After an anxious day when NASA’s Capstone spacecraft stopped responding to communication efforts, the space agency resolved the error and guided Capstone through a maneuver that put it on course for the Moon.
Capstone successfully completed an 11-minute booster burn around 11:30 a.m. EDT Thursday morning, according to a NASA blog update posted at 3:49 p.m. EDT Thursday. The burn is the first in a series of planned course-correction maneuvers for the 55-pound microwave-sized spacecraft during its month-long journey to enter lunar orbit in mid-November.
Capstone, or the Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment, launched from New Zealand on June 28 and successfully separated from the upper stage of its launch vehicle on July 4, at which time it seemed that all was going well for the spaceship.
But ground-based operators lost contact with Capstone late on July 4 after the spacecraft stopped transmitting and operators were no longer able to communicate with it through the Deep Space Network, a worldwide network of radio antennas that NASA uses to communicate with spacecraft beyond Earth’s orbit.
Now NASA knows why.
While checking out the spacecraft after it separated from the rocket’s upper stage, operators on the ground noticed inconsistent data and attempted to access Capstone’s diagnostic functions, according to another NASA blog update. But the operators “sent an incorrectly formatted command that caused the radio to not work,” the blog notes.
The update goes on to note that the spacecraft radio should have automatically restarted, but did not due to an issue with Capstone’s autonomous flight software. However, despite the software glitch, the system eventually cleared the error on its own and re-established contact with ground operators on Wednesday, July 6.
With communications backed up, Capstone began Thursday morning’s maneuver, an important part of its slow, unusual, but energy-efficient route to the Moon.
As of Thursday, Capstone is more than 289,000 miles from Earth and, in fact, beyond the orbit of the Moon, which is part of its unique “ballistic lunar transfer” design. Capstone will eventually reach a distance three times the orbit of the Moon, or 963.00 miles from Earth, before allowing the Sun’s gravity to pull it back to meet the Moon.
Once it reaches the Moon, Capstone will enter an unusual “almost rectilinear halo orbit,” tracing out a long oval with nearly flat sides and the Moon not centered, but tucked into one of the oval’s corners. This means that Capstone will fly relatively low over the Moon’s South Pole and high over the lunar North Pole.
Capstone’s mission is to explore the dynamics of this unique orbit ahead of NASA’s Lunar Gateway, a space station that NASA hopes to install in the same lunar orbit to support astronauts from its Artemis program as they explore the Moon beginning in 2025. .