High fliers - the story of Tim Peake and Astro Pi

By Russell Barnes. Posted

British ESA astronaut Tim Peake won’t be the only Brit aboard the International Space Station next year. David Crookes looks at how the Pi got into the sky and what it means for future generations

Today, British ESA astronaut Tim Peake made history as the first British astronaut to visit the International Space Station. For the next six months, he will achieve most children’s dreams as he lives and works 400 kilometres above the Earth to carry out a comprehensive science programme during a mission called Principia.

The full feature can be read in The MagPi 40

His role will be to run experiments using the unique environment of space and to try new technologies that may become crucial when humans begin to visit other planets such as Mars. But he will not be alone. Aside from living with five international colleagues, all of whom have spent years training for their difficult roles, Tim will be greeted by another Brit – one set to accompany him throughout his time away from Earth.

That extra ‘colleague’ will, of course, be the British‑made Raspberry Pi which are already waiting on board the ISS. Two Raspberry Pis were flown skywards on a Cygnus cargo freighter last week, going ahead of Tim thanks to a lack of room on the Soyuz flight. But it means the computers are all ready to be unboxed by the time Tim arrives. And then the fun and games can begin.

 Tim's British partner in science when he's up in the International Space Station

The Raspberry Pi’s space adventure is referred to as the Astro Pi mission and, while it hasn’t been an easy ride for those involved, it is certainly set to be rewarding. That’s because the computers have been equipped with an expansion sensor board called the Sense HAT, and have been placed inside a cutting-edge aerospace case that has been built to withstand any conditions space will throw at it. As well as allowing the Raspberry Pi to measure the ISS’s environment, follow its journey through space, and pick up the Earth’s magnetic field, it will give schoolchildren the chance to have their code run in space for the first time ever. And that, says Tim, is proving to be most exciting of all.

“[Astro Pi] has got a great sensor suite with temperature, pressure, humidity sensors, all sorts of things on it,” he told BBC television’s The One Show following the final press conference on 6 November. “So, the schoolkids basically coded programs that I’m going to run on board the Space Station, and this Astro Pi is going to be in various different modules running an experiment each week. I’m going to send down the data so that during the mission they can see [it], see what they’ve managed to achieve, and if they need to modify the code, they can send it back up to me.”

The Astro Pi was the brainchild of the UK Space Agency and the Raspberry Pi Foundation, although it was, according to David Honess, the Foundation’s education resource engineer, “a case of being in the right place at the right time”. Libby Jackson, the UK Space Agency’s astronaut flight education programme manager, was looking at ways to encourage children to think about the applications for space and the ISS. “When I was applying for my current role, the candidates were asked to prepare an idea for an activity that could inspire kids and at the time I knew about the Raspberry Pi,” she says. “I didn’t take that idea to the interview because I didn’t know enough and I was afraid I’d be asked questions I couldn’t answer.”

 Home for the next six months

The idea remained with her and when she was talking with UK Space, the UK space industry’s trade association, she confessed she couldn’t shake away the idea of having fun with the Raspberry Pi. “As it happened, someone mentioned that they had been talking to Eben Upton, the CEO of the Raspberry Pi Trading company, and so had a point of contact. A meeting was quickly set up,” she says.

The momentum began building solidly. At this time, David had just begun working with the Raspberry Pi Foundation and Eben had sent a casual email asking if anyone fancied accompanying him to a meeting with Airbus Defence and Space. David volunteered and found that Dr Stuart Eves, Airbus’s lead mission concepts engineer, was a passionate advocate of the Raspberry Pi. This resulted in the Pi Foundation being hooked up with Libby at the UK Space Agency: “We ended up in a meeting with the UK Space Agency and Tim Peake’s mission was on the table…”

A decision was soon taken to exploit the possibilities of that mission as much as possible, and so the idea of a competition to engage schools was seized upon. The belief was that it could doing,” explains David. “And we feel this is part of the answer.”

Once the go-ahead had been given, it was time to work out how the project would run. For Libby, the aim was to attach as much as possible to the Pi – “I knew the history of getting education payloads on the ISS,” she explains, hinting at the difficulties – but the problem was the tight schedule they had to work with. The Astro Pi mission was being put together around a year before the expected flight, so there was never going to be enough time to invite children to come up with an experiment and make it fly. “We turned things on their head and said if we fly the hardware as it exists and ask the kids what we should do with it, that would help in terms of time,” Libby continues. “It seemed the perfect solution.”

Pi in the sky

It is not the first time a bare-bones computer has gone into space (and it’s not incidentally the Pi’s debut either, given Dave Akerman’s efforts in strapping Pis to high-altitude balloons and taking snapshots from the edge of space). But while Arduinos were the first to boldly go where no other widely accessible device had gone before (on to satellites orbiting the Earth), Astro Pi was created to be different.

“Never before have we had a situation where the crew of the space station are using the same machine as your kids,” says David. “But this is that time: we created the Sense HAT add-on board for the Pi and we challenged schools to come up with computer science-based experiments that Tim would run on the space station.”

The response from schoolchildren amazed everyone, not only in the quantity of entries but in their quality. There were stories of children coding during their lunch breaks and working after school. The chance of having their code in space was proving to be a great motivator, and narrowing the experiments down to just seven winners proved tricky. “It came down to the completeness of the ideas and the quality of the coding,” reveals Libby. “The things the kids came up with are far more creative than adults.”

 Training for the big day

Indeed, the winners are certainly impressive. The Cranmere Code Club run by teacher (and The MagPi writer) Richard Hayler at the Cranmere Primary School tests the humidity surrounding Astro Pi. If fluctuation is detected, it is a possible indicator that an astronaut has come close, so the Pi will deliver a message on its 8×8 LED screen and take a photo via the camera, hoping to snap one of the ISS crew in action. “They are looking to see if humidity is a good indictor of the presence of the crew near the Astro Pi,” David explains.

SpaceCRAFT is equally ingenious, with Hannah Belshaw from the Cumnor House Girls School suggesting using the output as a CSV file from the Astro Pi sensors within Minecraft so that the environmental measurements are represented in the game. “SpaceCRAFT logs all sensors to fill a massive CSV file and it works with code on the ground that plays it back in Minecraft,” says David. Hannah dressed in a spacesuit to appear alongside Tim during his BBC interview.

One particular favourite among those involved with Astro Pi is Flags, created by Thirsk School under the watch of teacher Dan Aldred. The program uses telemetry data and the Astro Pi’s real-time clock to work out the ISS’s location. It searches its database to find the relevant flag and displays it on the screen with a phrase in the local language.

“It’s lovely because the children have looked and thought about where the astronauts are in the world,” says Libby. David agrees. “The crew will like it,” he made the code recognise the boundaries of different countries. If it’s above the sea, it shows a twinkly blue or green pattern.”

Watchdog, by Kieran Wand at Cottenham Village College, makes good use of the Astro Pi sensors by measuring the temperature, pressure, and humidity on board the ISS, raising the alarm if they move outside acceptable parameters. Trees, by EnviroPi – a team at Westminster School – points the NoIR camera on the Astro Pi out of the window and allows it to take images of the ground, after which it can produce a Normalised Differentiated Vegetation Index (a measure of plant health).

Radiation, by the team Arthur, Alexander, and Kiran, overseen by Dr Jesse Peterson at Magdalen College School, uses the Camera Module of the Pi to detect radiation, measuring the intensity of tiny specks of light. But there is always time for fun, and so Lincoln UTC’s Team Terminal, with teacher Mark Hall, have produced a suite of reaction games, together with a menu that the astronauts can use to select the one they fancy playing at that time.

Tim’s role

Tim will be able to move between these experiments via an app on board the Astro Pi, called the Master Control Program (a nod to the 1982 movie Tron). But he doesn’t have to keep checking it. The programs can run automatically. “There is a clock icon which will run program X for a set period,” David explains. “It ensures the programs are run for the right amount of time.”

 Tim Peake (far right) attends the final press conference before launch

Indeed, schedules have been specified, defining how many seconds each experiment should run for. “He can use the joystick to go down to the different programs and if he wants to run one, then he can press the ‘right’ button which shows an arrow on the screen and then starts that program,” says David. “The results are written to the SD card and they go into a folder called Transfer, which Tim can copy and send down to us.”

Tim will be conducting experiments of his own away from the Pi. One will involve studying metals using the on-board electromagnetic levitator, a furnace which heats the metals to 2,100°C and rapidly cools them in a gravityless environment. The removal of gravity allows for a more accurate observation of fundamental properties of different metals, alloys, and the rates of cooling.

He will also be looking at organisms placed on the exterior of the ISS to see how a lack of oxygen, extreme temperature changes, and radiation affects them. Perhaps most importantly, Tim will study the measurement of brain pressure in space. There has long been a worry that space exploration (and time on the ISS) can affect the vision of astronauts. As low gravity allows blood to rise, it increases brain pressure and pushing on the back of the eyes. Tim will help researchers at the University Hospital Southampton NHS Foundation Trust better understand the open fluid links between the brain and the ear that could form a better way of testing astronaut health.

But where does that leave the education part of his mission? “In the official world, Tim will have four hours of education activity time per expedition,” say Libby. With Tim working within Expedition 46 and 47, that equates to eight hours. It doesn’t sound a lot and Libby admits it isn’t – “in space everything floats, so we usually say work out how long it will take to do something on Earth and triple the time” – but Tim is brilliantly committed to ensuring the mission is fun for the next generation of children. To that end, he wants them to get the most out of it and share the mission. “He will spend a lot of Saturday afternoons working on education projects,” says Libby. “Astro Pi is one of our flagship education programmes and we’re looking forward to it. Education is going to be very important in Tim’s mission.”

As such, this could well be a turning point for the space industry in the UK. “Only a small number of people can be an astronaut, and that is what kids think about,” says David. “They also see space as abstract and only associate it with NASA. But we are showing the various roles and the possibilities. We’re calling it the Tim Peake effect and we hope that in five to ten years’ time we have a booming space industry [similar to the Apollo effect in the USA in the 1960s and 1970s, which boosted interest in science and engineering]. It’s a bold aim, but it’s everybody’s hope.”