CAPE CANAVERAL, Fla. -- A pair of communication satellites are ready to be launched into orbit today from the edge of a South American jungle riding atop an Ariane 4 rocket.

Liftoff from the Guiana Space Center in Kourou, French Guiana is expected between 7:16 and 7:58 p.m. Eastern Daylight Time (23:16 to 23:58 GMT).

Arianespace officials in Washington, D.C. report this morning that everything is on track for an on-time blastoff tonight.

Flying inside the Ariane 4 rocket's nosecone will be spacecraft built for companies based in Brazil and Egypt.

Brasilsat B4 was made by Hughes Space and Communications in the United States and will be operated by Embratel to provide Brazil with voice and data-relay services.

Nilesat 102 was made by the European consortium known as Astrium and will be operated the Egyptian firm Nilesat, providing direct broadcast, as well as digital television programming to users in northern Africa.

Today's scheduled launch will be the fifth for Arianespace this year and features the model of the Ariane 4 that uses two liquid-fueled strap-on boosters added to its first stage.

The launch vehicle's mission is expected to last less than a half-hour, with the separation of Brasilsat B4 targeted 21 minutes and 25 seconds after launch, followed moments later by the separation of Nilesat 102 at 26 minutes and 14 seconds after launch.