Student Amish Ralhan (UCL Electronic & Electrical Engineering), and his group won first prize for ‘Best Use of Hardware’ at the NASA 2014 International Space Apps challenge. Their project, named Android Base Station, allows smart phones to become wifi hotspots by connecting to satellites using a 3-D printed robotic arm. This automated, ultra-portable, satellite tracking station can log the changes in micro-satellites in orbit, and automatically use one offering the cheapest bandwidth.
The International Space Apps Challenge is a two-day hackathon where teams of technologists, scientists, designers, artists, educators, entrepreneurs, developers and students across the globe collaborated and engaged with publicly available data to design innovative solutions for global challenges. The competition took place at 95 locations around the world where more than 8,000 participants developed software, hardware, data visualizations, and mobile or web applications for the challenge that contributes to space exploration missions and help improve life on Earth.
Mr Ralhan’s group took on the ‘Phone sat – convert your smartphone into a satellite’ challenge. They noticed that the cost of satellite bandwidth varies a lot depending on the connection. The easiest, most expensive and slowest is geo-stationary. These far away satellites need only a fixed dish to access from Earth, but are expensive to put into space and have a lot of demand. The next busiest are those orbiting around the equator: they require a dish with one motor to track their orbit, are less expensive but still in high demand. The team proposed using the satellites in polar orbit. As the Earth is turning at 90º to their orbit, tracking these sources requires a dish that can point in any direction: this makes them under used and the cheapest source of bandwidth in inhabited latitudes.
Amish and team designed a solution where a user connects a satellite tracking device to an Android phone, which orients itself using its internal digital compass, GPS and gyroscope. Consulting a list of satellites, it finds the cheapest bandwidth available, and the 3D printed dish is pointed at the satellite for a final calibration. Now the phone can connect to the satellite, becoming a wifi hotspot that automatically switches to the cheapest satellite data connections at they appear over the horizon.
This project was created in three main parts: a database, stored on a server, of usable satellites, an Android phone application that uses a copy of the database to find a target to connect to and a pocket-sized, 3D printed robotic arm to automate tracking the moving target with any commercially-available small satellite modem antenna. Amish was responsible for building the robotic arm and programming the microcontroller that controls it.
“None of our team knew what we were going to build when we arrived at the SpaceApps challenge. During the sign-in, surrounded by pre-made groups that had organized in advance on-line, I was one of the loners only just starting to think of a problem to solve. Someone mentioned that satellite bandwidth was expensive and a price comparison service would be useful to someone – this statement turned into a group in search of a table to work on.
For there to be innovation, people need the freedom to try and fail. Events like the SpaceApps hack-a-thon are environments where strangers can come together to put together open data, re-usable micro-controllers and a few pence of 3D printed plastic parts to see if they can solve a problem. For a few, a hack-a-thon will result in winning: the rest get one of the best learning experiences you could hope for.
I am really excited to visit the NASA headquarters this autumn and experience one of the satellite launches. It’s like a dream come true!”
All work generated as part of this project is open source. The 3D printed physical tracker design is software-generated, so users customize the design according to the motor and modem they will be using.