Space Sunday: Nancy Grace Roman: the astronomer and the telescope

August 30th, 2026 saw the launch of the Nancy Grace Roman Space Telescope – potentially the most important space-based observatory yet launched from Earth, and the telescope which is genuinely the successor to the Hubble Space Telescope (HST) in terms of its mission and capabilities.

Also called the Roman Space Telescope (RST – which is how I’ll be referring to it going forward), the telescope has a multi-purpose mission and will seek to increase our knowledge in a number of areas. And it has been a long time coming.

RST: A Brief History of a Telescope

RST’s history goes back to the 2010 United States National Research Council Decadal Survey committee, which recommended a new space telescope with a focus on studying dark energy (not to be confused with dark matter, which is an entirely different concept!). In its original design, the telescope would carry a single large instrument, the WFIRST (Wide-Field Infrared Survey Telescope) with a 1.3 metre primary mirror.

However, in 2012, the US National Reconnaissance Office (NRO) offered NASA two “Hubble-class” telescope systems with 2.4 metre diameter primary mirror (the same as Hubble), but with a shorter focal length (allowing them to see far more of the night sky. One of these two units was folded into the new space telescope concept, which became the WFIRST-AFTA (Astrophysics Focused Telescope Asset), allowing the new telescope’s mission to be expanded and a portion of the overall cost of the mission – the design and fabrication of the actual telescope – to be largely eliminated.

The WFIRST mission was refined over the next few years, with initial funding in 2014 (US $54 million) allowing conceptual studies to be undertaken for the hardware, software, and mission objectives to be completed, with a further US $50 million added to this in 2015. By 2016, the overall science and technical parameters for the mission were in place:

• Primary mission duration: 5 years post-launch, at $2.7 billion, including all development, fabrication and launch costs and 5 years of science operations.
• Scientific studies:
  • Answering basic questions about dark energy – is the expansion of the universe caused by a new energy component, or the breakdown of Einstein’s general relativity; if a new energy, is it constant, or evolving with the universe? In this work, RST will be working alongside the European Space Agency’s (ESA) Euclid
  • Carrying out a census of exoplanets down to the size of our Moon using gravitational microlensing, whilst examining questions about the commonality of planetary systems, what determines an exoplanet’s habitability, etc.
  • Using a coronagraph to obtain the first direct images and spectra of very large planets orbiting our nearest neighbours.
  • Detecting primordial black holes.
  • Operational location: Sun-Earth Lagrange L₂ halo orbit, roughly 1.5 million km from Earth.

A graphic showing the Nancy Grace Roman Space Telescope’s (still called WFIRST) flight to, and orbit around, the Sun-Earth L2 position. Credit: NASA

These studies would be enabled by just two major instruments on the telescope – then still called WFIRST. The first of these is the Wide-Field Instrument (WFI)  – essentially a 300-megapixel camera supported by a series of specialised wide- and narrow-band filters which will allow the high-quality imaging of large parts of the sky around the telescope as well as focused imaging of specific groups of stars or of star systems from the visible to near-infrared. The second is the Coronagraph Instrument (CGI), a high-contrast coronagraph designed to suppress the light of stars to allow the imaging and spectrographic analyses of planets and their atmospheres as close as 0.15 arc seconds from their parent star.

Renamed the Nancy Grace Roman Space Telescope in 2020, the project has survived two attempts to cancel it under the Trump Administration, the impact of the COVID pandemic and, most recently, the somewhat premature and chaotic approach to shutting-down various programmes and operations at Goddard Space Flight Centre, the lead NASA centre for the mission, the RST project has remained largely on-time and has avoided going grossly over-budget (US $3.2 billion compared to the estimated US $2.7 billion).

Who Was Nancy Grace Roman?

Dr. Nancy Grace Roman (May 2025 – December 2025) was one of America’s leading astronomers and NASA’s first female executive, being the agency’s Chief of Astronomy through the 1960 and 1970s.

From an early age, she knew she wanted to be an astronomer; actually founding her own astronomy group at school at the age of 11. Encouraged by her music teacher mother and physicist-mathematician father, she enrolled in an accelerated astronomy programme designed to prepare late-coming high school students for college-level astronomy before attending the private Swarthmore College, Pennsylvania, from which she hoped to graduate to university.

At Swarthmore, the head of astronomy, Peter van de Kamp, was initially unimpressed with Roman’s desire to be an astronomer. However, after she had rebuilt two defunct student telescopes – work which she later felt contributed greatly to her innate ability as both an astronomical observer and in understanding instruments and technology – and seeing her dedication to research at the college’s observatory, he relented. He started personally teaching her astrometry – his own specialist field – before helping her obtain a position studying astronomy at the University of Chicago in 1946.

At Chicago she studied under three professors, including William Wilson Morgan. Whilst initially cold towards Roman, Wilson recognised her potential as she developed her PhD dissertation in 1949. Following her graduation, he invited her be his research associate. Thus began her career as a professional astronomer.

Initially focusing on stellar observations and research, Roman also took up lecturing, enjoying both roles. In the 1950s, and whilst still at the university, she became engaged in research on behalf of the US Naval Research Laboratory (NRL – among other things, and despite its title, a leading astronomical research institute), and many of her papers of stellar astronomy became the most respected and most-cited, both nationally and internationally, throughout the 1950s.

Her fascination with instruments and technology led her to becoming one of the first advocates for the use of computers for digital image processing. Taking her ideas to the university’s Chair of Astronomy at the University of Chicago – Subrahmanyan Chandrasekhar – she was told in no uncertain terms computers had “no place” in the field of astronomical observations and to stop wasting her time on such ideas.

It was around this time that Roman realised her academic career had hit a glass ceiling; universities almost never extended senior astronomy-related academic positions to women, nor offered them tenured research positions. As a result, she opted to leave university life and join the NRL, at that time a pathfinder in the relatively young field of radio astronomy.

Here she further enhanced her reputation as a both a stellar researcher and as a leading expert in the field of microwave spectroscopy. She also carried out pioneering work in the field of geodetics, which led to a request that she consult on the science programme for Project Vanguard in 1957, the NRL’s government-directed response to Russia’s Sputnik. This tweaked her interest in the potential for space-based astronomy, causing her to write several papers on the subject. Then, in 1959, she was approached with a request to create and lead a programme for space-based astronomy for the newly-formed NASA; a request which caused her some mixed feelings, as she recounted in later life:

I was not sure I wanted this NASA position… Taking a management position would mean giving up research. I had left teaching, which I enjoyed, when I left the University of Chicago and was not sure that I wanted to give up research… However, the chance to start with a clean slate to map out a programme that I thought would influence astronomy for fifty years was more than I could resist.

– Nancy Grace Roman, 2018

And so she joined NASA, initially as Head of Observational Astronomy, before rising to Chief of Astronomy at NASA’s Office of Space Science within a year.

At NASA, Roman pioneered virtually the entire astronomy programme, including selecting projects for study / execution as missions or parts of missions, overseeing budgets, recruiting staff, and so on. The post initially saw her encounter hostility from an astronomical community outraged at the idea that NASA was “sticking its nose” into their fields of study and potentially “stealing” grants and funding Earth-based observatories would otherwise receive. Her response to this was to implement a series of policies which NASA has since adhered to, placing the astronomical community as a whole at the heart of the agency’s astronomical programmes, both as participants and beneficiaries. In doing so, she not only ended the enmity, she turned the astronomical world into one of NASA’s most committed supporters.

Whilst not an original proponent of space-based telescopes, Nancy Grace Roman was the woman who brought them to reality through two long-running programmes. The first was the successful Orbiting Solar Observatory programme (OSO, 1961-1975), with eight such observatories were launched to study the 11-year sunspot activity in both UV and X-ray wavelengths. This was followed by the Orbiting Astronomical Observatory programme (OAO, 1966-1972). The second of these – OAO-2 Stargazer – became the world’s first successful deep-space orbital telescope, collecting data on galaxies, stars, planets and comets.

This pioneering work, together with the Small Astronomy Satellites of the 1970s convinced Roman of the viability of a large-scale orbital telescope, and for the last few years of her primary career at NASA, she devoted herself to bringing such an observatory – then simply called the Large Space Telescope (LST) – and its supporting infrastructure, into being.

This work directly led to the Hubble Space Telescope, the first of NASA’s first four Great Observatories. And not only did she directly help formulate the programme which would become Hubble, she became the voice that “sold” the entire idea to astronomers and the science community, who in turn sold it to the US government.

Regretfully, history has forgotten a lot in today’s Internet age, but it was Nancy in the old days before the Internet and before Google and e-mail and all that stuff, who really helped to sell the Hubble Space Telescope, organise the astronomers who eventually convinced Congress to fund it. Nancy Grace Roman was the Mother of the Hubble Space Telescope.

– Edward Weiler, HST Chief Scientist, 1979-1998, and speaking in 2011

After 21 years with NASA, Roman officially retired in 1979, although she continued in a consultancy position overseeing the implementation of one of the most influential factors of the Telescope’s mission: the implementation of the Space Telescope Science Institute (STScI), which initially oversaw Hubble operations and science programmes, then took on the James Webb Telescope (JWST) following its launch and commissioning, and which will now also manage the RST.

Following this, she entered the private sector, only to return to NASA for two years in 1995 as the head of the Astronomical Data Centre at Goddard Space Flight Centre. Following her second NASA retirement, she turned to teaching for 3 years before spending 10 years (2000-2010) recording astronomical textbooks for Reading for the Blind and Dyslexic.

Sadly, Nancy Grace Roman passed away in 2018, before seeing NASA’s latest space-based observatory fittingly named for her.

RST Launch Highlights

• Lift-off: 11:26 UTC, Launch Complex 39A, Kennedy Space Centre.
• Launch vehicle: SpaceX Falcon Heavy Block 5.
• Side booster separation: 2.5 minutes after launch, boosters recovered to Space Launch Complex 40 and Landing Zone 2, Cape Canaveral Space Force Station (CCSFS).

• Core booster: expended, Atlantic splashdown, no recovery.
• Upper stage: separation 4 minutes post-launch with payload fairings jettisoned 15 seconds later. Initial upper stage burn 4 minutes, 39 seconds.
• Orbital coast: 31 minutes.
• 11:54 UTC: second stage engine re-light and burn (3 minutes).
• 11:57 UTC: RST deployment from Falcon Heavy upper stage. Launch and deployment complete.

While both of the side boosters from the rocket made successful landings, only one booster was actually filmed making a touchdown. This is because SpaceX had turned on the cameras at landing Zone 1, CCSFS rather than Landing Zone 2 in error!

RST: Current Status and what’s Next?

Following separation from the Falcon Heavy upper stage, RST commenced a 90-day transit out to its Sun-Earth L₂ halo orbit. Ninety minutes after launch, the observatory successfully deployed its combined Solar Array Sun Shield (SASS) designed to both help protect its electronics and instruments from the Sun’s heat and convert that solar energy into electrical power for those instruments and systems.

Over the next few days / weeks the following will occur:

• Days:
  • Complete an initial “mid-course” correction to fine-tune its trajectory (within 24 hours of launch).
  • Deployment and testing of the main high-gain communications antenna, capable of transferring 1.4 terabytes of data from the observatory to Earth per day.
  • Unfurling and testing of the deployable aperture cover designed to protect the telescope’s optics from the glare of the Sun during certain periods of operation.
  • Initial power-up of the Coronagraph Instrument (CGI) and circuitry test, to be followed by pre-commissioning testing and calibration.
• Weeks:
  • Initial power-up of the Wide Field Instrument (WFI) and circuitry test, to be followed by pre-commissioning testing and calibration.
  • Second mid-course correction.
  • Science instruments initial commissioning (starting approx. 45 days into transit).

When operational, the WFI will be capable of capturing images of up to 1 billion pixels, capturing views of space 100-125 times wider than can be achieved by Hubble and with far greater clarity thanks to the use of 18 4K resolution detectors within the camera’s imager. The current commissioning plan means that RST will commence formal science operations in early 2027.