A potential new way to travel through space is set to launch aboard Rocket Lab's Electron rocket from Launch Complex 1 on New Zealand's Mahia Peninsula.
The mission, dubbed “Beginning of the Swarm,” will launch two payloads into sun-synchronous orbit. The launch is currently scheduled for April 23rd, with launch scheduled for 23:00 UTC.
One of the two payloads on board this mission is NASA's Advanced Composite Solar Sail System (ACS3). The goal is to test new composite materials that can be folded into something as small as a CubeSat and remain rigid when deployed into space.
For this test, the solar sail was designed to fit inside a 12-unit (12U) CubeSat measuring approximately 23 x 23 x 34 centimeters (9 x 9 x 13 inches). This is comparable in size to a microwave oven.
Solar sails deploy large sheets of metal that act like sails on a sailing ship. Use the boom to spread the sails just like on a boat. Rather than using chemical or electrical propulsion, these sails harness sunlight and solar wind to propel spacecraft and satellites.
Flying the sails is your secondary goal in this mission. The first objective is to unroll the entire sail in about 25 minutes and see how well it holds up.
Rendering the ACS3 solar sail in orbit. (Credit: NASA)
Here comes a whole new composite boom.
Johnny Fernandez of NASA's Langley Research Center said in an interview with NSF that telescopic boom technology has been around for some time, but small satellite deployment options made from carbon fiber-reinforced polymer materials are now possible. said it was only now.
“Recently, we have been able to use laminate by making the material extremely thin.” [and] It's a multilayer composite that was not possible 10 or 15 years ago,” Fernandez said.
Composite boom materials tested in ACS3. (Credit: NASA)
Folding booms were used until the Viking Mars Lander in the 1970s, but they were primarily made of metal. Therefore, problems arose when exposed to the sun for long periods of time.
“The application of the metal version has thermal expansion limitations,” Fernandez said. “It transforms into something like a taco-shaped structure.”
The same concerns arose when designing the NEA Scout mission, which flew aboard Artemis 1 but had no contact with ground controllers after liftoff.
“Mr Langley had been investigating the stability of the structure, and when examining the thermal properties it became clear that the boom was slowly deforming and becoming unflyable, so he immediately decided to investigate the mitigation openings. ,” Fernandez said.
Another problem arose when looking at how the boom was extended. Fernandez pointed out that missions like NEA Scout have a membrane that is split into four parts, with exposed metal booms that can be deformed.
The team is working on the ACS3 solar sail, which opens with a new composite boom. (Credit: NASA)
This issue led to a switch to single membranes. The next question was where to place the boom and what material to use.
“We had to change from a quarter configuration to one square to put the boom behind the sail, which acts as a sunshade,” Fernandez said. “That got me interested in finding a thermally stable version of these booms.”
Once reaching its planned orbit, ACS3 will deploy its solar cells, followed by its sails over a 25-minute period using four new composite booms. Deployment speed will be monitored by multiple cameras to determine efficiency and how well the solar sail maintains its shape.
Animation of the ACS3 deployment sequence. (Credit: NASA)
When unfolded, the square sail measures approximately 9 meters (30 feet) on a side.
As testing begins with the sail itself, its shape will continue to be monitored.
“If we can deploy and stretch the membrane during an event and capture camera data, that's already a success,” Fernandez said. “The second purpose is to use it.”
Another item they had to overcome was the deployment mechanism inside such a small CubeSat.
As a result, this is only a 40% scale prototype of what NASA plans to use in the future.
“Since this is a test of a large system, we wanted to use the same materials that fit into the CubeSat to test the same types of materials that would be expected to be used in a larger boom structure,” Fernandes said. said. “We're really approaching the limits of that technology.”
The team is working on the CubeSat from which ACS3 will be deployed. (Credit: NASA)
He noted that work is underway on a six times larger version of ACS3, and that the sail team is partnering with a team from German space agency DLR to work on the physical deployment mechanism. .
Fernandes said the technology is already being used in commercial applications, including in licensing booms of deployable communications antennas. But NASA is very interested in this material, especially when it comes to the Artemis moon program, he says.
“[NASA] The same type of roller structure is used on the lunar surface to deploy towers containing solar panels and deployable antennas for communication. [the] It's the gateway to the moon,” Fernandez said.
The mesh currently used in the parabolic dishes and reflectors being considered for lunar exploration poses its own problems, Fernandez said.
“On the Moon, mesh reflectors are prone to dust problems, so we needed a solid surface like a dish on Earth. Instead, we created a parabolic dish that folds up like an umbrella.” Fernandez said.
After testing the materials on a microgravity parabolic flight, the team is partnering with industry and academia to make this mission a success.
A rendering of the ACS3 solar sail fully deployed in orbit. (Credit: NASA)
This mission will also be accompanied by the New Space Earth Observation Satellite-1 (NeonSat-1). The high-resolution optical satellite developed by the Satellite Technology Research Center (SaTReC) of the Korea Institute of Science and Technology (KAIST), South Korea's leading science and technology institution, will be deployed as a technology demonstration for a planned future Earth observation satellite constellation. Ru. .
If all goes well with this prototype flight, KAIST plans to mass-produce 10 more satellites, bringing the total number of constellations to 11. The plan is to have all satellites in orbit by 2027.
Both satellites will be mounted on Rocket Lab's Electron rocket. On the company's fifth mission in 2024, his nine Rutherford engines in the first stage and a vacuum-optimized version of Rutherford will do most of the heavy lifting.
Electron's payload fairing after encapsulating the NEOSAT-1 and ACS3 payloads. (Credit: Rocket Lab)
This mission includes an additional third stage known as the Kick Stage. It uses a Curie engine, which can be fired multiple times to raise and circumferentially orbit it.
Rocket Lab says this mission is unique in that it places two different spacecraft in completely different orbits. Therefore, on this flight, the kick stage completes four different burns, including a final burn to accelerate destructive reentry after satellite deployment.
NEONSAT-1 will deploy into a 520-kilometer (323-mile) Earth orbit at a 97-degree inclination approximately 50 minutes after liftoff.
The second payload, ACS3, will be deployed in a 1,000-kilometer (621-mile) circular Earth orbit, also tilted at 97 degrees. This deployment is scheduled to occur one hour and 45 minutes after the mission begins.
(Lead image: Team working on NEONSAT-1 before launch. Credit: Rocket Lab)
