NetLander Thermal Control

The NetLander mission is planned for the middle term future to place four identical and low mass Surface Modules (SurfM) on four different surface locations of the planet Mars. A German consortium under the responsibility of the Institut für Planetologie, Münster, is developing the platforms for the SurfM’s. The present paper reports the work activities regarding the Surface Module Electronic Compartment (SEC) Thermal Contro

NetLander Thermal Control

The intention of the NETLANDER mission, is to establish for the first time a Network of stations on the surface of Mars. Four identical surface modules are equipped with science payloads dedicated to study the atmosphere and geosphere of Mars at four different landing locations spread over the two hemispheres. The mission duration will be one Martian year. The surface modules and their sensitive electronics compartments have to withstand a wide range of hostile conditions on Mars. Further constraints are given during flight, where heat can be exchanged only across small interfaces. The purpose of the NETLANDER thermal control system is to maintain the electronics and battery temperatures within a narrow band. Contrasting demands of reduced heat leaks and effective dump of surplus heat require new technologies and advanced design concepts to be satisfied under strict mass limits imposed. Recently, the first thermal test model with the original thermal equipment has been completed and tested. The model includes a high performance insulation combined with an innovative loop heat pipe system integrated into a one-to-one lander-structure. The paper describes the design and development activities as well as the ground test campaign performed in simulated Martian environment

MASCOT Thermal subsystem design

MASCOT is a lander built by DLR, embarked on JAXA’s Hayabusa-2, a scientific mission to study the asteroid 162173 1999 JU3. It is a small lander, less than 300x300x200mm?, with onboard payloads (camera, magnetometer, radiometer and IR spectrometer), developed in collaboration by DLR and CNES. MASCOT lands on the asteroid surface, after being released by Hayabusa-2 from a very close position above the asteroid surface, and investigates the asteroid surface. The thermal design of the lander represents one of the main challenges in the whole project because of multiple constraints, depending on the mission phase, mass, power and free space available. MASCOT, notwithstanding its small size, is equipped with redundant heat-pipe system, MLI blanket, heaters. The thermal design of the lander has been chosen after a trade-off phase concerning the technology which could suit better the opposing requirements of the mission: low heat exchange between the lander and the exterior (including the main spacecraft) in cruise, possibility to transfer all the heat dissipated by the internal paylaods and electronic boards during operations on asteroid surface. After selecting the heat-pipe technology as baseline, a development phase was undertaken by the partners both in terms of manufacturing, testing, thermal characterization phase and analitical modelling in order to match the thermal requirements. Heaters are used to assure the survival of the most delicated parts of the lander during cold cruise phases: the battery cells (only primary battery on-board), the electronic boards and the main payload. Strict requirements are given by the main spacecraft in terms of maximum power available to heat the lander during cruise. MLI blankets are used where the available space allows it, e.g. to extra insulate the Ebox from the rest of the lander creating a „hot compartment" and between the lander and the main spacecraft to reduce the heat exchange with it during cruise below the given limits. The whole thermal concept in all its parts undertook a detailed modelling phase in parallel to an experimental phase in vacuum chamber to improve the model and to qualify the system

A small mission for in situ exploration of a primitive binary near-Earth asteroid

We present a concept for a challenging in situ science mission to a primitive, binary near-Earth asteroid. A sub-400-kg spacecraft would use solar electric propulsion to rendezvous with the C-class binary asteroid (175706) 1996 FG3. A campaign of remote observations of both worlds would be followed by landing on the 1 km diameter primary to perform in situ measurements. The total available payload mass would be around 34 kg, allowing a wide range of measurement objectives to be addressed. This mission arose during 2004 from the activities of the ad-hoc Small Bodies Group of the DLR-led Planetary Lander Initiative. Although the particular mission scenario proposed here was not studied further per se, the experience was carried over to subsequent European asteroid mission studies, including first LEONARD and now the Marco Polo near-Earth asteroid sample return proposal for ESA’s Cosmic Vision programme. This paper may thus be of interest as much for insight into the life cycle of mission proposals as for the concept itself

Phase Change Material Heat Accumulator for the HEXAFLY Hypersonic Glider

From the launchers to the spacecrafts, various on-board systems have to be maintained within specified temperature limits. Phase Change Materials (PCM) offer the possibility to store thermal energy directly as latent heat of fusion. Among the advantages of a PCM device are the stability of temperature control, the absence of moving parts and a reduced mass. The HEXAFLY-INTERNATIONAL project aims to flight test an experimental vehicle above Mach 7 to verify its potential for a high aerodynamic efficiency during a free-flight. European Major Resarch Centers and Industries are collaborating on this challenge. The presented activity focus on the use of a Phase Change Material device already developed under ESA projects up to TRL 6. Two efficient heat accumulators using PCM will allow avoiding overheating of electronic units such as telemetry & telecommand receivers, transmitters and data acquisition units for the hypersonic flight. The paper presents the complete cycle of design and environmental testing for the two PCM Heat Accumulators selected for the flight. The conclusions will show the benefit of adopting a Phase Change Material Heat Accumulator