The James Webb Space Telescope - 100 times more powerful than the renowned Hubble - is finally ready for launch on a make-or-break mission to peek all the way back to nearly the Big Bang that created the cosmos, years behind schedule and billions over budget.
In addition to looking back in time, the James Webb telescope will aid in our understanding of the Universe's large-scale structure, and may even reveal whether it will continue to expand indefinitely.
It will peek into galaxies' centers, detecting supermassive black holes and assisting astronomers in understanding how these mysterious phenomena have developed over time. It will track the births and deaths of celebrities.
It will even look into our Solar System to explore the faintest objects on the outskirts of our cosmic neighborhood. It will also be able to peer into the reaches of worlds orbiting faraway stars.
"Nearly every area of astronomy that you can think of will be addressed," Christine Chen, an associate astronomer at STScI, told The Verge.
The telescope, constructed by Northrop Grumman, will be cooled by a five-layer sunshield the size of a tennis court that will be folded up for launch to collect the faint infrared emissions from the birth of space and time.
To disperse heat that would otherwise overwhelm and blind the telescope's sensors, the hair-thin layers must be deployed in space, precisely drawn taut and spaced by 16 to 18 inches.
Temperatures will be a sizzling 260 degrees Fahrenheit on the side facing the sun. The optics and instrumentation, on the other side, will be chilled to 370 degrees below zero, a 600-degree temperature difference. This equates to a sun protection factor (SPF) of around 1 million.
As a result, the operating temperature is less than 55 degrees above absolute zero, which is the theoretical value at which atoms freeze in place. As if that weren't enough, one of Webb's four science instruments has its own cooler, letting it operate at temperatures less than 10 degrees above absolute zero.
Webb's primary mirror is 21.3 feet wide, the largest ever launched, and has six times the light-gathering power of Hubble. It is composed of 18 gold-coated beryllium segments.
If Webb performs as intended, it will bring astronomers several hundred million years closer to the beginning of time than Hubble, a seemingly insignificant step given such vast durations. However, scientists feel that something really significant occurred in that short period of time.
It all starts at 7:20 a.m. EST on the morning of Christmas Eve. Webb will launch on a European Space Agency Ariane 5 rocket from Kourou, French Guiana. ESA provided two of Webb's four science instruments in addition to the rocket, while Canada provided a third as well as the fine-guidance system required to keep the telescope locked on target.