NASA's Wide-field Infrared Survey Explorer (WISE) MIDEX mission is surveying the entire sky in four infrared bands
from 3.4 to 22 micrometers. The WISE instrument consists of a 40 cm telescope, a solid hydrogen cryostat, a scan mirror
mechanism, and four 1K x1K infrared detectors. The WISE spacecraft bus provides communication, data handling, and
avionics including instrument pointing. A Delta 7920 successfully launched WISE into a Sun-synchronous polar orbit on
December 14, 2009. WISE was competitively selected by NASA as a Medium cost Explorer mission (MIDEX) in 2002.
MIDEX missions are led by the Principal Investigator who delegates day-to-day management to the Project Manager.
Given the tight cost cap and relatively short development schedule, NASA chose to extend the development period one
year with an option to cancel the mission if certain criteria were not met. To meet this and other challenges, the WISE
management team had to learn to work seamlessly across institutional lines and to recognize risks and opportunities in
order to develop the flight hardware within the project resources. In spite of significant technical issues, the WISE
satellite was delivered on budget and on schedule. This paper describes our management approach and risk posture,
technical issues, and critical decisions made.
The Wide-field Infrared Survey Explorer (WISE), a NASA Medium-Class Explorer (MIDEX) mission, is surveying the
entire sky in four bands from 3.4 to 22 microns with a sensitivity hundreds to hundreds of thousands times better than
previous all-sky surveys at these wavelengths. The single WISE instrument consists of a 40 cm three-mirror anastigmatic
telescope, a two-stage solid hydrogen cryostat, a scan mirror mechanism, and reimaging optics giving 6" resolution (fullwidth-
half-maximum). WISE was placed into a Sun-synchronous polar orbit on a Delta II 7320 launch vehicle on
December 14, 2009. NASA selected WISE as a MIDEX in 2002 following a rigorous competitive selection process. To
gain further confidence in WISE, NASA extended the development period one year with an option to cancel the mission
if certain criteria were not met. MIDEX missions are led by the principal investigator who in this case delegated day-today
management to the project manager. With a cost cap and relatively short development schedule, it was essential for
all WISE partners to work seamlessly together. This was accomplished with an integrated management team
representing all key partners and disciplines. The project was developed on budget and on schedule in spite of the need
to surmount significant technical challenges. This paper describes our management approach, key challenges and critical
decisions made. Results are described from a programmatic, technical and scientific point of view. Lessons learned are
offered for projects of this type.
WISE is a NASA MIDEX mission to survey the entire sky in four bands from 3 to 25 microns with sensitivity about
500 times greater than the IRAS survey. WISE will find the most luminous galaxies in the universe, find the closest
stars to the Sun, and detect most of the main belt asteroids larger than 3 km. WISE launch is scheduled in November,
2009 on a Delta 7320-10 to a 525 km Sun-synchronous polar orbit.
This paper gives an overview of WISE including development status and management approach. WISE flight system
design is single string with selected redundancy and graceful degradation. Wherever possible, design heritage from
prior missions is pursued and properly reviewed to reduce development time and cost. Further risk reduction is
achieved since the WISE spacecraft has no deployable mechanisms and no propulsion. Nonetheless, a complex space
mission with a sophisticated cryogenic IR telescope such as WISE demands a partnership of multiple organizations
in government research, academia, and industry. With a cost cap and relatively short development schedule, it is
essential for all WISE partners to work seamlessly together. This is accomplished by a single management team
representing all key partners and disciplines in science, systems engineering, mission assurance, project and contract
management. WISE uses a variety of management tools including frequent team interaction, schedule, milestone and
critical path analysis, risk analysis, reliability analysis, earned value analysis, configuration management, and
management of schedule and budget reserves. After a successful mission critical design review in June, 2007, WISE
has completed building most of the flight hardware, and started integration and test within payload and spacecraft.
The WISE observatory contains solid hydrogen to achieve cooling, which precludes many of the "test as you fly"
(TAYF) methods for the integration and test of the WISE flight system due to the hazardous nature of the solid
hydrogen. Additionally, there is reluctance to remove the optical cover after integration to the spacecraft due to increased
risk. This paper discusses the WISE approach to verification and validation (V&V) given these constraints. As payloads
increase in size and complexity more missions will necessarily deviate from the TAYF approach.
The WISE system combines full testing of the instrument while the fight system uses an interment simulator for many of
the flight system environmental tests. The test planning, simulator design, and the analyses which indicate why this
would be a low-risk V&V approach for the WISE mission are discussed.