(ORDO NEWS) — NASA is planning a mission to demonstrate the feasibility of repairing and upgrading satellites in Earth orbit.
The mission, called OSAM-1 (On-orbit Servicing, Assembly, and Manufacturing-1), involves sending a spacecraft equipped with robotic arms and all the necessary tools and equipment to repair, refuel or extend the life of satellites, even if these satellites were not intended for service in orbit.
The first test flight of OSAM-1 is scheduled for no earlier than 2026, it will go into low Earth orbit for rendezvous, acquisition and docking with the Landsat 7 Earth observation satellite, which has been in orbit since 1999.
During the flight, a first-of-its-kind refueling demonstration test will be conducted, and then the satellite will be transferred to a new orbit. While some parts of the mission are autonomous, human operators will perform most of the procedures and maneuvers remotely from Earth.
NASA says refurbishing satellites – rather than just letting end-of-life spacecraft drift in Earth orbit – is helping to reduce space debris and create a more sustainable future for space exploration.
In addition, the test flight will evaluate orbital robotic assembly and manufacturing, which many see as a technology needed for the future, such as for servicing long-duration human missions in the solar system, and building and maintaining structures in orbit around the Moon or Mars.
The original idea for a spacecraft to serve satellites came from the renowned NASA engineer Frank Chepollina, who was a former in-orbit spacecraft repairer. He led teams responsible for the planning and organization of five Hubble Space Telescope maintenance missions.
He helped develop the specialized tools and procedures that astronauts needed to use to successfully repair and upgrade the Hubble, keeping the telescope up and running for years longer than planned and installing better instruments and technology on each successive mission. He also led teams that developed methods for repairing other satellites in the early space shuttle era.
“It’s amazing to me that we’re just jettisoning satellites in orbit,” Chepollina told me in 2016 when I was touring the Robotic Operations Center, then called the Satellite Services Office at NASA’s Goddard Space Flight Center.
“It seemed like we had to find a way to fix these satellites for economic reasons and for the scientific benefit we could get. I wanted to find a way to fix and upgrade the satellites.”
Chepollina, now 85, only recently retired from NASA, but he has taught generations of engineers, never giving up on his dream of repairing satellites. After several service mission proposals, the concept was officially recognized as a mission and received a NASA budget. But there is still a lot of work to be done to be ready for launch by 2026.
“When you’re doing something for the first time, there’s a lot of new technology and procedures, and you inevitably run into obstacles and setbacks, and we’re no different,” said Ross Henry, OSAM-1 payload maintenance manager.
“We are dealing with several new systems, such as a new lidar system (Light Detection and Ranging), a unique fuel transfer system and two robotic arms [one of them is redundant], which can use eleven unique tools and adapters, each of which has specific purpose within the mission.
The main purpose of the first test flight of OSAM-1 will be to refuel Landsat 7, which is located at an altitude of about 705 km above the Earth. But because Landsat 7, like many other satellites, was never intended to be serviced, the OSAM-1 spacecraft can’t just stop next to it and connect the fuel hose.
OSAM-1 must first get close enough for one of the robot’s arms to catch Landsat 7, and then perform docking maneuvers using the original docking clip or the Marman ring on the satellite.
“Then we have a lot of work to do to gain access to the fueling station,” Henry explained. “OSAM-1 remote operators would have to cut through the multi-layer insulating thermal blanket and move it out of place to open the fill/drain valves.
But when they were closed before launch, these valves were covered with locking wires, so we would have to enter them with special scissors and cut them. In addition, there are safety caps that we will remove.”
OSAM-1 will carry 122 kg of propellant and it is planned to move 115 kg of propellant to Landsat 7 using a robotic arm and retractable hose system.
Of course, all this happens while both spacecraft are moving at a speed of about 26,500 km/h. OSAM-1 has six rendezvous and rendezvous cameras for use during rendezvous with Landsat 7.
Twenty-one more cameras are part of a dedicated vision sensor system to allow cameramen to see operations from all angles, while searchlights provide illumination to continue working even during orbital night, which occurs approximately every 50 minutes. The orbital period of Landsat 7 is 99 minutes.
The Goddard Robotic Operations Center includes a specialized testbed with black, curtained walls so that the total darkness of space is simulated when the lights are off. This allows for full immersion training using full-scale Landsat 7 and OSAM-1 mockups.
Landsat 7’s nominal science mission ended on April 6, 2022, and its main science instrument, the Advanced Thematic Mapper Plus (ETM+), was placed on standby. However, in its twenty-two years of operation, the satellite has provided a significant amount of data for land cover management and assessment, global change studies and mapping.
The OSAM-1 mission, after completion of maintenance and refueling, is planned to be deorbited and burned in the Earth’s atmosphere.
“At the same time, we recognize that we are flying a very capable vehicle with a reserve of fuel,” said Henry, “so many would like us to carry out a follow-up mission while we are in orbit. But at the moment nothing has been announced or funded.”
Henry said it was a great honor and joy for him to lead the effort to realize Frank Chepollina’s dream of having a real “tow truck” in orbit to service the satellites. Chepollina also has another dream – that many of these satellites, similar to evacuators, could build not only dwellings in space, but also large space telescopes capable, for example, of directly shooting distant exoplanets.
“What we’re demonstrating lays the foundation for future advances in the search for extraterrestrial life and, hopefully, the colonization of the solar system,” Henry said. “Decades later, I think you can appreciate that OSAM-1 will be the first US mission to demonstrate these capabilities in orbit.”
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