% This is the ADASS_template.tex LaTeX file, 24 Oct 2025.
% It is based on the ASP general author template file, but modified to reflect the specific
% requirements of the ADASS proceedings.

% This is the aspauthor.tex LaTeX file
% Copyright 2021, Astronomical Society of the Pacific Conference Series
% Revision:  29 November 2021

% To compile, at the command line positioned at this folder, type:
% pdflatex ADASS_template
% pdflatex ADASS_template
% This will create a file called ADASS_template.pdf

\documentclass[11pt,twoside]{article}

% Do NOT use ANY packages other than asp2021. 
\usepackage{asp2021}

\aspSuppressVolSlug
\resetcounters

% References must all use BibTeX entries in a .bibfile.
% References must be cited in the text using \citet{} or \citep{}.
% Do not use \cite{}.
% See ManuscriptInstructions.pdf for more details
\bibliographystyle{asp2021}

% The ``markboth'' line sets up the running heads for the paper.
% 1 author: "Surname"
% 2 authors: "Surname1 and Surname2"
% 3 authors: "Surname1, Surname2, and Surname3"
% >3 authors: "Surname1 et al."
% Replace ``Short Title'' with the actual paper title, shortened if necessary.
% Use mixed case type for the shortened title
% Ensure shortened title does not cause an overfull hbox LaTeX error
% See ASPmanual2010.pdf 2.1.4  and ManuscriptInstructions.pdf for more details
\markboth{Christophe~Arviset, Bruno~Merin et al.}{A 30-year journey through science data management}

\begin{document}

\title{A 30-year journey through science data management}

% Note the position of the comma between the author name and the 
% affiliation number.
% Authors surnames should come after first names or initials, eg John Smith, or J. Smith.
% Author names should be separated by commas.
% The final author should be preceded by "and".
% Affiliations should not be repeated across multiple \affil commands. If several
% authors share an affiliation this should be in a single \affil which can then
% be referenced for several author names. If only one affiliation, no footnotes are needed.
% See ManuscriptInstructions.pdf and ASP's manual2010.pdf 3.1.4 for more details
\author{Christophe~Arviset$^1$, Bruno~Mer\'in$^1$, Rachana~Bhatawdekar$^1$, Deborah~Baines$^1$, Mark~Bentley$^1$, Jos~de~Bruijne$^2$, Guido~de~Marchi$^2$, Arnaud~Masson$^1$, Vicente~Navarro$^1$, Jan~Reerink$^1$,  Hector~Perez$^3$,  Monica~Fernandez~Barreiro$^3$,  Jonathan~Cook$^3$,  Pablo~Perez~Gil$^3$,  Anastasia~Andres$^3$,  Ignacio~Leon$^4$, Ruben~Docasal$^4$,  Henrik~Norman$^5$,  Philip~Matsson$^5$}
\affil{$^1$European Space Agency, ESAC, Spain; \email{Christophe.Arviset@esa.int}}
\affil{$^2$European Space Agency, ESTEC, The Netherlands}
\affil{$^3$Starion for the European Space Agency, ESAC, Spain}
\affil{$^4$Aurora for the European Space Agency, ESAC, Spain}
\affil{$^5$WinterWay for the European Space Agency, ESAC, Sweden}

% This section is for ADS Processing.  There must be one line per author. paperauthor has 9 arguments.
\paperauthor{Christophe~Arviset}{Christophe.Arviset@esa.int}{0000-0002-2311-740X}{European Space Agency (ESA)}{ESAC}{Villanueva de la Ca\~nada}{Madrid}{28691}{Spain}
\paperauthor{Bruno~Mer\'in}{Bruno.Merin@esa.int}{0000-0002-8555-3012}{European Space Agency (ESA)}{ESAC}{Villanueva de la Ca\~nada}{Madrid}{28691}{Spain}
\paperauthor{Rachana~Bhatawdekar}{Rachana.Bhatawdekar@esa.int}{0000-0003-0883-2226}{European Space Agency (ESA)}{ESAC}{Villanueva de la Ca\~nada}{Madrid}{28691}{Spain}.
\paperauthor{Deborah~Baines}{Deborah.Baines@esa.int}{0000-0002-6923-3756}{European Space Agency (ESA)}{ESAC}{Villanueva de la Ca\~nada}{Madrid}{28691}{Spain}
\paperauthor{Mark~Bentley}{mark.bentley@esa.int}{0000-0002-4780-1767}{European Space Agency (ESA)}{ESAC}{Villanueva de la Ca\~nada}{Madrid}{28691}{Spain}
\paperauthor{Jos~de~Bruijne}{Jos.de.Bruijne@esa.int}{0000-0001-6459-8599}{European Space Agency (ESA)}{ESTEC}{Noordwijk}{Zuid-Holland}{2201 AZ}{The Netherlands}
\paperauthor{Guido De Marchi}{gdemarchi@esa.int}{0000-0001-7906-3829}{European Space Agency (ESA)}{ESTEC}{Noordwijk}{Zuid-Holland}{2201 AZ}{The Netherlands}
\paperauthor{Arnaud~Masson}{Arnaud.Masson@esa.int}{0000-0002-5602-1957}{European Space Agency (ESA)}{ESAC}{Villanueva de la Ca\~nada}{Madrid}{28691}{Spain}
\paperauthor{Vicente~Navarro}{Vicente.Navarro@esa.int}{0000-0002-7381-3470}{European Space Agency (ESA)}{ESAC}{Villanueva de la Ca\~nada}{Madrid}{28691}{Spain}
\paperauthor{Jan~Reerink}{Jan.Reerink@esa.int}{0000-0001-6558-5183 }{European Space Agency (ESA)}{ESAC}{Villanueva de la Ca\~nada}{Madrid}{28691}{Spain}
\paperauthor{Hector~Perez}{Hector.Perez@ext.esa.int}{0009-0005-0473-6941}{Starion for the European Space Agency (ESA)}{ESAC}{Villanueva de la Ca\~nada}{Madrid}{28691}{Spain}
\paperauthor{Anastasia~Andres}{Anastasia.Andres@ext.esa.int}{0009-0002-3982-0965}{Starion for the European Space Agency (ESA)}{ESAC}{Villanueva de la Ca\~nada}{Madrid}{28691}{Spain}
\paperauthor{Jonathan~Cook}{jonathan.paul.cook@ext.esa.int}{0009-0006-8367-321X}{Starion for the European Space Agency (ESA)}{ESAC}{Villanueva de la Ca\~nada}{Madrid}{28691}{Spain}
\paperauthor{Pablo~Perez}{Pablo.perez@ext.esa.int}{0009-0001-4231-9971}{Starion for the European Space Agency (ESA)}{ESAC}{Villanueva de la Ca\~nada}{Madrid}{28691}{Spain}
\paperauthor{Ignacio~Leon}{ignacio.leon@sscspace.com}{0009-0007-0056-1763}{Aurora Technology the European Space Agency (ESA)}{ESAC}{Villanueva de la Ca\~nada}{Madrid}{28691}{Spain}
\paperauthor{Henrik~Norman}{henrik@winterway.eu}{0000-0003-4189-3450}{Winter Way AB}{}{Lerum}{V\"astra G\"otaland}{44335}{Sweden}


% There should be one \aindex line (commented out) for each author. These are used to
% build up the author index for the Proceedings. The surname must come first, followed by
% initials. Note the use of ~ before each initial to control spacing.
% The \author entries (see above) have surname last. These \aindex entries have
% surname first.
% The Aindex.py command willl create them for you after you have constructed the \author
% The first entry should be the first author, for bold-facing the author index page-reference

%\aindex{FistAuthor1,~S.~A.}
%\aindex{Author2,~S.~B.}
%\aindex{Author3,~S.}


\begin{abstract}
Do you remember which computer you were using in 1995? What were the favourite operating systems and programming languages in the ADASS community back then? The World Wide Web was just born, and it has changed everybody’s life to a point nobody ever imagined.
When ESA decided to build the ISO Data Archive in 1995, no one expected this would be the beginning of a journey towards establishing the ESAC Science Data Centre. ESA’s Digital Library of the Universe is now covering more than 30 astronomy, planetary and heliophysics missions’ science archives and their associated data discovery portal (ESASky) and its close integration into the data exploitation platform (ESA Datalabs).
Information Technology is changing rapidly, and data archives also went through major changes over the last three decades, as well as their associated science data management hardware and software systems, including storage, databases, graphical user interfaces, data distribution, interoperability and now data exploitation through science platforms.

Hence, let’s go back in time and go through a 30-year journey of science data management, highlighting the Lessons Learned along the way!
\end{abstract}

% These lines show examples of subject index entries. At this stage these have to commented
% out, and need to be on separate lines. Eventually, they will be automatically uncommented
% and used to generate entries in the Subject Index at the end of the Proceedings volume.
% Don't leave these in! - replace them with ones relevant to your paper.
%\ssindex{FOOBAR!conference!ADASS 2019}
%\ssindex{FOOBAR!organisations!ASP}

% These lines show examples of ASCL index entries. At this stage these have to commented
% out, and need to be on separate lines. Eventually, they will be automatically uncommented
% and used to generate entries in the ASCL Index at the end of the Proceedings volume.
% The ascl.py command will scan your paper on possible code names.
% Don't leave these in! - replace them with ones relevant to your paper.
%\ooindex{FOOBAR, ascl:1101.010}


\section{From 1995 to 2025}
Looking at the world today where technology is evolving so quickly, it is worth looking 30 years back at what the state-of-the art devices were. Phones were landlines, used only to talk and  were deﬁnitely not yet "smart". Apple revolutionized the human-computer interactions with a mouse and graphical operating system. We used to listen to music through a Walkman and NCSA Mosaic navigator enabled people to easily access static information in remote places. Who could have bet then that the Internet would become part of any moment of our daily life?

The first ADASS conference took place in 1991 in Tucson, USA where presentations were provided through physical handwritten slides (PowerPoint and KeyNote did not exist then!), and we're now celebrating the 35th ADASS anniversary, demonstrating the sustainable interest and strength of this community over the last three decades, year after year, even despite some tragic worldwide events (9/11 tragedy in 2001 before ADASS in Victoria and the COVID pandemic in 2020 with the first full remote conference in "Granada") and some more joyful ones (Solar Eclipse in 2005 in San Lorenzo de El Escorial). The Virtual Observatory appeared for the first time as a concept in 2001 and has evolved through some bumpy roads to show its full potential at ADASS 2015 in Sydney, where new astronomical data centres reported VO implementation without having been involved in it before.

\articlefigure[width=1\textwidth]{88-Figure-ESAArchivesFamily.png}{fig-ArchivesFamiliy}{ESA Archives ever growing family.}

ESA strategy for data management for its Science missions has also very much evolved over time. In 1998, around the end of its in-orbit operations, the first public archive for ISO (Infrared Space Observatory) was released on the web, through a modern Java applet GUI, offering easy and fast access to all ISO data products. It took some time for other missions to adopt the same path, with XMM-Newton science archive released in 2002 and the Planetary Science Archive, hosting data from various ESA planetary missions. Building on these successes, ESA decided to host all its Science missions data archives within the ESAC Science Data Centre\footnote{\url{https://archives.esac.esa.int}} (ESDC), located in Villanueva de la Canada, close to Madrid, Spain. Understanding that data needs to be accessible to the scientific community as soon as available, Planck and Herschel were the first two archives to be ready at launch in 2009. Archives located in other places such as Cluster Active Archive and the Ulysses operational archive from ESTEC, Netherlands and the European HST Archive from ST-ECF, Garching, Germany were transferred to ESAC to ensure operations and maintenance within the same team, using similar technologies. Special efforts (almost "archeological" exploration) took place to gather data from very old missions (i.e. Giotto, Exosat, Ulysses). 

Taking profit of having several astronomical data archives at ESAC, and building on existing data interoperability VO standards, ESASky\footnote{\url{https://sky.esa.int}} was released in 2015. Gaia was the first mission to trigger significant technology changes for its data management, due to the volume, complexity and variety of its data. Other directorates at ESA leveraged on ESDC experience for the HREDA\footnote{\url{https://hreda.esac.esa.int/}} (Human and Robotic Exploration Data Archive) released in 2022, hosting all datasets from the experiments made on-board of the ISS (International Space Station), and through any other platforms. The upcoming big challenge is coming from Euclid, which data volume represents more than one order of magnitude greater than the total of all the other archives hosted at ESAC. 

\section{ESAC Science Data Centre in 2025}

Overall today in 2026, ESDC is hosting more than 30 missions science archives covering all ESA Space Science fields (astronomy, planetary, heliophysics and low-earth orbit platforms) as shown in Figure \ref{fig-ArchivesFamiliy}. All these archives are being developed, operated, and maintained by the same team, comprised of archive scientists and software engineers, organized along the four science fields mentioned above. 

ESA Science Archives Long Term Strategy is now based around three main pillars. First, enabling maximum scientific exploitation of Science datasets. ESA science missions' success is often being measured by the number of scientific papers written with mission data. Papers using archival data represent between 50\% and 75\% of them \citep{demarchiparmar2024}, so it is extremely important that science archives support this purpose. The Archive Scientist for the mission is responsible for gathering science cases and user requirements for their mission, and for working closely with the archive development team for the archive to ensure the archives efficiently serves the scientific community.  Second pillar is to ensure efficient long-term preservation of data, software and knowledge. While missions can last over several decades, they always come to an end one day. But the science continues well after the mission lifetime, and it is ESA responsibility to ensure that the science archives from legacy missions continue to be accessible and to produce new scientific papers. Last but not least, the third pillar calls for the development of cost-effective archives via integration in, and across, projects. In some cases, the archive is part of the data processing chain of the mission, so needs to be smoothy integrated into the mission Science Ground Segment's overall architecture. In some other cases, the mission data is within a multi-mission data infrastructure, benefiting from existing functionalities and where specific missions' requirements also need to be factored in.

\section{ESDC successes and Lessons Learned over the years}
 
\subsection{Science Archives are more than just FTP or JBOD}
In many people's mind, Archives consist only of dumping all data from the missions onto some FTP server for the community, a JBOD in other words (Just a Bunch of Disks). But archives are much more than this, and are full data management services as indicated in the Open Archiving Information System (OAIS) functional model (Figure \ref{fig-OAIS}, reproduced with permission from the Consultative committee for Space Data Systems (CCSDS\footnote{\url{https://ccsds.org/}})). 

From the back-end perspective, a lot of attention is paid to data curation, ensuring the best quality of the data being ingested into the archive, then extraction of metadata into the database to enable queries as per the science cases defined by the Archive Scientist. From the front-end perspective, the science archives offer more than just a list of products through FTP, but powerful data discovery and visualization services. These services allow scientists to search for particular regions of the sky or solar system objects, combining this with a wide variety of other search parameters based on science objectives. Visualization services also play an important role to help the scientists deciding what to retrieve from the archives. 

\articlefigure[width=1\textwidth]{88-Figure-OAIS-functional-model}{fig-OAIS}{Open Archiving Information System functional model.}

The administration part also represents a fair amount of work, with database administration, data and users access management, usage logging and reporting. And as archives must perdure over decades while technology evolves much more rapidly, preservation activities are required for technology evolution for all the archive subsystems. Another important aspect is the interoperability with other external archives services, delegating parts which are better done by other entities. The most scientifically useful example is the linking of data with their scientific publications. Allowing access to the scientific papers related to the data and vice-versa greatly enhances the usage of the data. While this linking was mostly done manually, there are real expectations that AI and NLP will help significantly in this process.

Overall, a science archive system can represent tens of thousands of lines of software code.

\subsection{Good architecture is the key and it evolves with time}
From their conception in the mid-90s, the ESAC Science Archives architecture has been based on a 3-tier model (Data layer, Server layer and Client layer, see Figure \ref{fig-Euclid-Arch}). The modular approach has been one of the best decisions, as it has allowed the archives subsystems to evolve, without the need to redevelop them all at once. 

From CDROM jukeboxes in 1998 to having all data available on hard disks for fast access, from commercial relational databases to open-source ones with community add-ins (pgsphere, postgis), from Java 1 to Java 18 for the server part, from Java Applet to Google Web Toolkit and now Angular for the GUIs, from interoperability with a VO translation layer toward a VO built-in approach, many evolutions have taken place smoothly over the last three decades \citep{I7-19_adassxxxv}. This has also allowed the archives to easily connect the archives to new key tools and services, such as ESASky, Astropy or ESA Datalabs. 

\articlefigure[width=1\textwidth]{88-Figure-Euclid-Arch}{fig-Euclid-Arch}{Euclid Archive 3-tier Architecture with VO built-in \citep{2025ASPC..541...28N}.}

\articlefigure[width=1\textwidth]{88-Figure-GUIs}{fig-ESDC-GUIs}{Evolution of Archives GUI evolution over time.  \emph{Left:} ISO Archive GUI in 1998.  \emph{Right:} European Hubble Archive in 2025.}

\subsection{ESASky: a window to the universe }
While the number of astronomical archives was growing at ESAC, we established the first ESA Science Archives Long Term Strategy in 2013. This was the result of intense brainstorming and discussions among scientists and software engineers within our department, defining new science cases. One of the main outcomes was the need to build a multi-mission archive. As the VO data interoperability protocols were getting to the right level of maturity, with increased implementation across ESA science archives and other data centres worldwide, we decided to leverage these and existing tools (in particular Aladin Lite from the CDS, Centre des Données de Strasbourg) to build a web‑based, science‑driven, multi-mission astronomical data discovery portal with simple, intuitive, and unified access to data initially from ESA and later on from a wide range of space‑ and ground‑based observatories worldwide. And ESASky was born and released in 2015 \citep{2018A&C....24...97G}.

Today, ESASky provides access to science‑ready images, spectra, and catalogues from a broad range of ESA astronomy missions, alongside various space observatories data from NASA, JAXA and ground-based observatory from ESO, LAMOST, and SDSS datasets, enabling comprehensive multi‑wavelength analysis. The tool is entirely web‑based and mission‑agnostic, requiring no prior knowledge of individual mission characteristics, thereby supporting both expert astronomers and non‑specialists. ESASky employs advanced visualisation technologies such as HiPS all‑sky mosaics and mission coverage maps (MOC) to efficiently display massive datasets. Users can interactively explore the sky, overlay footprints from multiple instruments, and compare observations across wavelengths in a unified environment. The portal supports multi-target searches, provides summarised observation metadata, and facilitates rapid retrieval of relevant data products. Additional capabilities include serendipitous searches of Solar System object observations and tools for observing, planning, including support for JWST preparation.

\section{The Virtual Observatory}
The International Virtual Observatory Alliance (IVOA) was created in 2002 with the primary mission to enable global, integrated access to astronomical data collected by observatories worldwide. The Alliance consists today of 23 members who participate at different levels \citep{2025ASPC..541...68A}. There is no specific budget for the IVOA and participation has fluctuated depending on the funding availability from each of its members. But today, the IVOA is a very stable organization, with established working groups and interest groups, a clear process to define recommended data interoperability standards, and meetings twice per year with over 100 participants. Over the years, the funding went from dedicated national VO projects towards less specific VO funding but work integrated within the astronomical data centres worldwide. While it was important in the early days to have people brainstorming about new standards, it became later on more effective to have the active participation of the data centres to ensure the VO standards were taken up and VO data services were deployed.

From the early days, there might have been some misconceptions of the VO, which can explain why sometimes the VO was considered as not successful in the community. Contrary to what some people might have expected, the Virtual Observatory is not a portal to access all astronomical data worldwide; neither is it the ultimate application in astronomy nor a major solution for data management. Instead, the VO is a data interoperability ecosystem between astronomical data providers, an alliance of members defining standards to build VO applications for multi-observatories data access, and overall a data management framework for building interoperable data services.

\articlefigure[width=.80\textwidth]{88-Figure-IVOA-Arch}{fig-IVOA-Arch}{IVOA Architecture and FAIR.}

The IVOA has tackled the data interoperability challenges well with an IVOA Architecture defined in 2010, which was FAIR before FAIR even existed (see Figure \ref{fig-IVOA-Arch}), and has been very stable since then. Most astronomical data today is accessible through VO protocols. Gaia is the perfect example, where data access leverages IVOA standards such as TAP, ADQL, UWS and Datalink and one can affirm that all astronomers using Gaia data are actually using the VO (and sometimes without knowing it). With the advent of big data and the associated science data platform, the next big challenge to address for the IVOA will be the smooth interoperability between these platforms.

\section{Big upcoming challenges and opportunities}

\subsection{User login or not login: that is the question and a changing answer}
In 2000, user login was required for all ESA science archive services. All archives had then a mix of proprietary and public data, mostly available through Graphical Web User Interfaces. Querying for data and metadata did not require login, but any data download request required user authentication and authorization. Archive usage statistics were then easy as all data downloads were associated with a user account.

In 2010, some of the ESA science archives only had public data, and alongside the usual Web GUI, APIs offered convenient scriptable access to the data. User login then became optional and only required when accessing proprietary data, on-the-fly reprocessed data and large data bundle (>a few GB). Archive usage statistics were then based both on users (when logged in) and IP addresses (for anonymous access), with a gradual increase of the latter over the former.

In 2016 with the first Gaia public data release, while all data was public the user login was reinforced to gain access to more advanced user services such as bigger data queries or user workspaces within the archive, but login was not required for standard services. Archive usage statistics continued to cover logged in user accesses and anonymous ones, with a clear bigger portion of the latter.

In 2025, while the amount of public data greatly exceeds the proprietary data and anonymous access through GUI or API represents the majority of accesses, we see our archive usage statistics polluted by Bots and LLM crawlers, with accesses which can be 1000 times bigger than the standard usage. While totally distorting the access statistics represents the risk of unrealistic and unreliable statistics, we also start to fear potential degradation of our services towards our real scientific community, due to other "users". Providing more advanced data services through an exploitation platform is another reason why re-instantiating user login for any data download is seriously considered for all our ESA science archives, as we had 25 years ago.

\subsection{Long Term Data Preservation Challenges}
Science missions usually span over several decades through their study, development, in-orbit operations and post-operations phases, during which dedicated mission budget is available and a small portion is for the development and operations of the mission science archive. When the mission enters into its legacy phase, there is no more dedicated funding for this mission, but the archive still needs to be maintained and operated, as many scientists continue to access its data to advance science, through refereed papers, value added products (e.g. catalogues) or educational purposes. Some limited funding is available within ESA through the Heritage Space Programme to cover the archives for missions in legacy. As all archives are being maintained by the same ESAC Science Data Centre team, these tasks can be done in a cost efficient manner as the same software developer continues to operate the legacy archives, while developing the ones for the new missions. But the archive cannot be totally frozen, as technology evolves, and legacy archives need migration from old technology to new ones (new database versions, more modern back-end frameworks and front-end GUIs). 

The number of archives in legacy will outnumber the ones of active missions, which is forcing us to reconsider the approach of having a single archive per mission. The Planetary Science Archive (PSA) already integrates all the planetary missions regardless of their phase and we're going to implement the same model for other science disciplines. A first public version of the HelioPhysics Archive (HPA, see Figure \ref{fig-HPA}) has been released in April 2025, starting with an advanced Field of View tool for the Solar Orbiter data, followed by a first version of a totally re-designed Solar Orbiter archive (July 2025). The two most recent heliophysics missions, Proba-3 and SMILE will have their archives directly released in HPA during the course of 2026, together with two legacy archives (ISS-SolACES and Ulysses). The rest of the heliophysics missions will gradually be moved to HPA. Similar approach has also started with astronomy missions with the building of the Astronomy Multi-missions Archive (AMA), although the wide variety of astronomy missions and associated archive services makes it more challenging.

\articlefigure[width=1\textwidth]{88-Figure-HPA}{fig-HPA}{ESA HelioPhysics Archive.}

\subsection{ESA Datalabs and the new data access paradigm}
The total volume of all ESA science archives up to 2024 was about 1PB, but Gaia and Euclid more than triple this amount by 2026 and Euclid \citep{2025ASPC..541...12D} will bring it to another order of magnitude by the beginning of the next decade. The big data era is now a reality, and not just because of the data volume, but also due to the variety and change velocity of data and metadata. For some of the new missions, Euclid in particular, the scientists will not be able to download the data to their premises to do their science. Hence, a paradigm shift is necessary: from a "bring the data to the user” approach towards "bring the user to the data”, through the development of science data exploitation platforms. ESA has been developing a platform called ESA Datalabs \citep{Navarro2024}, closely integrated with the existing archives. Beyond delivering this paradigm shift for new big data missions, it will also leverage AI and ML techniques to enable new data discoveries. Furthermore, ESA Datalabs offers a Virtual Collaboration Environment for scientists, where people can share their data and their code into a common workspace, and eventually publish their analysis software on the public applications store of ESA Datalabs. Moreover, ESADatalabs supports preservation of analysis software from legacy missions. This code can be published into the platform, directly available to end users, hence facilitating its installation and ensuring its long-term preservation and availability.

\section{Conclusions}
The ESAC Science Data Centre has been developing and operating over the last 30 years more than 30 science archives from ESA Space Science missions. More than just data repositories, the science archives are full data management systems that enables the scientific return of the missions to be maximised. Their robust and modular architecture has ensured their maintainability and has facilitated their technology evolution over time. The VO has been key for data interoperability among datasets and astronomical data partners worldwide. The next strategic step towards ensuring long-term sustainability will be to move from a dedicated archive for each mission towards multi-mission archives per scientific discipline. The big data era has arrived and the science data platforms such as ESA Datalabs will be key to ensure that the ESA Science Archives continue to serve best the scientific community in the best possible way.

\acknowledgements The authors would like to thank all the people who are or who have been part of the ESAC Science Data Centre over the years, as well as all supporting teams in particular the Programmatic IT section at ESAC, the missions' Science Operations Centres and Project Scientists, the Instrument Teams and missions' Consortia. They have been part of this data management journey over the last decades.

\bibliography{88-Arviset}  % For BibTex

% if we have space left, we might add a conference photograph here. Leave commented for now.
% \bookpartphoto[width=1.0\textwidth]{foobar.eps}{FooBar Photo (Photo: Any Photographer)}

\end{document}
