After nearly breaking, NASA's Deep Space Network "worked well" on Artemis II

Heckler said NASA’s science division, responsible for most of the missions using the DSN, provided the network’s managers with “positive feedback” after Artemis II. But the limitations of the network and the high demand continue to “create some asset contention” among NASA’s missions. “During Artemis I, we had a subsystem called the Private Cloud Appliance. This PCA actually failed during Artemis I. Because of that failure, that high visibility, we actually received some additional resources from our Moon to Mars program, and we were able to install, effectively, a new subsystem ahead of Artemis II,” Heckler said. The demand for signal is only going up. NASA and its commercial and international partners plan to launch numerous missions to the Moon in the next few years. NASA is working with commercial providers to construct ground antennas for a dedicated network for Moon missions, called Lunar Exploration Ground Sites (LEGS), to free up more capacity on the DSN to support other spacecraft. Commercial companies are also developing data relay satellites to fly in orbit around the Moon, supporting future landers and construction of a Moon Base. High-bandwidth optical communications may be another solution. NASA successfully tested a laser communications terminal on the Orion spacecraft on Artemis II. “We’re going to have to work as a community to deal with that higher level of contention during the Artemis missions themselves, but we’re doing everything to establish non-DSN, or new infrastructure, to take on that load and burden,” Heckler said Wednesday in a meeting of the Small Bodies Assessment Group. “Once that is in place, as we move forward with new mission commitments, we will just be more focused, I think, and more process-oriented in being able to commit to new missions or not,” Heckler said. One constraint on the 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 ones in Spain and Australia, is 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. The water contained glycol, causing it to be classified as an environmental hazard, officials wrote in a report after investigating the accident. The resulting flooding rendered the antenna inoperable. Investigators cited several technical and process causes. After troubleshooting a problem with the antenna’s emergency stops, technicians at Goldstone “overrode and bypassed multiple safeguards that normally would have prevented over-rotation,” officials wrote in the report. “The investigation revealed inadequate training, insufficient written procedures, a reliance on undocumented behaviors and tacit knowledge, and deficiencies in the antenna’s control logic,” officials wrote. “In addition to the root causes listed above, the hydraulic limit system—the final fail safe against over-rotation—was discovered to have been severely damaged to the point of inoperability in an unknown and undocumented prior incident.” Work logs indicated 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 and restore the antenna to service. “Our plan for that system is to combine any of the remediation after the mishap with an already planned upgrade cycle that will keep that system down into 2028,” Heckler said.