Mar 6 2014

Two Close Calls For ZACUBE-1 CubeSat

ZACUBE-1, FUNcube-1 and HiNCube in the deployment pod – Image credit Wouter Weggelaar PA3WEG

The amateur radio ZACUBE-1 satellite, launched with FUNcube-1 on November 21, 2013, recently had two close encounters with space debris. The ZACUBE-1 team have issued this press release:

CPUT ZACUBE-1 TshepisoSat

Week nine of the year will go down as quite an eventful week for ZACUBE-1 (TshepisoSat), literally dodging two bullets involving speeds in the kilometres per second range.

The first close approach notification arrived the morning of 25 February 2014 from the United States Joint Space Operations Center (JSpOC) through the The South African National Space Agency (SANSA) (A close approach notification is generated by the JSpOC to warn spacecraft operators when their spacecraft will come in close proximity to another object). The first order of business was the identification of the other object. In this case “SCC# 21422″. Our dance of death would be with the, now defunct, 2000 kg Russian built COSMOS 2151 launched in 1991. As ZACUBE-1 carries no propulsion system and with the COSMOS 2151 no longer functioning the only course of action was to closely monitor the situation.

TShepisosat ZACUBE-1 prior to being shipped to the Netherlands

It was determined that the close approach event would occur over the Antarctic and a search was started for possible ground stations that could listen for signals from ZACUBE-1 directly after the event. Help arrived in the form of our friends from the California Polytechnic State University in San Luis Obispo, California, United States. The Cal Poly ground station would see ZACUBE-1 approximately 30 minutes after the event and be able to listen for its transmitted telemetry beacon signal. In preparation ZACUBE-1 would be tracked and checked on the last two passes over South Africa (22:50 SAST 26/02/2014 and 00:26 SAST 27/02/2014) a few hours before the event to ensure that everything was OK and then again by the Cal Poly station.

With everything checking out and all systems nominal on the last pass over South Africa all we could do was wait for news from California.

Great success! With Cal Poly confirming that ZACUBE-1 was alive and well. We were able to further confirm this on the first pass over South Africa.

ZACUBE-1 TshepisoSat HF beacon antenna deployment unit – Image credit CPUT

This would have been enough excitement for the week, but soon after verifying that ZACUBE-1 was OK we received our second close approach notification! This time involving a piece of debris from a METEOR 2-5 satellite. The plan would be much the same, but with the event taking place over Brazil we tried to make contact with some stations in Brazil. Unfortunately nothing was heard over Brazil, but we received notification of ZACUBE-1′s signal from the University of Florida and again from the California Polytechnic State University.

We would like to thank everyone that helped out during this time, hopefully I did not leave anybody out. The folks from Cal Poly, University of Florida, the Brazilian radio amateurs that tried on very short notice and SANSA.

ZACUBE-1 carries a UHF beacon on 437.345 MHz and an HF beacon on 14099 kHz used to characterise the Superdarn antennas at the Antarctic which study the ionosphere.

ZACUBE-1 information
http://www.cput.ac.za/fsati
and
http://www.amsatsa.org.za/

First image captured by TshepisoSat (ZACUBE-1)
https://amsat-uk.org/2013/12/15/first-image-captured-by-tshepisosat-zacube-1/

Mar 6 2014

FUNcube-1 (AO-73) 100+ days in orbit

FUNcube-1 (AO-73) Spin Period

Last weekend FUNcube-1 (AO-73) reached the milestone of having been in space for 100 days – actually that should be clarified to mean “terrestrial” days as the spacecraft itself has been subjected to more than 1500 day/night cycles during this time.

FUNcube-1 (AO-73) – Image credit Wouter Weggelaar PA3WEG

We are very grateful to the 500+ stations who have been providing FUNcube-1 telemetry data to our Data Warehouse. We now have more than 1GB of data in the repository – this is an amazing effort and achievement from a spacecraft which is only transmitting at 1200bps. Thanks everyone and please keep it coming:)

From all the telemetry we can see that the spin rate decreased for a time but now is speeding up again. External temperatures span a range of 50C between the end of the sunlit phase and the end of the eclipse period. Even inside the spacecraft the temperatures range over 25C.

All the subsystems continue to work well and are “well in the green”.

The increased solar activity is certainly having an effect on the downlinked signal on many occasions. During such disturbances the signal appears to be being affected by ionospheric scintillation which distorts the BPSK stream and makes decoding much harder for some minutes at a time. This effect is not just apparent near the magnetic poles as can be seen in this paper: http://waas.stanford.edu/papers/IWG/sbas_iono_scintillations_white_paper.pdf

Users in the Northern hemisphere will have noticed that the evening passes in amateur mode are becoming shorter as the spacecraft enters sunlight again near the pole. This effect will increase as the season progresses and we will be testing a plan to change the operating schedule in a few weeks time. This test will involve placing the spacecraft into continuous amateur/transponder mode for a number of orbits – probably over a weekend.

Especially for educational users of FUNcube, we have placed all our schools outreach material on one page for easy reference. It can now all be found here: http://funcube.org.uk/education-outreach/

Mar 5 2014

OSCAR-11 / UoSAT-2 Celebrates 30 Years in Orbit

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

UoSAT-OSCAR-11 has now been in orbit for 30 years and remarkably its signal on 145.826 MHz FM (AFSK 1200 bps ASCII) is still being received.

UOSAT-2 / OSCAR-11 1984 Martin Sweeting G3YJO and Dave Bocks UoS standing

UoSAT-2 / OSCAR-11 Martin Sweeting G3YJO and Dave Bocks UoS standing

UoSAT-2, also known as UoSAT-OSCAR-11 or UO-11, was the second satellite designed and built by a team of engineers at the University of Surrey in Guildford, Surrey, UK and was the successor to UoSAT-1 / UoSAT-OSCAR-9 (see Hobby Electronics August 1981). It was launched from the Western Test Range at Vandenberg Air Base, in Lompoc, California along with LANDSAT-5 on a Delta 3920 rocket on March 1, 1984.

UO-11 was the most rapidly designed OSCAR, going from inception to launch in only five months. It was also the first amateur satellite to carry a digital communications package into Earth orbit, and the first to be controlled by a CPU running software written in the high-level programming language “Forth”.

UO-11 carries beacons in three amateur radio bands.

The 145.826 MHz beacon transmits FM Audio Frequency Shift Keying (AFSK) 1200 bps ASCII data. It the early years it also transmitted a voice message from the digitalker experiment.

The 435.025 MHz beacon transmitted either 1200 bps FM AFSK or 4800 bps PSK data. This beacon was used to downlink information from the Digital Store and Readout (DSR) Experiment, which includes CCD Earth image data, results from the Particle Wave Experiment, and engineering data from the RCA COSMAC 1802 CPU.

The 2401.5 MHz beacon transmitted FM and PSK signals. Antenna polarization for all three beacon transmitters is left-hand circular (LHCP). Only the 145.826 MHz beacon is now operational.

Read Usenet messages from 1984 about UoSAT-B / UoSAT-2

Martin Sweeting G3YJO listening to the UO-11 Digitalker

Information compiled by Clive Wallis G3CWV
https://web.archive.org/web/20150413193503/http://g3cwv.co.uk/oscar11.htm

UO-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/

Mar 5 2014

Galileo GPS closes down 23cm ATV Repeater DB0QI

AMSAT-UK Logo

The new Galileo GPS system that broadcasts across 1260-1300 MHz has resulted in the closure of a German ATV repeater.

The DARC report the Munich ATV repeater DB0QI has been closed down due to it jamming the Galileo Satnav Control Centre.

DB0QI was located 18 km from the Galileo GNSS receiver, another repeater that has been shut down is DB0ITV which was located 55 km from the receiver. It is believed both repeaters were running about 15 watts ERP.

DARC in Google English http://tinyurl.com/GermanyDARC

A 2006 Galileo GPS article by Peter Blair G3LTF highlighted the problems this system could cause, see
http://www.southgatearc.org/articles/galileo.htm

The Amateur Satellite Service has an important allocation at 1260-1270 MHz for Earth-to-Space (Uplink) communications. The Amateur Satellite Service has already seen its allocations at 2.4 and 5 GHz rendered unusable in urban areas due to WiFi and other licence exempt devices. The Amateur Satellite Service does not have any other global spectrum allocations in the key 915 MHz to 6 GHz region.

While the German announcement may relate to a single Galileo command station being used to test the initial satellites it clearly raises concerns about what will happen in a few years time when the full Galileo constellation is deployed and 1260-1300 MHz GPS units are in widespread use.

Mar 5 2014

Ham Radio Will Play Role in Simulated Mars Mission

The ARRL report when Ron Williams, N9UIK, and his team of “astronauts” head to “Mars” this spring, they’ll be taking Amateur Radio along, just as NASA space travelers have done.

Williams is part of Mission 2 (of four) in the Hawaii Space Exploration Analog and Simulation — HI-SEAS, in which participants will simulate living and working within a Martian outpost — actually a solar-powered dome at a remote site some 8000 feet up on the slopes of Mauna Loa. Conducted by the University of Hawaii and Cornell University, the project has partial funding from NASA.

“I am confident that when we eventually go to Mars, there will be some type of involvement with the Amateur Radio community,” Williams said, noting Amateur Radio’s long-standing role in space missions, including the International Space Station. “We would like to simulate this on this mission.” Part of that will mean integrating a 20 minute signal delay into all communications, whether via Amateur Radio or the Internet.

“This will simulate the distance, when greatest, between Earth and Mars,” explained Williams, a clinical neuropsychologist from Indiana. At 60, he’s the oldest member of the team; the youngest is 26. Williams, is one of two hams on this crew increment. The other is Ross Lockwood, VA6RLW, of Alberta.

“Our proposed outreach simulation to the Amateur Radio community will also involve this signal delay,” Williams continued. “To the best of our knowledge, this will be unique to any Amateur Radio special event ever conducted.” HI-SEAS also was able to obtain the special event call sign K6B for the project for nearly the entire length of the mission, instead of the typical 15 days.

Read the full ARRL story at
http://www.arrl.org/news/ham-radio-will-play-a-role-in-hi-seas-simulated-mars-mission