To Galileo
Relay/JOI Meeting photo
If something is needed that is mission-critical or has never before been tried, chances are that the Galileo Engineering Office (EO) will be the people in charge. They are the ones responsible for completely reloading the inflight CDS software next February, something that has never been done before on any interplanetary spacecraft. They are in charge of the smooth release of the Probe for its journey into Jupiter's atmosphere and the first use of the 400-N engine to deflect the Orbiter's trajectory to Io, after which it will acquire Probe Relay data, not to mention Jupiter Orbit Insertion (JOI).
Of course, those are the out-of-the-ordinary requirements of the mission. The EO is also responsible for all the normal Trajectory Correction Maneuvers (TCMs) that have kept Galileo on its unique boomerang course through the solar system, real-time monitoring of spacecraft subsystems, nonreal-time analysis of telemetry data to verify and predict spacecraft performance, and all of the Testbed-based analysis of spacecraft systems using actual Galileo hardware (flight spares, engineering models, etc.) located here at JPL.
The Engineering Office, led by Ralph Reichert and deputy Gary Kunstmann, is one of four offices within Galileo Flight Operations. The office oversees the Probe Engineering Team led by Pat Melia, the Navigation Team led by Bill Kirhofer and Lou D'Amario, and the Orbiter Engineering Team led by Howard Marderness and his two deputies, Bob Gounley and Bob Barry.
The largest of these teams is the Orbiter Engineering Team (OET), 84 people who pay close attention to the health and safety of the Orbiter. They monitor overall spacecraft subsystems, including the spacecraft's main computer (Command and Data Subsystem or CDS), the attitude control system (AACS), the electrical power and propulsion subsystems, the thermal health of the spacecraft, and its telecommunications link with the ground. They also staff the Testbed, where there are exact copies of the CDS, AACS (including sensors, such as gyros and star scanners), tape recorder, and power simulator so that software can be thoroughly tested before sending it to the spacecraft. From time to time, Principal Investigators also bring in their science instruments to do testing. The OET also supports the real-time command process, as well as software development and analysis.
Next in size is the Navigation Team, some 19 people who precisely design and control the spacecraft's flight path to achieve mission goals while using as little propellant as possible.
Finally, there is the Probe Engineering Team, a dedicated group of 7 people from Ames Research Center and the Hughes Space and Communications Company, who built the Probe and are responsible for its health and safety. (Ames is the NASA center responsible for development of the Probe in support of the Galileo Project.) Some team members are stationed at the Laboratory: Marcie Smith, the Ames Probe Manager, and Charlie Sobeck are spending more time here as the Probe mission nears, and Pat Melia from Ames has been assigned to the Laboratory for many years. Their big effort begins next year, when the Probe goes through its final checkout and release and the Probe Relay data acquisition activities occur.
Ralph looks back on the past five years since launch with a sense of accomplishment and amazement. "Galileo is probably the most complex and ambitious of any interplanetary mission," he says. "First, we had the encounter with Venus shortly after launch for the purpose of a gravity-assist and collecting science data, then the Earth and Moon, again for a gravity assist and to collect science data, then a first-time encounter with an asteroid (Gaspra), then Earth again, then another asteroid encounter at Ida, where we discovered a moon, then the unexpected challenge of Comet Shoemaker-Levy 9 came out of the blue, plus all the TCMs to get on the path to Jupiter and to support each of the encounters."
"Some missions are a single flyby of a planet," he notes. "So this is an amazing number of events to deal with and a major accomplishment for the whole flight team."
Other unexpected challenges the OET has helped resolve include the problem with the High-Gain Antenna and multiple CDS bus resets. "Each time a bus reset happens, we have to bring up the down string, reinitialize the spacecraft (e.g., turn the instruments back on), regenerate the onboard software sequence, and retransmit it back to the spacecraft."
Besides the many one-of-a-kind events surrounding release of the Probe and arrival at Jupiter, Ralph is well aware that the pace for his team will soon go into double time. Once in orbit around Jupiter, the spacecraft will require three Orbit Trim Maneuvers (OTMs) every orbit for 10 close encounters with Jupiter's satellites. That's about 30 OTMs over a 2-year period, compared to the 22 TCMs required during the previous 5 years.
Other major challenges are system testing the Phase 2 flight software for planetary operations and reloading the CDS flight software after JOI.
As Ralph looks to the future, he knows he can count on his team. "It's really been a pleasure working with some extremely talented and dedicated people on this project. Our teamwork is great because people are motivated to do the best job they can and collect the most science, while keeping the spacecraft safe. EO work may be stressful at times, but it's never boring because we deal with so many diverse subjects."
Ralph Reichert is a California native, born in San Francisco. He graduated from UCLA in 1967 with a B.S. and M.S. in Engineering, and soon after came to JPL. Over the past 25 years at the Laboratory, he has worked primarily on flight projects--beginning in mission analysis and operations on Mariner '71, and continuing through the Viking, Voyager, and Galileo missions. Prior to launch, Ralph was the leader of Galileo's Mission Operations System Design Team and the uplink process design lead. He and his wife, Kako, have a 16-year-old son who plays on the Arcadia High School Varsity Football Team, so they attend all the AHS and UCLA football games. He also enjoys power boating and snow skiing.
Gary Kunstmann, EO deputy manager, has been at the Laboratory for over 32 years. His background is in the engineering and management of systems, ranging from unmanned spacecraft to tactical intelligence fusion systems. Past assignments include managing systems engineering for the All Source Analysis System and being assistant manager of the SDIO Pathfinder Project. He also managed an Air Force autonomous spacecraft program, the software system for Ulysses, and participated in the development of command subsystems for Ranger, Mariner, Viking, Voyager, Galileo, and Magellan.
Gary earned B.S degrees in Electrical Engineering and Math from California Polytechnic University in Pomona and an M.E. in Engineering Management from UCLA. He is an avid bicyclist and often commutes to JPL by bicycle.
To Galileo
Relay/JOI Meeting photo
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