Galileo Messenger Archive

From 1981 to 1997, the Jet Propulsion Laboratory kept team members and space enthusiasts informed about the tortured path of the Galileo mission through a newsletter that ran mostly quarterly, with occasional interruptions, to 45 issues. They're being posted here thanks to the scanning effort of Patrick Wiggins, who had kept a complete set of the Messengers in excellent condition since receiving them.

The Galileo Messenger was only printed through the Prime Mission. By the time that ended in 1997, Internet access had become commonplace enough that communications about Galileo's mission status were transitioned to the Web.

Each Galileo Messenger is in PDF format, scanned in black and white at 200 DPI, amounting to about 1 Megabyte per page. Most issues are 4 pages, but some are more.

Links take you to the PDF documents. Below each link is a listing of the section headings within each newsletter and of the photos, diagrams, and artworks printed along with the text. You may also download Zipped collections of the bulletins:

  • Issues 1-21 (75 MB): Development to launch, April 1981, to November 1989
  • Issues 22-37 (109 MB): Cruise, February 1990 to September 1995
  • Issues 36-45: Prime Mission, February 1996 to October 1997

Issue 1, April 10, 1981
From the Project Manager; Meet the Team: Tom Gavin; The Messenger; The 1985 Galileo Mission Design; The Atmosphere Structure Experiment; Potpourri; The Spin Bearing Assembly
Photos: Tom Gavin; Al Seiff; Atmosphere Structure Experiment
Illustrations: Mission Plan; Satellite Tour; Probe Descent; Roll Rings; Slip Rings; Present System - Rotary Transformers

Issue 2, July 10, 1981
From the Project Manager; Meet the Team: Nick Vojvodich; The Relay Link; The Retro-Propulsion Module (RPM); The Near-Infrared Mapping Spectrometer (NIMS)
Illustrations: Spacecraft diagram with detail of probe relay antenna
Photos: Nick Vojvodich; The Retro-Propulsion Module (RPM); The RPM's 400-Newton Engine; The Near-Infrared Mapping Spectrometer (NIMS); Dr. Robert Carlson

Issue 3, May 3, 1982
From the Project Manager; ΔV-EGA Mission; Meet the Team: Bill O'Neil; Relay Radio Hardware; Reviews; Magnetometers; Potpourri
Photos: Bill O'Neil; Magnetometer Sensors and Collapsed Boom; Dr. Margaret Kivelson
Illustrations: Galileo Orbiter and Probe; ΔV-EGA Mission Plan; Probe Descent; Satellite tour

Issue 4, August 1982
From the Project Manager; Probe Mass Spectrometer; Great Balloon Drop; Meet the Team: Bob Mitchell
Illustrations: Shuttle, Centaur, and Galileo; Balloon drop; Galileo Probe
Photos: Gas Inlet Housing Structure; Dr. Hasso B. Niemann; Bob Mitchell

Issue 5, December 1982
From the Project Manager; Meet the Team: Dick Spehalski; S- and X-band antenna; Potpurri; Attitude and Articulation Control
Illustrations: Attitude and articulation control subsystem simplified functional block diagram
Photos: Probe integration; Dick Spehalski; antenna deployment test

Issue 6, March 1983
From the Project Manager; Flight Cabling; Thermal Blanketing; Probe Nephelometer; WWWWWH (Who, What, When, Where, Why, How.)
Photos: Retropropulsion module; orbiter despun section cabling; outboard magnetometer thermal blanketing (3 photos); Boris Ragent; Probe Nephelometer

Issue 7, June 1983
SAF Activities; Development Test Model; Ultraviolet Spectrometer; Development Test Model; From the Project Manager; Meet the Team: Larry Colin
Photos: Orbiter integration in SAF; Development Test Model; Engineers in SAF System Test Complex; Ultraviolet Spectrometer; D. Charlie Hord; DTM in modal pit; Dr. Larry Colin

Issue 8, October 1983
From the Project Manager; Galileo Open House; Meet the Team: John Givens; Single Event Upsets; WWWWWH
Illustrations: Galileo stowed in the Space Shuttle; Galileo in launch configuration
Photos: Development Test Model; Signatures; John Givens; Probe and Orbiter in SAF

Issue 9, December 1983
Dust Detection Experiment; From the Project Manager; Sandia; Semiconductors; WWWWWH; Meet the Team: Matt Landano; Static Test; Test and INtegration Status
Illustrations: Exploded view of Galileo spacecraft and Centaur upper stage
Photos: Dust Detector team; retropropulsion module; delivery of flight retropropulsion module to JPL; silicon wafer fabrication; JPL machine shop; Centaur adapter ring; Matt Landano; Development Test Model static test

Issue 10, April 1984
From the Project Manager; RTGs; Meet the Team: Wolfgang Hagenest and Don Kindt; Probe Delivery
Illustrations: RTG
Photos: William Butterworth examines probe heatshield; Probe descent module in aeroshell

Issue 11, September 1984
From the Project Manager; Meet the Team: Al Wolfe; RPM Access Test
Illustrations: Single Event Upset environment
Photos: John Casani and Prince Andrew; multi photo album of development and testing; RPM Access Test

Issue 12, December 1984
From the Project Manager; Centaur G'; Solid State Imaging; Meet the Team: Torrence Johnson
Illustrations: Launch timeline
Photos: Centaur; magnetometer boom thermal blanketing; Michael Belton; Solid State Imaging System; SSS optical sensor

Issue 13, July 1985
From the Project Manager; Environmental Tests; Q&A; Meet the Team: Neil Ausman, Jr. and Bill Fawcett; Minimum Capability Hybrid Simulator
Illustrations: JPL space simulator cutaway
Photos: Galileo Orbiter in the assembly room; vibration testing; thermal vacuum testing; Chuck Keith checks CDS breadboard; Cas Sagoian checks a logic analyzer

Issue 14, September 1985
Project Selects Orbital Tour; From the Project Manager; Shuttle Crew Visits JPL; Spin Bearing Assembly; Plasma Investigation; Meet the Team: Sanford Jones
Illustrations: orbital tour; spin bearing assembly cross section; slip rings and rotary transformers; separation of Galileo Orbiter Spun/Despun Sections
Photos: Cassani briefing Shuttle crew; Plasma Instrument; Lou Frank; Atlantis rollout; Chinese president Li Xiannian visits SAF; G-Prime rollout ceremony
Table: Satellite encounters at Jupiter

Issue 15, February 1986
From the Project Manager; Meet the Team: Frank Locatell; Q&A; Energetic Particle Detector
Photos: Galileo boxed for shipping; shipping convoy; Milt Goldfine; Frank Locatell; Energetic Particle Detector; Galileo at Kennedy; D. J. Williams

Issue 16, July 1986
From the Project Manager; Plasma Wave Investigation; Meet the Team: Maynard Hine; Software; Q & A
Illustrations: plasma torus surrounding Jupiter
Photos: test attachment of spacecraft to Centaur; Don Gurnett; Galileo propulsion team

Issue 17, December 1986
From the Project Manager; Radio Science; Meet the Team: David Smith
Illustrations: VEEGA trajectory; VEEGA antenna and thermal control modifications; radio occultations
Photos: H. Taylor Howard; David B. Smith

Issue 18, April 1987
From the Project Manager; Net Flux Radiometer; Aging: Its Effect on the Spacecraft; Meet the Team: Benny Chin
Illustrations: Net Flux Radiometer
Photos: Truck convoy crossing the California desert
Table: Potential asteroid opportunities; Larry Sromovsky; Shipping the spacecraft back to JPL; Benny Chin

Issue 19, December 1987
From the Project Manager; Trajectories: Planning a Course for Galileo
Illustrations: VEEGA trajectory
Photos: Second Annual Pre-Launch Picnic; Trajectory Group; Galileo Picnic photo album

Issue 20, August 1989
From the Project Manager; Happenings at the Cape; The PPR; Meet the Team: Milt Goldfine
Illustrations: PPR (exploded view)
Photos: Test and integration at Kennedy Space Center; The PPR; Dick Spehalski; Milt Goldfine

Issue 21, November 1989
From the Project Manager; Launch to Landing; Galileo: Up to Date; Checking Out the Probe; Galileo Mission Summary; What's in an RTG?
Photos: Launch at Last! [launch photo album]; Galileo's RTG

Issue 22, February 1990
From the Project Manager; Galileo's First Encounter: Venus is in View; Galileo: Up to Date
Illustrations: Venus flyby geometry
Photos: candids of the Flight Team
Tables: Galileo Mission Summary; Venus encounter timeline

Issue 23, April 1990
From the Project Manager; Galileo: Up to Date; Networking Out of This World [about the DSN]; Meet the Team Leader in the OET [Robert Kocsis]; For the Flight Team; So Long...[by R. J. Spehalski]
Illustrations: DSN antenna complexes;
Photos: Venus; Canberra's 70-meter antenna
Table: Galileo Mission Summary

Issue 24, July 1990
From the Project Manager; Galileo: Up to Date; Flying Into the Ion's Den [about the HIC]; A Flawless Mission by Design [about the Mission Design Team]
Illustrations: Heavy Ion Counter
Photos: Candids from the launch picnic; Ed Stone;
Table: Galileo Mission Summary

Issue 25, September 1990
From the Project Manager; Blending American and German Technology [about comm with German Space Operations Center]; Galileo: Up to Date; The Project Science Group; Providing Real-Time Support [about Mission Control, DSN Operations, Multi-Mission Control, and Computing Center Operations and Data Management]
Illustrations: Detailed Earth encounter diagram/timeline
Photos: The 30-meter antenna at the Weilheim Ground Station; candids from Weilheim; Joe Gleason
Table: Galileo Mission Summary

Issue 26, December 1990
From the Project Manager; The Sequence Team: Interpreting for Galileo; Keeping the Lines of Communication Open; Galileo: Up to Date
Photos: Venus through Galileo's eyes; Sequence Team; Venus from NIMS; MCCC staff
Table: Galileo Mission Summary

Issue 27, April 1991 (Special issue for Earth-Moon encounter, differing from usual format)
A Closer Look at the Earth and Moon; A Second Gravity Assist; A Glimpse at the Earth's Environment in Space; A Glance at the Earth Through New Senses; A Shakedown Cruise
Illustrations: Galileo trajectory; Earth's magnetosphere
Photos: the Moon from Galileo; Earth from Galileo; Antarctica; Simpson Desert in Australia

Issue 28, August 1991
From the Project Manager; Unfurling the HGA's Enigma; Galileo Status: Up to Date: The Spacecraft; The Probe; Phase II MOS Design; Ground Data Subsystem; Sequence Development; Tracking the Sequence of the SROP [Science Requirements and Operations Planning Team]
Illustrations: Diagram of partially deployed ribs; diagram of supposed midpoint restraint pin misalignment
Photos: HGA during pre-flight testing; view of spare antenna in four-stuck-rib scenario; SROP
Table: Galileo Mission Summary

Issue 29, February 1992
From the Project Manager; An Encounter with Gaspra; From the Mission Director; Up to Date: SFOC Activities; DSN Activities; Assessing Anomalies; Activating the Thrusters; Analyzing the HGA; Flying by Gaspra
Illustrations: Map of Gaspra; sun angles; Galileo Gaspra trajectory; comparison of camera FOV to Gaspra's projected location; Galileo Trajectory
Photos: Gaspra
Table: Galileo Mission Summary

Issue 30, September 1992
From the Project Manager; Up to Date: HGA Actions; Assessing Anomalies; Gaspra Science Return; Reaching Aphelion; Attitude Corrections; Navigation; GSOC Activities; Ground Computing Activities; Software Activities; Probe Checkout at Earth 2; Keeping the Ground Systems Office Running on Track
Photos: Two-image mosaic of Gaspra; Ground Systems Office personnel
Table: Galileo Mission Summary

Issue 31, February 1993
From the Project Manager; Observing the Moon in a Different Light; A Farewell to Earth; Gaspra's story continues; Up to Date: Operations Activity Summary; Attitude Control; Calibration and Characterization Activities; Probe Checkout; High-Gain Antenna Motor Activities; Anomaly Status; Ground Data Systems; Sequence Generation; Software; Communicating with Light [about the Galileo Optical Experiment or GOPEX]
Illustrations: hydrogen atoms and the geotail; Galileo's trajectory;
Photos: north polar region of the Moon; 18-image mosaic of the Moon (including pole); 42-image mosaic of Andes mountains; montage of Gaspra, Deimos, and Phobos; Northeast Africa; GOPEX test image; GOPEX laser fired from Table Mountain Observatory; Earth and Moon
Table: Galileo Mission Summary

Issue 32, September 1993
From the Project Manager; Ida Ho!; Controlling the Spacecraft with the MCT [Mission Control Team]; Up to Date: Operations Activity Summary; Attitude Control; Calibration and Characterization Activities; HGA Activities; Sun-Shade Retraction; Anomaly Status; Ground Data Systems; Sequence Generation; Software
Illustrations: Galileo trajectory; Ida flyby trajectory/timeline; Ida observation geometry
Photos: five-photo mosaic of Ida
Table: Galileo Mission Summary

Issue 33, February 1994
From the Project Manager; Steering a Course to Jupiter: Meet the Galileo Navigation Team; Revisiting the Asteroids: This Time It's Ida; Up to Date: Attitude Control; Special Telecommunications Test; Anomaly Status; Early Return of Ida Data; Sequence Generation; Ground Data System
Illustrations: comparison of Ida to Los Angeles;
Photos: The Galileo Navigation Team; comparison of Ida and Gaspra; mosaicked image of Ida
Table: Galileo Mission Summary

Issue 34, June 1994
From the Project Manager; Ida's Moon Discovered; Up to Date: Ida Encounter; Navigation; Gravity Waves; Routine Operations and Testing; Anomaly Status; Uplink Generation; Ground Data System; How Can an Asteroid Have a Moon?; Name That Moon!; Comet Codiscoverer Speaks at JPL; Comet Shoemaker-Levy 9 to Crash Into Jupiter; In Memory of James B. Pollack; Reader Survey
Illustrations: Binary orbits
Photos: Ida and its moon; Ida's moon; David Levy; chronological series of Ida over most of a rotation
Table: Galileo Mission Summary

Issue 35, December 1994
From the Project Manager; The Brilliant Death of Comet SL9; Solving for Dactyl's Orbit and Ida's Density; Up to Date: Ida Encounter; Dust Stream from Jupiter? Command Tests; Telecommunications; Anomaly Status; High-Gain Antenna; Uplink Generation; Ground Data System; Meet the Team: If It's Critical or Innovative, Call the Engineering Office; Survey Yields Encouraging Results; Galileo Home Page Now On Line; Q & A: plans to observe Jupiter's minor satellites?; Gaspra Regions Named After JPL Galileo Scientists
Illustrations: possible Dactyl orbits from Ida's south pole; map of Gaspra
Photos: Fragment W impact series; K Impact Data; Dactyl by Idashine; Galileo Relay/JOI meeting
Table: Galileo Mission Summary

Issue 36, May 1995
From the Project Manager; Ready to Go - The Probe Checkout Results; Galileo Educational Outreach; On My Own -- At Last! The Galileo Atmsospheric Probe Release; Meet the Remote Sensing Science Group; In Memory of John E. Zipse; Reloading the Operating System on Galileo's PC; Dust Streams from Jupiter - Our First in Situ Measurements of Jupiter's Environment!; Up to Date: CDS and AACS Inflight Loads; SL9 Observations / Data Return; Solar Wind Scintillation Experiment; Routine Operations and Testing; Command Tests; Telecommunications; Probe Checkout; Anomaly Status; Uplink Generation; A Comet's Fiery Dance at Jupiter; Q&A: why no image of Probe after separation? How does Probe wake up?
Illustrations: Galileo Probe; Probe Release Sequence Timeline; dust events over two years; light curves for SL9 impacts from Photopolarimeter; NIMS light curves
Photos: The Remote Sensing Science Group
Table: Galileo Mission Summary

Issue 37, September 1995
From the Project Manager; Jupiter at Last! Galileo's Longest Day: December 7, 1995: The Longest Day Begins; The Io Flyby; The Probe Relay; JOI; Radio Occultation; "The Morning After" Press Conference; Probe Release, a Night to Remember; Educational Outreach Corner; Overheard on the World Wide Web [an imagined letter from Galileo Galilei]; Meet the Fields and Particles Science Group; The Probe Science Instruments; Up to Date: Navigation; Dust Streams Continue; Plasma Science Checkout; Relay Radio Antenna; Gravity Wave Experiment; Uplink Planning Activities; Telecommunications/Ground System; Anomaly Status
Illustrations: Gaileo artwork; arrival trajectory diagram;
Photos: The Not Ready for Real-Time Players; the Fields and Particles Science Group; Probe LRD/EPI; Probe Helium Abundance Detector;
Table: Galileo Mission Summary

Selected Historical Resources

Historical planetary mission press kits and publications for Galileo and Voyager. Image datasets of outer planet moons from Voyager 2.