In this paper a solar sail magnetotail mission concept was examined. The 43 m square solar sail is used to provide the required propulsion for continuous Sun-synchronous apse-line precession. The main driver in this mission was found to be the reduction of launch mass and mission cost while enabling a nominal duration of 2 years within the framework of a demonstration mission. It was found that the i Work conducted at University of Glasgow: now at SciSys Ltd., Malcolm.Macdonald@scisys.co.uk ii Work conducted at University of Glasgow: now at EADS Astrium Ltd., Gareth.Hughes@astrium.eads.net iii Professor, Department of Mechanical Engineering, Member AIAA colin.mcinnes@strath.ac.uk iv Science Payload and Advanced Concepts Office, ESTEC alyngvi@rssd.esa.int

Results from the radar altimeters on board the Huygens probe are reported, noting the content of data archived on the NASA Planetary Data System and its ESA counterpart. These instruments provide unique high-resolution information on the topography and electrical properties of the Titan surface over a 15 km track across a boundary between a bright highland and the dark dissected alluvial terrain on which the probe landed. The highland appears similar to 100 m higher than the dark terrain. The dark terrain has a fairly high nadir radar backscatter, consistent with terrestrial lakebeds and alluvial surfaces, and shows small (5-10 m) elevation fluctuations. Possible signatures of surface or volume scattering in the backscatter amplitude and intermediate frequency spectrum are discussed. A previously undocumented characteristic of the Automatic Gain Control (AGC) on the flight altimeter is noted. (C) 2015 Elsevier Inc. All rights reserved.

The ESA Study “Sample Canister Capture Mechanism (SCCM) Design and Breadboard” has been conducted under the Mars Robotic Exploration Preparation (MREP) program. The Study is part of a set of feasibility studies aimed at identifying, analysing and developing technology concepts enabling the future international Mars Sample Return (MSR) mission. The activity focuses on the design of a mechanism that shall enable the Orbiter of the Mars Sample Return mission to recover a spherical Orbiting Sample (OS) coming from Mars surface that contains a set of soil samples. The design concept of such mechanism has been then demonstrated performing a set of Functional, Micro-gravity and Environmental tests on an Elegant Breadboard Model implemented during the Study. The paper focuses on design solutions implemented and lesson learnt raised during the mechanism development; starting from the design concept, the validation through the test activities including the parabolic flight, and the future possible improvements.

The paper provides recent updates about the ESA study: Sample Canister Capture Mechanism Design and Breadboard developed under the Mars Robotic Exploration Preparation (MREP) program. The study is part of a set of feasibility studies aimed at identifying, analysing and developing technology concepts enabling the future international Mars Sample Return (MSR) mission. The MSR is a challenging mission with the purpose of sending a Lander to Mars, acquire samples from its surface/subsurface and bring them back to Earth for further, more in depth, analyses. In particular, the technology object of the Study is relevant to the Capture Mechanism that, mounted on the Orbiter, is in charge of capturing and securing the Sample Canister, or Orbiting Sample, accommodating the Martian soil samples, previously delivered in Martian orbit by the Mars Ascent Vehicle. An elegant breadboard of such a device was implemented and qualified under an ESA contract primed by OHB-CGS S.p.A. and supported by Politecnico di Milano, Department of Aerospace Science and Technology: in particular, functional tests were conducted at PoliMi-DAST and thermal and mechanical test campaigns occurred at Serms s.r.l. facility. The effectiveness of the breadboard design was demonstrated and the obtained results, together with the design challenges, issues and adopted solutions are critically presented in the paper. The breadboard was also tested on a parabolic flight to raise its Technology Readiness Level to 6; the microgravity experiment design, adopted solutions and results are presented as well in the paper.

The Huygens Probe measured the electrical conductivity of Titan atmosphere from about 140 km down to the surface, employing relaxation and mutual impedance techniques. Previous analyses have shown some differences on the conductivity measurements obtained with two independent sensors-relaxation probe (RP) and mutual impedance probe (MIP). A 20-fold maximum discrepancy occurred around the conductivity peak at 60-70 km. To understand the nature of such discrepancy, we reassess the RP data by taking into account a geometrical factor related to the electrode finite size and the Debye length of the ionized medium. The present analysis implies replacing the standard Laplace field distribution by a more elaborated model considering the Poisson equation and the resistance between the RP electrodes and the medium. Although a complete understanding of the conductivity profile is still missing, this work brings RP and MIP data to a much better agreement. The conductivity maximum difference derived from the two sensors is now lower a factor of 2. This reassessment is also useful for future instruments and missions. (C) 2010 Elsevier Ltd. All rights reserved.

Physik in unserer ZeitVolume 40, Issue 5 p. 219-219 Editorial Kosmische Visionen Peter Falkner Dr., Peter Falkner Dr. ESA, Noordwijk, NiederlandeSearch for more papers by this author Peter Falkner Dr., Peter Falkner Dr. ESA, Noordwijk, NiederlandeSearch for more papers by this author First published: 01 September 2009 https://doi.org/10.1002/piuz.200990081AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume40, Issue5September 2009Pages 219-219 RelatedInformation

In 2008, ESA and NASA performed joint studies of two highly capable scientific missions to the outer planets: the Europa Jupiter System Mission (EJSM) and the Titan Saturn System Mission (TSSM). Joint Science Definition Teams (JSDTs) were formed with U.S. and European membership to guide study activities that were conducted collaboratively by engineering teams working on both sides of the Atlantic.

Scientific instruments for challenging and cost-optimized space missions have to reduce their resource requirements while keeping the high performance levels of conventional instruments. In this context the development of an instrument front-end ASIC (0.35 mu m CMOS from austriamicrosystems) for magnetic field sensors based on the fluxgate principle was undertaken. It is based on the combination of the conventional readout electronics of a fluxgate magnetometer with the control loop of a sigma-delta modulator for a direct digitization of the magnetic field. The analogue part is based on a modified 2-2 cascaded sigma-delta modulator. The digital part includes a primary (128 Hz output) and secondary decimation filter (2, 4, 8,..., 64 Hz output) as well as a serial synchronous interface. The chip area is 20 mm(2) and the total power consumption is 60 mW. It has been demonstrated that the overall functionality and performance of the magnetometer front-end ASIC (MFA) is sufficient for scientific applications in space. Noise performance (SNR of 89 dB with a bandwidth of 30 Hz) and offset stability (< 5 pT degrees C-1 MFA temperature, < +/- 0.2 nT within 250 h) are very satisfying and the linear gain drift of 60 ppm degrees C-1 is acceptable. Only a cross-tone phenomenon must be avoided in future designs even though it is possible to mitigate the effect to a level that is tolerable. The MFA stays within its parameters up to 170 krad of total ionizing dose and it keeps full functionality up to more than 300 krad. The threshold for latch-ups is 14 MeV cm(2) mg(-1).

Some of the secrets of the atmosphere of Titan have been unveiled by the Huygens Probe. The Permitivity Wave and Altimetry system detected a hidden ionosphere much below the main ionosphere, that lies between 600 and 2000 km. Theoretical models predicted a low altitude ionosphere produced by cosmic rays that, contrary to magnetospheric particles and UV photons, are able to penetrate down in the atmosphere. Two sensors: Mutual Impedance (MI) and Relaxation Probe (RP) measured the conductivity of the ionosphere by two different methods and were able to discriminate the two branches of electrical conductivity due to the positive and negative charges. The measurements were made from 140 to 40 km and show a maximum of charge densities ≈2 × 10 9 m −3 positive ions and ≈450 × 10 6 m −3 electrons at around 65 km. Here we present the altitude distribution of the concentration of positive ions and electrons obtained from the RP and MI sensors.

This chapter outlines the exploration strategies and associated techniques for the solar system in both the short and longer terms. Current spaceborne instrumentation based on various measurement principles is explained, ranging from imagers, spectrometers, altimeters to particle and plasma instruments for both, remote-sensing and in situ investigations. The benefits of instrument combinations and integration into instrument suites are discussed and examples of potential exploration suites are given for the investigation of planetary shape, size and mass, their surface and subsurface properties, moons and rings and the analyzing of planetary atmospheres, exospheres, ionospheres, and magnetospheres. Dedicated instrumentation suites for asteroids and comets are also outlined, as well as for the wide field of exobiology. A sample return approach is discussed. A summary of engineering and operational constraints is given, to illustrate the difficulty of final instrument selection for a particular mission. The chapter is concluded with an outlook.

In this paper a solar sail magnetotail mission concept was examined. The 43-m square solar sail is used to provide the required propulsion for continuous sun-synchronous apse-line precession. The main driver in this mission was found to be the reduction of launch mass and mission cost while enabling a nominal duration of 2 years within the framework of a demonstration mission. It was found that the mission concept provided an excellent solar sail technology demonstration option. The baseline science objectives and engineering goals were addressed, and mission analysis for solar sail, electric, and chemical propulsion performed. Detailed subsystems were defined for each propulsion system and it was found that the optimum propulsion system is solar sailing. A detailed tradeoff as to the effect of spacecraft and sail technology levels, and requirements, on sail size is presented for the first time. The effect of, for example, data acquisition rate and RF output power on sail size is presented, in which it is found that neither have a significant effect. The key sail technology requirements have been identified through a parametric analysis.