Up, Up, and Away

There is more excitement about space travel now than at any time since Neil Armstrong put the first boot print on the Moon. After those early days of experimentation and exploration, things started to feel a bit humdrum. First, the Moon missions ended. Then the space shuttle program was retired in 2011, leaving astronauts with little more than Soyuz spacecraft — in production since the 1960s — when they needed a lift beyond the grip of Earth’s gravity. We did not appear to be on a trajectory that would turn Star Trek into reality any time soon.

But then came the rise of commercial space travel, led by companies such as Blue Origin and, especially, SpaceX. Rapid technological advances ensued, and now rocket launches are almost a daily event. And of course the Starship test flights — sporting the most powerful rockets ever constructed — are making headlines around the world. These innovations are inspiring a new generation to reach for the stars.

But you cannot exactly get in on the action yourself. Space travel is still for a select few individuals and at a very high cost. But as Jorge Mata of Desafío inventor recently demonstrated, an amateur hacker can still probe the upper regions of the atmosphere on a shoestring budget. Mata has built a system that can travel over 18 miles into the sky and return images to the ground — no expensive radio equipment or licenses necessary.

Space may still be well above the ceiling of this balloon-based probe, but the pictures of black sky that its camera captures will have you feeling like a space explorer all the same.

The hardware for the build is more ordinary than you might expect. It contains an ESP32-CAM for general processing capabilities and capturing images. This is paired with rechargeable batteries, a charging circuit, and a DC-to-DC converter that increases the battery’s voltage.

The ESP32 may have plenty of wireless communications options, but Wi-Fi and Bluetooth are not going to cut it from a distance of 18 miles or more. For this reason, Mata included a private mobile radio walkie-talkie. These can be used by anyone without a license. However, they typically max out at a range of around three miles. But without surface-level obstructions like buildings and trees, they have no trouble transmitting from the stratosphere to the ground.

Mata wired the microphone of the walkie-talkie directly to GPIO pins of the microcontroller. That enabled him to precisely control the audio signals it sends. In that way, information can be encoded into the transmissions, which can then be decoded at a ground station. It was through this method, specifically by using slow-scan television encoding, that images were sent from the device back to the ground.

The only thing left to do is attach the hardware to a high-altitude balloon and let it go. One drawback of this solution is that the images captured by the ESP32-CAM have quite a low resolution. But in any case, there may be no cheaper or easier way to get a view of black sky with the glow of Earth’s atmosphere below.

Be sure to check out the build guide if you want to do some exploration of your own.