Preparations for Next Moonwalk Simulations Underway (and Underwater)
Space Reactor-1 Freedom will be the first spacecraft ever to demonstrate fission power beyond Earth’s orbit, traveling to Mars to deliver a science payload called SkyFall.
NASA/Alberto Bertolin
Destined for Mars and beyond, NASA’s Space Reactor-1 (SR-1) Freedom will be humanity’s first fission-powered spacecraft to travel outside Earth’s orbit. Announced during NASA’s “Ignition” event, this mission will demonstrate nuclear electric propulsion in deep space, and progress is underway on its key element: the nuclear power module. To expedite development of the spacecraft, NASA and its partners have mutually agreed to key contract actions that will advance the SR‑1 Freedom mission.
“These contract actions not only reduce technical risk and help us maintain momentum toward our 2028 launch, but they also strengthen collaboration across our partners,” said Steve Sinacore, SR-1 Freedom program director. “These actions keep SR‑1 Freedom on track and ensure we’re building the strongest possible foundation for NASA’s first fission‑powered voyage beyond Earth orbit while developing technology extensible to a vibrant space nuclear future.”
Space Reactor-1 Freedom’s nuclear power module, located at the end of the spacecraft’s boom, consists of a reactor that generates heat through nuclear fission and a power conversion system that converts that heat into electricity to power systems and electric propulsion.
NASA/Alberto Bertolin
Sierra Lobo Inc. will provide the nuclear power module’s closed Brayton cycle power conversion system, which converts thermal energy from its fission reactor into electrical power needed for SR-1 Freedom’s nuclear electric propulsion demonstration. The work will be conducted under the Space Flight Systems Development and Operations Contract III, awarded in 2024, to support spaceflight hardware design, development, testing, and operations at NASA’s Glenn Research Center in Cleveland.
The power conversion system will be integrated with the fission reactor, which is being designed and developed by the Department of Energy (DOE)’s Idaho National Laboratory to complete the nuclear power module. NASA and DOE incorporate thorough safety standards throughout the design and development of the SR-1 Freedom spacecraft, including interagency safety reviews, continuous oversight by a NASA chief safety officer, regulatory compliance, and a rigorous safety design process focusing on hazards, failure tolerance, and nuclear safety. In addition, the nuclear reactor portion of SR-1 Freedom will remain inactive until the spacecraft leaves Earth orbit.
Launching in late 2028, SR‑1 Freedom will deliver the SkyFall science mission, a team of three Mars helicopters evolved from the Ingenuity design, to collect scientific data, demonstrate exploration zones, and identify potential water sources. The mission will pave the way for deep space exploration and next‑generation fission-powered systems designed to keep NASA’s Moon Base operating through periods of darkness and in locations where solar power alone is not sufficient.
On Sept. 10, 2026, NASA commemorated the completed repairs of the Guam Remote Station’s central antenna with a ribbon-cutting ceremony.
Members of NASA, the Governor’s Office of Guam, military personnel, and family members gathered to celebrate the Guam Remote Station’s return to operations.
NASA
The ribbon-cutting event was held in front of the repaired central antenna. As of 2026, the newly hardened station has withstood two super typhoons more powerful than Mawar with minimal damage.
SCaN Deputy Manager for Network Operations Jena Garrahy addresses members of the Guam Remote Station ribbon-cutting event.
NASA
Guam Remote Station Site Manager Kristopher Copple was among those recognized during the ceremony.
Jena Garrahy (right), SCaN Deputy Manager for Network Operations, presents a certificate of recognition to Guam Remote Station Site Manager Kristopher Copple (left).
NASA
NASA’s Guam Remote Station is key to the Tracking and Data Relay Satellite (TDRS) constellation maintaining continuous communications with the International Space Station.
An artist’s concept of the International Space Station using NASA’s Tracking and Data Relay Satellite (TDRS) fleet to transmit data to Earth.
NASA
A 2023 aerial photo of the Guam Remote Station prior to Super Typhoon Mawar landing on the island.
Satellite image of NASA remote ground terminal located in Dededo area, Guam, released by U.S. commercial satellite company MAXAR.
MAXAR
An aerial photo of the Guam Remote Station immediately after Super Typhoon Mawar struck the station. of the station’s three ground antennas were demolished.
Satellite image of NASA remote ground terminal located in Dededo area, Guam, released by U.S. commercial satellite company MAXAR.
MAXAR
NASA celebrated the full restoration of its Guam Remote Station with a ribbon-cutting on Sept. 10, closing out more than three years of recovery after Super Typhoon Mawar devastated the site in 2023. Engineers from across the agency completed the final and most complex step of the rebuild on July 1, when they returned the station’s central antenna to service.
A rainbow arcs over the newly repaired Guam Remote Station antennas.
NASA
For nearly three decades, the Guam Remote Station has been one of three ground stations supporting NASA’s Tracking and Data Relay Satellites, or TDRS, a critical part of the Near Space Network. From 22,000 miles above Earth, the relays link spacecraft in low Earth orbit with the ground, allowing flight controllers to communicate with astronauts, command spacecraft, and receive mission data. The Guam station alone closes the “Zone of Exclusion,” a stretch of orbit beyond the relays’ line of sight. Without it, the International Space Station can lose contact with Earth for up to 20 minutes of every 90-minute orbit, an unacceptable risk for crewed missions.
On May 24, 2023, the Category 4 super typhoon struck Guam with 185 mph winds and more than 28 inches of rain, destroying two 16.5-meter antennas and damaging an 11-meter north antenna and the Inter Facility Link building at NASA’s station. The Zone of Exclusion reopened for the first time since 1998, cutting TDRS coverage to about 85% of a spacecraft’s orbit.
NASA made emergency repairs to the least-damaged antenna and borrowed two mobile terminals from the U.S. Army to expand coverage. The patchwork restored partial service within months, in time for a November 2023 spacewalk.
In early 2025, Congress dedicated disaster-relief funding to rebuild the ground station and harden the network against future storms. Construction began that summer and finished in summer 2026, when the rebuilt central antenna rejoined TDRS operations and the Zone of Exclusion closed once more. The same appropriation funded critical upgrades at three additional Near Space Network ground stations.
The return to service of the Guam Remote Station’s central antenna represents far more than the restoration of a critical piece of infrastructure — it is a testament to the dedication, resilience, and ingenuity of the people who made it possible.
Jena Garrahy
SCaN Deputy Program Manager for Network Operations
At the ribbon-cutting, representatives from NASA’s SCaN (Space Communications and Navigation) Division joined the station’s workforce and local leaders to mark the central antenna’s return to service. The Guam team, which led debris removal, site security, and on-island recovery, was recognized for its work to keep NASA connected to its missions through the outage and rebuild. A companion ceremony at NASA’s White Sands Complex in Las Cruces, New Mexico, honored the engineers and specialists across SCaN who supported the recovery off island.
“The return to service of the Guam Remote Station’s central antenna represents far more than the restoration of a critical piece of infrastructure — it is a testament to the dedication, resilience, and ingenuity of the people who made it possible,” said Jena Garrahy, Deputy Program Manager for Network Operations. “Through long days, challenging conditions, and unexpected obstacles, this team remained focused on the missions that depend on these critical assets every day.”
The Near Space Network is funded by SCaN, a division of NASA’s Research and Technology Mission Directorate, at the agency’s Headquarters in Washington. The network is operated out of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Repairs of the Guam Remote Station were managed out of NASA’s Glenn Research Center in Cleveland.
About the Author
Korine Powers
Lead Writer and Communications Strategist
Korine Powers, Ph.D. is a writer for NASA's SCaN (Space Communications and Navigation) Program office and covers emerging technologies, commercialization efforts, exploration activities, and more.
NASA’s X-59 quiet supersonic research aircraft reached its target speed and altitude for future community overflights for the first time during a flight on Friday, June 12, 2026. The milestone marked the first time the aircraft flew at Mach 1.4 and 55,000 feet — conditions it will fly when gathering community response data to its quiet sonic thump.
NASA/Lori Losey
NASA’s X-59 experimental aircraft reached a major milestone Friday, June 12, flying Mach 1.4 (about 924 mph) and an altitude of 55,000 feet, the conditions required for the aircraft to make future flights critical to its mission.
The X-59 still has months of performance testing ahead, but after those are complete, NASA’s Quesst mission will fly the aircraft over several U.S. communities to collect data on public perception of the quiet sonic thump it will make at supersonic speeds. Those community overflights will include flights at Mach 1.4 and 55,000 feet.
The milestone comes just days after the X-59’s first supersonic flight. That flight showed the aircraft performed as expected at Mach 1.1, but Friday’s mission conditions flight was an even more critical step for NASA.
NASA’s X‑59 eXternal Vision System (XVS) shows Mach 1.4 at 55,030 feet on Friday, June 12, 2026 during the aircraft’s first mission conditions flight, the approximate conditions it will fly when gathering community response data to its quiet “sonic thump.” The milestone marks the first time the aircraft flew at its designed speed and altitude.
NASA/Lori Losey
The X-59 was designed to fly supersonic without causing a loud sonic boom. However, for these early supersonic flights it has been accompanied by a NASA F-15 research aircraft, a traditional supersonic jet that causes booms obscuring any noise the X-59 makes. During upcoming flights, a shock-sensing probe mounted to the F-15 will gather measurements of the X-59’s shock wave signature, an early measure of its supersonic performance.
After the team conducts more tests at a variety of altitudes and conditions to complete envelope expansion, the X-59 will enter the acoustic validation phase of Quesst. During this phase, researchers will thoroughly measure the aircraft’s supersonic acoustic signature — the quiet thump it’s designed to make — to confirm it is performing as intended.
Each flight brings NASA one step closer to flying the X-59 over communities and gathering feedback that could help shape the future of commercial supersonic flight over land.
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