The Webb review comes as the House Science Committee, under Representative Lamar Smith of Texas, has been studying how well NASA estimates costs and manages big projects. The answer is, not so well. Testifying before the committee, NASA’s Inspector General Paul Martin criticized the agency’s culture of optimism, saying that project promise of scientific brilliance made them difficult to rein in. “While a few projects in NASA’s recent past have been canceled because of poor cost and schedule performance, a too-big-to-fail mentality pervades agency thinking when it comes to NASA’s larger and most important missions,” he told the committee in mid-June, according to a news bulletin from the American Institute of Physics.

The Webb telescope mirror is 6.5 meters in diameter, or just over 21 feet, compared with 2.4 meters for the Hubble. That makes it seven times larger than the Hubble in light-gathering ability. The Webb was designed to use that power to see farther out in space and deeper into the past of the universe and the smoky aftermath of the Big Bang.

The goal is to explore a realm of cosmic history about 150 million to one billion years after time began — known as the reionization epoch, when bright and violent new stars and the searing radiation from quasars were burning away a gloomy fog of hydrogen gas that prevailed at the end of the Big Bang.

That ambition requires the Webb to be tuned to a different kind of light than our eyes or the Hubble can see. Because the expansion of the cosmos is rushing those earliest stars and galaxies away from us so fast, their light is “red-shifted” to longer wavelengths the way the siren from an ambulance shifts to a lower register as it passes by.

So blue light from an infant galaxy bursting with bright spanking new stars way back then has been stretched to invisible infrared wavelengths, or heat radiation, by the time it reaches us 13 billion years later.