When NASA’s Orion capsule carried four astronauts around the Moon this April, the agency’s global web of giant radio antennas faced its toughest exam yet. The Deep Space Network — the system that keeps Mission Control talking to spacecraft across the solar system — nearly buckled under the load of Artemis I back in late 2022. This time, according to NASA officials, the network passed.
NASA’s Space Launch System (SLS) rocket and Orion spacecraft, secured to the mobile launcher, are seen at Launch Pad 39B, Saturday, Jan. 17, 2026, at NASA’s Kennedy Space Center in Florida. Image credit: NASA/Joel Kowsky
Key Takeaways:
New scheduling and coordination processes, plus a replacement for a subsystem that failed during Artemis I, helped the Deep Space Network handle Artemis II without major disruptions to science missions.
Demand keeps climbing: roughly 40 missions use the network today, about 40 more are expected within a decade, and the Nancy Grace Roman Space Telescope launching in August will outpace all previous NASA astrophysics missions combined in data volume.
A 70-meter antenna at Goldstone, California, remains out of service after an over-rotation accident flooded its base with an estimated 200,000 gallons of glycol-contaminated water; repairs will cost $4.1–4.6 million and keep it offline into 2028.
The contrast with four years ago is real. During Artemis I, the data-hungry Orion mission took priority over roughly 40 robotic science missions, forcing reduced or delayed downlinks from the James Webb Space Telescope, Mars rovers, and other high-profile spacecraft. Artemis II raised the stakes further — a crew of four flying more than a quarter of a million miles from Earth meant NASA wanted even more data from Orion than before.
Several factors worked in the network’s favor this time. At a little over nine days, Artemis II was far shorter than the 25-day Artemis I flight. It also carried fewer CubeSats. Artemis I had released 10 small satellites into deep space, many of which needed tracking and telecom services. Some were lost soon after deployment, and their operators asked the network’s giant dishes to hunt for them — piling extra work onto antennas already stretched thin by Orion.
Preparation mattered just as much as luck. “We learned a lot on Artemis I, and we actually put some new processes in place ahead of Artemis II, mostly focused around coordination and our scheduling processes with all the missions, not just the Orion vehicle itself,” said Greg Heckler, deputy program manager for capability development in NASA’s Space Communications and Navigation Program. “I think that worked well.”
Hardware got an upgrade too. “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.
NASA’s science division, which operates most of the missions relying on the network, gave its managers positive feedback after the flight. Still, Heckler acknowledged that high demand continues to create asset contention between missions competing for antenna time.
The squeeze has been building for years. NASA’s Office of Inspector General has repeatedly flagged the network’s aging infrastructure and limited bandwidth, noting in a review of the network’s growing workload that Artemis I consumed more than 900 hours of antenna support over its 25-day flight while suffering a temporary loss of in-flight communications. Worse, orbital geometry guarantees recurring traffic jams: every two years, Artemis missions occupy the same patch of sky — and therefore compete for the same antennas — as the network’s biggest customers, including the Perseverance rover and the Webb telescope.
One escape route runs through light rather than radio. Artemis II carried a laser terminal called O2O, the product of more than two decades of work by NASA and MIT Lincoln Laboratory, which beamed data from the Moon at up to 260 megabits per second — far beyond what conventional radio links deliver. Optical systems pack more information into smaller, lighter hardware, and a successful crewed-mission test brings the technology a step closer to routine use on the way to the Moon and, eventually, Mars.
Relief is also planned on the ground. NASA is working with commercial providers on dedicated antennas for lunar traffic, known as Lunar Exploration Ground Sites (LEGS), which would free up Deep Space Network capacity for other spacecraft. Companies are also developing data relay satellites to orbit the Moon and support future landers and base construction.
“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.
The math behind the crunch is unforgiving. Around 40 operating missions currently depend on the antennas in California, Spain, and Australia. About 40 more are projected to need the network over the next decade — and because most NASA missions outlive their design lives, the older ones rarely free up capacity on schedule. The Nancy Grace Roman Space Telescope, launching in August, will alone return more data through the network than every previous NASA astrophysics mission combined.
NASA has responded with stricter gatekeeping. “Before onboarding new missions to the DSN, we now strictly require a feasibility study to see if there’s enough capacity to make that type of commitment,” Heckler said. “So we’re trying to balance, through data and analysis, the new demands coming onto the system versus those legacy missions we have to support until they fly out due to natural causes.”
Managers are also auditing veteran spacecraft, some of which have pulled on the network for decades without updating their requirements. “Some missions are using more than what their paperwork would say,” Heckler said. “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,” he added.
Meanwhile, the network is working with one hand tied behind its back. An accident last September knocked out one of its three 70-meter (230-foot) antennas — the dishes reserved for NASA’s most distant missions — at the Goldstone Deep Space Communications Complex near Barstow, California. The dish was tracking the Juno spacecraft at Jupiter when it over-rotated, tearing cables and water lines in the fire suppression system. An estimated 200,000 gallons of water flooded the antenna’s base. Because the water contained glycol, it was classified as an environmental hazard, and the flooding left the antenna inoperable.
The investigation found a chain of failures. After troubleshooting a problem with the antenna’s emergency stops, technicians “overrode and bypassed multiple safeguards that normally would have prevented over-rotation,” officials wrote in their 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. 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 showed the hydraulic limit system was last tested in 2004. NASA estimates repairs will cost between $4.1 million and $4.6 million. “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.
Written by Vytautas Valinskas