Publications of Valery Broun
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See detailDescription of secondary payload of upcoming educational OUFTI-2 1U CubeSat for testing a new multilayer shield for protecting electronics against space radiations
Broun, Valery ULiege; De Dijcker, Sebastien; Werner, Xavier ULiege et al

Poster (2018, December)

We describe one of the secondary payloads of the educational OUFTI-2 satellite under development at the University of Liège, namely the one dedicated to the test of an innovative type of shielding that ... [more ▼]

We describe one of the secondary payloads of the educational OUFTI-2 satellite under development at the University of Liège, namely the one dedicated to the test of an innovative type of shielding that can protect electronic systems against space radiations, and that is well suited for small satellites. OUFTI-2 is a 1-U CubeSat, the main payload of which is a homemade radio repeater featuring D-STAR amateur-radio communications. We expect OUFTI-2 to be deployed from ISS, with a mission duration of about 6 months. The impact of space radiations on electronics depends mainly on the orbit/trajectory, mission duration, and possible protections. Such radiations cause well-known undesirable effects such as latch-ups. The protection against such effects is ideally achieved through a combination of device rad-hardening, physical shields, and defensive software. Here, we focus on the use of shields. One limitation with using such shields is the corresponding added volume and weight. The innovative type of shield to be tested aboard OUFTI-2 consists of a multilayer laminate structure, combining doped resin and Wolfram (tungsten) heavy alloy. It has the advantage of being light-weight, robust, and reliable. The part of the board containing the shields-test payload consists mainly of three identical electronic circuits, resp. without any shield, with a classical 2-mm aluminum shield, and with the new multilayer shield. The 1st part of each circuit is a RADFET (a p-channel MOSFET optimized for ionizing dose measurement), whose threshold voltage ΔV varies with the total dose D in a known way, essentially according to ∆V=A (1-e^(-B D) ), where A and B are parameters depending upon the RADFET used. One measures ΔV. The 2nd part contains 2 op-amp-based circuits. In one, one measures the offset voltage, and in the other the output noise voltage level. One also measures the temperature, T. ΔV, the two op-amp parameters, and T constitute the quadruplet of data measured periodically, and ultimately sent to the ground. During flight, we will use ΔV and T to deduce D at each sampling time. For each such time, we will also compute the total dose via the ESA SPENVIS simulation software using the known flight trajectory up to that time. Of course, we will also compare the protection provided by both types of shields, and in relation to the absence of a shield. The measurements of the two op-amp parameters will allow us to see how these parameters evolve as a function D. [less ▲]

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See detailCubesats activities at the University of Liège
Werner, Xavier ULiege; Broun, Valery ULiege; De Dijcker, Sébastien ULiege et al

Conference given outside the academic context (2017)

Detailed reference viewed: 49 (13 ULiège)
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See detailOUFTI-2 educational CubeSat project of University of Liège, Belgium
Guillaume, Thibaut; Rikir, Adrien; De Dijcker, Sébastien ULiege et al

Scientific conference (2017, May 03)

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See detailOUFTI-1 : comment les étudiants belges ont envoyé un satellite en orbite
Verly, Jacques ULiege; Kerschen, Gaëtan ULiege; Werner, Xavier ULiege et al

Conference given outside the academic context (2016)

Detailed reference viewed: 58 (7 ULiège)
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See detailThermal-vacuum and vibration test campaigns that led to the OUFTI-1 nanosatellite being fully qualified by ESA for launch and operation in Earth orbit
De Dijcker, Sébastien ULiege; Werner, Xavier ULiege; Broun, Valery ULiege et al

Conference (2015, September)

OUFTI-1’s test campaigns were divided into two phases. The goal of Phase 1 is to demonstrate that the different functionalities of the satellite work as intended. The goal of Phase 2 is to subsequently ... [more ▼]

OUFTI-1’s test campaigns were divided into two phases. The goal of Phase 1 is to demonstrate that the different functionalities of the satellite work as intended. The goal of Phase 2 is to subsequently demonstrate that the satellite can withstand the launch into orbit, and then work properly in the conditions of space. The corresponding tests thus involve both thermal-vacuum environmental tests (in appropriate test chambers) and vibration tests (on appropriate vibration pods). The conditions simulated during these tests are as close as possible to those that the satellite will encounter during its mission, covering as many cases as possible, amid uncertainties, since neither the launcher nor the orbit were known prior to the tests. Both phases involve the flight model (FM), in accordance with the so-called "protoflight" approach. [less ▲]

Detailed reference viewed: 116 (8 ULiège)
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See detailArchitecture of educational OUFTI-1 nanosatellite of University of Liège, as tested in preparation for space flight
Werner, Xavier ULiege; De Dijcker, Sébastien ULiege; Broun, Valery ULiege et al

Poster (2015, September)

Overview of the OUFTI-1 nanosatellite space segment. The OUFTI-1 project was initiated in September 2007. The nanosatellite is a one-unit (1U) CubeSat. Its main payload is - in essence - a D-STAR repeater ... [more ▼]

Overview of the OUFTI-1 nanosatellite space segment. The OUFTI-1 project was initiated in September 2007. The nanosatellite is a one-unit (1U) CubeSat. Its main payload is - in essence - a D-STAR repeater in space, potentially the first one ever. D-STAR is an amateur-radio (“ham”), digital radio communication - protocol (with associated equipment) allowing the simultaneous transmission of voice and data, such as GPS coordinates and call-signs. [less ▲]

Detailed reference viewed: 92 (5 ULiège)
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See detailOverview of the ground facilities for controlling the OUFTI-1 nanosatellite and for routing its radio-communications through the worldwide D-STAR repeater network
Werner, Xavier ULiege; De Dijcker, Sébastien ULiege; Broun, Valery ULiege et al

Poster (2015, September)

Overview of the current state and upgrade plan of the OUFTI-1 nanosatellite ground segment. The OUFTI-1 project was initiated in September 2007. The OUFTI-1 nanosatellite is a one-unit (1U) CubeSat. Its ... [more ▼]

Overview of the current state and upgrade plan of the OUFTI-1 nanosatellite ground segment. The OUFTI-1 project was initiated in September 2007. The OUFTI-1 nanosatellite is a one-unit (1U) CubeSat. Its main payload is - in essence - a D-STAR repeater in space, potentially the first one ever. D-STAR is an amateur-radio (“ham”), digital radio-communication protocol (with associated equipment) allowing the simultaneous transmission of voice and data, such as GPS coordinates and call-signs. The satellite was tested in 2014 and 2015 within the ESA’s Education Office Fly Your Satellite! (FYS) project, and it is now fully qualified and ready for launch and operation in space. [less ▲]

Detailed reference viewed: 64 (4 ULiège)