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Why do we need huge rovers when there is a ball-sized SORA-Q?
Lunar rovers are usually presented as large machines with cameras, drilling rigs and a set of scientific instruments. The Japanese LEV-2, named SORA-Q, went the other way. The device the size of the palm went to the moon in the form of a small sphere, opened up after coming to the surface and almost two hours worked next to the planting module SLIM.
SORA-Q was part of the Smart Lander for Investigating Moon, or SLIM, which the Japanese Aerospace Exploration Agency JAXA sent to the moon. In 2024, the lander reached the surface, and a small robot LEV-2 surveyed the section around the module, removed SLIM and transmitted the selected images without constant control from Earth.
For space missions, this format is not important because of the miniature in itself. A small rover is easier to place inside the device, it is easier to deliver to the target and it is cheaper to develop than a full-fledged lunar rover. It does not replace a large mobile laboratory, but can quickly give engineers what is often lacking after landing: an external view of the device and the nearest surface.
Miniature size immediately creates several problems. In a small case can not be put a large battery, a powerful transmitter and a serious processor. The chassis also works at the limit: the microrobot wheels cope worse with irregularities, and the energy reserve does not allow you to correct motion errors for a long time.
The lunar soil only strengthens these limitations. Regolit consists of dust, small debris and particles, fragmented by micrometeorite impacts over billions of years. For a large rover, a loose layer can be a normal section of the route. For a device the size of a palm of a small hole, a stone or a wheel drawdown is already becoming a serious obstacle.
JAXA engineers did not make a smaller copy of the classic rover. To the project attracted TIY, a Japanese toy manufacturer. The company had experience with transformable mechanisms, where the ball opens and turns into a wheeled machine. In the lunar mission, this principle received practical meaning: the rover could be laid in a compact volume for the flight time, and then open the chassis already on the moon.
LEV-2 was flying like a small area. At the final stage of the mission, SLIM released two small devices, LEV-1 and LEV-2. After coming to the surface, the SORA-Q opened the body, and the two halves began to work like wheels. The axis of rotation was specially shifted relative to the center, so that the rover did not just roll over the dust, but better cling to loose soil.
Displacement of the axis is important for regolith. An ordinary small wheel can quickly burrow if the ground crumbles under it. LEV-2 movement turned out to be more uneven, but useful: the device, as it were, pushed itself forward and was easier to get out of the soft layer. This mechanics grew out of the toy idea, but on the moon solved quite a serious engineering problem.
Communication also had to be built not according to the usual scheme. LEV-2 could not constantly send data directly to Earth: this would not have enough energy and the capabilities of the transmitter. Therefore, the rover worked in conjunction with the LEV-1. SORA-Q transmitted photos and service data to the neighboring device, and LEV-1 had already sent information to the mission control center.
Autonomous work was necessary from the very beginning. It is impossible to control such a robot from the Earth as a radio machine: the signal is delayed, the communication channel is limited, and the battery is not designed for a constant exchange of commands. Therefore, SORA-Q itself crossed between modes, moved next to SLIM, took pictures and chose data for transmission.
On the surface of the moon, the LEV-2 worked for about 108 minutes. During this time, the device managed to inspect the nearest site, remove the landing module and the surrounding landscape, then transmitted the selected images via LEV-1. After that, the connection was lost, but the short work was enough to check several solutions at once: the disclosure of the hull, the movement on the regolith, autonomous algorithms and the transmission of data through the partner apparatus.
SLIM shots from the side were one of the main results. For engineers, such personnel are important not as spectacular photos, but as a technical inspection of landing. From them you can understand the position in which the module was, how it stands on the ground and what is around after touching the surface. The lander itself is not always able to show its own position, and a small external observer closes this space without sending a large rovers.
LEV-2 is not designed for tasks that are performed by large lunar rovers with drills, spectrometers and other scientific equipment. But the microrobot is suitable for quick reconnaissance next to the landing module. He can check the nearest soil, remove the state of the equipment, examine the hard-to-reach area and give the mission team information for which a large device is not always justified.
The experience of SORA-Q shows that a separate class of small scouts may appear in lunar missions. JAXA and COMY tested the working circuit: spherical enclosure for flight, after separation, offset axes of wheels for regolith, autonomous choice of actions and data transmission via LEV-1. The next step for such robots is working in groups, delivering small sensors and inspecting places where a large rover will not get or where it is simply unprofitable to send it.
Lunar rovers are usually presented as large machines with cameras, drilling rigs and a set of scientific instruments. The Japanese LEV-2, named SORA-Q, went the other way. The device the size of the palm went to the moon in the form of a small sphere, opened up after coming to the surface and almost two hours worked next to the planting module SLIM.
SORA-Q was part of the Smart Lander for Investigating Moon, or SLIM, which the Japanese Aerospace Exploration Agency JAXA sent to the moon. In 2024, the lander reached the surface, and a small robot LEV-2 surveyed the section around the module, removed SLIM and transmitted the selected images without constant control from Earth.
For space missions, this format is not important because of the miniature in itself. A small rover is easier to place inside the device, it is easier to deliver to the target and it is cheaper to develop than a full-fledged lunar rover. It does not replace a large mobile laboratory, but can quickly give engineers what is often lacking after landing: an external view of the device and the nearest surface.
Miniature size immediately creates several problems. In a small case can not be put a large battery, a powerful transmitter and a serious processor. The chassis also works at the limit: the microrobot wheels cope worse with irregularities, and the energy reserve does not allow you to correct motion errors for a long time.
The lunar soil only strengthens these limitations. Regolit consists of dust, small debris and particles, fragmented by micrometeorite impacts over billions of years. For a large rover, a loose layer can be a normal section of the route. For a device the size of a palm of a small hole, a stone or a wheel drawdown is already becoming a serious obstacle.
JAXA engineers did not make a smaller copy of the classic rover. To the project attracted TIY, a Japanese toy manufacturer. The company had experience with transformable mechanisms, where the ball opens and turns into a wheeled machine. In the lunar mission, this principle received practical meaning: the rover could be laid in a compact volume for the flight time, and then open the chassis already on the moon.
LEV-2 was flying like a small area. At the final stage of the mission, SLIM released two small devices, LEV-1 and LEV-2. After coming to the surface, the SORA-Q opened the body, and the two halves began to work like wheels. The axis of rotation was specially shifted relative to the center, so that the rover did not just roll over the dust, but better cling to loose soil.
Displacement of the axis is important for regolith. An ordinary small wheel can quickly burrow if the ground crumbles under it. LEV-2 movement turned out to be more uneven, but useful: the device, as it were, pushed itself forward and was easier to get out of the soft layer. This mechanics grew out of the toy idea, but on the moon solved quite a serious engineering problem.
Communication also had to be built not according to the usual scheme. LEV-2 could not constantly send data directly to Earth: this would not have enough energy and the capabilities of the transmitter. Therefore, the rover worked in conjunction with the LEV-1. SORA-Q transmitted photos and service data to the neighboring device, and LEV-1 had already sent information to the mission control center.
Autonomous work was necessary from the very beginning. It is impossible to control such a robot from the Earth as a radio machine: the signal is delayed, the communication channel is limited, and the battery is not designed for a constant exchange of commands. Therefore, SORA-Q itself crossed between modes, moved next to SLIM, took pictures and chose data for transmission.
On the surface of the moon, the LEV-2 worked for about 108 minutes. During this time, the device managed to inspect the nearest site, remove the landing module and the surrounding landscape, then transmitted the selected images via LEV-1. After that, the connection was lost, but the short work was enough to check several solutions at once: the disclosure of the hull, the movement on the regolith, autonomous algorithms and the transmission of data through the partner apparatus.
SLIM shots from the side were one of the main results. For engineers, such personnel are important not as spectacular photos, but as a technical inspection of landing. From them you can understand the position in which the module was, how it stands on the ground and what is around after touching the surface. The lander itself is not always able to show its own position, and a small external observer closes this space without sending a large rovers.
LEV-2 is not designed for tasks that are performed by large lunar rovers with drills, spectrometers and other scientific equipment. But the microrobot is suitable for quick reconnaissance next to the landing module. He can check the nearest soil, remove the state of the equipment, examine the hard-to-reach area and give the mission team information for which a large device is not always justified.
The experience of SORA-Q shows that a separate class of small scouts may appear in lunar missions. JAXA and COMY tested the working circuit: spherical enclosure for flight, after separation, offset axes of wheels for regolith, autonomous choice of actions and data transmission via LEV-1. The next step for such robots is working in groups, delivering small sensors and inspecting places where a large rover will not get or where it is simply unprofitable to send it.
