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Liu, Feng-Chuan

Publications and source records attributed to Liu, Feng-Chuan.

The WISE Satellite Development: Managing the Risks and the Opportunities

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.

Risk Management

Managing the Development of the Wide-Field Infrared Survey Explorer Mission

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 (full-width-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-to-day 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.

cryogenic

Update on the Wide-field Infrared Survey Explorer (WISE)

The Wide-field Infrared Survey Explorer (WISE), a NASA MIDEX mission, will survey the entire sky in four bands from 3.3 to 23 microns with a sensitivity 1000 times greater than the IRAS survey. The WISE survey will extend the Two Micron All Sky Survey into the thermal infrared and will provide an important catalog for the James Webb Space Telescope. Using 1024(sup 2) HgCdTe and Si:As arrays at 3.3, 4.7, 12 and 23 microns, WISE will find the most luminous galaxies in the universe, the closest stars to the Sun, and it will detect most of the main belt asteroids larger than 3 km. The single WISE instrument consists of a 40 cm diamond-turned aluminum afocal telescope, a two-stage solid hydrogen cryostat, a scan mirror mechanism, and reimaging optics giving 5 resolution (full-width-half-maximum). The use of dichroics and beamsplitters allows four color images of a 47' x47' field of view to be taken every 8.8 seconds, synchronized with the orbital motion to provide total sky coverage with overlap between revolutions. WISE will be placed into a Sun-synchronous polar orbit on a Delta 7320-10 launch vehicle. The WISE survey approach is simple and efficient. The three-axis-stabilized spacecraft rotates at a constant rate while the scan mirror freezes the telescope line of sight during each exposure. WISE has completed its mission Preliminary Design Review and its NASA Confirmation Review, and the project is awaiting confirmation from NASA to proceed to the Critical Design phase. Much of the payload hardware is now complete, and assembly of the payload will occur over the next year. WISE is scheduled to launch in late 2009; the project web site can be found at www.wise.ssl.berkeley.edu.

aster

The Legacy of the Low Temperature Microgravity Physics Facility

The Jet Propulsion Laboratory (JPL) has been building the Low Temperature Microgravity Physics Facility (LTMPF) as a multi-user research facility for the International Space Station. Because of the recent Presidential Exploration Initiative placed on NASA, NASA has informally told JPL to phase out the development of the LTMPF, assuming a suspension of funding at the end of fiscal year 2004. Over the last five years of development of the Facility, a tremendous legacy of both scientific and technical progress has been made, and a significant amount of flight hardware has been built. During these last few months of remaining funding, the LTMPF plans on finishing some remaining development efforts, archiving the hardware (flight and engineering models), software, and capturing the knowledge generated for possible future missions. These possible future missions could include gravitational or relativistic physics experiments (around the Earth or the Moon), charged particle physics experiments away from the Earth, possible other fundamental physics experiments in a Code U-developed free flyer orbiting the Earth, or even gravitational mapping experiments around the Moon or possibly Mars. LTMPF-developed technologies that are likely to have substantial impact on such future missions include SQUID magnetometers and thermometers, ultra-high-performance cryogenics, and high-Q superconducting resonators.

Larson, Melora

The Low Temperature Microgravity Physics Facility: Progress and Status

The Jet Propulsion Laboratory (JPL) is developing the Low Temperature Microgravity Physics Facility (LTMPF). The LTMPF is a multiple user and multiple flight facility that will provide a long duration low temperature environment for performing state of the art experiments at the International Space Station (ISS). During each mission, two distinct primary experiments will be accommodated. Secondary experiments utilizing the hardware built for the primary experiments will also be accommodated during each mission. Over the past year, much progress has occurred on the LTMPF as the flight hardware has started to be built. Also, many changes have occurred. Last summer, the initial flight of the LTMPF was delayed until early 2008 by a 2-year slip in the delivery of the Japanese Experiment Module (KIBO) Exposed Facility of the ISS, where the LTMPF will be attached when it flies. Finally, the experiments that will fly as part of the first mission have been changed so that one Gravitational and Relativistic experiment and one Low Temperature Condensed Matter experiment will fly on each flight of the LTMPF. Therefore, the experiments that will fly on the initial mission of the LTMPF will be DYNAMX and the Superconducting Microwave Oscillator Experiment (SUMO).

Larson, Melora

A low temperature facility for experiments on the International Space Station

The Jet Propulsion Laboratory (JPL) is currently developing the Low Temperature Microgravity Physics Experiments Facility (LTMPEF), a multiple user and multiple flight facility that will provide a long duration low temperature environment on board the International Space Station. The LTMPEF will be attached to the Japanese Experiment Module (KIBO) Exposed Facility of the International Space Station with an initial flight starting in late 2005. The LTMPF is a self contained, reusable, cryogenic facility containing a 180-liter superfluid helium tank, two experiment packages, and electronics to provide experiment control and telemetry. Two distinct primary experiments will be accommodated during each mission, and secondary experiments requiring no additional hardware beyond that built for the primary experiments will also be accommodated during each mission. Detailed technical capabilities of the Facility will be presented, along with a brief description of the six science investigations currently selected to fly on the first two missions.

International Space Station

Research Opportunities on the Low Temperature Microgravity Physics Facility (LTMPF) on the International Space Station

The Low Temperature Microgravity Physics Facility (LTMPF) is a state-of-the-art facility for long duration science Investigations whose objectives can only be achieved in microgravity and at low temperature. LTMPF consists of two reusable, cryogenic facilities with self-contained electronics, software and communication capabilities. The Facility will be first launched by Japanese HIIA Rocket in 2003 and retrieved by the Space Shuttle, and will have at least five months cryogen lifetime on the Japanese Experiment Module Exposed Facility (JEM EF) of the International Space Station. A number of high precision sensors of temperature, pressure and capacitance will be available, which can be further tailored to accommodate a wide variety of low temperature experiments. This paper will describe the LTMPF and its goals and design requirements. Currently there are six candidate experiments in the flight definition phase to fly on LTMPF. Future candidate experiments will be selected through the NASA Research Announcement process. Opportunities for utilization and collaboration with international partners will also be discussed. This work is being carried out by the Jet Propulsion Laboratory, California Institute of Technology under contract to the National Aeronautics and Space Administration. The work was funded by NASA Microgravity Research Division.

Liu, Feng-Chuan