Weather in Mars!

Vaisala has just published a new video describing the robotic weather station aboard NASA’s Perseverance rover, which is currently conducting investigations on the planet Mars. 

The video features Jose Antonio Rodriguez Manfredi, MEDA (Mars environmental dynamic analyzer) Principal Investigator, who explains how the instrumentation is characterising, monitoring and studying atmospheric dynamics on Mars. This information, he explains, will be essential in the preparation for future human visits – helping to design astronaut suits for example.

• More Vaisala videos of this project.

• How's the weather on Mars? (Aerospace America - Jul/Aug'21)

@VaisalaGroup @aiaa @NASAPersevere @_Enviro_News #Astronautics #Automation 

More news from the Red Planet!

NASA’s Perseverance rover has now spent its first months on the surface of Mars. The testing and deployment phase is proceeding well, and after the first technology demonstration with the Ingenuity helicopter, the rover is commencing the continuous scientific measurements. With the arrival of the humidity and pressure measurement instruments onboard Perseverance, the first meteorological network on another planet is being created.

This picture, taken by Perseverance’s navigational camera,
shows the MEDA HS humidity measurement instrument. 

The Perseverance rover landed successfully on Mars in February 2021 and will now explore an ancient river delta in the Jezero Crater for at least the next Martian year, which is approximately two Earth years. After the landing, the rover stretched its robotic arms and has already delivered a good number of high-quality photos, videos, and audio samples back to Earth.

The rover’s Mars Environmental Dynamics Analyzer (MEDA) instrumentation suite, developed by a Spanish-led research consortium, has also been deployed. MEDA is a weather station that has been developed specifically for the conditions on Mars. Instruments by the Finnish Meteorological Institute (FMI) and Vaisala are included in the MEDA suite to measure pressure and humidity conditions on Mars. The measurements and local wind data provided by the MEDA suite is also used by the Ingenuity Helicopter.

The measurement instruments need to be able to deliver reliable high-quality measurements even after the long space journey.

“Accurate and reliable science-based measurements are at the core of Mars research. That’s why it is great to receive verification that our sensors are working in the extreme conditions on Mars, even after the demanding space journey. Vaisala’s measurement technology is at its best in challenging measurement conditions,” says Liisa Åström, Vice President of Products and Systems at Vaisala.

“The equipment on Mars needs to work in all conditions and is tested accordingly. Manufacturing, testing, and finalizing the measurement instruments has been a major project lasting many years, so it feels great to see the instruments finally at work on Mars,” summarizes Maria Hieta, Research Engineer at FMI.

Hieta continues: “For instance, the humidity measurement instruments on Perseverance have gone through a tough selection process. FMI built 13 different instrument models around the humidity sensor, and these models were tested several times in harsh conditions such as very low temperatures. Additionally, the tests exposed them to vibration and shocks. The most reliable model was chosen as part of the MEDA equipment.”

First measurements reflect expectations
The MEDA equipment has now delivered the first round-the-clock measurement series on pressure and relative humidity to Earth. The measured values correspond to what was expected.

“The pressure levels and variation according to the time of day in the Jezero Crater reflect our models well. Relative humidity is practically zero (0% RH) during the day and rises during the night as the local temperature falls to nearly -80 °C. For comparison, 20 percent relative humidity is considered very low on Earth, and relative humidity near zero is hardly ever measured. The pressure data has also let us observe dust devils passing Perseverance, showing them as fast and sharp declines in the pressure signal,” explains Maria Genzer, Group Leader of Planetary Research and Space Technology at FMI.

Martian weather conditions and atmosphere interest Finnish researchers
The Perseverance rover has been designed to explore Mars’ conditions and geology as well as to search for signs of ancient life. Even though signs of life are fascinating, Finnish researchers are especially interested in the Martian atmosphere.

“Earth and Mars share a lot of similarities, which is why we find the study of Mars’ atmosphere so fascinating: it helps us to understand the behavior of Earth’s atmosphere. Additionally, dust storms on Mars can be harsh, so it is crucial to be able to predict the storms if we are to send manned space missions to Mars in the future. For this reason, Mars needs a weather station network,”Maria Genzer says.

Meteorological observation network based on Finnish expertise Perseverance and the Curiosity rover, which landed on Mars in 2012, provide measurements approximately 3,700 kilometers apart from each other. Both rovers carry similar Finnish pressure and humidity measurement instruments, which deliver data that is sent to Earth for analysis.

The data from the rovers, combined with observations from NASA’s InSight Lander on Mars, form the first three-point meteorological observation network on another planet. The network will enable even more accurate modeling of Mars’ atmosphere and its phenomena.

“In the future, we hope to get more measurement points on Mars. This is the ultimate goal for example in our MetNet program, in which we are developing small probes that will impact and penetrate Mars’ surface. These probes would then form a comprehensive meteorological observation network on the planet,” explains Maria Hieta.

The Mars 2020 mission is a part of NASA’s Mars exploration program. One of the main tasks of the Perseverance rover is to gather and store a series of rock and soil samples that can be brought back to Earth for analysis in the future. Finnish technology is scheduled to be launched to Mars again in 2022 aboard the ExoMars mission by the European Space Agency (ESA) and the Russian space agency Roscosmos.

* Read-out coverage on the Perseverance project & Mars Explanation. 

@VaisalaSuomi, @VaisalaGroup @NASAPersevere @_Enviro_News #Astronautics #Automation #Mars

Continuing the European exploration tradition.

John O’Sullivan has has over 20 years’ experience in the automation and control sector delivering solutions to the life-science industry in Ireland. He is currently Engineering Director with Douglas Control and Automation.

He has always had a fascination with aviation and space, leading him to gain his PPL in 2003 and to study Astronomy and Planetary Science with the Open University. He was awarded a Certificate in Astronomy and Planetary Science and a Diploma in Physical Science by the OU some years ago as well as a Diploma in Project Management from the Cork Institute of Technology. He was an unsuccessful candidate for the European Space Agency (ESA) Astronaut Corps in 2008.

He has now published “In the footsteps of Columbus” (ISBN-10: 3319275607), telling the story of the ESA astronauts and their work on board the International Space Station over its first decade and how they have lived on board, helped construct the space laboratory and performed valuable scientific experiments.

ESA has contributed the Columbus science laboratory as well as the Copula, the Leonardo PMM and the ATV supply ship to the station’s infrastructure but it is the human endeavour that captures the imagination. From brief visits to six month expeditions, from spacewalking to commanding the Earth’s only outpost in space, ESA astronauts have played a vital role in the international project.

Extensive use of colour photographs from NASA and ESA depicting the experiments carried out, the phases of the ISS construction and the personal stories of the astronauts in space highlights the crucial European work on human spaceflight.

Published by Springer Praxis it may be purchased directly from the publisher as a paperback or as an e-book.

Scanning the skys!

Motion sub-system is selected for ultra-precision plate scanner at the Royal Observatory of Belgium

The DAMIAN ultra-precision scanning system at the Royal Observatory of Belgium (ROB) fulfils a significant part of a global programme for the digitisation of astrometric plates and aerial photographic images that span over a century and has shaped our understanding of the world, the solar system and the universe. With more than three million plate images estimated in the astronomical community alone, the programme was borne out of a need to provide a much needed centralised archive for the digital age, to enhance the accuracy of predictive ephemerides and not least to preserve the heritage of this important work where media deterioration is an increasing problem, particularly for older photographic processes. As part of an international network of institutions involved in similar work, the ROB has become a global centre of excellence particularly where extreme levels of accuracy are required such as astrometry plates.

One particular exacting project example at the ROB involves digitising thousands of photographic plates for the US Naval Observatory. Taken over a period of 30 years several decades ago, using a 26-inch refractor telescope, the photographs record the moons of Mars, Jupiter and Saturn. By combining the process with highly sophisticated measurement and prediction software, DAMIAN can actually fill in many gaps that have hitherto been difficult to calculate. By improving this understanding of the interactive motions and internal structure models of these solar system bodies, the accuracy of calculation for their future positions over time is significantly improved. Other work carried out has similar significant implications for galactic kinematics, space surveillance and other areas of research in high precision aerial mapping.

The ROB began development of the DAMIAN (Digital Access to Metric Images Archives Network) digitiser with a study that produced design specifications for a 350 mm x 350 mm X-Y scanning motion system. To ensure the perfect reproducibility of the original analogue photographic images, the positional accuracy and repeatability targets needed to be an order above the inherent accuracy for the plates. This value was interpreted in the region of 0.5 microns over the whole scanning area with respect to a fixed telecentric objective of a sophisticated digital camera system. To ensure the fastest possible throughput, the motion system required a full move displacement of 10 mm in less than half a second including acceleration, deceleration and settling time and once in position, the stability (jitter) requirement was just 20 nanometres. These factors would ensure that the plates could be fully scanned and archived in a matter of minutes rather than older methods which were less accurate and required hours of processing. The machine specification also called for automatic loading of the glass photographic plates and film rolls, with a working duty cycle close to 24/7 continuous and unattended operation - so high reliability, low maintenance and long working life were also critical factors.

To realise such extreme precision and dynamic performance, the ROB chose Aerotech for a complete motion sub-system based upon its ABL3600 series open-frame air bearing table in a custom engineered system solution that included a lapped granite base plate, a granite bridge with a vertical focussing axis for the camera and optical assembly, plus a photographic plate holder, plate storage tower and fully automatic transport system.

Now delivered and fully commissioned, the DAMIAN digitiser is housed in a temperature and humidity controlled clean room, maintained to within 0.1ºC and 1%RH. Aerotech’s ABL3600 series X-Y stage includes a preloaded, high-stiffness air bearing system that has been perfected over many product generations featuring powerful dual brushless and slotless linear motors on each axis with glass scale linear encoder servo feedback. Two granite rails form a reference for the lower axis and both axes are referenced to a lapped granite surface plate with passive air isolation to maximise vibration stability.  In combination with this positioning system and fundamental to the machine's overall dynamic performance, Aerotech's linear technology servo amplifiers guarantee exceptionally smooth motion, high bandwidth and outstanding in-position stability with zero backlash or hysterisis. The friction free mechanics also provide the added benefit of very low maintenance and an essentially limitless working life. The large through aperture of the open frame design allows back illumination for the plates and images. The design of the ABL3600 has a pedigree of successful applications in semiconductor fabrication and test, and is a well matched solution for demanding scanning microscopy, imaging and step & repeat positioning applications.

For the ROB, Aerotech extended the ABL3600's normal working travel range from 250 mm to 350 mm in both axes. For such high precision applications, Aerotech's HALAR calibration firstly ensures optimal levels of accuracy, bi-directional repeatability, straightness and flatness for each axis then performs error mapping with laser based measurement systems at Aerotech's state-of-the-art metrology lab - with the calibration file pre-configured on the motion controller.  During tests at Aerotech and on-site at the ROB, object locations on a calibrated test plate were repeated to within 70 nanometres over a usable X-Y travel range of 335 mm – this far exceeded the original working specification.  Other impressive results included geometric test for accuracy and repeatability to better than +/- 0.1 micron and the displacement speed and  in-position stability performance were fully met.

The DAMIAN ultra-precision scanning system includes a full cable management system and was delivered complete with Aerotech's A3200 Automation Platform motion control system which controls the main X-Y axes as well as several other motion axes for film wind, plate stacking and tray height adjustment. The ROB took care of interfacing the A3200 to its own imaging software using a step and repeat procedure with alignment accuracy ensured using selected objects on the photographic media. Images are recorded at stand-still, thus the need for such high in-position stability.
The  PC based software-only motion and machine controller provides position, velocity and time information to  Firewire® interfaced linear technology servo drives.  A range of optional modules include HMI, soft PLC and vision control. The fully deterministic controller can be programmed using Aerotech’s own AEROBasic™, RS274 G-code and LabviewTM. Alternatively programmers can call upon the powerful Microsoft® .NET development environment to help reduce project development timescales with C, C++, VisualBasic® or Delphi based programming.

This application is fairly typical for Aerotech's engineered systems approach where customers provide their own very specialised expertise in combination with a fully tested and certified motion sub-system which fulfils a very intrinsic 'enabling technology' element for the entire system.