The Mid-Infrared Instrument (MIRI) is one of four scientific instruments on the James Webb Space Telescope (JWST)
observatory, scheduled for launch in 2018. It will provide unique capabilities to probe the distant or deeply dust-enshrouded
regions of the Universe, investigating the history of star and planet formation from the earliest universe to
the present day. To enable this the instrument optical module must be cooled below 7K, presenting specific challenges
for the environmental testing and calibration activities.
The assembly, integration and verification (AIV) activities for the proto-flight model (pFM) instrument ran from March
2010 to May 2012 at RAL where the instrument has been put through a full suite of environmental and performance tests
with a non-conventional single cryo-test approach.
In this paper we present an overview of the testing conducted on the MIRI pFM including ambient alignment testing,
vibration testing, gravity release testing, cryogenic performance and calibration testing, functional testing at ambient and
operational temperatures, thermal balance tests, and Electro-Magnetic Compatibility (EMC) testing. We discuss how
tests were planned and managed to ensure that the whole AIV process remained on schedule and give an insight into the
lessons learned from this process. We also show how the process of requirement verification for this complex system
was managed and documented. We describe how the risks associated with a single long duration test at operating
temperature were controlled so that the complete suite of environmental tests could be used to build up a full picture of
MIRI is one of four instruments to be built for the James Webb Space Telescope. It provides imaging, coronography and
integral field spectroscopy over the 5-28.5um wavelength range. MIRI is the only instrument which is cooled to 7K by a
dedicated cooler, much lower than the passively cooled 40K of the rest of JWST, and consists of both an Optical System
and a Cooler System. This paper will describe the key features of the overall instrument design and then concentrate on
the status of the MIRI Optical System development. The flight model design and manufacture is complete, and final
assembly and test of the integrated instrument is now underway. Prior to integration, all of the major subassemblies have
undergone individual environmental qualification and performance tests and end-end testing of a flight representative
model has been carried out. The paper will provide an overview of results from this testing and describe the current
status of the flight model build and the plan for performance verification and ground calibration.
This paper elaborates the system engineering methods that are being successfully employed within the European
Consortium (EC) to deliver the Optical System of the Mid Infa-Red Instrument (MIRI) to the James Webb Space
The EC is a Consortium of 21 institutes located in 10 European countries and, at instrument level, it works in a 50/50
partnership with JPL who are providing the instrument cooler, software and detector systems.
The paper will describe how the system engineering approach has been based upon proven principles used in the space
industry but applied in a tailored way that best accommodates the differences in international practices and standards
with a primary aim of ensuring a cost-effective solution which supports all science requirements for the mission.
The paper will recall how the system engineering has been managed from the definition of the system requirements in
early phase B, through the successful Critical Design Review at the end of phase C and up to the test and flight build
activities that are presently in progress. Communication and coordination approaches will also be discussed.
The present paper describes the different steps leading to the Flight Model integration of the Mid-Infra Red IMager
Optical Bench MIRIM-OB which is part of the scientific payload of the JWST. In order to demonstrate a space
instrument capability to survive the challenging space environment and deliver the expected scientific data, a specific
development approach is applied in order to reduce the high level of risks. The global approach for MIRIM-OB, and the
principal results associated to the two main models, the Structural Qualification Model for vibration and the Engineering
and Test Model for optical performance measured in the infra red at cryogenic temperature will be described in this
MIRI is the mid-IR instrument for the James Webb Space Telescope and provides imaging, coronography and integral
field spectroscopy over the 5-28μm wavelength range. MIRI is the only instrument which is cooled to 7K by a dedicated
cooler, much lower than the passively cooled 40K of the rest of JWST, which introduces unique challenges. The paper
will describe the key features of the overall instrument design. The flight model design of the MIRI Optical System is
completed, with hardware now in manufacture across Europe and the USA, while the MIRI Cooler System is at PDR
level development. A brief description of how the different development stages of the optical and cooling systems are
accommodated is provided, but the paper largely describes progress with the MIRI Optical System. We report the
current status of the development and provide an overview of the results from the qualification and test programme.
The MIRI is the mid-IR instrument for JWST and provides imaging, coronography and low and medium resolution spectroscopy over the 5-28μm band. In this paper we provide an overview of the key driving requirements and design status.