posted 07-16-2023 10:23 AM               

Space Cover 710: Marisat - First Dependable Maritime Communication

Today we all take our cell phones for granted. We can make a call from almost anywhere in the world and instantly get connected. But what if you were on a ship in the middle of the ocean? With the many communication satellites in orbit today it is even easy to make a phone call from the middle of the ocean. This wasn't always the case. Sometimes ships would be out of communication with shore stations for up to 48 hours. Message delays could sometimes be almost 12 hours from sending to receiving.

It wasn't until the Marisat satellites were launched in 1976 that there was finally a reliable communications network for commercial shipping vessels. Hughes Aircraft built three Marisat satellites under contract with Comsat Satellite Corporation. These were to be launched on Delta rockets from Cape Canaveral and placed in geostationary orbit with one satellite over each ocean. In 1981, Inmarsat took over control of the Marisat system and provided the base for the Inmarsat network in use today for maritime communications.

All three Marisat satellites were highly successful and operated into the 1990's before being retired and placed in graveyard orbits. In fact, Marisat-2 was moved in its orbit in 1999 to provide communications for the Amundsen-Scott Research Station at the South Pole. It was finally retired in 2008 after 32 years in service. To date, it is the longest serving communications satellite.

The covers pictured are for each of the Marisat launches. Marisat-1, placed over the east Atlantic Ocean is postmarked at Patrick AFB has a Bob Whitney cachet. Marisat-2, placed over the Pacific Ocean is postmarked at Cape Canaveral and has a Space Voyage cachet. Marisat-3, placed over the Indian Ocean is postmarked at Cape Canaveral and also has a Bob Whitney cachet but in a different color which was quite common for Bob to do.

posted 07-21-2023 11:29 AM               

Unfortunately, I did make an intentional error of using a different satellite artwork as part of the cachet graphics. At the time, I didn't have a specific Marisat satellite cachet available, so I diverted to using a prior-used but different satellite likeness.

The word COMSAT, also used as part of the rubber stamp impression, was though directly related to the Marisat program as an operating company of the nearly 1,500-pound synchronous satellites that had been used for commercial shipping at sea and by the U.S. Navy.