NASA’s CISSTONE (Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment) was launched from New Zealand with a Rocket Labs rocket on Wednesday morning. As of Wednesday afternoon, CubeSat is safely in low orbit on Earth and en route to experience a longer, more economical orbit to the Moon and a revolutionary new lunar orbit that will allow future crew missions to the Moon. What’s new – CAPSTONE will go where many spaceships – and many people – have gone in the past, but it will get there in a whole new way. The CubeSat mission will test a very long but very efficient route to the Moon, called a ballistic orbital orbit. It will also test a lunar orbit that has not been tested before, called an almost straight halo orbit: a stretched oval of an orbit that passes over the Moon’s north and south poles. This very stable trajectory will allow future missions such as the Gateway to further expand their fuel reserves and remain in constant radio communication. While in lunar orbit, CAPSTONE will also test a communications system that will help future lunar missions track their positions in space without relying on Earth-based monitoring. CAPSTONE will work with NASA’s Lunar Reconnaissance Orbiter to continuously measure the distance between the two spacecraft and then use it as a basis for calculating the positions of ships. CAPSTONE appeared on Tyvak Nano-Satellite Systems, Inc. before launch. Dominic Hart Why it matters – Everything that CAPSTONE does will immediately pave the way for future crew missions to the Moon. The nearly straight halo orbit is the same orbit that NASA plans to use for the Gateway space station, which will eventually orbit the Moon with a full-fledged astronaut crew to provide a docking station for lunar landings and refueling missions. communications and other support for Artemis missions to the Moon. And the ballistic lunar orbit will help keep Artemis and Gateway running. Artemis crews will follow the most direct route, which means they will launch their propellers to transport the spacecraft from Earth orbit to the lunar orbit. But for unmanned missions, such as supply deliveries to future lunar outposts, the ballistic lunar orbit will be more fuel efficient and less expensive. This image shows CAPSTONE orbiting the Moon.NASA Digging into the details – When the Apollo spacecraft landed on the Moon, it was about a three-day voyage, but the CAPSTONE voyage will take four months on the ballistic lunar orbit. The route is “driven by gravity”, as NASA puts it, which means that CAPSTONE will use gravity, not its own propellers, to change its speed and position. Six days from now, CAPSTONE’s Lunar Photon Third Stage Amplifier will launch the satellite on a long deep space cruise. Eventually, the Earth’s gravity will pull the spacecraft back to Earth and the Moon – the “ballistic” part of the route’s name. Just 1.5 million kilometers from home, the Sun’s gravity will propel CAPSTONE into an extremely wide orbit around the Earth. the lowest point in the orbit will intersect with the Moon. As CAPSTONE hovers back toward Earth and the Moon, it will only need a few small push-ups from its propellers to stay on track. One last little maneuver will change the speed of the CAPSTONE so that the Moon’s gravity can capture it in lunar orbit – this is the “transport” part. On paper, physics works well, and NASA engineers have performed tens of thousands of simulations to design and practice CAPSTONE’s long but surprisingly fuel-efficient path to the Moon. But the spacecraft flies this route to ensure that it will work just as well in practice. And once it reaches the Moon, CAPSTONE will be installed in a strange orbit around the Moon’s poles. It is called an almost straight halo orbit (NRHO): “almost straight” because the orbit is so long, elongated oval that its sides are almost straight, and “halo” because it orbits the Moon’s poles instead of its equator. At its closest approach, CAPSTONE will travel approximately 1,600 km above the Moon’s north pole. at the other end of its orbit, the spacecraft will be about 76,000 km from the south pole of the Moon. This animation shows CAPSTONE’s new orbit around the Moon. Advanced Space The gravitational influence from both the Earth and the Moon will help keep the spacecraft steady on this orbit, so CAPSTONE will not have to fire its propellers too often or for too long. “The burns will be timed to give the spacecraft an extra boost as it naturally creates momentum – this requires much less fuel than a more circular orbit,” said Elwood Agasid, deputy program director for small spacecraft technology at the Ames Research Center. NASA. a statement. This means that a spaceship can stay in orbit much longer with the same amount of fuel than it could on a more conventional orbit. NASA estimates that a large spacecraft such as the Gateway will be able to remain in lunar orbit for about 15 years. Meanwhile, the orbit around the Moon’s poles will keep CAPSTONE – and later, the Gateway – in constant radio communication with the Earth and the lunar surface. During the Apollo missions, the command unit lost contact with both Mission Control and the astronauts on the lunar surface for about 48 minutes at a time, orbiting the far side of the moon. Gateway crews will not have this problem. What’s next – CAPSTONE will spend the next four months on its way to the Moon. For six months thereafter, the small spacecraft will send home data on its orbital dynamics and communication work with the LRO, along with a few other experiments. NASA plans to launch the first Gateway components in test by the end of 2024. NASA will begin with the power and propulsion model and the Habitation and Logistics Outpost, which will combine crew space, science facilities, berths and command and control for the rest of the station. NASA, meanwhile, has not yet set a date for the launch of Artemis 1. Engineers are still reviewing data from a basic pre-release test on June 20. LEARN SOMETHING NEW EVERY DAY.
