Voyager 2

Voyager 2 Voyager 2 is an interstellar space probe launched by National Aeronautics and Space Administration in 1977 as part of the Voyager program. Designed and managed by Jet Propulsion Laboratory, the probe conducted the only close reconnaissance of Uranus and Neptune and later became the second human-made object to enter interstellar space after Voyager 1. Built from work at California Institute of Technology and launched from Cape Canaveral Space Force Station, Voyager 2 carries scientific instruments, a Golden Record authored under the direction of Carl Sagan, and continues to return data via the Deep Space Network.

Mission overview

Voyager 2 was conceived within NASA's Voyager program and funded through projects administered by Congress and coordinated with teams at Jet Propulsion Laboratory, California Institute of Technology, and contractors including Lockheed Martin and TRW Inc.. The mission exploited a rare planetary alignment predicted by Gary Flandro to implement a gravity-assist "Grand Tour" trajectory enabling encounters with Jupiter, Saturn, Uranus, and Neptune using the technique advanced from studies at Ames Research Center and tests at Lewis Research Center. Project leadership included managers and engineers drawn from Jet Propulsion Laboratory and scientific investigators affiliated with institutions such as California Institute of Technology, Cornell University, University of Iowa, Brown University, and Massachusetts Institute of Technology. Communication and data return relied on the Deep Space Network stations at Goldstone Observatory, Canberra Deep Space Communications Complex, and Madrid Deep Space Communications Complex. Mission governance involved coordination with Office of Management and Budget and reporting to United States Congress oversight committees responsible for NASA appropriations.

Spacecraft design and instruments

The spacecraft bus was developed at Jet Propulsion Laboratory with components fabricated by contractors including Martin Marietta, Hughes Aircraft Company, and TRW Inc.. Power was provided by three plutonium-fueled MMRTG predecessors called RTGs, manufactured by Mound Laboratories under contracts with Atomic Energy Commission successors; electrical systems were overseen by Goddard Space Flight Center engineers. Attitude control, telemetry, and command subsystems were designed using heritage from Mariner program missions and integrated by teams at Jet Propulsion Laboratory. Scientific payloads were provided by research groups at California Institute of Technology (Pasadena), Cornell University, University of Iowa, University of Colorado Boulder, University of California, Berkeley, University of Michigan, University of Arizona, University of Maryland, Stanford University, University of California, Los Angeles, University of Tennessee, University of Hawaii, Scripps Institution of Oceanography, Smithsonian Astrophysical Observatory, Jet Propulsion Laboratory, NASA Ames Research Center, NASA Goddard Space Flight Center, Los Alamos National Laboratory, and Brookhaven National Laboratory. Instruments included the Imaging Science Subsystem developed from designs used on the Mariner 10 mission, the Ultraviolet Spectrometer contributed by University of Colorado Boulder, the Infrared Interferometer Spectrometer from Jet Propulsion Laboratory teams, the Plasma Science (PLS) instrument from University of Iowa, the Magnetometer from University of California, Los Angeles collaborators, the Low-Energy Charged Particles instrument built with California Institute of Technology participation, the Cosmic Ray System from California Institute of Technology and California Institute of Technology associates, and the Planetary Radio Astronomy experiment developed with involvement from University of Iowa and Cornell University. The Golden Record was curated by a committee chaired by Carl Sagan with contributions from Ann Druyan, Frank Drake, Jon Lomberg, and others.

Trajectory and mission timeline

Voyager 2 launched on August 20, 1977, from Cape Canaveral Space Force Station using a Titan IIIE/Centaur rocket provided by contractors including Martin Marietta and General Dynamics. The trajectory used gravity assists at Jupiter and Saturn to redirect the spacecraft for encounters with Uranus and Neptune—a plan developed from dynamics research at Jet Propulsion Laboratory and advocated by scientists at NASA Ames Research Center and California Institute of Technology. Key mission milestones include the Jupiter flyby in July 1979, the Saturn flyby in August 1981, the Uranus encounter in January 1986, and the Neptune encounter in August 1989. Post-planetary tour operations transitioned Voyager 2 to a heliospheric cruise managed by Jet Propulsion Laboratory and supported by the Deep Space Network. In November 2018, Voyager 2 crossed the heliopause and entered interstellar space, a boundary whose study involved researchers at Princeton University, University of California, Berkeley, Harvard University, Johns Hopkins University Applied Physics Laboratory, and Southwest Research Institute. Mission extensions have been approved by NASA oversight panels and scientific review boards, with continued operations coordinated through Jet Propulsion Laboratory and funding from NASA.

Planetary encounters

During the Jupiter encounter, instruments developed by teams at California Institute of Technology, Cornell University, University of Iowa, and University of Arizona observed atmospheric dynamics, volcanic activity on Io discovered earlier by Voyager 1, and ring structure studied by investigators at Smithsonian Astrophysical Observatory. The Saturn flyby yielded detailed observations of Titan and the ring system, with scientific analysis led by groups at Cornell University, Jet Propulsion Laboratory, and NASA Goddard Space Flight Center. Voyager 2's Uranus encounter provided the first close-up images of an ice giant, revealing a tilted magnetic field and new moons; research teams from University of Colorado Boulder, University of Hawaii, University of Arizona, and California Institute of Technology contributed to interpretations. The Neptune flyby returned the only close approach data on Neptune's Great Dark Spot, high-speed winds, and the moon Triton with geyser-like plumes; investigators from California Institute of Technology, Cornell University, Brown University, and Jet Propulsion Laboratory led follow-up studies. Scientific results from these encounters have been published and analyzed by researchers at Science (journal), Nature (journal), Proceedings of the National Academy of Sciences, Astrophysical Journal, Icarus (journal), and within reports to NASA and affiliated institutions.

Interstellar mission and current status

After the planetary tour, Voyager 2 continued outward to study the heliosphere and interstellar medium. Instruments from institutions including Princeton University, University of Iowa, Boston University, Institute for Advanced Study, and Southwest Research Institute measured plasma density, magnetic fields, and cosmic rays, enabling teams at Jet Propulsion Laboratory and NASA to determine the crossing of the heliopause. In 2018 Voyager 2 became the second spacecraft to enter interstellar space, corroborating measurements made earlier by Voyager 1 and prompting comparative studies at Caltech, Harvard University, Massachusetts Institute of Technology, University of Chicago, Columbia University, and Stanford University. The probe remains contactable via the Deep Space Network, with operations supported by mission scientists at Jet Propulsion Laboratory and program managers at NASA; telemetry is analyzed by investigators at institutions such as Cornell University, University of Michigan, University of California, Berkeley, Los Alamos National Laboratory, and Brookhaven National Laboratory. Aging systems and decaying RTG output have required mission teams including Jet Propulsion Laboratory engineers and NASA program offices to manage power budgets, instrument shutdowns, and command sequences, while the Golden Record continues to symbolize human culture in deep space as presented by Carl Sagan and collaborators. Category:Spacecraft launched in 1977