Sun day soon - solar storm solutions for aviation

Materials World magazine
,
29 Oct 2012

How can the aviation industry cope in the face of a solar storm? Michael Bennett went along to the Institute of Engineering and Technology to find out.

 

After a period of relative calm, this year the sun began a new cycle that is forecast to be much more lively. This could mean solar storms that have untold consequences for the electrified modern world.

Engineers, academics and space scientists gathered at the Institute of Engineering and Technology in London in September, to discuss how society would cope with such an event and look at possible ways to protect infrastructure.  

The sun’s behaviour can be unpredictable and result in one-off phenomena, such as solar flares, coronal mass ejections (CMEs) and geomagnetic storms. Previously something of a fringe topic, the issue of space weather has now been formally added to the UK Cabinet Office’s National Risk Register of natural emergencies, and sits in the same risk bracket as extreme hot and cold weather scenarios.  

Professor Mike Hapgood, Head of Space Environment Group at Rutherford Appleton Laboratory in Oxfordshire, UK, explained how the largest known solar flare, the Carrington Event of 1859, caused communications problems even though the use of telegraph systems was only in its infancy. Although the use of optic fibre in telephone lines would preclude the same type of disruption now, he highlighted how the rest of society, from food supplies to banking and transport, is now predicated on electrical systems, making the impact much more severe.  

Although most space weather since the Carrington Event has been fairly inconsequential, Hapgood drew attention to events in July 2012, when a huge CME appeared out of the west side of sun, causing a storm that missed Earth by nine days. ‘The danger is something like this hitting Earth and stirring up a major storm,’ he said.  

Captain Bryn Jones, a pilot for Virgin Atlantic, discussed the potential impacts on commercial air travel, pointing out that although the majority of aeroplanes currently flying use inertia reference systems that are independent from outside sources, future systems will use GPS, which is more susceptible to interference from space weather. ‘The more technology we deploy, the more we increase our vulnerability,’ he said. Keith Ryden from Qinetiq, based in Farnborough, UK, agreed, pointing out that aircraft hydraulics are now being replaced by electronics. ‘Mosfet (metal-oxide-semiconductor field-effect transistors) can fail quite completely in a neutron storm. They literally pop. The most important thing is to obtain goal test data on the chips, but that is expensive at the moment.’  

Meanwhile Stuart Eves, Lead Mission Concepts Engineer for UK-based company Surrey Satellite Technology, offered some insight from a stakeholder’s perspective. He outlined the problems solar storms can cause for satellites, such as wiping them of data, reducing the charge capacity of solar panels or even just temporarily disorientating them, all of which are costly to the owner.  

Engineering around these unpredictable and rare events poses a challenge to equipment designers, and Eves discussed some possible materials solutions. Shielding would be an obvious one, he said, but ‘In general we are keen to not just add material to spacecraft – non-functioning dead mass makes it heavier’. He gave the example of a current satellite that was made by his company, the Galileo In-Orbit Validation Element, which receives adequate shielding from 4mm of aluminium.  

Another problem for designers is that because of their rarity, little data exists about solar storms. ‘It’s a catch-22 situation,’ said Eves. ‘We win a contract to build a satellite, then when we start thinking about how to build it, we wonder what the radiation environment is – but we don’t know. That’s what we are being sent up there to investigate.’  

Most attendees agreed that more information is a priority. ‘I don’t think we are doing very well at correlating space weather models,’ said Rami Qahwaji, Professor of Visual Computing at the University of Bradford, UK. He added that with different industries needing different types of data, closer collaboration between science and industry, and more active information sharing, could help the sector prepare for the eventuality of a serious solar storm.