DOI:10.1049/ree.1982.0053

出版商:IERE    

年代:1982

数据来源: IET

摘要:

TheUOSATProject commenced at the University of Surrey in 1979 to investigate the feasibility of, and the engineering problems associated with, the design, construction, launch and orbital operation of a relatively small and inexpensive spacecraft capable of a worthwhile contribution to the scientific, engineering and educational communities.The paper outlines the background to the project and the objectives of theUOSATmission. After describing briefly the experiments on board the spacecraft, the paper deals with the design and fabrication of the satellite, the philosophies underlying these and the test and procurement procedures. Details of the project management and the resources necessary are given. The paper concludes with a summary of the present status of the spacecraft and its experiments.

DOI:10.1049/ree.1982.0054

出版商:IERE    

年代:1982

数据来源: IET

摘要:

The dynamics ofUOSATafter launch are briefly reviewed and also the stages which are believed necessary to achieve a transition from an arbitrary state of nutation to one of damped gravity gradient and correct Earth-centred orientation. Novel algorithms have been developed as a form of adaptive commutation using the on-board magnetorquer.

DOI:10.1049/ree.1982.0055

出版商:IERE    

年代:1982

数据来源: IET

摘要:

Two computer systems have been incorporated into theUOSATspacecraft, the primary spacecraft computer being based on the RCA CDP 1802 microprocessor, and the secondary computer on the Ferranti F100 system.This paper describes the system philosophy and design consideration of the primary computer, particularly as regards its operation in a space environment where low power and reliability are essential. An overview of the general system is given and the various interfaces to the other spacecraft systems and experiments are also described.

DOI:10.1049/ree.1982.0056

出版商:IERE    

年代:1982

数据来源: IET

摘要:

UOSATsecondary computer provides a system for the evaluation of higher risk computing technologies, including a 16-bit bipolar microprocessor and large static o.s. memories. The system has both simple interfaces the satellite and a simple loading command structure. A significant feature of the design is the provision for lowpower operation in which the processor consumes a high supply current only when computing tasks are being undertaken.

DOI:10.1049/ree.1982.0057

出版商:IERE    

年代:1982

数据来源: IET

摘要:

Earth imaging systems have, in the past, involved the construction of fairly complex photographic and photoelectrical conversion techniques. Furthermore, the format of data transmission has restricted the widespread use such data in educational establishments due to the fairly complex and costly receiving and display apparatus required. In this paper the development of a simple imager using a two-dimensional c.c.d. array is described. The design considerations were to reduce power consumption, weight and size, and to assemble the data in a format that could be received with very simple apparatus and displayed on a domestic television receiver. The resolution of the camera is 256 x 256 pixels with a 16-level grey scale; ground coverage is approximately 480 km square.

DOI:10.1049/ree.1982.0058

出版商:IERE    

年代:1982

数据来源: IET

摘要:

single canted turnstile antenna is used for satellite transmission and command reception in the v.h.f. and f. bands. Details of the antenna hybrid and coupling filters are given, together with performance measurements. The v.h.f. and u.h.f. beacons use 5th overtone oscillators 72 MHz, and a multistage varactor modulator provides sufficient phase modulation with overall frequency multiplication of only x 2 at v.h.f. and x 6 at u.h.f. Some unusual aspects of the design and construction are described.

DOI:10.1049/ree.1982.0059

出版商:IERE    

年代:1982

数据来源: IET

摘要:

University of Surrey amateur scientific satellite, UOSA T carries a set of phase related beacons on 7, 14, and 29 MHz enabling experiments to be carried out trans-ionospheric propagation at the four frequenciesbeacons, which deliver 100 mW each, are synthesized the 7 MHz master oscillator and combined into one two 2-5 m monopoles tuned against the satellite body 15-metre boom. Modulation is by on/off carrier and be routed from the telemetry system or the primary spacecraft computer.

DOI:10.1049/ree.1982.0060

出版商:IERE    

年代:1982

数据来源: IET

摘要:

The paper discusses the design and construction of the UOSA T microwave beacons. Several interesting design features are apparent, and these have been employed in an attempt to provide space-borne microwave transmissions for use with low-cost ground stations. In particular, difficulties due to excessive range loss have been partially overcome by the use of sophisticated design techniques, without the need for high power consumption from the satellite.

DOI:10.1049/ree.1982.0061

出版商:IERE    

年代:1982

数据来源: IET

摘要:

This paper describes the telemetry system for the satelliteUOSAT) designed and built in the Department of Electronic and Electrical Engineering of the University of Surrey. The function of the telemetry system is to encode outputs of sensors, located around the spacecraft, into specified data formats prior to transmission via downlink transmitters. In addition, information relating to the status sub-systems and data from on-board experiments require similar encoding. The basic philosophy of the telemetry system aims at providing a continuous and comprehensive surveillance of spacecraft systems for engineering purposes and a number of data formats to for different ground station facilities.

DOI:10.1049/ree.1982.0062

出版商:IERE    

年代:1982

数据来源: IET