NASA’s next big space telescope has left Earth, but it’s not ready to start observing the heavens just yet.
The Nancy Grace Roman Space Telescope launched yesterday (Aug. 30), riding a SpaceX Falcon Heavy rocket into the heavens. Astronomers are very excited about Roman, for it’s expected to discover thousands of new exoplanets and shed light on mysterious dark energy and dark matter, among other accomplishments.
Such science work is a few months off, however. Here’s a brief rundown of the next steps for the Roman team.
A long journey
The first order of business is getting Roman to its destination. The 42-foot-long (12.7 meters) scope isn’t staying in Earth orbit; it’s headed to the sun-Earth Lagrange Point 2 (L2), which lies about 930,000 miles (1.5 million kilometers) from our planet in the Marsward direction.
There are multiple reasons to target L2, which also hosts NASA’s James Webb Space Telescope (JWST) and Europe’s Euclid probe.
“At this special place in space,” NASA officials wrote in a Roman explainer, “gravitational forces balance to keep objects in steady orbits with very little assistance.”
“Roman’s barrel-like shape will help block out unwanted light from the sun, Earth and moon, and the spacecraft’s distant location will help keep the instruments cool,” they added. “The thermal stability of an observatory at L2 will provide a ten-fold improvement beyond Hubble in much of the data Roman will gather.”
And don’t worry about Roman and JWST bumping heads; though their cosmic addresses will be the same, they won’t actually share space.
“Like Webb, Roman will trace out a large orbit around the actual L2 point — much larger than the moon’s orbit around Earth — and the two will easily be kept far apart,” NASA wrote in a different Roman piece.
It’ll take Roman about 30 days to fly out to L2 and settle into its looping orbit there. A new round of work will then begin for the Roman team.
Checking Roman out
That work is “commissioning” — making sure that all of Roman’s systems and subsystems are working properly, as is its science gear, which consists of the Wide Field Instrument (WFI) and the Coronagraph Instrument (CGI).
WFI “is a 300-megapixel infrared camera that will allow scientists to look very far back in time,” NASA officials wrote in the explainer. “Seeing the universe in its early stages will help unravel how it has expanded throughout its history, which will hint at how it may continue to evolve.”
CGI is a technology demonstration that will block the light of distant stars, allowing Roman to spot a wealth of previously unknown alien worlds.
“It will be far more powerful than any other coronagraph ever flown, seeing planets that are almost a billion times fainter than their host star,” NASA officials wrote.
Roman should be ready to begin its science work in early 2027, according to the nonprofit Planetary Society. Its science life is slated to last five years, but astronomers are doubtless hoping for more. And there’s precedent for such optimism; after all, NASA’s Hubble Space Telescope is still going strong today, more than 36 years after its launch.
Hubble is a special case, given that astronauts repaired and upgraded it over the course of five servicing missions between 1993 and 2009. But other NASA space telescopes have far outlasted their warranties without such help. For example, the Chandra X-ray Observatory is operational in Earth orbit today, more than 25 years after its launch — and it has overcome budget issues along the way.
