Journal Publication on Oxide Formations in MoS2

In addition to her “day job” within the European Space Tribology Laboratory (ESTL), Project Scientist Kristine Dreva has found the time to publish a journal article on the effect of temperature in molybdenum disulphide (MoS2) coatings, investigating the structural changes with temperature increase and linking any changes to friction and wear behaviour. This article was produced in collaboration with University of Leeds, where Kristine is in the final stages of her PhD focusing upon solid lubricant development and analysis.

Thin films of PVD MoS2 are one of the most commonly used solid lubricants for space applications due to their excellent friction and wear properties under vacuum. However their tribological properties in moist air environments are less encouraging, due to increased wear rates and higher friction. As exposure to air is often unavoidable, extensive research into the failure mechanisms of MoS2 in air is essential to understand the optimal operating conditions required to minimise damage to the coating’s lamellar structure.

Kristine’s recent journal article analyses how a small temperature increase can affect oxide formation and water desorption within the coating, and how this links to the coating tribological performance. The difference between running MoS2 coating in air at room temperature and at 75deg.C is clear, where a protective 3rd body film is generated at increased temperature.

This article will be published in March’s issue of Surface and Coatings Technology, and can be accessed via the following link, or by This email address is being protected from spambots. You need JavaScript enabled to view it..

Kristine Dreva

The Wonderful World of In-Situ Bearing Testing

Ever wondered what’s really happening in a bearing contact? What happens when you run a solid lubricated bearing in air? How a grease lubricant behaves compared to an oil? The Advanced Bearing Test Rig (ABTR) at ESTL is helping us answer those questions.

The Advanced Bearing Test Rig (ABTR) at ESTL

Tribology is complicated. Various tribometers exist to remove some of this complexity so that lubricant behaviour can be studied in simplified contacts in some detail, but eventually the performance of new/existing lubricants needs to be evaluated in real components. This is where ESTL’s Advanced Bearing Test Rig (ABTR) can help.

Traditional bearing test rigs might only allow you to measure the bearing torque which is useful but lacks context. Is that high friction due to wear, a lack of lubricant or maybe even too much lubricant? The ABTR allows us to measure preload changes, electrical resistance changes and most importantly the axial shaft displacement which is a measure of the average lubricant film thickness in the bearing contacts. This can be done under vacuum and across different temperatures. Such information allows us to detect which lubrication regime the bearing is operating in, how much of the ball/raceway contact area is metal-to-metal when in boundary lubrication and even the very first onset of wear as the lubricant becomes less effective.

Recent work using our ABTR facilities has included the ongoing validation of a new self-lubricating polymer cage material, a promising replacement material for PGM-HT. This study, presented at the ESMATS 2021 conference, and also available in Europe and Canada online through our Members Area in our Technical Memo (ESA-ESTL-TM-0297 01-) showed a potential improvement in lifetime and performance based on the test results.

Typical axial shaft displacement measurement from ABTR for an oil lubricated bearing at different temperatures

For more information on the ABTR and how ESR Technology’s in-situ bearing measurements can benefit your space applications, please contact Research and Development Engineer This email address is being protected from spambots. You need JavaScript enabled to view it..

Hazards 31

Technical Paper on “Comparisons of the Predictions on the dispersion model DRIFT with the data for Hydrogen, Ammonia and Carbon Dioxide” to be presented at Hazards 31 Virtual Conference

The increased interest and use of decarbonisation technologies highlights the importance of establishing the validity of existing consequence tools traditionally used for hydrocarbon and chemical hazards when applied to these new technologies.

DRIFT is an integral model developed by ESR Technology for predicting the dispersion of gaseous and two-phase releases in the atmosphere. The technical paper presents the results of new validation studies comparing DRIFT predictions with previously published dispersion data for hydrogen, ammonia (FLADIS) and carbon dioxide (CO2PIPETRANS). Key aspects differing from previous DRIFT validation are:

  • Hydrogen – application at lower molecular weight and higher pressure
  • Ammonia – interaction of ammonia with condensed water and the effects on aerosol composition and cloud behaviour
  • Carbon dioxide – inclusion of the thermodynamic effects of dry ice sublimation

For further information please contact Terry Atkinson at This email address is being protected from spambots. You need JavaScript enabled to view it. or visit

Hazards 31

Hazards 31

Technical Paper on “Linking critical competencies with major accident hazards” to be presented at Hazards 31 Virtual Conference

The importance of competence in the management of major accident hazards has been recognised for some time. However, developing effective systems to support this has proved to be difficult.

This presentation describes a recent scope of work for a North Sea Duty Holder that aimed to develop an effective system for identifying critical high-level competencies across an organisation, with a clear and transparent link to major accident hazards.

It dispels the myth that competence can only be achieved by sending people on training courses and highlights that people at all levels of the organisation need to have competence in the management of major accident hazards.

For further information please contact Terry Atkinson at This email address is being protected from spambots. You need JavaScript enabled to view it. or visit

Hazards 31

ESR Technology to Drive Sustainable Solid Lubricant Development for Space

ESR Technology is proud to announce the award of a contract from the European Space Agency to develop a new solid lubricant solution for long-life space mechanism applications.

To meet increasingly demanding performance requirements in terms of mission duration, telecom satellite mechanisms (and many others too) have for many years employed solid lubrication, typically very thin films (a fraction of the thickness of a human hair) of low shear strength metals such as lead (Pb) applied by magnetron sputtering. Typical applications include ball bearings and gears of Solar Array Drive Mechanisms (SADMs) and associated actuators, deployment actuators/damping devices and antenna pointing/trimming mechanisms.

Lead BearingBearing

However, concerns over the environmental and health aspects associated with the use of lead in many industrial applications, including for space, continue to grow. In 2018 lead was identified as a Substance of Very High Concern (SVHC) by the ECHA (European Chemicals Agency), and whilst not imminent, there is a high likelihood of its prohibition under the EU REACH legislation for environmental reasons. Latest indications are that lead prohibition could come within the next 5 years.

In anticipation of the need to migrate current telecom space applications onto alternative, equally high performance, but more sustainable solid lubricants, the European Space agency has recently kicked-off a two year lubricant development project which is led by ESR Technology. Working alongside our project partners, Light Coatings Ltd and The University of Southampton, in this project ESR Technology will develop an enhanced, lead-free solid lubricant for space use; a task which will draw on the collective expertise of the team in solid lubricant development and production, assessment of lubricants operating in vacuum, analytical capabilities and productisation for the space market.

For more information on this project and how ESR Technology is leading the development of sustainable solid lubricants for space applications, please contact Principal Project Scientist This email address is being protected from spambots. You need JavaScript enabled to view it..

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