Saft lithium-ion battery system to power ExoMars Rover
Saft has signed a contract with Airbus Defense and Space to develop a new lithium-ion battery system to power the ExoMars Rover, a key vehicle part of the ExoMars programme which aims to explore for evidence of life on Mars. Lithium-ion batteries are a favourable choice as they are light and the cells can still perform in demanding temperature fluctuations of around -40 °C to 85+.
The objective of the ExoMars Programme is to search for evidence of current or extinct life on the red planet as part of a branch of science called exobiology. The 300 kg (661 lbs) Rover will land on the surface of Mars before moving between a number of sites and drilling into the surface to capture samples for analysis by its onboard scientific instruments.

Saft has signed a contract worth more than €1 million (US$1.1 million) from Airbus Defence and Space Ltd (UK) to develop, to qualify and to test a specific lithium-ion (Li-ion) battery system to power the ExoMars Rover vehicle. The Rover is the key component of the ExoMars Programme , run jointly by the European Space Agency (ESA) and Roscosmos, the Russian Federal Space Agency. Thales Alenia Space Italia SpA is the ExoMars prime contractor.

Battelle smart grid technology for human deep space missions Battelle has completed work on a contract from NASA Glenn Research Center exploring how smart grid technology could help astronauts safely explore deep space. Battelle and Elequant, the US subsidiary of Grupo AIA, have submitted a final report on the technology, which uses Battelle’s patented HELM (Holomorphic Embedding Load-Flow Method) algorithm (earlier post) to increase the reliability and operation of both deep-space manned missions beyond Mars, as well as terrestrial applications to the all-electric passenger aircraft that are on design boards now. The need for intelligent, fault-tolerant autonomous control of the spacecraft power management and distribution system is paramount for deep space missions. The technology mathematically guarantees stable operation of the power system and should an electrical fault occur, can chart a solution from power failure to recovery, leaving astronauts to perform other important tasks. The second phase of the NASA contract calls for a test of the approach on an Earth-bound microgrid representing a deep space module’s power system. The potential answer for deep space power safety and reliability is designed to prevent blackouts on Earth and has been marketed and sold to North American power suppliers. This potential answer for deep space power safety and reliability is designed to prevent blackouts on Earth and has been marketed and sold to North American power suppliers.

The ExoMars Rover’s power system will comprise solar panels capable of producing 1200 Wh working in combination with Saft’s 1142 Wh (nominal) battery system. The system will store the energy generated by the solar panels to ensure uninterrupted operation during the Martian night.

The ExoMars Rover battery system is based on Saft’s high energy density (264 Wh/l and 150 Wh/kg) MP (medium prismatic) 176065 Integration xtd 5.6 Ah cells. Saft developed the xtd series to ensure reliable, high performance power for outdoor industrial equipment in demanding applications including oil and gas, utility management, industrial automation, lighting and signaling, tracking and automotive telematics.

An advantage of these Li-ion cells is their compact, lightweight design that minimizes the overall battery mass, so that more of the mission payload can be utilized for scientific instrumentation. Furthermore, the cells have been developed to deliver high performance in demanding operating conditions, even when subject to extreme fluctuations in temperature from -40 ˚C to +85 ˚C.

Because any potential life on Mars may take the form of delicate bacterial cultures, ESA has placed a high priority on ‘planetary protection’. This requires an exceptionally high level of cleanliness to avoid contaminating any complex organic molecules that may be found.

Saft is scheduled to deliver the battery system before the end of 2016 to meet ESA’s launch plans for 2018. It is being manufactured in an ultra clean environment to ensure planetary protection.