Space Weather and Satellite Phones (and Pagers)

Satellite phone availability can be adversely affected by solar flares.

While yesterday’s post addressed itself to HF and GPS, for completeness, I should have included satellite phones. I’ve worked in the space business pretty much since 1989 but began to taper off in 2003. I have seen just about every form of hype imaginable, and I have yet to see an 100% reliable system deployed. Even without solar activity, space is a hostile place.

As said, satellite phone availability can be adversely affected by solar flares. The impacts can range from simple communications quality degradations to relay satellite functional collapse (e.g., Galaxy 15). Depending on satellite and constellation design these outages can run from an irritating spate of bad quality to requiring the capitalization,  building and launching of a new satellite(s).

Satellite design robustness, hardware age, and how many satellites are in the constellation are all variables that make predicting system availability under stress difficult at best. Predicting the magnitude of a solar event more than about three days out is not with us yet. Space weather is still substantially an experimental art for all we have learned.

So when your satphone provider explains what a great back-up satphones are for HF, get out your grains of salt. When you use a satphone during a significant solar event, throw a few of those grains over the shoulder of choice.

There is no good answer for this. Very large satellite, geosynchronous transponder systems are very robust, but their constellations tend to be built on single satellites orbiting over fixed longitudes. This allows them to avoid the Van Allen Belts. but these tend to be “trunk” systems involving large ground stations. Small satellite, highly populated constellations (e.g., IRIDIUM, Globalstar, etc) which orbit in multiple inclined planes at much lower altitudes may be able to tolerate a few degraded satellites, but their complex orbits tend take them through the Van Allen regions on for short periods virtually every orbit. These Van Allen Belts get pumped up during solar events. This means that while a satellite might miss the first order impact of a flare, the residual impact of Van Allen pumping gets them.


Is there a solution? No, not one non-military subscribers can/will pay for, but do keep in mind that text services will tend to make it through when voice is too degraded to be useful. Even so, while Galaxy IV (1998) was lost to solar and other destructive phenomenology, the economic*, communications** and healthcare*** impact of the loss of text and data services was instructive.

Keep in mind satellite losses/degradations from solar activity occur frequently, but satellite operators are able to adjust for a significant majority.

For a bottom line, Robust global communications usually include HF and satphone with both SMS text and voice. But even so, one should not expect 100% availability or functionality when the Sol is flaring.

Earth-orbiting TRACE satellite, NASA

*”… such as the failure of the Galaxy IV satellite in May  1998. The failure of that one satellite left about 80-90% of the 45 million pager customers in the  US without service for 2-4 days and 5400 of 7700 Chevron gas stations without pay-at the-pump capability. This failure left employees processing credit payments with the manual system they had long since forgotten.” “PROTECTING COMMERCIAL SPACE SYSTEMS: A CRITICAL NATIONAL SECURITY ISSUE” Charles H. Cynamon, Major, USA, Air Command & Staff College,

**”The loss of this satellite was very disruptive to telecommunications in the United States. Pagers were affected greatly; service was not restored for days. Wire news services, like Reuters, were also affected. The TV network CBS had to use alternate means of transmitting its programs, as did NPR.” Wikipedia, Galaxy IV

***”Given the linkages among infrastructures, a cascading failure could well cross infrastructure boundaries, as demonstrated by the 1998 Galaxy IV satellite failure. When the PanAmSat Galaxy IV communication satellite rotated out of its orbital position in May, 1998, over 80 per cent of the digital pagers in the U.S. went off-line. Cable and broadcast transmissions were affected, as were credit card authorizations and ATM transactions. This event could have serious human impacts as many hospitals and healthcare providers in the United States faced a crisis in emergency communications when they could not page doctors and other care givers. This is particularly critical in a healthcare system which, in the quest for increased efficiency and productivity like much of the economy, relies on just-in-time service delivery. (The impacts of privatization, business reengineering, and process streamlining on infrastructure reliability and hence, service delivery, are discussed later in this paper.)” Toward More Robust Infrastructure: Observations on Improving the Resilience and Reliability of Critical Systems, Richard G. Little, AICP, National Research Council


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