Note: the Github repo is not the primary repo; it’s here for visibility.

Quick links


For a long time, I’ve had an idea for a project: to simulate a mission to
Proxima Centauri on a computer in real time. There’s a couple reasons I want to
do this: I think it’s an interesting exercise in keeping a computer running for
a long time (just over 1900 days, if my math is right), and because I’m a space
nerd. It just seems like a cool idea. I sketched out the idea
in Mathematica,
then wrote some Go code.

What exactly is this? I wrote some code that is a very basic simulation of
a flight to the star Proxima Centauri. In the real world, I plan to run a
single process for nearly five and a quarter years. If it fails or stops, the
mission is lost, simulating the requirement for a stable control system for the
ship. This means that if I move, I can’t just turn the system off. I’ve set a
“launch” date for my 35th birthday, which is when the system is finalized and
the simulation can’t be touched. That means I’ll be just over 40 years old when
it finishes, which is a little sobering.


  • cmd/flightconn: the flight control software
  • cmd/flightconnui: Python code that drives the eInk display
  • cmd/flightsim: speedrun the flight to verify the calculations
  • cmd/flightsim_test: the flight simulator as a Go test
  • cmd/missionctl: the web frontend
  • cmd/relay: fetch updates from the flight control software and post to mission control
  • comms/: ZeroMQ connectivity; the UI receives updates from the flight control software over ZeroMQ.
  • database/: database configuration to talk to mission control
  • handler/: HTTP handlers
  • milestones/: calculate the various milestones as described in the notebook
  • mission/: the flight simulator core software
  • ops/: various operations bits, such as the SQL schema and systemd service files
  • physics/: the physics calculations behind the software
  • rat/: convenience functions for dealing with math/big.Rat

System overview

Raspberry Pi / flight hardware

The flight control software runs on a Raspberry Pi 3B.

  • flightconn runs the flight. flightconn sets up an HTTP endpoint
    that dumps the current flight information as JSON, and a ZeroMQ publisher
    that broadcasts updates regularly.
  • flightconnui receives updates from flightconn over a ZeroMQ subscriber
  • relay runs as a cronjob to regularly sync flight updates to mission
    control. It posts updates to missionctl as HTTP push requests.

Mission control

missionctl currently runs in a Heroku instance. It receives updates via an
HTTP post.


Install the eInk drivers for the 2.7″ PaPiRus hat

sudo apt install python3 python3-pip
curl -sSL | sudo bash
sudo papirus-setup

NB: this also installs git.

Add i2c-rtc,mcp7940x=1 to the dtcoverlay to enable the RTC.

Install the zeroMQ drivers.

sudo apt install libczmq-dev python3-zmq

Install Go and build tools

I install Go using this method.


This software is released under the Blue Oak Model License v1.0.0.

Blue Oak Model License

Version 1.0.0


This license gives everyone as much permission to work with
this software as possible, while protecting contributors
from liability.


In order to receive this license, you must agree to its
rules. The rules of this license are both obligations
under that agreement and conditions to your license.
You must not do anything with this software that triggers
a rule that you cannot or will not follow.


Each contributor licenses you to do everything with this
software that would otherwise infringe that contributor’s
copyright in it.


You must ensure that everyone who gets a copy of
any part of this software from you, with or without
changes, also gets the text of this license or a link to


If anyone notifies you in writing that you have not
complied with Notices, you can keep your
license by taking all practical steps to comply within 30
days after the notice. If you do not do so, your license
ends immediately.


Each contributor licenses you to do everything with this
software that would otherwise infringe any patent claims
they can license or become able to license.


No contributor can revoke this license.

No Liability

As far as the law allows, this software comes as is,
without any warranty or condition, and no contributor
will be liable to anyone for any damages related to this
software or this license, under any kind of legal claim.


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