaway programs by resetting the controller. 
Our idea of making socket connection that connects the entire sub modules of the satellite is presented in this paper. This socket could contain all I/O ports from the processor, different power lines etc.The I/O Board provides serial peripheral interface (SPI), I2C, USART, ADC etc. to communicate with submodules of other sub-systems.The DCMI is used to interface the payload and collect the science data.

Abstract document

IAC-13,D1,4,11,x19184.brief.pdf

Manuscript document

(absent)