Viewing The Solar Poles

The Ulysses spacecraft was designed to study the Sun’s polar regions, solar wind and the three-dimensional nature of the Sun’s radiation. To achieve this, the probe performed the first gravity assist manoeuvre around Jupiter to enter a polar orbit around the Sun. Launched in 1990 from the space shuttle Discovery, the Ulysses mission was planned to last 5 years but would exceed expectations by lasting over 18 years.

Ulysses Spacecraft Fast Summary Facts!

  • Type:  Orbiter
  • Destination: Sun
  • Status:  Decommissioned
  • Launch Location:  Cape Canaveral, Florida
  • Launch Date:  October 6th 1990
  • Arrival Date:  June 30th 2009
  • Mission Duration:  Planned 5 years, Extended to 18 ½ years

Interesting Facts About The Ulysses Spacecraft

  • Ulysses' objective was to study and map the solar wind (and radiation) that streams non-stop from the Sun’s poles which had never been studied before. The Sun’s solar wind produces a huge bubble in interstellar space called the heliosphere. It was able to do this nearly 4 times longer than originally planned.
  • The probes electronics were powered and heated by a radioisotope thermoelectric generator (RTG).
  • The scientific instruments onboard were able to detect and measure the solar wind particles, magnetic fields, energetic particles, radio and plasma waves, dust and gas, X-rays, and gamma rays.
  • The Ulysses spacecraft was launched into low-Earth orbit (LEO) in the payload bay of the shuttle Discovery, on October 6th
  • Once in LEO, the Ulysses set course for Jupiter, arriving in February 1992 where the probe performed the gravity-assist manoeuvre that swung it south, away from the ecliptic plane, into its unique solar orbit that would take it over the sun's south and north poles.
  • This would not be a sungrazing mission though, as Ulysses was 300 million kilometres (2.0 AU) above the Sun's poles when passing over them.
  • Ulysses’ orbit around the Sun, which takes it out past Jupiter, takes 6 years to complete.
  • The Ulysses spacecraft completed three passes of the Sun’s north and south poles over its 18+ year mission.
  • One of the key discoveries was that the strength of the solar wind has grown steadily weaker since the Space Age!
  • Another discovery Ulysses made was that the polar regions of the Sun are cooler and their solar wind travels at a uniform speed of 750 km/s (1.68 million mph); twice as fast as the wind that emerges from the Sun’s equatorial zone!
  • The probe also crossed the paths of several comet tails, analyzing their ion components.
  • Ulysses was a joint ESA/NASA mission. With the partners providing various spacecraft components and launch services.
  • A joint ESA/NASA team at the Jet Propulsion Laboratory (JPL) managed the probes operations and data management, with the Ulysses spacecraft tracked by NASA’s Deep Space Network.
  • Ulysses was finally deactivated on 30 June 2009 after its planned 5-year mission lasted 18 years, 8 months and 24 days.
Ulysses Spacecraft
Ulysses Orbit
Ulysses at Jupiter
Ulysses Solar Mystery
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