EXOMARS: SAMPLE PREPARATION AND DISTRIBUTION SYSTEM AND INSTRUMENTS UNDER DEVELOPMENT

摘要

Kayser-Threde has been assuming a leading role in a number of studies and projects addressing space robotics with applications ranging from vision systems, manipulation systems and active space debris removal (e.g. the On Orbit Servicing projects OLEV and DEOS) to mechanical subsystems for the ESA-Roskosmos 2018 ExoMars rover mission [1,2]. This paper describes recent results from the on-going development of the Sample Processing and Distribution Subsystem (SPDS) for the ExoMars rover as well as programmatic plans for evolutions of its design targeted to other missions, as well as development activities on regolith sampling devices. The SPDS is being developed by Kayser-Threde under direct subcontract to TAS-I to supply the scientific instruments of the ExoMars rover with granular Mars rock and soil samples of a specific particle size distribution. This is achieved through a set of mechanisms making up the SPDS which crush, meter ('dose') and distribute the subsurface samples acquired by the ExoMars drill. The sequence of operation can be controlled from ground but pre-defined operational sequences are embedded in the control electronics and will operate the SPDS in a semi-automated way. Throughout the ExoMars Phase B work since 2007, the emphasis has been to develop and test breadboards and engineering models of the different SPDS mechanisms, in parallel to doing the preliminary flight design. Hence, high fidelity H/W models now exist for all of the mechanisms, and functional tests of the complete SPDS have been performed at ambient laboratory conditions and in simulated Mars environment. Moreover, parabolic flight campaigns have been conducted to address the influence of reduced gravity (Mars) on the flow of the granular samples from one SPDS mechanism to the next and to support validation of a numerical simulation of the powder flow. Systems like the SPDS are suitable not only for in-situ missions as ExoMars, but also for sample return missions which require a preliminary screening of the samples collected, as well as possibly call for mechanical pre-treatment and metering prior to transfer into the sample return canister. Candidate missions include the planned Roskosmos series of lunar landing and sample return missions Luna-Glob / Luna-Resurs / Luna Sample Return targeted to the lunar poles. Likely design modifications for a lunar polar application are associated with manipulation and handling of ice-rich samples and their protection from premature loss of their volatile contents. To this effect, recent testing performed with the SPDS on ice-containing samples provide confidence in its suitability also for this type of materials.