PRISMA Space Segment consists of a single small-class spacecraft, with a mass less than 850 kg, on a sunsynchronous orbit.
As already mentioned, the satellite is composed of
• payload PAN / hyperspectral
• PDHT for Payload data handling and transmission to ground
• platform
PRISMA payload includes a hyperspectral camera with VNIR and SWIR detectors as well as a panchromatic ones. Moreover, the payload is equipped with lossless data compression devices.
PDHT (Payload Data & Transmission) is devoted to storing acquired data in its internal P/L memory and to ground via a dedicated X-band link.
PRISMA platform provides all the functionality to ensure the functioning of the satellite and the palyload in particular.
The main characteristics of the satellite are listed in the table below:
|
2.17 m x 1.47 m x 3.59 m |
|
|
Mass |
~ 800 Kg |
|
Solar Panels |
1320 W EoL |
|
Power |
450 W medi |
| Pointing accuracy |
~ 100 arcsec @ 3s |
|
Pointing sensitivity |
~ 70 arcsec @ 3s |
|
Off-nadir capability |
21° |
|
TM/TC |
S band |
| Propulsion |
Hydrazine based, DV ~ 120 m/s |
|
AOCS Actuators |
· Reaction wheels · Magneto-torquers |
|
AOCS Sensors |
· Sun sensors · Star sensors · Magnetometer · Gyros · GPS |
|
Launcher |
VEGA |
The following figure shows the layout of the PRISMA satellite. The solar panel is stationary and, in order to optimize the sizing of the power subsystem, the satellite attitude will be maintained nominally to point the solar panels towards the sun, moving "Earth-pointing" ini synch only during the image acquisition and download:
The main characteristics of the satellite (typical reference values) are listed in the table below:
|
Dimensions |
|
|
Mass |
|
|
Solar panel |
|
|
Power |
|
|
Pointing Accuracy |
|
|
Pointing Sensitivity |
|
|
Off-nadir Capability |
|
|
TM/TC |
|
|
Propulsion |
|
|
AOCS Actuators |
|
|
AOCS Sensors |
|
|
Launch |
|
|
Redundancy |
