NASA's mini-spacecraft CAPSTONE just launched on its journey to the Moon

25kg CubeSat the size of a bar fridge will plot course for Gateway space station, pave way for human boots on Moon

Rocket Lab has sent NASA's Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) spacecraft on its way to the Moon atop an Electron rocket launched from New Zealand.

The launch had been subject to a number of delays, but at 09.55 UTC today, the Electron lifted off from Rocket Lab's Launch Complex 1 on the Mahia Peninsula of New Zealand.

Liftoff! #CAPSTONE launched aboard a @RocketLab Electron rocket to pave the way for future @NASAArtemis missions to the Moon and beyond.

What’s next for the microwave oven-sized satellite? Check out https://t.co/dMVnvEQcfC for updates. pic.twitter.com/VVoAOjSYbD

— NASA (@NASA) June 28, 2022

The launch delivered Photon (Rocket Lab's multi-purpose spacecraft, with heritage from the Electron Kick Stage) into orbit around the Earth. The Electron was supposed to have been launched from Rocket Lab's Virginia pad, but delays in getting the Autonomous Flight Termination System certified meant that things got shifted back to New Zealand.

CAPSTONE itself is designed to check out the near rectilinear halo orbit (NRHO) planned for the Gateway.

The orbit is at a balance point between the influence of the Moon's and Earth's gravities and, according to NASA, is both an ideal staging area for missions to the Moon and requires minimal energy to maintain. It is an elongated orbit and, once inserted, the 25kg (55 pound) CubeSat – which measures 34cm x 34cm x 61cm (c 13.4in x 13.4in x 24in) – will come within 1,000 miles (1,600km) of one lunar pole on its near pass and 43,500 miles (70,000km) from the other pole at its peak.

CAPSTONE will orbit for at least six months in order to validate predictions for the location. It will also demonstrate spacecraft-to-spacecraft navigation (a plan calls for communication with the Lunar Reconnaissance Orbiter to measure the distance between the two spacecraft and calculate CAPSTONE's position in space) and communication with Earth.

There remains a good deal of work to do before CAPSTONE reaches its orbit. Now in an initial Low Earth Orbit, the Lunar Photon Spacecraft must place the stack on a ballistic lunar transfer. From tomorrow, apogee raising burns are expected around once a day for five days before the stack has accelerated to the point where the increasingly elliptical Earth orbit can be escape. Within 20 minutes of the final burn (six days after launch) CAPSTONE will be released by Photon and commence a four-month cruise to NRHO.

At time of writing, the second burn of the Lunar Photon engine has been completed.

We've just had word of a successful second HyperCurie burn. From here, HyperCurie will perform apogee raising burns around every 24 hours for the next five days, before a final burn on the sixth day to set CAPSTONE on a trans lunar injection.

— Rocket Lab (@RocketLab) June 28, 2022

Things will now settle into a daily routine until the final burn to send CAPSTONE off towards the Moon. ®