Solar Flares - Vulnerability of GPS

Whilst GPS is commonly associated with satellite(ejected hot plumes of plasma and radiation from the
navigation and wayfinding, many technologies andsun), have long been known to be able to damage and
computer networks rely on the GPS satellite systemeven disable satellites.
for a source of accurate time.GPS is particularly vulnerable because of the high
GPS time servers utilise the onboard atomic clocks oforbits of geostationary satellites (some 22,000 miles
the global positing satellites and use this stable andup) this leaves them unprotected by the earth's
accurate time source as a basis for their NTPmagnetic field.
synchronisation (Network Time Protocol)However, following the recent solar activity there has
GPS has become the preferred source of atomicbeen no reported damage to the GPS system but as
clock time for many network operators. There areso many people rely on satellite navigation and GPS
other methods where UTC (Coordinated Universaltime for NTP servers could a future solar storm lead
Time) can be used; radio signals and across theto havoc on Earth?
internet to name but two sources, but none is asWell the short answer is yes; GPS satellites have
secure or readily available as GPS.been in orbit for several decades and while redundant
Unlike radio signals, GPS is available everywhere onsatellites were introduced into the system many have
the planet, is never down for scheduled maintenancebeen used up due to previous failures and it would only
and is not commonly vulnerable to interference. It alsotake a couple of disabled satellite to cause real
doesn't have any security implications like connectingproblems for the network.
across an internet firewall to an online time server can.Fortunately, help is at hand as the Europeans, Russians
However, this doesn't mean GPS is completelyand Chinese are all working on their own GPS
invulnerable as recent news reports have suggested.equivalents which should work hand-in-hand with the
It has been recently reported that a sunspot (sunspotAmerican GPS network allowing GPS receivers to
1092) the size of the Earth has flared up and apick and choose from all four GNSS networks (Global
massive coronal ejection (solar flare), described in theNavigational Satellite Systems) ensuring that even if a
press as a "solar tsunami" which was suggested to bereally violent solar storm hits in the future there will be
large enough to satellites and wreck power andmore than enough geo stationary satellites to ensure
communications grids.no loss of signal.
Solar activity, such as sunspots and solar flares