A LOCAL-NETWORK INTEGRATED INTO A BALLOON-BORNE APPARATUS

A local network is incorporated into an apparatus for a balloon-borne experiment. A balloon-borne system implemented in the apparatus is com posed of subsystems interconnected through a local network, which intr oduces modular architecture into the system. The network decomposes th e balloon-borne system into subsystems, which are similarly structured from the point of view that the systems is kept under the control of a ground station. The subsystem is functionally self-contained and ele ctrically independent. A computer is integrated into a subsystem, keep ing the subsystem under the control. An independent group of batteries . being dedicated to a subsystem, supplies the whole electricity of th e subsystem. The subsystem could be turned on and off independently of the other subsystems. So communication among the subsystems needs to be based on such a protocol that could guarantee the independence of t he individual subsystems. An Omninet protocol is employed to network t he subsystems. A ground station sends commands to the balloon-borne sy stem. The command is received and executed at the system, then results of the execution are returned to the ground station. Various commands are available so that the system borne on a balloon could be controll ed and monitored remotely from the ground station. A subsystem respond s to a specific group of commands. A command is received by a transcei ver subsystem and then transferred through the network to the subsyste m to which the command is addressed, Then the subsystem executes the c ommand and returns results to the transceiver subsystem, where the res ults are telemetered to the ground station. The network enhances indep endence of the individual subsystems, which enables programs of the in dividual subsystems to be coded independently. Independence facilitate s development and debugging of programs, improving the quality of the system borne on a balloon. (C) 1998 Elsevier Science B.V. All rights r eserved.