Ulysses: 12 extra months of valuable science



 
Over more than 18 years of observations above and below the poles of the Sun, the ESA/NASA Ulysses mission has made fundamental contributions to our understanding of the Sun itself, its sphere of influence (the heliosphere), and our local interstellar neighbourhood. The mission provided the first-ever map of the heliosphere in the four dimensions of space and time.

Ulysses was launched by Space Shuttle Discovery in October 1990. It headed out to Jupiter, arriving in February 1992 for the gravity-assist manoeuvre that swung the craft into its unique solar orbit. It orbited the Sun three times and performed six polar passes. The mission was shut down on 30 June 2009 because of the declining power.

The design of the Ulysses spacecraft was dictated by the large distances from Earth and the Sun (up to 950 million km from Earth, 810 million km from the Sun).

At such distances, solar power could not provide enough electricity so a Radioisotope Thermoelectric Generator (RTG) was provided. A large antenna (1.65-m diameter) was necessary to communicate with Earth from large distances. The thermal design had to accommodate the widely-varying temperatures during the mission. The electronics were hardened to withstand the strong radiation in the vicinity of Jupiter during the close fly-by in 1992.

ESA provided the spacecraft, built by Astrium GmbH, Friedrichshafen, Germany (formerly Dornier Systems). NASA provided the Space Shuttle for launch, the inertial upper stage and the payload assist module to put Ulysses into its correct orbit. NASA also provided the RTG to power the craft and its payload.

ESA’s European Space Research and Technology Centre (ESTEC) and European Space Operations Centre (ESOC) have been managing the mission in coordination with NASA’s Jet Propulsion Laboratory (JPL). Ulysses has been tracked by NASA’s Deep Space Network. A joint ESA/NASA team at JPL has overseen spacecraft operations and data management. Teams from universities and research institutes in Europe and the United States provided the nine instruments onboard.

The Ulysses legacy
 
After more than 18 years of observations of the Sun, the heliosphere and our local interstellar neighbourhood, the joint ESA/NASA mission Ulysses is coming to an end, and the spacecraft will be switched off on 30 June 2009.

Ulysses
 
Since its launch in 1990, Ulysses has constantly monitored how much stardust enters the Solar System from the interstellar space around it.

Longest-running ESA-operated spacecraft
 
ESA's Angold and NASA's Smith during Ulysses final webcast
 
Nigel Angold, ESA Mission Operations Manager (L) speaks with Ed Smith, NASA's Ulysses Project Scientist (R), during live webcast of final Ulysses ground station pass, 30 June 2009. Webcast recorded at the Ulysses Mission Support Area (MSA), NASA/JPL.



Release date: 1 July 2009