Recent from talks
PROBA-3
Knowledge base stats:
Talk channels stats:
Members stats:
PROBA-3
PROBA-3 is a dual-probe technological demonstration mission by the European Space Agency devoted to high-precision formation flying to achieve scientific coronagraphy. It is part of the series of PROBA satellites that are being used to validate new spacecraft technologies and concepts while also carrying scientific instruments. It lifted off aboard ISRO's PSLV-XL rocket from Satish Dhawan Space Center in Sriharikota, India. The project is managed by Damian Galano.
PROBA-3 consists of two independent, three-axis-stabilized spacecraft: the Coronagraph Spacecraft (CSC) and the Occulter Spacecraft (OSC). The spacecraft will fly close to each other on a highly elliptical orbit around the Earth, with an apogee at 60,500 km altitude.
ESA said that by flying in tight formation about 150 metres apart, the Occulter will precisely cast its shadow onto the Coronagraph’s telescope, blocking the Sun’s direct light. This will allow the Coronagraph to image the faint solar corona in visible, ultraviolet and polarised light for many hours at a time.
Along the apogee arc, when the gravity gradient is significantly smaller, the two spacecraft will autonomously acquire a formation configuration, such that the CSC remains at a fixed position in the shadow cast by the OSC. The CSC hosts a coronagraph, which will then be able to observe the Sun's corona without being blinded by the intense light from the photosphere. Given the diameter of the occulter disk on the OSC and the intended corona observation regions, the CSC must be approximately 150 meters from the OSC and maintain this position with millimetric accuracy, both in range and laterally. The scientific objective is to observe the corona down to about 1.1 solar radius in the visible wavelength range.
Besides formation flying for coronagraphy, some demonstration manoeuvers (retargeting and resizing) will be attempted during the apogee phase of the orbit, as well as a space rendezvous experiment.
The formation acquisition and control is performed on-board by metrology equipment and actuators. The metrology equipment comprise a laser-based system providing high-accuracy relative position estimate, a video-based sensor with a coarser precision but wider field of view, and a shadow position sensor providing finest precision when the CSC is in the vicinity of the target position in the shadow cone.
After the apogee arc, the formation is broken by impulsive manoeuvers executed by the spacecraft. The two spacecraft are placed on a relative trajectory that passively ensures no risk of collision during the perigee passage, when the spacecraft altitude goes down to 600 km. Along the perigee phase of the orbit, the two spacecraft acquire GNSS data to derive a precise estimation of the relative position and velocity, which is propagated for a few hours up to the reacquisition of the metrology before the next apogee arc.
The CSC and OSC exchange sensor data and commands through a radio-frequency inter-satellite link to coordinate their activities. Scientists hope that PROBA-3’s unique vantage point will provide new insights into the origins of coronal mass ejections (CMEs) – eruptions of solar material that can disrupt satellites and power grids on Earth. The mission will also measure total solar irradiance, tracking changes in the Sun’s energy output that may influence Earth’s climate.
Hub AI
PROBA-3 AI simulator
(@PROBA-3_simulator)
PROBA-3
PROBA-3 is a dual-probe technological demonstration mission by the European Space Agency devoted to high-precision formation flying to achieve scientific coronagraphy. It is part of the series of PROBA satellites that are being used to validate new spacecraft technologies and concepts while also carrying scientific instruments. It lifted off aboard ISRO's PSLV-XL rocket from Satish Dhawan Space Center in Sriharikota, India. The project is managed by Damian Galano.
PROBA-3 consists of two independent, three-axis-stabilized spacecraft: the Coronagraph Spacecraft (CSC) and the Occulter Spacecraft (OSC). The spacecraft will fly close to each other on a highly elliptical orbit around the Earth, with an apogee at 60,500 km altitude.
ESA said that by flying in tight formation about 150 metres apart, the Occulter will precisely cast its shadow onto the Coronagraph’s telescope, blocking the Sun’s direct light. This will allow the Coronagraph to image the faint solar corona in visible, ultraviolet and polarised light for many hours at a time.
Along the apogee arc, when the gravity gradient is significantly smaller, the two spacecraft will autonomously acquire a formation configuration, such that the CSC remains at a fixed position in the shadow cast by the OSC. The CSC hosts a coronagraph, which will then be able to observe the Sun's corona without being blinded by the intense light from the photosphere. Given the diameter of the occulter disk on the OSC and the intended corona observation regions, the CSC must be approximately 150 meters from the OSC and maintain this position with millimetric accuracy, both in range and laterally. The scientific objective is to observe the corona down to about 1.1 solar radius in the visible wavelength range.
Besides formation flying for coronagraphy, some demonstration manoeuvers (retargeting and resizing) will be attempted during the apogee phase of the orbit, as well as a space rendezvous experiment.
The formation acquisition and control is performed on-board by metrology equipment and actuators. The metrology equipment comprise a laser-based system providing high-accuracy relative position estimate, a video-based sensor with a coarser precision but wider field of view, and a shadow position sensor providing finest precision when the CSC is in the vicinity of the target position in the shadow cone.
After the apogee arc, the formation is broken by impulsive manoeuvers executed by the spacecraft. The two spacecraft are placed on a relative trajectory that passively ensures no risk of collision during the perigee passage, when the spacecraft altitude goes down to 600 km. Along the perigee phase of the orbit, the two spacecraft acquire GNSS data to derive a precise estimation of the relative position and velocity, which is propagated for a few hours up to the reacquisition of the metrology before the next apogee arc.
The CSC and OSC exchange sensor data and commands through a radio-frequency inter-satellite link to coordinate their activities. Scientists hope that PROBA-3’s unique vantage point will provide new insights into the origins of coronal mass ejections (CMEs) – eruptions of solar material that can disrupt satellites and power grids on Earth. The mission will also measure total solar irradiance, tracking changes in the Sun’s energy output that may influence Earth’s climate.