STEAM: How professors built a spaceship to finally unlock the secrets of the Sun

'My instruments, they kind of sniff out the exhaust coming from the Sun'

Monday, 4th July — By Tom Foot

solar

The Solar Orbiter [European Space Agency]

AT the centre of our solar system, more than 100 million miles away from Earth, a spacecraft no bigger than a milk cart is shedding new light on the mysteries of our Sun.

The Solar Orbiter may be a long way from home but some of its key instruments were designed and built here, by scientists at University College London in Bloomsbury.

One of the university’s top physics experts spoke to the New Journal this week about the pioneering project that was 20 years in the making and how the data beamed back is causing “a great deal of scientific head-scratching”.

Professor Christopher Owen said: “Over the years we have built instruments for many major space missions; to Saturn and Jupiter, visiting comets and most of the Solar System bodies, now dropping in close to the Sun. We have really big telescopes looking at dark matter and also mapping the Milky Way.”

The Solar Orbiter – the most complex scientific laboratory ever to have been sent to the Sun – is trying to understand what is going on at its edges.

The UCL instruments measure the sun’s “exhaust” and also how it creates what experts call “space weather”, while beaming breathtaking images and films back to “giant dishes” on Earth.

Professor Owen said: “The Sun provides light and warmth and we wouldn’t be here without it. But it also emits charged particles that make up the solar wind – and they are very volatile. This affects the space around the planets and particularly the Earth.

“We’ve known injections from the Sun to have wrecked spacecraft and disrupt electricity substations. The interaction between the solar wind and the Earth is called space weather.

“My instruments, they kind of sniff out the exhaust coming from the Sun.

“We are trying to get a feel for what’s happening in that engine room. If you want to think about what we are doing try to imagine you we’re looking at waves coming up to the beach and you wanted to try and find out why they are coming in like that from the ocean.”

Professor Owen and, below, an image of the Sun [UCL]

He added: “As the data comes in there is a lot of scientific head-scratching going on now with us trying to understand what all this means.”

The space adventure has been 20 years in the making but the orbiter only reached the Sun just before the lockdown in 2020.

Professor Owen said because of virus rules he had been “communi­cating and commanding instruments on the spacecraft often on the outside of the Sun, from my son’s nursery”, adding: “Because everyone was locked out of the command centre, we had to be watching a screen in Germany through a webcam facing their computers.”

It can take 30 minutes for a signal to transmit back to the Earth onto “big dishes 10 metres wide”, mainly in Argentina, eight hours a day.

In March, the solar orbiter took its closest approach yet to the Sun – known as “perihelion” – taking the clearest ever shots of the Sun and revealing unexplored regions of its polar regions.

The Sun’s temperature can be 15 million degrees at its core ranging to 5,500 degrees at its surface. The orbiter’s heatshield has been made to withstand 500 degrees.

Professor Owen’s father was a draughtsman who designed equipment for mines while he was the first person in his family to go to university.

He agreed there was an unquestionable romance to deep space exploration, but the reality was that a scientist’s day to day could be quite mundane.

“We as scientists saw what it was that was needed to be measured. A whole bunch of people created the instruments and spacecraft. It’s working and as scientists now we need to close that loop by answering all those questions that were asked 20 years ago.

“People come to me and say it’s all so incredible, and I do think yes it is a little bit different now that you mention it. But generally it just feels really like what we do, it’s normal.

“Also, it comes with its fair share of headaches. For example, once you launched it – it’s gone, you can’t fix it. There is so much paperwork beforehand. You have to prove it’s going to work – so much of it is just form-filling. Trust me there is some aggravation when you are filling out another ‘product assurance question­naire’.”

Professor Owen said he had fallen into his field “almost by accident” and felt like he had “randomly wandered to where I am without really making any [career] decisions”.

He said: “When I was 13, I messed up my chemistry exams and dropped that – but somehow came top of the year in physics. I had a few job offers after university but nothing I fancied, so I took this PhD in space physics. I haven’t managed to leave university yet.”

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