The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Summary of the results of the untreated and PDA205 analyses.

<p>All terms are dimensionless. is the probability that the observed is not significantly different from zero, according to the weighted <i>t</i>-test described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0150694#pone.0150694.s002" target="_blank">S2 File</a>.</p

Comparing linear and power-law models.

<p>Outer ellipses show 95% CI on each parameter. (a) Power law exponent, <i>β</i>, against the logarithm of reference facility for the power law model: no correlation is observed (<i>p</i> = 0.49). (b) Pressure independent flow, <i>Q</i>₀, against the logarithm of facility for the linear fit: a strong correlation is observed (<i>p</i> < 10⁻⁶), suggesting that the linear model is inappropriate. (c) Pressure-independent flow against power law exponent: a strong correlation is observed: <i>p</i> < 10⁻⁶, indicating that non-zero <i>Q</i>₀ values are a result of the non-linearity in the <i>Q</i> − <i>P</i> relationship. (d) Comparison between log facility predicted by linear and power law models. Red line shows average over-prediction of ≈103% by the linear model.</p

Comparison of facility for unpaired eyes using the ‘Cello plot’.

<p>Unpaired analysis of facility for PDA205 treated and control eyes. Each data point shows the reference facility, <i>C</i>_<i>r</i>, with the error bars showing 95% confidence intervals from the regression fitting of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0150694#pone.0150694.e095" target="_blank">Eq 10</a> (1.96<i>s</i>_reg). Shaded regions show best estimates of the sample distributions, with the geometric mean and two-sigma shown by the thick and thin horizontal lines respectively. Dark central bands show 95% CI on the mean values.</p

Selecting an appropriate model for the flow-pressure relationship.

<p>(a) A sample flow-pressure curve for the enucleated mouse eye perfusion shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0150694#pone.0150694.g001" target="_blank">Fig 1b and 1c</a>. Points show measured data with 95% confidence intervals. Blue: linear fit (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0150694#pone.0150694.e003" target="_blank">Eq 3</a>), <i>C</i> = 9.1 <i>nl</i>/<i>min</i>/<i>mmHg</i>, <i>Q</i>₀ = −27.8 <i>nl</i>/<i>min</i>. Red: power law (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0150694#pone.0150694.e094" target="_blank">Eq 9</a>), <i>C</i>_<i>r</i> = 5.4 <i>nl</i>/<i>min</i>/<i>mmHg</i>, <i>β</i> = 0.44. Shaded regions show 95% confidence bounds. (b) The facility as calculated by the linear and power law models. Black markers show <i>Q</i>/<i>P</i>, which is independent of the fit, and green markers show facility as calculated according to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0150694#pone.0150694.e093" target="_blank">Eq 8</a>, (<i>Q</i> − <i>Q</i>₀)/<i>P</i>, showing the large influence of the model on the calculated facility. (c) and (d) show equivalent plots for a more non-linear case. Linear fit, <i>C</i> = 14.2 <i>nl</i>/<i>min</i>/<i>mmHg</i>, <i>Q</i>₀ = −66.2 <i>nl</i>/<i>min</i>. Power law, <i>C</i>_<i>r</i> = 5.4 <i>nl</i>/<i>min</i>/<i>mmHg</i>, <i>β</i> = 0.85.</p

The <i>iPerfusion</i> system.

<p>(a) Schematic of the experimental setup. Inset shows internal (green), external (red) and resultant (blue) pressures acting on the eye. Flow (b) and pressure (c) traces from a sample mouse eye perfusion. Red highlighted regions show steady-state periods, over which data were averaged.</p