WASHINGTON – The combination of the approaching “solar maximum” and the deployment of a new generation of compact yet vulnerable satellite electronics has space weather experts gearing up their efforts to prevent disruptions to communications, navigation and other vital networks.
The 11-year cycle of maximum solar flare activity is expected to peak in 2013 or 2014. One of the largest solar flares in years hit the Earth in March, but NASA observers reported that its impact on the power grid and communications was limited based on the angle at which it hit Earth.
As the sun begins flinging greater amounts of high-energy protons, ions, ultraviolet radiation and other energetic particles towards Earth, the latest generation of satellites stuffed with compact, low-power electronics will undergo a sort of trial by fire. A fundamental problem, experts said, is that dielectric materials used to make low-power space components can be penetrated and damaged by high-energy particles cast off by the sun.
If not properly shielded, space systems used to control GPS navigation systems, for example, could be degraded or knocked out of service at the height of solar storms. (Solar flares also temporarily increase atmospheric drag on low-orbiting satellites, something NASA says is good for getting rid of space junk but bad because it reduces the lifetime of functioning satellites.)
Space weather experts concerned about the impact of the next solar maximum on satellite electronics are preparing to measure the properties of a highly-charged space environment while gauging the effects of the next wave of space weather on the latest generation of satellites.
The take-away for me, from the NASA video, was that there's a tradeoff with CO2 (and NOx) that I was previsouly unaware of. An "inconvenient truth" for Al Gore, essentially.
As much as CO2 might act as a greenhouse gas inside the atmosphere, it also shields Earth from these solar storms. Which says to me, there's a balance between heat allowed in from the sun, and heat kept in.
Don't know exactly what the sensitivity of this mechanism is to CO2 levels. It would be really nice to see some of this "bigger picture" get some of the usual press hype.
As to the effect on electronics in space, these have been well known for some time, I think.
We saw something of a corollary to this problem during the powered descent of Curiosity on Mars on Aug. 6. The rover carried two wind sensors on "mini-booms". In the folded position on the rover's deck, one of the mini-booms was exposed to blast.
You guessed it: It eventually failed, most likely because one of its boards was damaged by Mars dust or pebbles kicked up by the rocket motors on the sky crane. The guys at JPL should be anticipated this, and put extra shielding on the exposed mini-boom.
So far, it's about the only thing they got wrong. The dust covers used to protect Curiosity's camera lenses all worked. The scientist in charge of the high-res camera said the other day that, for the engineers, the landing was "7 minutes of terror," but waiting to see whether the lens on her camera was protected from rocket blast was "30 days, or [Martian] sols, of terror...."
This is old news for people in the business. The problem is all the "smart guys" who run some risk analyses and convince themselves that their COTS-cobbled payload (the bus guys, they're not so risk tolerant) will meet the mission success probability number, and sell that story to the program watchdogs and the insurance company, and launch brittle junk that fails as soon as one assumption is invalidated. Such as, when your once-a-decade LET=80 ion shows up the first week you're on orbit and you sold the story that parts that latch up only over LET=40 have an acceptably low probability of it happening. Then your power supply fries and your billion dollar bird commences to tumble uselessly.
You can't afford to loft enough shielding to take the critical particle rate to zero. The parts have to be good if you need certainty. But too many folks would rather believe the statistics (because it makes the cost story work), never mind that your sample size is one when you get down to the care-about and that one is damn expensive. 3/4 the cost and dead before payback is not a winner, but the jokers who make that call will be promoted, with any luck, before the proof comes back to earth in a flaming ball of space junk.
If it is important, it better be shielded. Let's also hope watchdogs are in place to properly manage the devices (i.e. keep from going out of control) in the event that they don't experience a fatal blast, but only experience a temporarily disruptive blast. Interestingly, I saw a recent article about NASA planning to send up some cheaper satellites contolled by Android Phones (small in size and limited in scope).
Aside from purpose-built short life satellites why on earth would any responsible satcom or science satellite builder NOT use rad hardened systems and components??? If those designers think that COTS is the solution for all applications then they should find a different job...
Join our online Radio Show on Friday 11th July starting at 2:00pm Eastern, when EETimes editor of all things fun and interesting, Max Maxfield, and embedded systems expert, Jack Ganssle, will debate as to just what is, and is not, and embedded system.