NASA CAPSTONE update: CubeSat just 1 day away from ballistic lunar transfer to Moon

NASA’s CAPSTONE CubeSat, which launched on June 28, is just one day away from setting off to the Moon. The CubeSat was launched by Rocket Lab from New Zealand’s Mahia at 3:36 pm IST as an onset to NASA’s mission to return astronauts to the lunar surface. In a recent update, Rocket Lab, which rented its Electron rocket to NASA for the mission, revealed that the engineers would now send CAPSTONE on, what they call, a lunar ballistic transfer to reach the Moon.

The CAPSTONE mission

Before understanding how engineers would make CAPSTONE reach its destination, let us first take a brief look at the mission's objective. This mission, or the CubeSat, is meant to test and verify the Near Rectilinear Halo Orbit (NRHO) around the Moon, which is considered gravitationally stable. Testing and verifying this orbit is necessary because this is where the lunar Gateway, meant to support NASA's Artemis programme, will be installed.

The Gateway is envisioned as a space station in the lunar orbit to provide astronauts with living quarters, access to the lunar surface, a lab for science and research and ports for visiting spacecraft. Besides, this, NASA also aims to test a navigation system, developed by Advanced Space, that will measure its absolute position in orbit through interaction with NASA's Lunar Reconnaissance Orbiter (LRO) without relying on ground stations for navigation support.

Transferring CAPSTONE into the lunar orbit

In order to execute a lunar ballistic transfer, Rocket Lab engineers have been performing a series of orbit-raising burns to manoeuvre the CubeSat and make it leave Earth's orbit. It is worth noting that while CAPSTONE was launched to the low-Earth orbit (LEO), the CubeSat is actually attached to a secondary rocket, called Photon, which would carry it beyond the LEO. Since June 28, the engineers have performed seven burns and the eighth and final burn is scheduled at 12:26 pm on July 4. 

(Illustration of CAPSTONE's orbital burns; Image: Rocket Lab)

During its eighth burn, the CubeSat will be approximately 13 lakh kilometres from Earth. According to Rocket Lab, the CAPSTONE-carrying Photon is equipped with a small Hyper Curie engine which has propelled the CubeSat around 4 lakh kilometres from Earth. On July 4, this engine will finally inject the CAPSTONE into the lunar orbit after accelerating 39,400 km per hour.