QUOTE (Brian Swift @ Mar 24 2021, 04:47 AM)
I started to wonder if that chip's Wi-Fi/Bluetooth would be used to communicated with Perseverance, but wikipedia say comm is via 900 MHz Zigbee.
That's correct. Here is a bit more details about Ingenuity telecommunication system:
"Once separated from the host spacecraft (lander or rover), the Mars Helicopter can only communicate to or be
commanded from Earth via radio link. This link is implemented using a COTS 802:15:4 (Zig-Bee) standard 900 MHz
chipset, SiFlex 02, originally manufactured by LS Research. Two identical SiFlex parts are used, one of which is an
integral part of a base station mounted on the host spacecraft, the other being included in the helicopter electronics.
These radios are mounted on identical, custom PC boards which provide mechanical support, power, heat distribution,
and other necessary infrastructure. The boards on each side of the link are connected to their respective custom antennas.
The helicopter antenna is a loaded quarter wave monopole positioned near the center of the solar panel (which also
serves as ground plane) at the top of the entire helicopter assembly and is fed through a miniature coaxial cable routed
through the mast to the electronics below. The radio is configured and exchanges data with the helicopter and base
station system computers via UART.
One challenge in using off-the-shelf assemblies for electronics systems to be used on Mars is the low temperatures
expected on the surface. At night, the antenna and cable assemblies will see temperatures as low as -140 C. Electronics
assemblies on both base station and helicopter will be kept “warm” (not below -15 C) by heaters as required. Another
challenge is antenna placement and accommodation on the larger host spacecraft. Each radio emits approximately
0.75 W power at 900 MHz with the board consuming up to 3 W supply power when transmitting and approximately
0.15 W while receiving. The link is designed to relay data at over-the-air rates of 20 kbps or 250 kbps over distances of
up to 1000 m.
A one-way data transmission mode is used to recover data from the helicopter in real time during its brief sorties.
When landed, a secure two-way mode is used. Due to protocol overhead and channel management, a maximum return
throughput in flight of 200 kbps is expected while two-way throughputs as low as 10 kbps are supported if required by
marginal, landed circumstances."