# Flight Logs

AstroNav Nano stores mission data as CSV files.

## Leaving USB mode

When using USB configuration mode:

1. Finish editing files.
2. Close applications that are using the drive.
3. Safely eject the AstroNav Nano drive.
4. Wait for the board to leave storage mode.

On Windows, use:

**Safely Remove Hardware / Eject**

Avoid disconnecting power while a write is active.

## EXITUSB

The serial command:

```text
EXITUSB
```

can also request that the board leave USB storage mode.

## Retrieve a flight log

After a completed flight:

1. Confirm landing.
2. Follow your normal recovery procedure.
3. Remove power safely.
4. Disconnect hazardous loads.
5. Connect AstroNav Nano through USB.
6. Open the `logs` directory.
7. Copy the relevant CSV file.

Flight files use a format similar to:

```text
Flight_XXXXXXXX.csv
```

Keep the original log unchanged.

Perform analysis on a copy.

## Logged data

A flight log may contain:

- Sample counter
- Time in milliseconds
- Power mode
- Flight state
- Pyro state
- Acceleration
- Rotation
- Pressure
- Temperature
- Altitude
- Vertical velocity
- Roll
- Pitch
- Health bits

## Reviewing a flight

Pay particular attention to state transitions:

```text
Idle
↓
Boost
↓
Coast
↓
Pyro Fired
↓
Landed
```

Compare recorded flight behavior with independent mission information where possible.

Review any warnings or fault conditions before drawing conclusions from the data.