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Stationkeeping Monte Carlo Simulation for the James Webb Space TelescopeThe James Webb Space Telescope (JWST) is scheduled to launch in 2018 into a Libration Point Orbit (LPO) around the Sun-Earth/Moon (SEM) L2 point, with a planned mission lifetime of 10.5 years after a six-month transfer to the mission orbit. This paper discusses our approach to Stationkeeping (SK) maneuver planning to determine an adequate SK delta-V budget. The SK maneuver planning for JWST is made challenging by two factors: JWST has a large Sunshield, and JWST will be repointed regularly producing significant changes in Solar Radiation Pressure (SRP). To accurately model SRP we employ the Solar Pressure and Drag (SPAD) tool, which uses ray tracing to accurately compute SRP force as a function of attitude. As an additional challenge, the future JWST observation schedule will not be known at the time of SK maneuver planning. Thus there will be significant variation in SRP between SK maneuvers, and the future variation in SRP is unknown. We have enhanced an earlier SK simulation to create a Monte Carlo simulation that incorporates random draws for uncertainties that affect the budget, including random draws of the observation schedule. Each SK maneuver is planned to optimize delta-V magnitude, subject to constraints on spacecraft pointing. We report the results of the Monte Carlo simulations and discuss possible improvements during flight operations to reduce the SK delta-V budget.
Document ID
20140007519
Document Type
Conference Paper
Authors
Dichmann, Donald J. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Alberding, Cassandra M. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Yu, Wayne H. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
June 13, 2014
Publication Date
May 5, 2014
Subject Category
Astrodynamics
Report/Patent Number
GSFC-E-DAA-TN14095
Meeting Information
International Symposium on Space Flight Dynamics 2014(Laurel, MD)
Funding Number(s)
OTHER: 18593-14-1
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Keywords
Stationkeepting
Monte Carlo
Libration Point Orbit

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