DirecTV and Dish Network are the two major players. Both have been around for several years and are well established. The newcomer is Voom, offered by Rainbow DBS, a subsidiary of New York-based Cablevision Systems Corp.

Although the specifics of each service vary because of the programming packages offered, they all work generally the same way in electronically delivering television into your home.

Each using their own networks of satellites, fiber optic lines and cable systems, the direct broadcast firms gather programming from the major broadcast and cable companies to at least one central location and then transmit the signal up to specially designed, high-powered satellites orbiting 22,300 miles above the equator.

At that altitude, a satellite orbits the Earth at the same speed as the planet rotates. As seen from the ground, the satellite appears to hover in the same spot in the sky, thereby being in constant contact with an entire hemisphere. The orbit is called geostationary.

This trick of nature and technology allows satellite receiver dishes on the ground to be rigidly pointed in one direction, making it easy to build small, affordable dishes that can be attached to rooftops, a pole or even the railing on an apartment balcony. Also helping to keep dish sizes down is the high-powered nature of the signal beamed from space.

The signal is bounced from a home-user's dish and focused onto electronics at the end of a short boom. From there it is fed through wiring to one or more receivers inside the home.

The benefit is obvious: Any homeowner, no matter how far removed from civilization or the nearest cable TV junction, can receive digital quality television programming.

Case in point: The Cape Canaveral Bureau of SPACE.com is located in busy Port Canaveral, just a hop across some water from the Walt Disney Cruise terminal. But for a variety of reasons related to cost and recent construction in the area, the local cable company has not extended its service to the area.

Our building sits as an isolated island in an ocean of industrial buildings that are otherwise completely wired. For us, a direct broadcast service is just the ticket.

The situation is the same in nations such as Indonesia and Japan, where hundreds of islands make it impractical to run cable everywhere.

Millions of households all over the planet receive their television programming from space today. In the United States, according to information released by the companies, DirecTV has more than 11.2 million subscribers and Dish Network has surpassed nine million.

DirecTV came first.

Launched in June 1994, the El Segundo, Calif.-based company offers more than 225 channels. It is a unit of Hughes Electronics Corp.

A key sales advantage for DirecTV is its exclusive agreement with the National Football League to make every regional game on Sunday afternoon available to subscribers. This makes it possible for a Minnesota Viking fan who lives in Florida to never miss a game, and during timeouts see what's happening around the league.

Company officials credit the longstanding NFL deal for being a significant factor in consumers choosing DirecTV over the competition. The company reached its first million customers by the end of 1994.

Dish Network, meanwhile, continues to hold its own. Launched in December 1995, the company gained its first million customers by the end of 1997 and has since steadily grown its subscriber base.

A subsidiary of EchoStar Communications, Corp., the Littleton, Colo.-based company offers more than 500 channels of digital programming throughout the United States, including an extensive array of foreign-language programming.

The new kid on the block is Voom, which just recently rolled out its hardware and program offerings following the launch earlier this year of the Rainbow 1 direct broadcast satellite.

Cablevision already provides traditional cable television service to three million households in the New York City area and other eastern locations, and now with this first satellite it hopes to provide similar programming to customers across the nation.

The key selling point for Voom, which sets it apart from both DirecTV and Dish Network, is the number of high-definition television (HDTV) channels it offers -- 39, at present count, of which 21 are exclusive, commercial free HDTV channels with original programming.

Voom also is touting 10 HDTV movie channels, plus all the usual cable channels you would expect from any provider.

Picking between the three companies is a matter of personal choice.

Voom is still new so it doesn't have a track record built up in terms of reliability and customer service.

DirecTV and Dish Network are both reliable services with nearly identical programming if all you're interested in are the basics. Sports enthusiasts might lean toward DirecTV, while those wanting to see what's on around the rest of the world might find Dish Network's foreign channels of interest.

In the interest of full disclosure, the SPACE.com office at Cape Canaveral uses Dish Network because, unlike DirecTV, the basic setup receives NASA TV. The agency channel is available on DirecTV if you purchase a more advanced dish system.

Choosing between a direct broadcast system and your neighborhood cable TV -- if you have that choice -- depends on all the usual factors of price and customer service. But there are other things to consider that you may not have thought of.

Direct broadcast systems deliver their signal in digital format, which means the picture and sound is crystal clear. But if you don't have a big TV or above average sound system, you may not notice the difference between that and regular cable.

Instead, the choice between satellite and cable is made easier depending on the number of televisions you have and your need to be able to tune different channels on each TV.

Cable can pretty much be strung to as many TVs as you want, and each can be tuned in separately. But with a satellite system, each TV needs its own receiver at an added cost.

In this writer's home, cable was available. So we have cable television wired throughout the house to keep our three pre-teen and teenage children happy. We also purchased DirecTV several years ago specifically for the NFL Sunday Ticket and, having long since paid for the hardware and met our one-year of programming requirement, only use the system now during football season.

Once the kids move out and go to college, and we only need to "feed" two televisions, we'll use DirecTV exclusively for all our standard and premium programming and cancel our cable.

The primary drawback to direct broadcast is sometimes poor reception during intense precipitation. Here in Florida, on any summer afternoon during our daily thunderstorms, we can expect the satellite signal to be lost for a few minutes during the worst of the downpour.

Moreover, friends and relatives living in Minnesota say they have the same problem with snow and must remember to shovel the satellite dish from time to time during winter. And, finally, those living among tall trees may not be able to get service. The receiver needs a direct line of site to the orbiting satellite. A retailer can answer questions about this latter limitation.

So what does the future have in store?

The industry is changing rapidly and no one can say for sure what new products and services will take hold. But the joining of space-based broadcast systems with computers and other digital recording devices such as TIVO is ready to change the way we watch television.

Combine these possibilities with broadband Internet access, improvements in wireless connectivity and widespread availability of flat panel displays -- and the possibilities seem almost as big as space itself.