Landing on water - how to prepare

[bgoczan]

Hi everyone!

Our last two flights were landed near water bodies which made us a little worried. Our plan is to prepare for the unlikely event of water landing without any damage in the avionics system or the science payload.

I would like to discuss if anyone in the forum had landed on water and/or made prepararions for water landing.

Our main concern is that electronic devices not quite like water while they powered on.
The other question is floating. And of course, recovery.

I would be happy if you would share your experience or opinion on this topic.

Thank you!

[Shulman]

I am from Northern Ontario and so when we fly we are dodging bodies of water and marshland on all sides.

Landing sight of the Moonshot Mission:

We have yet to land right in the water, but my Byonics tracker did get fried by water when we lost the payload in the bush for five days in the melting snow (Snowday: A Canadian HAB Adventure). So we have tried to mitigate the risk through...

1) Spot Trace anti-theft device is waterproof and sent beacons while wet

2) we only set the launch date when the flight path prediction indicates that we are unlikely to hit the water

3) after the Snowday flight we put the new Byonics tracker in a milk bag for the flight and seal it around the antenna cable with elastics (in Canada we buy milk in a bag so this is just a thick plastic bag)

4) we use a PITS (Pi in the Sky) board and it was not damaged when it got wet - it does not transmit while in water but once everything evaporates data and images were still on the SD card and the tracker was just fine on the next flight

5) we use a very flat styrofoam payload shape (12" x 12" x 3") so that if the payload lands in the water chances are it will stay upright and we basically seal the bottom of the payload around the antennas and then cut very narrow slits near the top of the box for cameras since we use PiCameras with ribbon cable and the smallest hole possible for wires to the exterior sensors - we hope all of this will buy us some time while we make our way out to the payload in the lake

6) prayer, but the effectiveness of this is difficult to assess

[bgoczan]

Thank you for sharing your experience.
(Fun fact in Hungary we also used to buy milk in bags, it is not so common now, but it was 15 years ago)

[dgerson]

I think it definitely can be done, but some other things to keep in mind:

1. If you don't want water to get into your payload, don't only think about the payload design but also think about the parachute and cord situation - it's possible for your parachute to act as a weight/sail and pull your payload container over.

2. Definitely try to use water proof containers where possible. GoPro cameras and other camers have great water proof containers. This can be harder for sensors - but often you have the sensor exposed, but the associated electronics better protected.

3. Another thing is to have electronics programmed to shut off at a certain altitude - to try and have things no longer powered on at landing if they get wet.