| 1. |
- Blomberg, Lars G., et al.
(författare)
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MEFISTO - An electric field instrument for BepiColombo/MMO
- 2006
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Ingår i: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 38:4, s. 672-679
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Tidskriftsartikel (refereegranskat)abstract
- MEFISTO, together with the companion instrument WPT, are planning the first-ever in situ measurements of the electric field in the magnetosphere of planet Mercury. The instruments have been selected by JAXA for inclusion in the BepiColombo/MMO payload, as part of the Plasma Wave Investigation coordinated by Kyoto University. The magnetosphere of Mercury was discovered by Mariner 10 in 1974 and will be studied further by Messenger starting in 2011. However, neither spacecraft did or will measure the electric field. Electric fields are crucial in the dynamics of a magnetosphere and for the energy and plasma transport between different regions within the magnetosphere as well as between the magnetosphere and the surrounding regions. The MEFISTO instrument will be capable of measuring electric fields from DC to 3 MHz, and will thus also allow diagnostics of waves at all frequencies of relevance to the Hermean magnetosphere. MEFISTO is a double-probe electric field instrument. The double-probe technique has strong heritage and is well proven on missions such as Viking, Polar, and Cluster. For BepiColombo, a newly developed deployment mechanism is planned which reduces the mass by a factor of about 5 compared to conventional mechanisms for 15 in long booms. We describe the basic characteristics of the instrument and briefly discuss the new developments made to tailor the instrument to flight in Mercury orbit.
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| 2. |
- Ivchenko, Nickolay, et al.
(författare)
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Fast deployment of wire booms without residual oscillations
- 2007
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Ingår i: 18TH ESA Symposium On European Rocket And Balloon Programmes And Related Research. ; , s. 211-216
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Konferensbidrag (refereegranskat)abstract
- We present a method of fast deployment of wire booms from spinning bodies without residual oscillations. A two dimensional model of the boom-spacecraft system is developed, and analysed both theoretically and by means of numerical simulation. It is shown that for constant deployment rate, the equilibrium state during the deployment is a constant deflection angle of the boom with respect to radial direction. Oscillations about the equilibrium state are damped, so after sufficiently long deployment the boom assumes the equilibrium deflection angle. This allows to bring the boom to the radial position by introducing a period of deployment at half the rate, with its duration equal to half of the oscillation period.
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