Of the three remaining options, we can eliminate the IQSpaceComm model due to lack of demonstrated flight heritage. While it is significantly cheaper, they have been extremely cagey about the true TRL, which is not a trait that is desirable when it’s such an integral part of the spacecraft.
Therefore, we have two options to choose from (specs pulled from datasheets, see above table):
| Attribute | SkyLabs NANOlink-2 (base) | SatLab SRS-4 |
|---|---|---|
| Size | 95x91x12mm | 93x87.2x17.5mm |
| Mass | 110g | 253g |
| Modulation Schemes | Offset QPSK (OQPSK) | BPSK/QPSK/8PSK |
| Encoding | CCSDS | CCSDS |
| RX coding | BCH56 | convolutional code, reed-solomon |
| TX coding | Reed-Solomon 223, 1/2 convolutional code | Reed-Solomon 223, convolutional |
| Data rate | 4M symbols/s | 5M symbols/s |
| Output Power | Max 1W (30dBm) | 20dBm-33dBm |
| Input Sensitivity | -86dBm @4Mbps OQPSK | -122dBm |
| TX Band | 2.2-2.3GHz | 2.2-2.29GHz |
| RX Band | 2.025-2.110GHz | 2.025-2.110GHz |
| Supply Voltage | 5V | 5.1V min |
| Power consumption | 6W max, 1.9W Rx only | 10.8W max, 1.5W Rx only |
| Interface | LVDS (high speed) CAN (low speed, redundant), a few GPIO broken out | CAN (slow), RS-422 (speedy), Ethernet (super speedy), future LVDS support |
| Connector | Power + comms in one custom harness, debug headers | Harwin Gecko connector, power+comms in one header, seperate headers for debug/LVDS |
| Price | 32,950 euro | 28,100 euro |
We have selected the SatLab SRS-4 for the following reasons: