Quick Facts: Cassini UltraViolet Imaging Spectrograph (UVIS)

False-color image of Saturn's rings

Saturn’s rings, as seen in the ultraviolet, show there is more ice toward the outer part of the rings than the inner part. This image was taken with the LASP-built Ultraviolet Imaging Spectrograph (UVIS). (Courtesy NASA/JPL/University of Colorado)

Mission Introduction

Cassini completed its initial four-year mission to explore the Saturn System in June 2008 and the first extended mission, called the Cassini Equinox Mission, in September 2010. The spacecraft made even more exciting discoveries in a second extended mission called the Cassini Solstice Mission, which concluded on September 15, 2017, when the Cassini orbiter was intentionally deorbited into Saturn’s atmosphere. Since Cassini arrived at Saturn just after the planet’s northern winter solstice, the final extension permitted the first study of a complete seasonal period.

Cassini launched in October 1997 with the European Space Agency’s Huygens probe. The probe was equipped with six instruments to study Titan, Saturn’s largest moon. It landed on Titan’s surface on Jan. 14, 2005, and returned spectacular results. Meanwhile, Cassini’s 12 instruments have returned a daily stream of data from Saturn’s system since arriving at Saturn in 2004. Among the most important targets of the mission were the moons Titan and Enceladus, as well as some of Saturn’s other icy moons. Towards the end of the mission, during its “Grand Finale” set of 22 orbits, Cassini made a remarkable series of dives between the planet and its rings.

Approximately 1,300 academic and industrial partners in 16 European countries participated in 32 different states in the US. The mission was managed for NASA by the Jet Propulsion Laboratory in Pasadena, California, and for ESA by the European Space Technology and Research Center in Noordwijk, the Netherlands. The Italian Space Agency contributed the orbiter’s 4 meter diameter high-gain antenna for communications and portions of other orbiter science experiments. The United States supplied batteries and two science instruments for Huygens.

Cassini UVIS Instrument

The Ultraviolet Imaging Spectrograph Subsystem (UVIS) was a set of telescopes used to measure ultraviolet light from the Saturn system’s atmospheres, rings, and surfaces. The UVIS also observed the fluctuations of starlight and sunlight as the sun and stars move behind the rings and the atmospheres of Titan and Saturn, and determined the atmospheric concentrations of hydrogen and deuterium. (Courtesy LASP)

LASP Roles

LASP provided:

  • The UltraViolet Imaging Spectrograph (UVIS) instrument
  • UVIS instrument Principal Investigator, Larry Esposito
  • Operation/control of the UVIS instrument and its experiments

LASP Instrument

The Cassini Ultraviolet Imaging Spectrograph (UVIS) was part of the remote sensing payload of the Cassini Orbiter spacecraft.

UVIS science objectives included investigation of the:

  • Chemistry, clouds, and energy balance of the Titan and Saturn atmospheres
  • Neutrals in the magnetosphere
  • Surfaces and tenuous atmospheres of icy satellites
  • Deuterium/hydrogen (D/H) ratio for Titan and Saturn
  • Structure and evolution of Saturn’s rings

For more information about the Cassini mission, see:

Quick Facts

Launch date: October 15, 1997
Launch location: Kennedy Space Center, Cape Canaveral, Florida
Launch vehicle: Titan IV-B/Centaur
Mission target: Saturn
Mission duration: 7 year journey to Saturn, 10 years+ in Saturn System
Other key dates:

  • Saturn orbit insertion: July 1, 2004
  • End of mission: September 15, 2017

Other organizations involved:

  • Jet Propulsion Laboratory
  • Max Planck Institute for Solar System Research

CassiniClick on the image to view a PDF (756 KB) of Cassini-UVIS FAQs.