by Gerry Oberst

China experienced its equivalent of “Captain Midnight” in late June this year. Although the facts are murky, and may never be fully known, it appears that the members of the Falun Gong spiritual movement overpowered the regular feed to the Sinosat 1 satellite and broadcast a banner for several minutes on channels of China Central Television.

There are varying reports on the Chinese incident. Most of China Central Television’s 10 channels, and the same number of provincial channels on the same satellite, experienced interruption from 10 seconds up to 15 minutes, according to early Hong Kong and Australian news reports. Some even said Chinese television was disrupted for eight days, which is not credible, given the technology.

Press reports labeled this a case of “sophisticated hacking” and said this is a sign of a new level of attempts to circumvent government suppression. Regardless of who blasted the Sinosat satellite, it is hardly new, sophisticated or even hacking. The U.S. Federal Communications Commission (FCC) faced a similar deed almost two decades ago and devised a simple regulatory response.

A disgruntled college dropout with a technical bent and access to a satellite uplink transmitted the forever-famous “Captain Midnight” message from the Central Florida Teleport in April 1986. In what now seems strikingly naive, this part-time operations engineer struck a blow against pay TV, scrambling the HBO signal with a four and one-half minute message complaining about the $12.95 monthly charge.

In response, the satellite operator threatened to move Galaxy 1 into a new orbit, and in an understated way an influential politician said this act represented “a major potential threat to the nation’s entire communications system.” The FBI, brought onto the scene to track down the malefactor, soon apprehended Captain Midnight.

Ten years earlier, the FCC had suggested the idea of adopting requirements for an automatic transmitter identification system (ATIS). Within three months of Captain Midnight’s daring exploit, the FCC resurrected the idea and relying on its usual fast paced methods, adopted ATIS rules four years later.

The ATIS rule has now been in effect for more than a decade, based on a subcarrier signal carrying identification in digital format. No longer controversial or costly, it has a nice mixture of old and new technology. The rule requires automatic activation of the embedded signal in uplinks, carrying the station call sign, telephone contact number and unique serial number that the operator on duty cannot defeat, all keyed in International Morse Code that no one can read anymore. At the time, the FCC estimated the cost of each encoder to be about $2,000, which it thought was a small incremental cost to the total investment for each earth station.

Aside from the usual accidental interference, especially from satellite news gathering and other occasional space segment users, there have not been high profile reports of deliberate satellite interference in the United States since that time. Naturally, interference and jamming happens frequently in the occasional use sector, but usually by accident or incompetence rather than deliberate piracy.

Rumors abound, however, in other parts of the world. One former Eutelsat engineer said the system had no end of problems in the early ’90s when bits of the newly broken-up USSR could not agree on who were the new owners of the transponders, and so took turns uplinking at high power to take over the space segment. Likewise, Kurdish politicians experienced transmission interruptions to their satellite television channel, in the mid-’90s, blaming it on either Turkey or Iraq.

Interrupting a commercial satellite signal, however, is not an especially sophisticated issue. All it takes is a stronger signal on the right frequency and polarization. The technical chat room community noted, not long after the Chinese incident, all the Falun Gong would need is a 5-meter earth station anywhere in Asia that could see the Sinosat satellite.

Stronger encryption on the telemetry, tracking and control (TT&C) frequencies for satellites have been in place since the Captain Midnight episode to avoid future signal interruption. Loss of TT&C links would be quite a different and far more significant matter.

In any event, the Chinese incident was not really “hacking.” Although it resembles a denial of service attack in the computer jargon and some call it “information warfare,” it is not in the same league. It is not a good development in the satellite world. Nevertheless, again from the chat room community: “There is nothing new here. This is an old ‘strong signal override’ trick. These aren’t the hackers you’re looking for. You can go about your business. Move along…”