The observation of space has deep roots in Padua and its University. From the mathematical-astrological studies of Pietro d’Abano in the 14th century, to the construction of intricate mechanical astronomical devices by Giovanni Dondi dell’Orologio in the 15th century, and culminating in the scientific revolution brought about by Galileo Galilei during his eighteen years of teaching in Padua, the study of our solar system and the cosmos has always been a central focus of research in this city.
With the technological advancements of the 20th century, it became possible to send spacecraft beyond Earth's atmosphere, marking the beginning of the space exploration era. Close observation of planets, comets, and asteroids through satellites and space probes necessitated cutting-edge scientific research to develop advanced scientific instruments.
Among the pioneers in this field, Giuseppe Colombo (1920-1984), professor of Celestial Mechanics in Padua, played a fundamental role. A collaborator with NASA, he was among the first in Italy to promote the idea of organised space exploration among academic and space agency circles. His insights led to the success of NASA's Mariner 10 mission to Mercury in 1974, and to the development of the tethered satellite project. His legacy is a long, unbroken thread that connects all past, present, and future international space missions in which our University is involved.
Imagine unspooling a 20-kilometer cable with a satellite weighing about half a ton at its end. We are in space, and to ensure its functionality in such environmental conditions, the cable only needs to be a few millimeters in diameter.
This long tether ensures orbital control of the satellite, and if the cable is conductive, it can alter the satellite’s orbit by interacting with Earth's electromagnetic field to generate enough electricity to be used as propulsion. The long cable also allows access to the lower layers of the atmosphere, where satellites cannot orbit because they would quickly fall due to atmospheric drag, being too close to Earth.
Developed based on the ideas of Mario Grossi and designed using Giuseppe Colombo’s research, the Tethered Satellite System (TSS) was launched into orbit with NASA missions in 1992 and 1996. Despite technical issues in the first mission and the cable snapping, which caused the loss of the satellite in the second, the results confirmed the validity of the scientific principles, allowing further development and research into this innovative system.
Today, the cable has evolved into a more durable and conductive aluminum tape, forming the basis of a system developed in Padua to deorbit satellites at the end of their life (E.T. PACK), bringing them into collision with Earth’s atmosphere. This solution is increasingly necessary due to the overcrowding of Earth's orbital space and the high number of space debris objects surrounding our planet.
The E.T.PACK project, funded by the European Innovation Council (EIC), is the evolution of electrodynamic tether systems, with TSS-1 being its precursor. These new ribbon-based systems have the capability to move satellites at altitudes ranging from 250 to 2,000 kilometers above Earth's surface, using electrodynamic forces generated by the interaction between the ribbon and the near-Earth space environment. In other words, they are "electrodynamic space sails" that do not require chemical propellant to carry out maneuvers or orbital changes. The system employs a 420-meter-long ribbon and will be integrated into larger satellites in the future. At the end of the satellite's life, E.T.PACK will activate to ensure a swift re-entry, guiding the satellite to burn up in Earth's atmosphere, thus reducing the number of non-operational satellites in orbit.
E.T.PACK system ribbon deployer
Prototype used for laboratory testing.
For further information: etpack.eu
Ribbons for the future E.T.PACK-F mission, used for hypervelocity impact tests with small debris to assess their survivability in the space environment.
Polyether Ether Ketone (PEEK) ribbon
This light yellow ribbon is mounted in series with the aluminum ribbon to facilitate the final stages of deployment.
1200-H19 aluminum alloy ribbon
This silver-colored ribbon, 25 mm wide, has a minimal thickness to ensure it remains lightweight and flexible.
Samples of tethers designed for individual missions to meet electrical, mechanical, thermal, and micro-meteoroid impact survival requirements.
Beige-coloured conductive wire
Externally insulated with Copper/Teflon/Kevlar/Nomex materials. Used in the TSS-1 and TSS-1R missions (1990s).
White-coloured non-conductive wire
Made of braided Spectra-1000 filaments. Used in the SEDS-I and SEDS-II missions (1990s).
Bare conductive wire (green-coloured)
Insulated conductive wire (gold-coloured)
Made of braided aluminium around a Kevlar core, these two wires are mounted in series in the final construction. Used in the ProSEDS project (2000s).
When designing a satellite, before building the final version, a detailed model called an "engineering model" is created. This model is a replica of the final satellite in terms of shape, size and functionality.
The model is placed in environments that simulate space conditions, such as extreme temperatures or reactions to sudden movements and vibrations, to ensure the satellite can withstand the challenges of being in orbit.
These tests are crucial because they help identify and resolve potential issues before the actual satellite is built and launched into space. This process reduces the risk of malfunctions and ensures the satellite operates as expected once it reaches orbit.
This model represents one of the two telescopic booms that would be extended from the TSS satellite once it reached 20 km from the Space Shuttle.
The boom carries various scientific instruments at its tip to measure the electrical and magnetic properties of the surrounding environment at a maximum distance of about 3 meters from the satellite. This allows scientists to study the satellite’s ability to collect electrons from the surrounding environment, enabling the flow of current through the electrodynamic tether.
Imagine launching a probe into deep space to uncover the secrets of comets and distant planets. Space travel is one of humanity's most complex challenges, requiring scientific, engineering, and technological expertise to overcome the difficulties of a hostile environment.
When Giotto painted Halley's Comet in the Scrovegni Chapel in Padua, he could not have imagined that, seven centuries later, we would be able to study it through close-up photographs. This became reality in 1985, when Padua collaborated with the European Space Agency (ESA) on the mission that sent the Giotto probe into space to study Halley's Comet. Eight months and 150 million kilometers later, the probe captured unprecedented images thanks to the Halley Multicolor Camera (HMC). Another comet was the subject of the Rosetta mission. Launched in 2004, the probe reached comet 67P/Churyumov-Gerasimenko after more than ten years of travel, including two and a half years in hibernation. The OSIRIS optical instrument provided the world with images of the comet's nucleus and coma, leading to significant scientific discoveries about the formation and behaviour of comets.
Reaching Mercury requires more energy than reaching the outer edge of the solar system. Until 2004, when NASA launched its MESSENGER probe, the data provided by the Mariner 10 probe were the only ones available to scientists for many years. In 2018, ESA and the Japan Aerospace Exploration Agency (JAXA) launched the BepiColombo probe, named after the Paduan mathematician. Its “eyes” (the SIMBIO-SYS optical instrument) were developed in Padua, and once it reaches Mercury's orbit, they will allow us to study and deepen our understanding of the planet.
Of the five probes sent to encounter Halley's Comet, Giotto came the closest, reaching a distance of 596 km from the comet. Using the Halley Multicolour Camera, it captured over 2,000 images of the nucleus and inner coma.
The nucleus of Halley turned out to be much darker than expected (darker than soot), leading scientists to revise the understanding of comets as "dirty ice balls".
Spare mirror of the Halley Multicolour Camera (HMC)
Padua contributed not only to defining the mission but also to the construction of the camera itself, producing the 45° mirror and sunshield.
The OSIRIS optical system aboard the Rosetta probe captured unique images of the comet's nucleus and its gas and dust emissions. These images led to significant scientific discoveries about the formation of comets and their activity.
3D model of the comet's nucleus
The 1:10,000 scale model was produced by combining thousands of images and measurements from OSIRIS's Wide Angle Camera (WAC) and Narrow Angle Camera (NAC).
OSIRIS revealed that the comet’s nucleus consists of at least two separate objects, held together by the weak gravity of the system.
SIMBIO-SYS is the suite of three optical instruments on the BepiColombo mission: a high-resolution camera (HRIC) for detailed studies of Mercury’s surface, a stereo camera (STC) to provide 3D global coverage and color images, and a Visible-NIR spectrometer (VIHI) for analyzing surface composition.
The stereoscopic images and spectra captured by SIMBIO-SYS will be processed to create a global 3D map of the entire planet.
Exploded Structural Model
of the three units that make up SIMBIO-SYS (HRIC, STC, VIHI).
When we imagine a spacecraft floating in space, we often picture it moving gracefully to the rhythm of a Strauss waltz, influenced by Kubrick’s cinematic vision, which has become part of our collective imagination. However, every success—and every failure—is the result of years of planning and collaboration among a global network of people and organisations: international space agencies, research centres, and universities, all united to achieve the impossible.
Studying future space missions means imagining with freedom, while at the same time planning every detail with precision. This requires interdisciplinary skills, access to specialised hardware and software infrastructure, and constantly updated knowledge, along with a schedule that accounts for the time span between a probe's launch and its arrival at its destination. At the same time, the freedom of research and teaching, inherent to universities, is essential for pushing the boundaries of knowledge.
From the first collaborations with NASA to the projects with various space agencies that have involved our University over the past forty years, the future of aerospace research passes through Padua. The Plato mission, scheduled for 2026, will observe more than 300,000 stars in search of new planets outside our solar system, possibly discovering some that may be habitable. In 2028, the Rosalind Franklin rover, part of the ExoMars program, will explore the surface of Mars, moving autonomously and collecting samples up to a depth of two meters. One of the major challenges of the next decade will be the exploration of Uranus, the second farthest planet from the Sun. NASA’s Flagship Uranus Orbiter and Probe mission could provide answers to fundamental questions: how did our solar system originate? How have celestial bodies evolved?
Mathematician, physicist, and engineer, Giuseppe Colombo (Padua 1920-1984) revolutionised our understanding of space dynamics with his innovative theories. A professor at the University of Padua from 1961, he conducted research in astronomy, astrophysics, and celestial mechanics. In just a few years, his scientific reputation grew to the point where he was considered one of Europe’s foremost experts in the field, sought after by the United States and recruited by the Smithsonian Astrophysical Observatory to tackle the challenges of the new space age.
His most famous contribution is related to the exploration of Mercury. Invited by NASA to discuss the Mariner 10 mission, scheduled for 1973, Colombo suggested a modification to the probe’s trajectory, allowing for three flybys of the planet instead of one. This led to the collection of a significantly larger amount of data.
Another major insight tied to Giuseppe Colombo’s name, along with Mario Grossi, is the principle of the tethered satellite system (TSS). This innovation is particularly suited to the weightless environment of space. The tether can be used to explore new engineering solutions such as space elevators or microgravity platforms, which could be applied to orbital stations in the future. Colombo’s ingenuity contributed to various space exploration projects, including the design of the Giotto probe, the Solar Probe mission, the orbital planning of the Voyager spacecraft, and even the discovery of a new gap between Saturn’s rings, later named the “Colombo Gap.”
Nicknamed "the mechanic of the heavens" or simply “Bepi,” Giuseppe Colombo remains a prominent figure in the international scientific community thanks to his brilliant insights and interdisciplinary genius.
