'Nearly there': NASA-backed CAPSTONE set to enter Moon's special orbit on November 14

After its launch on June 28, the CAPSTONE CubeSat will enter the Moon’s orbit on November 14, NASA informed. Designed and built by Terran Orbital, the roughly $30 million orbiter is owned by Advanced Space on behalf of NASA and has the objective of testing the Moon’s Non-rectilinear Halo Orbit (NRHO).

The CubeSat weighs around 25 kg, is as big as a microwave oven and will prove to be a stepping stone toward building the Lunar Gateway, a space station around the Moon. 

NASA says that CAPSTONE will enter the orbit at a speed of over 6,000 km at 5:48 am IST on November 14 and it would take five days of data analysis to confirm the successful insertion. 

CAPSTONE mission objective

Short for Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment, CAPSTONE, will circle the Moon while in the NRHO for at least six months. The NRHO is special because the gravitational pull due to the Earth and Moon establishes a semi-stable orbit. NASA says that gravity here does most of the work in this orbit as a spacecraft has to spend less fuel to maintain its position. While in this orbit, CAPSTONE will come as close as 1,609 km from one lunar pole whereas it will be 70,000 km far from the other (as shown in the image below). 

(The NRHO; Image: NASA)

If the fuel efficiency in the NRHO turns out as expected, NASA, under the Artemis Program would build the Gateway that could be parked there for at least 15 years. The Gateway is essential as it would serve as an experimental lab and habitat for astronauts while aiding future Moon landings. 

The CubeSat will also demonstrate new spacecraft-to-spacecraft navigation technologies that will allow probes to determine their location without relying on ground-based tracking systems in the future. This demonstration will be conducted by connecting CAPSTONE with NASA's Lunar Reconnaissance Orbiter orbiting the Moon since 2009.

CAPSTONE nears the end of its journey

The mission teams have carried out five manoeuvres since CAPSTONE's launch to line up its trajectory for insertion into the NRHO. The spacecraft has also suffered multiple glitches along the way, one of which sent the spacecraft wildly tumbling into space and forced it to enter safe mode. Last week, however, teams conducted the final burn after the CubeSat was rescued from safe mode. 

"What this CAPSTONE team has overcome to date has been incredible, showing resilience while gaining valuable knowledge.  We are grateful to the exceptional individuals who have gone above and beyond for their tireless work on recovery efforts," said Bradley Cheetham, principal investigator for CAPSTONE, in an official statement.