The European Organisation for Astronomical Research in the Southern Hemisphere (ESO) is the foremost intergovernmental astronomy organisation in Europe and the world's most productive ground-based astronomical observatory. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries.
ESO operates three unique world-class observing sites in northern Chile: La Silla, Paranal and Chajnantor (home to ALMA), and the ESO Headquarters are located in Garching, near Munich, Germany.
At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory, and will host and operate the southern array of the Cherenkov Telescope Array, the world's largest and most sensitive high energy gamma-ray observatory. ESO is a major partner in ALMA. On Cerro Armazones, ESO is building the 39-metre Extremely Large Telescope (ELT), which will become "the world's biggest eye on the sky" and whose operations will be fully integrated into the Paranal Observatory.
**Summer Students Chile 2026**:
Paranal
Deadline 27/10/2025
For the summer period 2026 starting early January, ESO is offering five projects for the Maintenance, and Engineering Department (MSE), and five projects for the Paranal Science Operations Department (PSO). Below is a brief description of each of these departments, followed by the projects available.
The **Paranal Science Operations**Department (PSO) consists of 60 persons of more than a dozen different nationalities. PSO's mission is the production of high-quality astronomical data and to maintain or improve the scientific performance of Paranal's instruments. This includes the VLTI 2nd generation instruments Gravity & Matisse,



the Adaptive Optics Facility (AOF) on UT4 and the planet hunter ESPRESSO.
**List of Projects MSE Department**:
**I. Mechanics Project "Technical evaluation of replacing inflatable seals by brush strips"**:
During day-time the telescopes of Paranal are closed and stopped in a parking position, and we use inflatable seals in order to seal the gap between movable and fixed parts of the enclosures of the telescopes. The main goals of the inflatable seals are:
- Avoiding the entrance of rain and high humidity during bad weather conditions.
- Avoiding the entrance of dust and sand coming from desert during high winds
- Avoiding the entrance of sun light/rays during day-time, to create a dark environment inside the enclosure for the calibrations of the observation instruments
We want to evaluate if replacing the inflatable seals by plastic brushes strip may be a technical option, for this we need to carry on a study considering the following:
- Designing, and with the support of the Paranal Machinery Workshop, implementing a test bench to simulate the seal condition and technically evaluates the brushes strip as a technical solution to replace the inflatable seals.
- Developing and implementing a criteria to measure the effectiveness of the brushes for blocking the pass of humidity, water and light.
- Measuring the frictions/forces needed to displace the fixed vs the movable surfaces covered/interfaced by the brushes,



and extrapolating it to the Enclosure condition, i.e. to 100 mt perimeter length. Estimating the increase of torque and power, that would be required for the motors of the Enclosure rotation system.
- The durability, to estimate the degradation duration of the elastic properties of brushes bristle.
- Determine if it would be advisable and/or necessary to use one or more brushes row in parallel.
- Proposing a low impact design and procedure to replace current inflatable seal by the brushes strip.
**Student Profile**:
- Execution or Civil Mechanical Engineer.
- Mechanical Technician from a Professional Institute or University
- Drawings in Autodesk Cad or Inventor files
**Shift and Duration**:
The schedule will be eight days on duty and six days off duty (8x6) with accommodation provided on site. The internship will last for two months, January and February.
**II. Software Project "Enclosure and hydrostatic bearing system LCU replacements"**:
The Unit Telescopes at the Paranal Observatory are already 25 years old, and in the context of the Obsolescence management, we try to remove the VME control systems. The Enclosure and Hydrostatic bearing system Local Control Unit (LCU) are simple systems that can be completely replaced by processes on a Worskstation and opcua communication technology.
The work is done with support from electronics group that will provide the signal maps and enable opcua on the PLC used to replace this system. For the student it will be a good opportunity to know PLC technoplogy, SW development cycle and communication protocols. Two interns will be selected to work on each system (enclosure and hydrostatic bearing system).
**Student Profile**:
- Software engineer student in

📌 Summer Students Chile 2026 (El Paranal)
🏢 European Southern Observatory
📍 El Paranal