By Dr. Gary Deel, Ph.D., J.D.
Faculty Director, School of Business, American Military University
This article is the second article in a four-part series profiling space agencies around the world. This article looks at the ESA’s most prominent 20th-century official space policy, Horizon 2000, and the pivotal missions that followed from it. Read the first article here.
Since the ESA’s inception, this organization has executed a number of missions and programs aimed at furthering space exploration and development. Some of these missions were independent ESA pursuits.
Other missions were partnerships with other international space agencies, such as the United States National Aeronautics and Space Administration (NASA), the Japan Aerospace Exploration Agency (JAXA) and the French Centre National d’Etudes Spatiales (CNES). Still other missions have been coordinated efforts with private-sector companies, including satellite operators such as EUMESTAT and Inmarsat.
Get started on your Space Studies Degree at American Military University.
European Space Agency Created Horizon 2000 Initiative in 1984
In 1984, the ESA drafted a long-term plan called Horizon 2000. This initiative addressed contemporary and future space and science programs through the end of the century. Horizon 2000 continued funding and support for several missions that were already in progress at the time of its inception, including
- The International Ultraviolet Explorer (IUE) – The IUE was a collaborative project with NASA and the UK Science Research Council. It consisted of an astronomical observatory satellite launched in 1978, designed to study the universe in the ultraviolet light spectra. The original mission plan was three years, but the satellite’s operational life was extended for 18 years until it was shut down permanently in 1996.
- Hipparcos – Hipparcos was a satellite launched by the ESA in 1989 with the aim of perfecting precision astrometry and measuring positions of celestial objects in space. Hipparcos was operated for more than four years until it was deactivated in 1993.
- Ulysses – Ulysses was another joint venture with NASA and the Canadian Research Council. It was a robotic space probe, launched in 1990, that orbited the Sun and took measurements. The Ulysses mission was expected to last five years, but it survived 18 years until it was decommissioned in 2009.
The Four Cornerstone Missions of Horizon 2000
In addition to the pre-existing missions of IUE, Hipparcos and Ulysses, Horizon 2000 set forth a new agenda for the space agency that included four “cornerstone” missions:
- Cornerstone 1 – Cornerstone 1 included two components. The first was the Solar and Heliospheric Observatory (SOHO), a joint mission with NASA. Launched in 1995, its aim was to study solar and space weather forecasting. SOHO was intended as a two-year mission, but after more than 20 years in space, SOHO is still operational today. It is likely to be funded through at least 2022.
The second component, Cluster, consisted of a constellation of four satellites that were designed to study the Earth’s magnetosphere. Cluster was originally launched in 1996, but sadly the rocket blew up in-flight due to software errors with the launch telemetry.
Fortunately, ESA rebooted the mission and relaunched Cluster II in 2000. The second attempt was successful. Cluster II was planned as a five-year mission, but it too is still currently operational.
- Cornerstone 2 – Cornerstone 2 consisted of the XMM-Newton mission, an x-ray space telescope that was launched in 1999 to study x-ray sources in deep space. XMM-Newton was only slated to last two years, but the craft is still operational today and its funding still receives the ESA’s support.
- Cornerstone 3 – Cornerstone 3 was the Rosetta mission, which consisted of a space probe equipped with a lander called Philae. Rosetta was launched in 2004 and arrived at its destination – Comet 67P/Churyumov-Gerasimenko – in 2014. It studied the comet carefully and sent pictures back to Earth. Finally, it deployed the Philae lander, which was intended to analyze samples of the cometary surface and relay data back to Earth.
Philae was designed to land softly on the cometary surface and then secure itself with a kind of harpoon cabling system that jettisoned from the lander’s feet on impact. However, something went wrong on touchdown, and the lander’s harpoon system failed to secure it.
The lander is believed to have bounced and tumbled, and to have eventually settled in an area of the comet that is in near-permanent shadow. Because the lander relied on solar power to maintain its systems and instruments, its battery power eventually depleted and the lander was lost forever.
- Cornerstone 4 – Finally, Cornerstone 4 consisted of the Herschel mission. Herschel was a partnership with NASA to build the largest infrared telescope ever developed. It was launched in 2009 and was operational through 2013. It was sent to the L2 Lagrangian point in the Earth-Sun system, and its infrared capability allowed it to see some of the coldest and dustiest objects in the universe.
Three Additional Missions from Horizon 2000
In addition to the four cornerstone missions, the ESA Horizon 2000 plan established three medium-sized missions to be completed over the next few decades:
- Huygens – Huygens was a space probe, launched in 1997, which was part of the Cassini-Huygens spacecraft sent to the Saturnian system. In 2004, Huygens (the lander) separated from Cassini (the orbiter).
In 2005, Huygens successfully landed on Saturn’s moon Titan, making it the farthest space probe landing from Earth in history. The probe was designed to collect atmospheric and ground-based data on Titan and relay it back to Earth. It completed its mission, surviving for approximately 90 minutes on Titan’s surface.
- The International Gamma-Ray Astrophysics Laboratory (INTEGRAL) – INTEGRAL is a space telescope that the European Space Agency launched in 2002 to study gamma-ray emissions from deep space. It was the first of its kind to do so before NASA launched the Fermi space telescope in 2008.
INTEGRAL was only intended to be a two-year mission. However, it has maintained enough fuel to continue operations and is still active today. Provided that funding is not cut sooner, it is slated to be deorbited in 2029.
- Planck – The ESA launched the Planck mission in 2009 which consisted of an observation satellite designed to map the cosmic microwave background radiation of the universe at infrared frequencies. The Planck mission picked up the baton from NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) mission, which ran from 2001 to 2010.
The Planck mission helped to refine our measurements of the background radiation, and consequently, our understanding of such phenomena as the Big Bang, matter density, and even the existence of dark matter. The mission was originally planned to last just over a year, but it was extended for almost four and a half years until the satellite was decommissioned in 2013.
In the next installment of this article series, we’ll look at how the ESA expanded the Horizon 2000 space policy into the 21st century with Horizon 2000+.
About the Author
Dr. Gary Deel is a Faculty Director with the School of Business at American Military University. He holds a J.D. in Law and a Ph.D. in Hospitality/Business Management. Gary teaches human resources and employment law classes for American Military University, the University of Central Florida, Colorado State University and others.