Conceptual image of CAPSTONE orbiting the Moon. Image: NASA
An important milestone has been reached in the recently launched CAPSTONE mission, as the small spacecraft, which moves at more than 24,000 miles per hour, has escaped from low Earth orbit and begun its four-month journey to the moon.
CAPSTONE, short for Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment, said goodbye to low Earth orbit this morning, according to NASA. The 55-pound (25-kilogram) cubesat is now traveling to the Moon, where it will enter an almost rectilinear halo orbit (NRHO) on November 13th.
This is the same orbit planned for the next lunar walkway; the new mission aimed to assess the suitability of NRHO on a smaller scale. Once built, and as part of NASA’s Artemis program, Lunar Gateway will be used to support a sustainable, long-term human presence on and around the Moon.
CAPSTONE was launched from New Zealand on a Rocket Lab Electron rocket on 28 June. The cubesat had been orbiting the Earth while connected to the Photon upper stage of Rocket Lab. A total of seven maneuvers were performed over six days, during which CAPSTONE’s orbit was constantly raised. CAPSTONE finally reached a maximum distance of 810,000 miles (1.3 million kilometers) from Earth, which is more than three times the Earth-Moon distance. Photon released its payload once the pair reached 24,500 miles per hour (39,500 km / h), the speed required for CAPSTONE to escape from Earth orbit.
NASA’s CAPSTONE: Flying a new path to the moon
CAPSTONE is now on a ballistic lunar transfer trajectory to the Moon, a complicated but efficient trajectory in which the spacecraft will follow “dynamic gravitational contours in deep space,” as NASA explains:
Spending little energy, CAPSTONE will traverse these contours marked by a series of planned trajectory correction maneuvers. At critical times, the CAPSTONE team at the Advanced Space mission operations center will command the spacecraft to fire its thrusters to adjust course. Terran Orbital Corporation in Irvine, California, designed and built CAPSTONE and developed a new technology that allows the spacecraft to perform maneuvers while maintaining control of the spacecraft with propellers only.
When CAPSTONE reaches the Moon, its approach will be perfectly aligned for the insertion of NRHO, the crux of its path. While going at 3,800 miles per hour [6,116 km/hr]he will perform his delicate propulsion maneuver timed precisely to enter orbit, like a flying trapeze artist jumping from one bow to another with a decisive and acrobatic movement.
NRHO represents an ideal gravitational sweet spot for Lunar Gateway. Here, the gravitational pull of Earth and the Moon interact to allow for an almost stable orbit, “allowing physics to do most of the work of keeping it in orbit around the Moon,” according to NASA. CAPSTONE will spend six months at NRHO, during which time it will travel up to 2,100 miles (3,400 km) from the North Pole of the Moon to its nearest step and 47,000 miles (76,000 km) from the South Pole to the farthest.
In addition, CAPSTONE will test a navigation system in which the probe will measure its location relative to NASA’s Lunar Reconnaissance Orbiter and without the benefit of Earth stations on Earth.
More: Astronauts can suffer a decade of bone loss for months in space.