The comparison of masses and sizes of the Neptunian satellites and of Pluto and Charon to the sec... more The comparison of masses and sizes of the Neptunian satellites and of Pluto and Charon to the secondaries of the planetary, Jovian, Saturnian and Uranian systems support the hypotheses, first, that an initial Neptune's satellite system may have been disrupted, second, that Triton may have been the system perturber and, third, that Pluto (or a parent body of Pluto and Charon) was initially a giant satellite of Neptune. Based on recent theoretical works on perturbed proto-planetary nebula and noting the similarity of some characteristics of Neptune and Uranus, a theoretical mean distance ratio of primeval gaseous rings around Neptune is tentatively deduced to be about 1.475, close to the value of the Uranian system. An exponential distance relation gives possible ranges of distances at which smalI satellites and/or ring structures could be found by Voyager 2, close to Neptune.
The advanced fluid physics module: How to achieve scientific goals for Spacelab D2
The general design of the Advanced Fluid Physics Module (AFMP), a multipurpose multiuser facility... more The general design of the Advanced Fluid Physics Module (AFMP), a multipurpose multiuser facility dedicated to research on basic phenomena of fluid behavior in a microgravity environment, is introduced. Its accommodation for the Spacelab D2 mission is described. In the course of the AFMP technical development, the performance of the instrument was upgraded to ensure that scientific objectives set for the five experiments on board Spacelab D2 could be met. In addition, specific experimental equipment, in the form of discs and a cell, were developed to be mounted on the AFMP for the experiment realization to provide superior experimental capabilities to the AFPM facility.
EuroGeoMars campaign at Mars Desert Research Station: Preparing for Future Mars Landers and Sample
Background: Surface science is one of the prime objectives of current and future Mars, Moon, or p... more Background: Surface science is one of the prime objectives of current and future Mars, Moon, or planetary missions and encompasses a wide range of activities from global mapping via specific studies of localised regions until microscopic scales. The studies of rocks and soil in situ, or with sample return missions, require the development of systematic multi-instruments protocols, characterisation diagnostics, and merging of data from various techniques. Both photogeology and mineralogical wide scale mapping have been performed to some extent previously so significant new surface science results may only come from co-ordinated multi-instrument operations operating from the surface. EuroGeoMars MDRS campaign: The goal of the mission (from 24 January to 1 March 2009) is to demonstrate and validate a procedure for Martian surface in-situ and return science. This chain begins with characterisation of the local surface and close sub-surface environment, before moving on to sample extract...
Perfect crystals of biological macromolecules are needed to reveal structural information necessa... more Perfect crystals of biological macromolecules are needed to reveal structural information necessary for the understanding of their functions. Weightless conditions encountered during orbital space flights have been used for the past 20 years to grow better and larger crystals. The facilities and instruments used until now to grow crystals in space have primarily focused on growing crystals for post-flight analysis, and to a lesser extent on the understanding of phenomena associated with the crystallization processes. The Protein Crystallization Diagnostics Facility (PCDF), a new facility presently under development at DASA/Dornier under a contract of the European Space Agency (ESA), will fly on the International Space Station in 2002-2003. This new instrument will allow for the observation and study of the crystallization processes of biological macromolecules over long periods in microgravity using advanced diagnostics instruments, including video microscopy, dynamic light scattering, and Mach-Zehnder interferometry. This paper presents the actual design features of the PCDF and addresses the foreseen utilization scenario. 0022-0248/99/$ -see front matter 1999 Elsevier Science B.V. All rights reserved. PII: S 0 0 2 2 -0 2 4 8 ( 9 8 ) 0 0 8 6 5 -3
We describe the field demonstration of astrobiology instruments and research methods conducted in... more We describe the field demonstration of astrobiology instruments and research methods conducted in and from the Mars Desert Research Station (MDRS) in Utah during the EuroGeoMars campaign 2009 coordinated by ILEWG, ESA/ESTEC and NASA Ames, with the contribution of academic partners. We discuss the entire experimental approach from determining the geological context using remote sensing, in situ measurements, sorties with sample collection and characterization, analysis in the field laboratory, to the post sample analysis using advanced laboratory facilities.
The Advanced Fluid Physics Module (AFPM) is a multi-purpose, multi-user instrument for investigat... more The Advanced Fluid Physics Module (AFPM) is a multi-purpose, multi-user instrument for investigations on fundamental behaviour of liquid zones in a microgravity environment. The AFPM instrument is presently in its final development phase and is intended to fly on the second German Spacelab D2 mission in 1992. The technical features of the AFPM instrument and its accommodation for the D2 mission are described. The five fluid physics experiments selected to be performed with AFPM on D2 are also addressed.
“Fly Your Thesis!—An Astronaut Experience” is an educational programme launched by the ESA Educat... more “Fly Your Thesis!—An Astronaut Experience” is an educational programme launched by the ESA Education Office that aims to offer to European students the unique opportunity to design, build, and eventually fly, a scientific experiment as part of their Master or Ph.D. thesis. Selected teams accompany their experiments onboard the Zero-G aircraft for a series of three flights, each consisting of
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Papers by V. Pletser