Rocket Lab: Shooting for the Moon

Rocket Lab will launch a CubeSat to the Moon as part of a historic pathfinding mission to support NASA’s Artemis program. The Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) will place a CubeSat into the first elliptical lunar orbit of any spacecraft.   

CAPSTONE is a precursor to Gateway, which will act as a Moon-orbiting outpost for the Artemis program. The Artemis program is putting humans back on the Moon, including the first woman on the Moon and the first person of colour on the Moon. 

CAPSTONE will help to reduce the risk for future spacecraft by validating innovative navigation technologies as well as verifying the dynamics of this unique orbit.

The orbit will be a significantly elongated orbit that has been previously known as near rectilinear halo orbit (NRHO). The orbit is located at a precise balance point between the Earth’s and the Moon’s gravities, which makes it stable for long term missions such as Gateway, and requires minimal energy to maintain. 

The rocket launching CAPSTONE to space is Rocket Lab’s Electron launch vehicle. Since 2017, Electron rockets have delivered over 100 satellites to orbit. Electron will provide the initial ride to low Earth orbit for both the Lunar Photon upper stage and the CAPSTONE CubeSat. 

Once low Earth orbit is reached, the Lunar Photon upper stage will deliver the CAPSTONE spacecraft into its highly efficient ballistic transfer orbit to the Moon. Lunar Photon will orbit the Earth in elliptical phasing orbits over nine days to build up velocity for Trans Lunar Injection (TLI) to deploy CAPSTONE.

CAPSTONE will be launched from the Rocket Lab Launch Complex 1 in New Zealand’s Mahia Peninsula. The launch window is scheduled between May 3 and May 15.  

Once CAPSTONE makes its 3-month journey, it will orbit the polar area of the Moon for at least six months to understand the characteristics of the orbit. CAPSTONE aims to validate the power and propulsion requirements for maintaining this unique orbit as predicted by NASA’s models. It also aims to demonstrate if the innovative spacecraft-to-spacecraft navigation solutions are reliable. 

To test the navigation capabilities CAPSTONE has a second dedicated payload flight computer and radio that will perform calculations to work out where the CubeSat is in its orbital path. Since 2009, the Lunar Reconnaissance Orbiter (LRO) has been orbiting the Moon, and this will serve as the reference point for CAPSTONE. CAPSTONE and the LRO will communicate directly and using data obtained from this crosslink, will measure how fast it is from LRO and how fast that distance changes, thereby determining CAPSTONE’s position in space.

The spacecraft-to-spacecraft information will be used to evaluate CAPSTONE’s autonomous navigation software. If successful, this software will allow future spacecraft to determine their location without relying solely on tracking from Earth.

The launch of CAPSTONE and testing its capabilities and cutting edge operations will pave the way for small and more affordable space exploration missions not just to the Moon, but to Mars and further throughout the solar system.