• [AMSAT-UK] UWE-4 News: Successful first demonstration of orbit control

    From AMSAT-UK via rec.radio.info Admin@21:1/5 to All on Wed Jul 22 20:01:14 2020
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    UWE-4 News: Successful first demonstration of orbit control on a 1U CubeSat

    Posted: 22 Jul 2020 04:09 AM PDT https://amsat-uk.org/2020/07/22/uwe-4-news-successful-first-demonstration-of-orbit-control-on-a-1u-cubesat/

    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.

    Several 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


    UWE-4 435.600 MHz


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