The question of whether there is life on Mars has fascinated mankind for generations, and it is the question the Curiosity and ExoMars missions are attempting to answer. Air Liquide is involved in these two exploration programmes, which aim to detect any possible traces of life.
Mars hit the headlines again this week following the discovery of what seems to be a giant lake of liquid water. Buried beneath the ice near the red planet’s South Pole, this is a significant milestone in the quest to determine whether life exists there.
Found by the Italian Space Agency (ASI), the presence of liquid water at the base of the Martian polar caps has long been suspected but not observed. The lake beds are similar to those explored by NASA’s robotic rover Curiosity, which is fitted with Air Liquide technology, and show water was present on the surface of Mars in the past.
NASA previously found research to suggest liquid water flows intermittently on the Martian surface, but this is the first sign of a persistent body of water on the planet in the present day.
This is the second big discovery on Mars in just over a month. At the beginning of June, Curiosity found new evidence preserved in rocks that suggests the planet could have supported ancient life, as well as new evidence in the Martian atmosphere that relates to the search for current life on the Red Planet.
Was there ever – or is there still – life on Mars? Curiosity landed on the red planet in August 2012 in order to answer that question. It discovered traces of water but was ultimately unable to take water samples from these wet areas for fear of destroying any life that may exist there. It ran the risk of contaminating the surface of Mars with terrestrial microbes that it may have brought with it.
The exploration rover on the next mission to Mars, ExoMars 2020, will be sterilised. This robot, a veritable laboratory on wheels, will be launched in August 2020 on a Proton rocket. It will be fitted with a drill for taking samples from deep under the surface, far from the cosmic rays and oxidation that destroy organic matter.
Air Liquide was tasked with installing the SAM (Sample Analysis at Mars) chromatograph’s capillary tubes, which is used to separate Martian molecules before they are analysed by Curiosity’s instruments. It was the Tier One company’s unique micro-brazing and micro-soldering expertise, developed on its site in Sassenage, France, that enabled Air Liquide to be part of the Curiosity project.
In particular, a technique for crimping the capillary tubes before brazing was developed to meet the requirements of the space industry.
“NASA people were really welcoming and impressed by ‘this French guy’ from Air Liquide who was brazing such tiny tubes,” said Benoît Hilbert (left), Managing Director of Air Liquide Advanced Technologies, as he spoke to gasworld about Air Liquide’s involvement in more detail.
“Air Liquide had already collaborated with NASA on several programmes, including the MELFI cryogenic refrigerator aboard the International Space Station and the Cryosystem transport and storage dewar, which was regrettably cancelled after the Columbia space shuttle accident.
“We have supplied other sub-systems for space applications, notably the Planck and Herschel programmes, or more recently other cryocoolers for earth observation applications.”
“Air Liquide has also contributed to French, European, Russian and even Chinese space programmes.”
“It is obviously very exciting to be part of such projects and to know that our expertise is at work millions of kilometres away out in space, looking for answers to some of the most fundamental questions of mankind.”
For both the Curiosity and ExoMars programmes, Air Liquide was approached by the LISA (Laboratoire Interuniversitaire des Systèmes Atmosphériques) and LATMOS (Laboratoire Atmosphères, Milieux, Observations Spatiales) laboratories.
“In both cases, LATMOS/LISA were the prime contractors of a scientific instrument for which the Air Liquide knowhow on welding and brazing on extremely fine parts under space quality conditions was required. Air Liquide had been recommended after the good performances realised on the Planck dilution cooler,” Hilbert revealed.
The SAM-GC instrument (Sample Analysis at Mars – Gas Chromatograph) was designed and manufactured by LATMOS/LISA. “The capillaries to braze were 0.25mm large and 0.05mm thin. Our technician, in charge of the project, assembled the final parts of the chromatograph on NASA’s site in Washington. This operation required extraordinarily fine solders, with unparalleled precision,” he explained.
“After SAM instrument delivery to NASA, some parts had been damaged and Air Liquide was requested to come to the Goddard NASA center to repair. In particular, the detector had to be changed and damaged capillaries had to be repaired.”
The ExoMars programme launches in 2020 and as with Curiosity, Air Liquide has been tasked with assembling the capillary tubes for the chromatograph in the mission’s main instrument, the MOMA (Mars Organic Molecule Analyser), which was developed by LISA to detect biological activity. This work, carried out in an ISO5 clean room, is all the more painstaking because the MOMA must be sterile in order to avoid contaminating any potential life on the planet.
“The contribution from Air Liquide to MOMA is more significant than on SAM,” Hilbert said. “On MOMA, beyond the capillaries and other components welding, a miniature pressure regulation valve and a miniature latch valve have been developed and qualified.”
“The pressure regulation valve (called PCV) is based on a design of a thermal valve initially developed by the Max Planck Institute and used on the ROSETTA mission (COSAC instrument) and curiosity (SAM) as a high pressure isolation valve.”
“On MOMA the valve will also have a regulation function. The added complexity on MOMA was the high cleanliness requirements.”
Concluding, Hilbert said, “The possibility of life on Mars is still an open question, but the hope of finding evidences of life (past or present) is not totally abandoned and space exploration continues on Mars.”