An Integrated Design Environment (IDE) for Small Satellites, (pdf 951 KB), Sunil Gavini
VIKSAT1 is the first in series of small satellites being designed and developed by the Center for Research in Electronics and Aerospace Technology (CREATE), with support from NASA Glenn Research Center, at Cleveland State University. Traditional small satellite design methods use a sequential and methodological approach. This includes usage of many design and simulation software packages, including tools for electronics simulation, orbit analysis, structural dynamics, and power distribution. This requires expertise in all of these software packages by the satellite design team. The result is often extended time duration for the satellite design, because one phase of the design may be dependent on other phases. A particular phase often needs some other phases to be completed so that it can use their results.
Major changes are required in the satellite design process because of increasing technology, increasing onboard processing capability, and continuing emphasis on low-cost missions. In this paper we propose a new method for satellite design and analysis. With IDE (Integrated Design Environment), satellite analysis and design is an evolving process. This is a single software package that can be used for design, integration, testing, launch and orbital operations support. It can also be used for commanding from the ground station and other purposes. The IDE incorporates a six step process in order to design and operate the spacecraft for this software
Figure 1:VIKSAT1 model figure
The research mainly involves in the creation of the IDE that unifies the software involved in each phase of satellite development. The IDE will not only allow users to design and build small satellites, but also allows for ready retrieval of information. This is a type of “knowledge capture” with which satellite design expertise can be leveraged for future small satellite design projects.
Test System Development for Spacecraft Subsystems, (pdf 11KB), Vilesh Salunkhe
This paper presents the work done in building a test board to test the individual subsystems of the small satellite VIKSAT1 currently being developed at Cleveland State University The various subsystems of the satellite include the C&DH (command and data handler), the heart of the satellite, which controls and coordinates the subsystems, and requests information about the states of the subsystems. The SPI (serial peripheral interface) protocol is used for the transfer of information within the satellite. The Test board is required, to test the subsystems functionality in the standalone mode, before assembling them on the satellite.
The test circuit uses a Microchip PIC16F877 microcontroller to simulate the C&DH by sending the same set of commands to the subsystem connected to the test board, which the C&DH would send during the actual operation of the satellite. The response from the subsystem is recorded by the test board, relayed to a PC, and verified to check whether the subsystem is functioning correctly.
The PIC16F877 operates in the following two modes:
1) USART mode, used to communicate with the ground computer. In this mode the test board simulates the transfer of data from the C&DH to the ground computer.
2) SPI mode, used to simulate the information transfer environment in the satellite.
The SPI mode allows 8 bit of data to be transmitted and received simultaneously.
The test board program is an assembly language program which can be modified to adapt the test board for each subsystem. The subsystems that are tested with the Test Board include the Command and Data Handling System, Power Subsystem, Camera subsystem, Altitude control and Determination.