A team of scientists at the University of Sussex will be amongst the first people to use the James Webb Space Telescope to find and study the most distant objects in the Universe.
The world's most powerful telescope was successfully launched into space on Christmas Day, taking off from Kourou spaceport in French Guiana at 12.20pm on an Ariane 5 rocket.
The telescope is designed to answer unsolved questions about the universe, and look further back in time than ever before to 400 million years after the Big Bang, the UK Space Agency says.
It was originally meant to leave on Christmas Eve, but a forecast of high-level winds at the spaceport forced it to be postponed.
Watch the moment the James Webb Telescope is launched into space- Video from NASA/PA
Preparation for the project began in 1996, and construction was completed in 2016.
The launch was initially planned for earlier this month, but several setbacks including a communications issue and an incident requiring an extra round of checks on the telescope pushed the date back.
The JWST's partners are the European Space Agency, Nasa and the Canadian Space Agency.
Dr Stephen Wilkins, Head of Astronomy at the University of Sussex, leads a team of scientists who will be amongst the first to use the Telescope. The cosmologists will map the dark matter around galaxies with the aim of unlocking the secrets of the mysterious substance that makes up the majority of matter in the universe.
He said, "The James Webb Space Telescope is the long-awaited successor to Hubble, which launched more than 31 years ago.
"Like Hubble we expect Webb to transform our understanding the Universe from our own backyard, the Solar System, to the very first stars and galaxies to form almost 14 billion years.
He added, "Here at the University of Sussex we'll use Webb to study the distant Universe, including hopefully finding examples of the first stars and galaxies to form.
"I study the most distant galaxies in the Universe observed only a few hundred million years after the Big Bang. These galaxies are faint, partly because they're so far away but also because they haven't had time to form many stars yet - and their light is shifted into the infrared by the expansion of the Universe.
"These galaxies are effectively "invisible" to existing observatories. Webb, with its large mirror and infrared optimisation, however, should be able to see them.
Professor Wilkins added, "Webb is so much more powerful than its predecessors that we might find something entirely unanticipated - and "unknown unknown" to quote Donald Rumsfeld.
"Astronomy is littered with examples where looking at the Universe in more detail has thrown up new mysteries, e.g. dark matter and dark energy.
"It's really the extremely sensitive infrared coverage and the fact Webb will obtain both imaging and spectroscopy. The latter is vital for probing the composition of alien atmospheres and tracking how heavy elements are built up across the history of the Universe.
On Twitter, Sussex astronaut Tim Peake urged people to watch the telescope launch, posting, "Going far tomorrow? Spare a thought for the #JWST which will be travelling 1.5million Km to begin it’s orbit around L2."
He also tweeted his congratulations to all those involved in the successful launch.