| タイトル | Heuristic Modeling for TRMM Lifetime Predictions |
| 本文（外部サイト） | http://hdl.handle.net/2060/19960035777 |
| 著者（英） | Sharer, P. J.; Jordan, P. S.; DeFazio, R. L. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 1996-05-01 |
| 言語 | eng |
| 内容記述 | Analysis time for computing the expected mission lifetimes of proposed frequently maneuvering, tightly altitude constrained, Earth orbiting spacecraft have been significantly reduced by means of a heuristic modeling method implemented in a commercial-off-the-shelf spreadsheet product (QuattroPro) running on a personal computer (PC). The method uses a look-up table to estimate the maneuver frequency per month as a function of the spacecraft ballistic coefficient and the solar flux index, then computes the associated fuel use by a simple engine model. Maneuver frequency data points are produced by means of a single 1-month run of traditional mission analysis software for each of the 12 to 25 data points required for the table. As the data point computations are required only a mission design start-up and on the occasion of significant mission redesigns, the dependence on time consuming traditional modeling methods is dramatically reduced. Results to date have agreed with traditional methods to within 1 to 1.5 percent. The spreadsheet approach is applicable to a wide variety of Earth orbiting spacecraft with tight altitude constraints. It will be particularly useful to such missions as the Tropical Rainfall Measurement Mission scheduled for launch in 1997, whose mission lifetime calculations are heavily dependent on frequently revised solar flux predictions. |
| NASA分類 | Spacecraft Design, Testing and Performance |
| レポートNO | 96N30516 |
| 権利 | No Copyright |
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