The First Cubesat To Fly And Operate On The Moon Has Successfully Arrived

Rocket Lab After a journey of nearly five months, going far beyond the Moon and back, the small CAPSTONE spacecraft has successfully entered lunar orbit. “We’ve received confirmation that CAPSTONE has reached a nearly straight halo orbit, and that’s a huge, huge step for the agency,” NASA’s chief of exploration systems development, Jim Free, said Sunday night. “It just completed its first insertion burn a few minutes ago. And over the next few days they will continue to refine its orbit and it will be the first cubesat to fly and operate on the Moon.” This is an important orbit for NASA, and a special one, because it is really stable, and requires only a small amount of propellant to keep it in place. At its closest point to the Moon, this approximately one-week orbit passes within 3,000 km of the Moon’s surface, and at other points it is 70,000 km away. NASA plans to build a small space station, called the Lunar Gateway, here later this decade. But before then, the agency is starting small. CAPSTONE is an unmanned, commercial mission funded, in part, by a $13.7 million grant from NASA. Developed by a Colorado-based company called Advanced Space with help from Terran Orbital, the spacecraft itself is modest in size, just a 12U cube with a mass of about 25 kilograms. It could comfortably fit inside a mini-fridge. Advertising
The spacecraft launched in late June on an Electron rocket from New Zealand. Electron is the smallest rocket to launch a payload to the Moon, and its developer, Rocket Lab, has pushed the capabilities of its booster and upper photon stage to the max to send CAPSTONE on its long journey to the Moon. This was Rocket Lab’s first deep space mission. After separating from its rocket, the spacecraft spent nearly five months traveling to the Moon, following what is known as a ballistic lunar transport that uses the Sun’s gravity to follow an extended orbit. Along the way, flight controllers managed to solve a spin problem that could otherwise have resulted in the loss of the spacecraft. This was a roundabout path, bringing the spacecraft more than three times the distance between Earth and the Moon before turning back, but requiring relatively little propellant to reach its destination. For example, the burn performed by CAPSTONE on Sunday afternoon to transition to a nearly straight halo orbit was extremely tiny. According to Advanced Space, the vehicle burned its thruster for 16 minutes at about 0.44 Newtons, equivalent to the weight of about nine pieces of standard printer paper. CAPSTONE will not only serve as a pathfinder in this new orbit—verifying the theoretical properties formulated by NASA engineers—it will also demonstrate a new autonomous navigation system around and near the Moon. This Cislunar Autonomous Positioning System, or CAPS, is important because there is a lack of stable tracking elements near the Moon, especially as the cislunar environment becomes more crowded over the next decade. The mission is planned to operate for at least six months in this orbit.