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The introduction to Launch Window Trade Analysis for the James Webb Space Telescope reads:

The James Webb Space Telescope (JWST) is a large-scale space telescope mission designed to study fundamental astrophysical questions. General topics include studying the assembly of galaxies, planetary systems / origin of life, birth of stars / proto-planetary systems and the concept of first light / re-ionization. One of the primary trade analyses for JWST determines when the observatory can successfully launch. This is traditionally called the launch window trade analysis.

This paper presents the first launch window analysis for JWST with the inclusion of higher fidelity propulsion finite-burn modeling. Significant requirements affecting the JWST orbit design are the overall Libration Point Orbit (LPO) size, the avoidance of any Earth/Moon eclipses, and propulsion/other hardware restrictions. This launch window trade analysis focuses on meeting these requirements and finds feasible epochs to launch the JWST observatory under these conditions. The paper first presents an in-depth view of the JWST mission with emphasis on the requirements and constraints affecting the launch window analysis. The full trade study is then described alongside its methodology. Finally, results that observe the overall nature of the launch window with the updated JWST models are presented with final conclusions and future development.

The 2014 presentation James Webb Space Telescope Launch Window Trade Analysis by Wayne Yu (NASA GSFC) and Karen Richon (NASA GSFC) 5 May 2014, 24th International Symposium on Space Flight Dynamics (ISSFD) includes the following slide with the text

Over a single launch day, the JWST orbit launch time is critical to its success. The allowable daily launch window exists within the launch window trade space of 11:30 – 14:00 UTC.

Question: What is "trade space" in the context of libration orbit mission design? (used in trade analysis and trade study)


slide #7 screenshot from the 2014 presentation "James Webb Space Telescope Launch Window Trade Analysis" https://ntrs.nasa.gov/citations/20140008970 by Wayne Yu (NASA GSFC) and Karen Richon (NASA GSFC)

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It's just a space in the mathematical sense, the range of input variables which the trade off considers.

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    $\begingroup$ That would certainly make sense. Phase space for example is a well-defined six dimensional space with three spatial and three velocity components; trade space is a less rigorously defined space of parameters. It will be interesting to find out if "trade" really comes from "trade". $\endgroup$
    – uhoh
    Mar 7 at 22:20
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    $\begingroup$ in avionics design we shortened the phrase 'design trade-off limits' to trade space. Our 'space' included materials, technologies, size, weight, power, design time. We would "trade" some of this to get some of that, trying to reach an optimal balance of all factors. $\endgroup$
    – BradV
    Mar 9 at 14:29
  • $\begingroup$ after closely looking at the plot and its legend I wonder how 11:30 is included in the tradespace. the magenta trajectory blatantly violates the no eclipses requirement. $\endgroup$
    – BradV
    Mar 9 at 14:31

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