Day 1

Read the unrolled twitter thread here.

We’re going to circumnavigate the world with a droneship

Andrew’s next hobby project is here.

The goal is to complete an around the world ocean trip, autonomously navigating 25,000 miles over the course of one year. The droneship will be streaming to X live via Starlink through the whole journey.

Will it work? Who knows. Do we have a specific goal? Not really. We're just here for the grand adventure and the inevitable memes.

Why??

Insatiable curiosity, or just poor impulse control? Honestly, building stuff is fun. I like to wade into the deep end of subjects I’m not qualified for and come out the other side with a story and a new skill.

A lot of things inspired this idea. For my day job, I build spacecraft + satellites which orbit the earth. When I watched our reentry footage (), it was a conscious altering thing to watch the camera film all the way from orbit to sitting on the desert floor. It just puts things in perspective, that we live on this giant but ultimately tiny blue marble. To have hardware in my hand that went on a journey around the entire control volume that we as humans occupy, that’s special.

Wired had a hilarious quote in their LK99 interview, which I have come to like. “McCalip preferred not to dwell, but instead chose to focus on what he had set out to do: making the thing”.

So that’s what we’re going to do. We’re going to build the thing.

I’m reminded of that intro to the movie Primer.

“…They took from their surroundings what was needed... and made of it something more…”

A year ago

A year ago to the day, and coincidently my birthday, the LK99 madness kicked off with this tweet.

The entire saga was an absolute blast. We did it live and in public. The outpouring of support was unreal. From national labs to twitter anons, we were all just peers. For a moment, it looked like nature had gifted us with something extraordinary.

I remember at one point, we were one of the top Twitch streams in the world, with a webcam pointed at the door of a furnace. It was 100% on the fly improvisation as problems came up. From trying to buy red phosphorus, to building our own vacuum ampules, we just live tweeted the entire process as it was happening. It was a meme and coffee fueled rager of a week, where no one slept, and the entire world watched.

What I took away from this is that people love seeing real-life engineering adventures unfold live. It tapped into a deep-seated desire for authentic stories, rather than crafted Hollywood ones.

The webcam incident stuck with me, and a few weeks ago someone happened to mention it, and that got me thinking. What is something dramatic that would unfold over a long period of time, that the internet could get excited about? What’s a journey we could go on, where no one knows how it will end? Could we do something that no one has ever done, in our nights and weekends, for pocket change?

Trawling for likes:

I can’t believe how lucky we are on the timing. Starlink Mini just hit the market and is the enabling tech of this whole project. Of course, we’re going to livestream from this thing 24/7. The home base for this project is X (the everything app). We’ll also put updates up on the website. But X is where it’s at. @elonmusk has no idea what I’m planning to do with Starlink, and SpaceX isn’t sponsoring this in any way, though I may need to call in some favors to get my dish enabled for ocean roaming?

On the site, we’ll set up a live video stream from the Gopro, alongside the full set of telemetry channels. The route will be published as well, full transparency.

Honestly, the absolute best case scenario is if it gets picked up by pirates that were monitoring the boat’s Twitter account while the world watches live. Peak entertainment.

The boat. Why Bob?

It’s a reference to the Bobiverse, a fantastic scifi series where a von neumann probe is loaded with a human consciousness and sent out into the universe.

It’s also a pun.

The team:

My lab partner in crime is back for this one. PhD astrophysics sailor who spent a year in the Arctic. @lepsthomas

Cracked PLC test engineer @Jeff15603296 is doing all things software for this project. We’ll be hijacking his NI-killer PLC infrastructure for the backend and server side stuff.

@laskerer is going to make magic happen on the bizdev front. This idea don't have a business component, so I'm interested to see how he does it 😂

Some of these people don’t even have a Twitter presence, that’s how locked in they are. I’ll do my best to drag them online.

•Sam Knoles
•Marat Kulakhmetov
•Jordan Croom

Project Bob: Day 1

Let’s take stock of where everything is right now. We’ve been working for a few weeks to do the sanity checks, and we’re looking okay so far. It’s not physically impossible.

Excel:
•Energy budget feels within 25%
•Mass budget has been worked over is probably within 10%
•Prop budget is largest uncertainty. Need to conduct propeller experiments to downselect a diameter and pitch.
•Hull drag numbers anchored by DELFTship software.

CAD:
•Reasonably mature.
•Center of gravity and buoyancy in reasonable locations with all mass props accounted for

Hull:
•A twitter anon has incredibly kindly volunteered their giant CNC 5 axis.
•Goal is to buy foam this week and finalize geometry in ~10 days.
•Cutting and fiberglass in ~3 weeks

Propulsion:
•Not super mature.
•Keel is roughed in.
•Down selected to a prop drive after the failure of the magnetic coupler approach
•17-4 SS helical coupler candidate bought, needs testing. Can it survive 500mil cycles at 10deg off axis

Rudder:
•Basic rear mounted skeg/rudder chosen.
•Unsure about sizing. Our turning radius is way less critical than most other small boats.

Solar:
•Sunpower cells selected as array type
•MPPT need a final decision. Thinking Victron?

Batteries:
•18650s, but no brand decided. A kind twitter anon has donated 100 cells already. Undecided if these will be for development or the real flight pack.
•Packs need to be spot welded and assembled. Might get some help from the gundo boys.

PCB:
•Architecture for the deadman switch has been roughed in. More on that later. This is super important.
•Schematic design this week.

Software:
•Docker stack is being borrowed from previous applications. It has tens of thousands of hours of runtime and is fairly battle hardened.
•Grafana / InfluxDB / Telegraf contains in the process of being set up.
•Haven’t got my hands on a Starlink Mini yet to test what networking will be like.

Administrative:
•Website set up. This is mainly for the blog. We found out last time in LK99 that its hard to tell a story in hundreds of chronological twitter posts. I’ll mirror all content there.
•Givebutter donation site setup. This is going to cause a tax headache if donations actually happen.
•Youtube live account set up. We also found out the hard way in LK99 that you need to do this far in advance. I still need to work on the software stack to handle the Starlink video retrieval scripts. We’ll need to automate this in a server and continually stream the chunks as we bring them back every hour.

What’s this word, antipode?

To make it a true circumnavigation according to the rulebooks, you must meet the following:

Start and finish: The trip must begin and end at the same location
Direction: Travel in one general direction, preferably continuously
Distance: Travel a distance that is equal to or more than the length of the equator (24,900 miles or 40,075 kilometers)
Antipodes: Touch at least one pair of antipodes, which are two spots on opposite sides of the Earth
Equator: Cross the equator at a minimum of two points

We’re going to follow a variation of the classic clipper route. Because we’re launching out of Los Angeles, we’ll need to drive up into the Indian Ocean. See here.

As far as we can tell, no individual or non-professional group has ever accomplished an unmanned autonomous full circumnavigation. Two notable efforts were:

Saildrone circumnavigated Antarctica, but did not complete the larger journey of 25,000+ miles. saildrone.com/news/unmanned-…

Seacharger was a brilliantly successful hobby attempt that went 6,500 miles before a rudder failure. seacharger.com

Our route is going to take us to some of the most extreme places in the world. The southern Arctic Ocean is legendary for its weather. I’m hoping to use live weather satellite data to perform some maneuvering around major storms. These waves of the things of nightmares.geodatos.net/en/antipodes/u…

The weather?

Our thoughts about the southern Arctic Ocean are something like this.

The roaring forties have legendarily bad weather. It has been a terrifying place to take a boat, in both ancient times and modern day.

Seeing those videos had a large effect on our design of hull for the boat. Obviously, it should be able to self-right itself even if flipped over 180deg. The construction of the hull needed to be more similar to a buoy right than a ship, with a solid interior of closed cell marine foam.

Originally a more optimized trimaran hull was desirable for solar area efficiency, Unfortunately we couldn’t settle on what an acceptable load case would be to design the top solar deck to. If you have a breaking wave hit the deck, this is a huge dynamic load of hundreds of pounds per square foot. The risk of undersizing your cantilever beams in your deck is just too scary, the risk/return doesn’t seem to close on this concept.

Budgets. What do we have to work with. Let’s do some hand calcs

Everything in engineering should start with an excel sheet. Do your rough sizing, order of magnitude estimates, sensitivity studies.

In this case, we have a few critical coefficients that everything in the project is heavily dependent on. This is a multivariable optimization problem where we’re bounded primarily by power generation and consumption.

•Watts per newton of propeller thrust.
•Watt-hour/meter^2/day of solar collection
•Newtons / meter^2 of hull drag

Let’s tackle one at a time

Electrical: Power is everything:

(my favorite piece of media so far)

We’re going to have to watch every watt of consumption. If we consider our end of journey 24hr avg power output, we’re looking at 38 watts for the whole ship.

Starlink is the HUGE consumer. Average power during upload is going to be 30w. This is basically the entire propulsion budget, so we’re going to need to get this duty cycle to <10% of overall time. Burst uploading large chunks of video every 2-4hr is probably the way. Would people rather see a 5fps 1080p stream or a 480p 24fps stream?

Rudder servos need to be powered off most of the time. The average Hitec digital servo draws 1200millwatts. The strategy will be to turn on the servo at perhaps a 1% duty cycle. We’re mostly going in a straight line after all.

Gopros are very power hungry. Avg consumption looks to be around 3 watts. But if we’re not shooting video, that defeats a major point of the project. I think we’ll keep one camera powered down as a backup / diagnostic rear facing camera. Another power savings is that we’re not going to run the livestream GoPro at night. That’s a 36watt-hour savings!

ESCs are fairly efficient. I’ve chosen a Tmotor Alpha ESC with sinusoidal field oriented control. Should be one of the most efficient on the market. If you have any better suggestions, I’m all ears. Perhaps 250mw of power dissipation in the FETs.

Pis are reasonable. A 3+ in idle condition is going to draw about 1.2watts. We’ll send the secondary backup Pi into a sleep mode after the watchdog GPIO on the primary goes high.

GPS. A sparkfun gps with an I2C bus is quite low, hundreds of milliwatts.

All this needs to go into the avionic budget sheet with duty cycles. Last time I checked, we’re at 6 watts on a 24hr averaged basis.