Starlink Project
UK astronomical computing project supplying data reduction software and hardware.
Jonathan Umba · CC0
The Starlink Project—called Starlink by its users and simply The Project by its developers—was a UK initiative in astronomical computing that created general-purpose data reduction software. Until the late 1990s, it also provided computing hardware and system administration staff to UK astronomy institutes. In this way, it resembled the US IRAF project. Although formal work began in 1980, funding had been secured and some development had already started the year before. The project ended when the Particle Physics and Astronomy Research Council cut its funding in 2005. The Joint Astronomy Centre then released its own updated version in 2006 and took over maintenance; this responsibility shifted again in mid-2015 to the East Asian Observatory. The most recent version came out on 2025 November 26. Some of the software is now licensed under the GNU GPL, while other parts remain under the original custom license. From the start, the project was designed to handle the growing flood of data astronomers faced. A 1982 paper noted that astronomers were returning from observing runs—typically a week at a remote telescope—with over 10 gigabits of data on tape. By the end of the project, it was rolling out libraries to manage images exceeding 4 gigabytes each. The project bought hardware in bulk (at a discount), hired professional system administrators, and employed developers to write astronomical data-reduction applications for the UK astronomy community and beyond. At its peak in the late 1980s and early 1990s, it operated at about 30 sites, mostly at UK universities with astronomy departments, plus the Joint Astronomy Centre in Hawaii (home to UKIRT and the James Clerk Maxwell Telescope). The number of active developers ranged from five to over a dozen. By 1982, the project had 17 staff serving roughly 400 users at six sites, using seven VAX machines (six VAX-11/780s and one VAX-11/750) with about 6.5 GB of total disk space. These systems were networked from the beginning, first via DECNET and later X.25. Between 1992 and 1995, the project switched to UNIX (and moved networking to TCP/IP), supporting Digital UNIX on Alpha systems and Solaris on Sun Microsystems hardware. By the late 1990s, it also supported Linux, and by 2005 it ran on Red Hat Linux, Solaris, and Tru64 UNIX.
- Latest release date
- 2025 November 26
Lore & Background
From its beginning, the project aimed to cope with the ever-increasing data volumes which astronomers had to handle. A 1982 paper exclaimed that astronomers were returning from observing runs with more than 10 Gigabits of data on tape; at the end of its life the project was rolling out libraries to handle data of more than 4 Gigabytes per single image. The project provided centrally-purchased (and thus discounted) hardware, professional system administrators, and the developers to write astronomical data-reduction applications for the UK astronomy community and beyond. At its peak size in the late 1980s and early 1990s, the project had a presence at around 30 sites, located at most of the UK universities with an astronomy department, plus facilities at the Joint Astronomy Centre, the home of UKIRT and the James Clerk Maxwell Telescope in Hawaii. The number of active developers fluctuated between five and more than a dozen. By 1982, the project had a staff of 17, serving about 400 users at six sites, using seven VAXen (six VAX-11/780s and one VAX-11/750, representing a total of about 6.5 GB of disk space). They were networked from the outset, first with DECNET and later with X.25. Between 1992 and 1995 the project switched to UNIX (and switched the networking to TCP/IP), supporting Digital UNIX on Alpha-based systems, and Solaris on systems from Sun Microsystems. By the late 1990s it was additionally supporting Linux, and by 2005 it was supporting Red Hat Linux, Solaris, and Tru64 UNIX. It was about this time that the project open-sourced its software (using the GNU General Public License; it had previously had an 'academic use only' licence), and reworked its build system so that the software could be built on a much broader range of POSIX-like systems, including OS X and Cygwin. Though it was not explicitly funded to do so, the project was an early participant in the Virtual Observatory movement, and contributed to the IVOA. One of its VO applications was TOPCAT, development of which continues, with AstroGrid funding.
Reader's Guide
The Starlink Project produced a number of applications and libraries, including GAIA (the main GUI application, acting as a general astronomical image viewer and front end to many other applications), ORAC-DR (a data processing pipeline for incoming data, tightly integrated with the Starlink suite), KAPPA (a suite of general-purpose data-analysis and visualisation tools offering facilities not in IRAF, such as handling of data errors, quality masking, and a graphics database), CCDPACK (for reducing CCD-like data), AST (a library for handling World Coordinate Systems, partly based on SLALIB), SLALIB (a library for accurate positional-astronomy applications), HDS (a Hierarchical Data System that predates the Hierarchical Data Format), NDF (the project's principal data format built upon HDS), and ADAM (a standardised software environment initially designed as a telescope control system). The project also produced a number of cookbooks on various astronomical topics. By the end, the project's code base consisted of around 100 components, totalling around 2,100,000 source lines of code written by the project or curated by it, in various languages including Fortran, C, C++, Java, Perl and Tcl/Tk, plus another 700,000 lines of customised third-party code. Part of the software is relicensed under the GNU GPL while some of it remains under the original custom licence. At present, though funding for the project has ceased, the software is still available, either as pre-built distributions, or from a Git repository. The Astrophysics Source Code Library maintains an entry on Starlink.
Did You Know?
- The project was formally started in 1980, though funding had been agreed, and some work begun, a year earlier.
- The latest version of Starlink was released on 2025 November 26.
Gallery
Frequently Asked Questions
What is the Starlink Project?
The Starlink Project was a British astronomical computing initiative that built general-purpose data reduction software for the research community. Users typically called it simply 'Starlink,' while the developers themselves referred to it as 'The Project.'
What did the Starlink Project actually provide to UK astronomers?
In addition to its software suite, the project supplied computing hardware and dedicated system administration staff to UK astronomy institutes through the late 1990s. Its core deliverable was a set of general-purpose data reduction tools used across British observatories and universities.
When did the Starlink Project start and when did it close?
Funding was secured and early development began in 1979, with formal work kicking off in 1980. The project came to an end in 2005 after the Particle Physics and Astronomy Research Council cut its funding.
How does the Starlink Project relate to the US IRAF project?
The two are commonly described as parallel efforts on opposite sides of the Atlantic, with Starlink serving the UK community much as IRAF served American astronomers. Both provided shared computing infrastructure and standardized data reduction pipelines to their respective national research groups.
Why is the Starlink Project still talked about in astrophotography circles?
It gave UK-based observers and researchers access to standardized reduction pipelines and shared hardware at a time when such resources were otherwise cost-prohibitive. Its 2005 shutdown effectively ended an era of centrally funded astronomical computing in Britain, leaving a lasting gap in the community's shared tooling.
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