From École Polytechnique Fédérale de Lausanne(CH): “Army of robots pushes the limits of astrophysics”

From École Polytechnique Fédérale de Lausanne(CH)

Sarah Perrin

One thousand newly-minted microrobots created in EPFL(CH) labs will soon be deployed at two large-scale telescopes in Chile and the United States. These high-precision instruments, capable of positioning optical fibers to within a micron, will vastly increase the quantity of astrophysics data that can be gathered – and expand our understanding of the Universe.

The Universe is expanding, but there is still a great deal that we don’t know. How fast is it spreading? Why is the process speeding up, pushing various celestial objects away from each other, when the force of gravity should instead be drawing them together? What roles do dark matter and dark energy play? Questions like these – which are central to current astrophysics research – may soon find answers, thanks to a fleet of EPFL(CH)-designed microrobots.

These microrobots developed by EPFL(CH) scientists are expected to produce a surge in the amount and quality of astrophysics data we can gather thus expanding our knowledge. It consists of a collection of 1000 tiny robots which were recently manufactured and delivered to Ohio State University(US). In time they will be fitted to two telescopes – The Irénée du Pont telescope at the NOIRLab Carnegie Institution for Science’s Las Campanas Observatory in Chile, and the Sloan Foundation telescope at New Mexico’s Apache Point Observatory – which are part of the international Sloan Digital Sky Survey (SDSS). EPFL(CH) is playing an active role in the SDSS (see our article from July 2020).

NOIRLab Carnegie Las Campanas 2.5 meter Irénée Dupont telescope, Atacama Desert, over 2,500 m (8,200 ft) high approximately 100 kilometres (62 mi) northeast of the city of La Serena, Chile.

SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude2,788 meters (9,147 ft).

Apache Point Observatory, near Sunspot, New Mexico Altitude 2,788 meters (9,147 ft).

The robots will be used to automate the positioning of hundreds of optical fibers which serve to direct the telescopes towards objects in space. The primary targets will be stars within our own galaxy, the Milky Way. By measuring the stars’ luminosity, scientists can calculate the “redshift” (i.e., the increase in the emitted light wavelength) of nearby galaxies that harbor black holes or that are part of clusters, and determine how far away they are. These measurements will help flesh out SDSS’ 3D map of the Universe’s stars and galaxies.

A painstaking task

Up to now the optical fibers in the SDSS telescopes have been positioned by hand – a lengthy painstaking task that demands extreme precision. For the telescope to be able to observe celestial objects, hundreds of fibers need to be placed in holes set in a massive aluminum plate. There is no room for error: each fiber has to be positioned to the nearest micron to ensure that the image is perfectly in focus.

Under the current method, it takes a month to select the target stars and design, manufacture and drill the plates, which are then dispatched to the observatory. Then an experienced pair of hands needs 45 minutes to correctly position the thousand fibers. What’s more, on observing nights, twenty minutes are required to switch plates, during which the telescope is offline. “The Swiss robots speed up this process by orders of magnitude opening up the possibility of large-scale spectroscopic time-domain exploration”, rejoice Juna Kollmeier, Director of the SDSS-V project.

The positioner robots are expected to be operational at the Sloan telescope this fall and in Chile early next year.

Doubling and tripling the number of stars observed

“In addition to huge gains in flexibility and accuracy, we also hope to substantially increase the number of objects we can observe,” says Mohamed Bouri, head of EPFL’s(CH) Rehabilitation and Assistive Robotics group and the scientist in charge of designing the robots and getting them up and running. “This will allow us to shorten observation times and double or triple the number of stars and galaxies we can target. We will also be able to use spectroscopy to observe elements of the variable universe, such as exploding stars,” says Jean-Paul Kneib, head of EPFL’s(CH) Laboratory of Astrophysics (LASTRO).

This initiative is being spearheaded by EPFL’s(CH) Astrobots group, which aims to promote synergies between the fields of astrophysics and robotics. Since 2013, this cross-disciplinary group has been developing robotic systems to make astronomical observations more efficient. By late 2019, working closely with the University of Michigan(US) and the University of California at Berkeley(US), the group had already helped build 5000 robots for the Dark Energy Spectroscopic Instrument (DESI), which is designed to better understand dark energy.

There is little doubt that the DESI and SDSS will expand the horizons of both astronomers and astrophysicists alike, resulting – in the years to come – in a richer and more detailed map of the Universe. But this is just the beginning: EPFL(CH) scientists are already hard at work on a new generation of smaller, equally robust microrobots.

See the full article here .


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The EPFL-École polytechnique fédérale de Lausanne(CH) is a research institute and university in Lausanne, Switzerland, that specializes in natural sciences and engineering. It is one of the two Swiss Federal Institutes of Technology, and it has three main missions: education, research and technology transfer.

The QS World University Rankings ranks EPFL(CH) 14th in the world across all fields in their 2020/2021 ranking, whereas Times Higher Education World University Rankings ranks EPFL(CH) as the world’s 19th best school for Engineering and Technology in 2020.

EPFL(CH) is located in the French-speaking part of Switzerland; the sister institution in the German-speaking part of Switzerland is the Swiss Federal Institute of Technology in Zürich(CH) (ETH Zürich(CH)). Associated with several specialized research institutes, the two universities form the Swiss Federal Institutes of Technology Domain (ETH(CH) Domain) which is directly dependent on the Federal Department of Economic Affairs, Education and Research. In connection with research and teaching activities, EPFL operates a nuclear reactor CROCUS; a Tokamak Fusion reactor; a Blue Gene/Q Supercomputer; and P3 bio-hazard facilities.

The roots of modern-day EPFL(CH) can be traced back to the foundation of a private school under the name École spéciale de Lausanne in 1853 at the initiative of Lois Rivier, a graduate of the École Centrale Paris and John Gay, the then professor and rector of the Académie de Lausanne. At its inception it had only 11 students and the offices was located at Rue du Valentin in Lausanne. In 1869, it became the technical department of the public Académie de Lausanne. When the Académie was reorganised and acquired the status of a university in 1890, the technical faculty changed its name to École d’ingénieurs de l’Université de Lausanne. In 1946, it was renamed the École polytechnique de l’Université de Lausanne (EPUL). In 1969, the EPUL was separated from the rest of the University of Lausanne and became a federal institute under its current name. EPFL(CH), like ETH Zürich(CH), is thus directly controlled by the Swiss federal government. In contrast, all other universities in Switzerland are controlled by their respective cantonal governments. Following the nomination of Patrick Aebischer as president in 2000, EPFL(CH) has started to develop into the field of life sciences. It absorbed the Swiss Institute for Experimental Cancer Research (ISREC) in 2008.

In 1946, there were 360 students. In 1969, EPFL(CH) had 1,400 students and 55 professors. In the past two decades the university has grown rapidly and as of 2012 roughly 14,000 people study or work on campus, about 9,300 of these being Bachelor, Master or PhD students. The environment at modern day EPFL(CH) is highly international with the school attracting students and researchers from all over the world. More than 125 countries are represented on the campus and the university has two official languages, French and English.