UWE-4 News: Successful first demonstration of orbit control on a 1U CubeSat

UWE-4 News: Successful first demonstration of orbit control on a 1U CubeSat

Altitude of UWE-4 since launch on December 27, 2018

Altitude of UWE-4 since launch on December 27, 2018

The University Wuerzburg Experimental Satellite 4 (UWE-4) successfully used its propulsion system in order to conduct orbit control. The 1U CubeSat, developed and built at the Chair for Robotics and Telematics, is equipped with the electric propulsion system NanoFEEP which has been developed by TU Dresden.

UWE-4 LogoSeveral manoeuvres have been performed within 11 days between June 23rd – July 3rd 2020 such that the altitude of the CubeSat was reduced by more than 100 m, compared to an average of 21 m with natural decay. This marks the first time in CubeSat history that a 1U CubeSat changed its orbit using an on-board propulsion system.

As chance would have it, the team of UWE-4 received a conjunction data message (CDM) in the morning of July 2nd 2020 from the United Air Force’s 18th Space Control Squadron. A conjunction of UWE-4 with a non-operational Iridium satellite (ID: 34147) in the morning of July 5th 2020 with a minimum range of about 800 m was a threat to the safety of UWE-4. An analysis has shown that the altitude of UWE-4 would already be below the Iridium satellite at the time of conjunction. Thus the on-going altitude lowering manoeuvre could only improve the situation and can be considered as a collision avoidance manoeuvre. No further CDMs have been issued regarding this possible conjunction. An analysis of the orbit of the two spacecraft after July 5th 2020 results in a closest approach of more than 6000 m.

Lowering the altitude of a spacecraft in low earth orbit (LEO) is equivalent to a reduction of its lifetime, since satellites in LEO usually burn up during re-entry due to the friction with the Earth’s atmosphere. Thus, this experiment is a concept demonstration of a de-orbiting manoeuvre shown at the smallest class of spacecraft in LEO. Today, there is no commitment to carry a propulsion system for spacecraft. However, due to the vastly increasing number of satellites in mega constellations such obligations are being discussed in the space agencies of several space faring countries. The experiment of UWE-4 presents a de-orbiting solution for the fraction of space debris of operational but unused satellites of today and for the mega constellations of tomorrow.

Stay tuned for more updates on UWE-4 and the upcoming launch of NetSat – a formation flying nano-satellite mission from our partner institute Center for Telematics which is expected to be launched September 2020!

Kind regards,

The UWE‑4 Team

UWE-4: First NanoFEEP thruster ignition
https://amsat-uk.org/2019/03/04/uwe-4-first-nanofeep-thruster-ignition/

UWE-4 435.600 MHz
http://www7.informatik.uni-wuerzburg.de/forschung/space-exploration/projects/uwe-4/

Get The Details…
m5aka AMSAT-UK

Powered by WPeMatico

OSCAR Satellite QSO Party 1 Aug – 22 Sept

OSCAR Satellite QSO Party 1 Aug – 22 Sept

Fun in space with Amateur RadioThe objective of the AMSAT-UK OSCAR Satellite QSO Party is to encourage all radio amateurs around the world to get on the air and make contacts via satellites during northern hemisphere summer. We would like to attract both seasoned die-hard operators as well as all newcomers who are just getting involved.

While points are given per QSO this isn’t a contest, but we hope it will encourage people to get on the air and enjoy the excitement of making contacts through satellites.

The AMSAT-UK OSCAR Satellite QSO Party will be supported by an online leaderboard which will be available from the start of the event which runs from 00:00 GMT on 1st August until 23:59 GMT on 22nd September.

Prizes will be awarded to those from first to thirteenth place and are open to both AMSAT-UK and non-members around the world.
● First Place £250 Amazon Voucher
● Second Place £150 Amazon Voucher
● Third Place £50 Amazon Voucher
● Fourth to Thirteenth Place One Year AMSAT-UK Membership

Download the rules for the AMSAT-UK OSCAR QSO Party

Leaderboard https://leaderboard.amsat-uk.org/

Get The Details…
m5aka AMSAT-UK

Powered by WPeMatico

Unauthorized transmissions in 144 MHz satellite allocation

Unauthorized transmissions in 144 MHz satellite allocation

Water Vitalizer Interference - DC4CX

Water Vitalizer Interference – DC4CX

The DARC reports unauthorized transmissions are taking place in the 144 MHz satellite segment of the 2m amateur radio primary allocation.

A translation of the DARC post reads:

In the 144.010 MHz to 144.020 MHz range, illegally operated transmitters are increasingly being operated as “water vitalizers” or “water energizers”. The manufacturer specifies 144.015 MHz as the transmission frequency in its product description.

The DARC EMC department asks for further information with location information about conspicuous signals in this frequency range, in preparation for collective complaints.

The devices apparently generate fields with considerable field strength and a long range. The signals appear increasingly in the morning or in the evening. The illegal transmitters are typically in operation for 5 to 60 minutes (integer multiples of 5 minutes). The signal is generally very stable in frequency, but occasionally shows short-term fluctuations of up to a few 100 Hz. Otherwise the carrier is not further modulated.

The frequency range 144.000 MHz to 146.000 MHz is assigned to the amateur radio service in Germany as the primary exclusive user.

A video of the interference caused by these devices and a map showing some of the cases so far detected in Germany can be seen at https://www.darc.de/der-club/referate/emv/

Get The Details…
m5aka AMSAT-UK

Powered by WPeMatico

SpaceX to launch AMSAT-EA EASAT-2 and Hades satellites

SpaceX to launch AMSAT-EA EASAT-2 and Hades satellites

AMSAT-EA Hades PocketQube

AMSAT-EA Hades PocketQube

Spain’s national amateur radio society URE says SpaceX expect to launch the EASAT-2 and Hades satellites in December 2020.

AMSAT-EA, the URE satellite group, is building the satellites together with the European University of Madrid. The launch has been managed through the space broker Alba Orbital based in Glasgow.

EASAT-2 and Hades will be launched into a sun-synchronous orbit between 500 km and 600 km and their main function is to act as analog and digital repeaters for radio amateurs. There is also a camera for SSTV transmissions provided by the Czech Republic that has already flown on the United States Marine Academy PSAT-2 satellite, and has now been adapted to fit into the PocketQube satellites.

Both satellites are based on the PocketQube 1.5P (7.5 x 5 x 5 cm) architecture and represent an evolution of the previous GENESIS platform, whose GENESIS-L and GENESIS-N satellites are expected to fly before the end of the year with Firefly, in a joint collaboration with Fossa Systems and LibreSpace, which also launch their own satellites, all of them within the Picobus dispenser, developed by the latter.

IARU has coordinated these frequencies:
• Hades – uplink 145.925 MHz, downlink 436.888 MHz 
• EASAT-2 – uplink 145.875 MHz, downlink 436.666 MHz

IARU Satellite Frequency Coordination pages http://www.amsat.org.uk/iaru/

Source URE https://tinyurl.com/SpainURE

Get The Details…
m5aka AMSAT-UK

Powered by WPeMatico

1240-1300 MHz discussed at CEPT SE 40 meeting

1240-1300 MHz discussed at CEPT SE 40 meeting

CEPT LogoThe 69th meeting of CEPT ECC Working Group SE-40, held June 23-25, discussed the amateur radio 1240-1300 MHz band, the meeting documents are now available.

Several contributions were received for the ECC Report dealing with the coexistence between the radionavigation-satellite service and the amateur service in the frequency band 1240 – 1300 MHz. The contributions were incorporated in the draft ECC Report. The CPG arrangements for the preparation of WRC-23 for AI 9.1 topic b) was noted.

The Russian Federation noted:
1240-1260 MHz is by the GLONASS system
1260-1300 MHz are used by EU’s Galileo, Beijing’s Beidou, Japan’s QZSS and is planned to be used by Korea’s KPS.

Among the documents available in Input, Info and Minutes are:
• SE40(20)052 Amateur Repeaters – IARU-R1
• SE40(20)051 Section 2 update WI_39 – IARU-R1
• SE40(20)050 Annex Draft report RNSS Amateur – Russian Federation
• SE40(20)049 Suggestions for RNSS and Amateur Service Compatibility – Russian Federation
• Info 1 Amateur repeaters 23 cm – IARU-R1
• Info 3 Letter to SE40 chairman on updated of ITU-R M.1092 – European Commission
• Minutes
• SE40(20)56A3 (1) Draft Report Amateur vs RNSS

Download the meeting documents from
https://www.cept.org/ecc/groups/ecc/wg-se/se-40/client/meeting-documents/?flid=27561

Get The Details…
m5aka AMSAT-UK

Powered by WPeMatico