WATCH LIVE: NASA successfully launches its newest space telescope

NASA's Nancy Grace Roman Space Telescope, perched atop a SpaceX Falcon Heavy rocket, is seen at sunrise at Kennedy Space Center in Florida. Joel Kowsky/NASA hide caption

A new NASA space telescope launched Sunday from the Kennedy Space Center in Florida that will help scientists probe the nature of dark matter, dark energy, and other mysteries of the universe.

The Nancy Grace Roman Space Telescope, which is about the size of a tour bus, lifted off at 7:26 a.m. ET on SpaceX's Falcon Heavy rocket. The 18,000-pound spacecraft is now on a million-mile journey that will take it to its new home in space

Roman has an unusual origin story: Initially designed as a spy telescope for the National Reconnaissance Office, the spacecraft was donated to NASA instead. The new telescope is named for Nancy Grace Roman, NASA's first chief astronomer who was known as the 'Mother of Hubble' for her championing of the iconic Hubble Space Telescope. Her namesake observatory will have the sharpness of Hubble but a field of view that is at least 100 times larger, allowing it to image huge swaths of the sky at once.

Before it can do that, the Roman Space Telescope will have to get to its new home in the sky about a million miles away. Roman will live at the second Sun-Earth Lagrange point known as L2. There, the competing gravitational pulls of the Earth and the Sun help the telescope keep a steady orbit while using minimal fuel. The James Webb Space Telescope orbits at this point, which gives the spacecraft an unobstructed view of the sky.

"It takes us a good three-plus months to get out there, and we're spending that time checking everything out and doing a whole bunch of calibrations and making sure everything is working the way we know it can," said NASA's Jeremy Perkins, an integration and test scientist on the mission. "It's basically like our time to kick the tires and just make sure that the focus is right, the pointing is right."

Roman is on a kind of ghost hunt, searching for more evidence of dark matter — mysterious, invisible stuff whose gravitational influence appears to hold galaxies together and define the overarching structure of the cosmos. Roman will study how gravity subtly affects the path of light along great distances throughout a massive survey of the sky. By doing this, the telescope will help map both normal and dark matter, giving scientists a better understanding of just what this elusive substance might be.

Astronomers will also use Roman's observations to uncover dark energy, the strange force that is believed to drive the expansion of the universe. Scientists' understanding of dark energy comes from observations of a kind of exploding star known as a Type Ia supernova. These supernovas appear to shine at known and predictable brightness throughout the cosmos, giving them the nickname of 'standard candles'. By cataloguing even more of these supernovas, scientists hope to develop a better understanding of how dark energy works, which could fundamentally change the way astronomers view the universe.