---
title: "Nancy Grace Roman Telescope Exceeds Image Clarity Estimates by Nearly 30% After Final Calibration"
description: "NASA has completed calibration of the Wide Field Instrument on the Nancy Grace Roman Space Telescope, achieving an optical error of 63 nm RMS—nearly 30% better than expected. Next up is coronagraph calibration for direct exoplanet imaging."
date: 2026-10-17T10:58:39.287Z
lang: en
url: https://xab.info/en/posts/nancy-grace-roman-telescope-wfi-calibration-exceeds-estimates
tags: [nasa, roman-space-telescope, infrared-astronomy, exoplanets, space-calibration, dark-energy]
author: "Alexander Buran"
publisher: "XAB.info"
---

# Nancy Grace Roman Telescope Exceeds Image Clarity Estimates by Nearly 30% After Final Calibration

![Two female engineers analyzing telemetry data on multi-screen monitors](https://xab.info/media/2026/10/17/teleskop-nancy-grace-roman-kalibrovka-wfi-preczennost-30/teleskop-nancy-grace-roman-kalibrovka-wfi-preczennost-30-1.webp)

## Key Points

- WFI error after final adjustment measured 63 nm RMS versus the projected 90 nm—an improvement of nearly 30%
- Secondary mirror adjustment was approximately 1/16th the diameter of a human hair
- Coronagraph instrument calibration for direct exoplanet imaging will begin in the coming weeks
- The telescope launched on August 30, 2026, and is currently orbiting near the L2 Lagrange point

The Nancy Grace Roman Space Telescope (RST) team has completed the calibration of the primary wide-field instrument and fine-tuned its focus. Launched on August 30, 2026, aboard a Falcon Heavy rocket from Space Launch Complex 39A at the Kennedy Space Center in Florida, the telescope underwent a series of detector, filter, and thermal system tests following the activation of its primary wide-field multi-spectral infrared camera, the Wide Field Instrument (WFI), in September. NASA engineers announced that the image quality has surpassed pre-launch estimates.

### Optical Error: 63 Nanometers Instead of 90

The WFI image quality requirement was set at 90 nanometers RMS—an optical error roughly one thousand times thinner than a human hair. Following final adjustments, the actual error of the Wide Field Instrument measured 63 nanometers RMS, which is nearly 30% better than calculated. "All cosmic survey images will be even sharper than we expected," said Alden Jurling, senior optical engineer for the project. By comparison, this level of precision means the optical system is operating at a standard that was not even guaranteed before launch.

### Correction Smaller Than a Coin's Thickness

Achieving the required results demanded microscopic adjustments to the secondary mirror's position. According to the team, the mirror was shifted by approximately one-sixteenth of the diameter of a human hair. Jurling offered a vivid comparison: if the secondary mirror were scaled up to the height of the Empire State Building, the adjustment would be smaller than the thickness of a single-cent coin. Initially, the coronagraph instrument's image was slightly out of focus, though to a lesser extent than anticipated during design, making the correction relatively straightforward.

### Significance for the Mission's Scientific Program

"Many of the mission's primary goals would be impossible without the WFI, so seeing it function properly is both a thrill and an enormous relief," said Dave Hickey, systems engineer. Named after Nancy Grace Roman, NASA’s first chief astronomer, the telescope is designed to study dark energy, dark matter, exoplanets, and the large-scale structure of the universe. Its field of view is significantly wider than those of Hubble and James Webb, allowing it to survey vast regions of the sky in a relatively short time. NASA expects Roman's observations to discover about 100,000 new exoplanets and gather data on over two billion galaxies.

### What's Next: Coronagraph and Direct Exoplanet Imaging

In the coming weeks, the team will continue calibrating the coronagraph instrument and its mirrors. Following this phase, testing will begin on the system's ability to block starlight for the direct imaging of exoplanets—one of the mission's key scientific scenarios. The telescope is currently orbiting the Sun-Earth L2 Lagrange point, located approximately 1.5 million kilometers from Earth, and is undergoing pre-flight testing prior to transitioning to its primary science program.

## Fact-Check & Sources

- [Телескоп NASA Nancy Grace Roman превзошёл расчётную чёткость изображения почти на 30%](https://www.ixbt.com/news/2026/10/17/teleskop-nasa-nancy-grace-roman-prevzosel-rascetnuiu-cetkost-izobrazeniia-pocti-na-30.html) - Primary source: 63/90 nm RMS figures, quotes from Jurling and Hickey, secondary mirror adjustment details
- [Космический фотоаппарат для внеземных цивилизаций: чем займется телескоп Nancy Grace Roman](https://tass.ru/kosmos/26170685) - Confirmation of launch date: August 30, 2026, 07:26 EDT
- [NASA запустило космический телескоп Nancy Grace Roman](https://www.newsru.co.il/science_hitech/30aug2026/nancy_grace_roman_144.html) - Context: Falcon Heavy, LC-39A, L2, 100k exoplanets, Nancy Grace Roman naming
- [NASA: телескоп Nancy Grace Roman позволит собрать данные о более 2 млрд галактик](https://belta.by/tech/view/nasa-teleskop-nancy-grace-roman-pozvolit-sobrat-dannye-o-bolee-2-mlrd-galaktik-798493-2026/) - Confirmation of scientific program scale (2+ billion galaxies)

## FAQ

### What is the WFI and why is it needed?

The Wide Field Instrument is the primary wide-field multi-spectral infrared camera on the Nancy Grace Roman Space Telescope. It is designed for wide-field infrared surveys of the sky to study dark energy, dark matter, galaxy distribution, and discover exoplanets.

### How precise is the optics after calibration?

The error measured 63 nanometers RMS against the design requirement of 90 nm RMS. This represents an improvement of nearly 30%, meaning images will be sharper than initially projected during design.

### When will the telescope begin its primary science operations?

In the coming weeks, the team will finish calibrating the coronagraph and its mirrors, followed by demonstrations of starlight suppression. The main science program will commence after successful completion of all pre-flight tests.

### Where is the telescope located right now?

The Nancy Grace Roman Space Telescope is orbiting near the Sun-Earth L2 Lagrange point, roughly 1.5 million kilometers from Earth. The transit to L2 and system deployments took about three months following its launch on August 30, 2026.