“Once that’s in place, as we move forward with new mission commitments, I think we’ll be more focused, and more process-oriented in whether or not to commit to new missions,” Heckler said.
key antenna offline
One hurdle on DSN is an accident last year that knocked one of the network’s three 70-meter (230-foot) antennas offline at the Goldstone Deep Space Communications Complex near Barstow, California. This antenna, along with similar antennae in Spain and Australia, are used to communicate with some of NASA’s most distant missions.
The 70-meter dish was tracking NASA’s Juno spacecraft at Jupiter last September when it “over-rotated” and damaged cables and water lines in the facility’s fire suppression system. An estimated 200,000 gallons of water flooded the base of the antenna. Authorities wrote in a report after investigating the accident that the water contained glycol, causing it to be classified as an environmental hazard. The resulting flood disabled the antenna.
Investigators cited several technical and procedural reasons. After troubleshooting the problem with the antenna’s emergency stop, Goldstone’s technicians “overrides and bypasses multiple safety measures that normally prevent over-rotation,” officials wrote in the report.
“The investigation revealed inadequate training, inadequately written procedures, undocumented behavior and reliance on tacit knowledge, and deficiencies in Antenna’s control logic,” officials wrote. “In addition to the root causes listed above, the hydraulic limit system – the final failure safeguard against over-rotation – was discovered to have been severely damaged to the point of inoperability in an unknown and unspecified prior event.”
Work logs indicate that the hydraulic limit system was last tested in 2004.
NASA officials estimate it will cost between $4.1 million and $4.6 million to repair the antenna and restore service. “Our plan for that system is to combine any post-accident measures with a previously planned upgrade cycle that will keep that system shut down until 2028,” Heckler said.
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