It has taken 15 years but finally NASA's James Webb Space Telescope is set to be launched into space on Christmas Day.
It's the biggest and most powerful telescope ever made and at 10 billion U.S. dollars, it is also the most expensive.
Named after James Webb, the man who led NASA during the 1960s, the 7-ton space telescope is 100-times more powerful than the Hubble.
It's been designed to look deeper into the Universe and detect events as far back as 13.5 billion years ago, near the time of the Big Bang.
"What Webb is going to do, it's going to push beyond that, and it's going to be sensitive to galaxies that are more distant and younger that really formed closer to the start of the universe. So in that way, we're going to see towards the beginning of the universe closer than ever before with Webb."
It's infrared vision is so powerful it can detect the heat of a bumblebee on the moon.
It is equipped with mirrors the size of several car parking spots and its sunshade is the size of a tennis court.
But, while being dubbed the heir to the Hubble telescope, experts say the two shouldn't be compared.
"James Webb Space Telescope is often called the successor to the Hubble telescope, but that's really slightly a misnomer because, first of all, the Hubble telescope still operating, and may operate for another five or 10 years, if we're lucky. And secondly, it's a very different kind of telescope. The Hubble telescope is optimized to see the part of the universe that our eyes can see, whereas the James Webb telescope is optimized to see in the infrared part of the spectrum, which gives us a whole different set of information about the universe."
Currently, the blast off is scheduled for the 25th at around 9:20 PM Korea Time.
But even if the lift off is successful, the most daunting part of the mission will be unfolding the gigantic mirror and sunshield and locking them into position.
NASA has never attempted such a complicated series of steps remotely and many of the mechanisms don't have backups.
NASA, then, will be hoping for something of a Christmas miracle.
Kim Cheong-ah, Arirang News.