Foreseen Changes regarding La Silla, Paranal and APEX Instrumentation and Facilities

La Silla

  • Depending on successful commissioning, the Near Infra-Red Planet Searcher (NIRPS) will be offered in Period 110.
  • SoFI is expected to be decommissioned towards the end of Period 108 or during Period 109 for the installation of the Son of X-shooter (SoXS), while EFOSC2 will be decommissioned once SoXS enters regular operation on the NTT, which is expected for Period 111.
  • ULTRACAM is expected to be offered for the last time in Period 108 due to the expiry of the current agreement.



The expected Paranal Instrumentation and Facilities to be offered in Period 109 and changes foreseen for Periods 110 and 111 are presented at the overview page.


  • Further improvements of the new Phase 1 system (p1) will take place in Period 109 and following.

UT instruments and facilities

  • MOONS - the Multi-Object Optical and Near-infrared Spectrograph – is expected to be installed at the UT1 Nasmyth A focus during the second quarter of 2023.
  • The VLT Visitor Focus at UT1 will be available until the installation of the field corrector lens for MOONS, currently foreseen to take place during Period 109
  • Depending on the results of the ongoing commissioning, additional observing modes with CRIRES may be offered in Period 109.
  • ERIS, the Enhanced Resolution Imager and Spectrograph, is expected to be installed and commissioned during the first quarter of 2022 at the UT4 Cassegrain focus, if the conditions for international travel are favourable. Pending successful commissioning, ERIS might be offered in Period 110. 
  • The Laser Frequency Comb (LFC) is expected to be operational by Period 110 for use with ESPRESSO.

VLTI instruments and facilites

  • Provided successful commissioning, MATISSE may be offered with the GRA4MAT fringe tracker for chopping on ATs and UTs starting in Period 109. In addition, the HIGH+ resolution set-up is expected to be offered for Monitoring Programs starting in Period 109.
  • Commissioning of the polarimetry mode of PIONIER is ongoing. Depending on the success of the commissioning, the mode may be offered in Period 109.
  • The recoating of the UT+VLTI coude train will continue with M5s and M7s. This activity will be performed one UT at a time, each time implying a two-month unavailability for VLTI+UT operations.

Survey telescopes and instruments

  • Due to the installation of 4MOST, Period 108 is expected to be the last period of operations of VIRCAM.
  • Similarly, Period 108 is the last period for which the operation of VST and OmegaCAM is guaranteed under the current agreement between ESO and INAF.


  • ESO does not plan to offer APEX beyond Period 110, corresponding to the end of the current APEX agreement.