CRIRES+ extended the capabilities of CRIRES, the CRyogenic InfraRed Echelle Spectrograph. It transformed this VLT instrument into a cross-dispersed spectrograph to increase the wavelength range that is covered simultaneously by a factor of ten. In addition, a new detector focal plane array of three Hawaii 2RG detectors with a 5.3 μm cut-off wavelength replaced the existing detectors. Amongst many other improvements a new spectropolarimetric unit was added and the calibration system has been enhanced. The instrument was installed at the VLT on Unit Telescope 3 beginning of 2020 and successfully commissioned and verified for science operations during 2021, partly remote from Europe due to the pandemic. The instrument was subsequently offered to the community from October 2021 onwards. This article describes the performance and capabilities of this development and presents on sky results.
KEYWORDS: Systems engineering, Process engineering, Observatories, Mirrors, Astronomy, Thirty Meter Telescope, Large telescopes, Telescopes, Databases, Optical instrument design
The new class of Extremely Large Telescopes (ELTs) has implemented more rigorous systems engineering processes and tools for requirements management than has been used in past observatory projects. The similarities and differences between these activities at the ESO-ELT, GMT, TMT, and NOIRLab US-ELTP projects are summarized. We show that, while the key steps of the requirements management process are common among the ELTs, each project has implemented its own variation of the processes and tools tailored to its needs.
KEYWORDS: Systems engineering, Systems engineering, Telescopes, Image quality, Computer aided design, Observatories, Control systems, Astronomical telescopes, Inspection, Space telescopes, Safety
One of the critical activities in the systems engineering scope of work is managing requirements. In line with this, E-ELT devotes a significant effort to this activity, which follows a well-established process. This involves optimally deriving requirements from the user (Top-Level Requirements) through the system Level 1 Requirements and from here down to subsystems procurement specifications.
This paper describes the process, which is illustrated with some practical examples, including in particular the role of technical budgets to derive requirements on subsystems. Also, the provisions taken for the requirements verification are discussed.
After having completed the phase B (front-end design) of the several subsystems, the E-ELT project is entering into the
construction phase. The subsystems specifications, interface control documents and accompanying technical
documentation resulting from the said design activities are being drafted along with the statements of work needed for
the tendering processes.
This paper presents an overview of the Systems Engineering Plan for the construction phase focusing on the specific
systems engineering processes. The goal is to ensure that this phase is developed following an efficient systems
engineering approach based on the lessons learned during phase B. The ultimate objective is that the E-ELT meets the
science requirements defined by the users while the risk of overruns in cost or schedule, which might otherwise originate
from the lack of a system perspective, is minimized.
The E-ELT has completed its design phase and is now entering construction. ESO is acting as prime contractor and
usually procures subsystems, including their design, from industry. This, in turn, leads to a large number of
requirements, whose validity, consistency and conformity with user needs requires extensive management.
Therefore E-ELT Systems Engineering has chosen to follow a systematic approach, based on a reasoned requirement
architecture that follows the product breakdown structure of the observatory. The challenge ahead is the controlled flow-down
of science user needs into engineering requirements, requirement specifications and system design documents.
This paper shows how the E-ELT project manages this. The project has adopted IBM DOORTM as a supporting
requirements management tool. This paper deals with emerging problems and pictures potential solutions. It shows
trade-offs made to reach a proper balance between the effort put in this activity and potential overheads, and the benefit
for the project.
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