UOSAT-2 – OSCAR-11

OSCAR-11 (AKA UoSAT-2 and UO-11) celebrated its 30th birthday in space on 01 March! It was designed, built and launched within a period of six months, using commercially available ‘off the shelf’ components (COTS). Once again, congratulations to Professor Sir Martin Sweeting G3YJO, his team at the University of Surrey and the groups of radio amateurs who also contributed to the project.

This report covers the period from 01 January 2013 to 05 March 2014. During this time there have been no significant changes apart from the gradual drift of the on-board clock. There was also an advance of one day in the displayed date. This was caused by a known leap year problem in the date chip, which has always existed since launch. Owing to the large accumulated time/date error 29 February 2012 on the satellite occurred in January 2013 on Earth!  The satellite has been transmitting on a regular cycle of 10.35 days on followed by 10.35 days off.

Good copy has been obtained obtained from decoded telemetry frames and many reports have been posted on the DCARR general satellite status website http://oscar.dcarr.org/

The satellite continues to be subjected to eclipses during each orbit, resulting in weaker signals at those times. During the winter in the UK the evening passes were in the Earth’s shadow, and very weak signals have been received, which could not be demodulated and could be only detected with the receiver in CW mode . As the longer daylight hours of summer approach, the evening passes in the UK should gradually become clear of eclipses, resulting in stronger signals. Eclipses are expected to continue until 2019.

The on-board clock gained 98 seconds during the 14 month reporting period, which is comparable with the 60 seconds gain per year when the satellite was launched. There is however a large accumulated error of 307.54090 days slow. This was caused mainly by the clock stopping during eclipses, when there was also an unknown drain on the power supply. The units of the least significant digit correspond approximately to seconds (0.86 seconds actually).

UOSAT 2 / OSCAR-11 with Dave Brock UoS kneeling Christine Sweeting G6APF and Neville Bean G8NOB

At the present time, while OSCAR-11 is operating in a predictable way, please DO NOT send reports or files by e-mail. However, could all listeners continue to enter their reports on the general satellite status website http://oscar.dcarr.org/ . This is a very convenient and easy to use facility, which shows the current status of all the amateur satellites, and is of use to everyone. Reports around the expected times of switch-on and switch-off are of special interest, especially for times 13:00 to 18:00 and 22:00 to 08:00 UTC, to when the satellite is out-of-range in the UK .

The VHF beacon frequency is 145.826 MHz.  AFSK FM ASCII Telemetry. The satellite is operating in the default mode, controlled by the watchdog timer, with a cycle time of 20.7 days. 10.35 days on followed by 10.35 days off.

An extended version of this report is available on my website, and new listeners to OSCAR-11 should read this for
further information. The URL is http://www.g3cwv.co.uk/oscar11.htm

Martin Sweeting G3YJO testing the UOSAT-2 UO-11 digitalker

This page contains links to the report, a short audio clip to help you identify the satellite and a file of recent telemetry received. The website also contains an archive of news & telemetry data which is updated from time to time, and details about using a soundcard or hardware demodulators for data capture. There is also software for capturing data, and decoding ASCII telemetry.

The easiest way to check whether OSCAR-11 is operational is to look at the General Satellite Status website
http://oscar.dcarr.org/index.php .

If you place this bulletin on a terrestrial packet network, please use the bulletin identifier $BID:U2RPT159.CWV, to
prevent duplication.

73 Clive G3CWV xxxxx@amsat.org (please replace the x’s by g3cwv)

OSCAR-11 / UOSAT-2 Celebrates 30 Years in Orbit
https://amsat-uk.org/2014/03/05/oscar-11-uosat-2-celebrates-30-years-in-orbit/

OSCAR-11 page on the DK3WN satellite blog at http://www.dk3wn.info/p/?cat=47

SSTL Blog – Happy 30th Birthday to UOSAT-2
http://www.sstl.co.uk/Blog/March-2014/Happy-30th-Birthday-to-UoSAT-2-

OSCAR-9 and OSCAR-11 TV News Reports
https://amsat-uk.org/2011/10/30/oscar-9-and-oscar-11-tv-news-reports/

BBC Micro ASTRID UoSAT receiver and AMSAT-UK Software Library
https://amsat-uk.org/2011/12/11/bbc-micro-and-amsat-uk-software-library/

Oscar 11

Clive Wallis G3CWV provides an update on the UK Amateur Radio satellite Oscar 11 which has completed nearly 28 years in orbit.

This report covers the period from September  1 to December 28 2011.

The satellite has continued to operate in a very predictable way since the last report, and no changes have been observed. During this time the satellite has been heard reliably during its ten-day transmission periods. Excellent signals have been reported from stations located around the world, and good copy obtained from decoded telemetry frames.

The easiest way to check whether OSCAR-11 is operational is to look at the General Satellite Status website http://oscar.dcarr.org/index.php . You can also calculate the operating schedule from the last switch-off time, which was December 28, 2011 at 15:00 UTC (approx), using 10.35 days off followed by 10.35 days on.

Reception reports have been received from Gustavo LW2DTZ, Bob KI0G, Rolf HB9TSO and Francesco IT9JRU.  Many thanks to all and those who posted to the status website.

The satellite is currently in eclipse during all evening passes over the UK, resulting in lower signal strengths at these times.  Owing to the gradual precession of the orbit, the season for eclipses of the evening passes is longer this year compared with the winter last year.

The on-board clock continues to gain, 28 seconds during the current reporting period, and 112 seconds since regular transmissions were resumed at the end of August 2010. There is however a large accumulated error of 308.54303 days slow. This was caused mainly by the clock stopping during eclipses, when there was also an unknown drain on the power supply. The units of the least significant digit correspond approximately to seconds (0.86 seconds actually).

The VHF beacon frequency is 145.826 MHz.  AFSK FM ASCII Telemetry. The satellite is operating in the default mode, with a cycle time of 20.7 days. 10.35 days on followed by 10.35 days off.

At the present time, while OSCAR-11 is operating in a predictable way, I no longer need direct reports or files by e-mail. However, could all listeners continue to enter their reports on the general satellite status website. This is a very convenient and easy to use facility, which shows the
current status of all the amateur satellites, and is of use to everyone. Reports around the expected times of switch-on and switch-off are of special interest, especially for times 12:00 – 18:00 and 22:00 – 07:00 UTC, when the satellite is out-of-range in the UK . The URL is http://oscar.dcarr.org/index.php

A longer version of this report report is available on my website, and new listeners to OSCAR-11 should read this for further information. The URL is http://www.g3cwv.co.uk/oscar11.htm
This page contains a links to the longer report, a short audio clip to help you identify the satellite and a file of the last telemetry received. The website also contains an archive of news & telemetry data which is updated from time to time, and details about using a soundcard or hardware demodulators for data capture. There is also software for capturing data, and decoding ASCII telemetry.

If you place this bulletin on a terrestrial packet network, please use the bulletin identifier $BID:U2RPT157.CWV, to prevent duplication.

73 Clive G3CWV xxxxx@amsat.org (please replace the x’s by g3cwv)

AMSAT-UK publishes a colour A4 newsletter, OSCAR News, which is full of Amateur Satellite information. Free sample issue at http://www.uk.amsat.org/on_193_final.pdf Join online at http://tinyurl.com/JoinAMSAT-UK