Displaying items by tag: Iridium

Iridium NEXT is a planned satellite constellation, foreseen to replace the Iridium constellation.

Iridium NEXT is a second-generation worldwide network of telecommunications satellites, consisting of 66 satellites and six in-orbit and nine ground spares. These satellites will incorporate features such as data transmission which were not emphasized in the original design. The original plan was to begin launching new satellites in 2014. Satellites will incorporate additional payload such as cameras and sensors in collaboration with some customers and partners. Iridium can also be used to provide a data link to other satellites in space, enabling command and control of other space assets regardless of the position of ground stations and gateways. The constellation will provide L-band data speeds of up to 1.5 Mbit/s and High-speed Ka-Band service of up to 8 Mbit/s. The existing constellation of satellites is expected to remain operational until Iridium NEXT is fully operational.

The Iridium constellation is owned and operated by Iridium Communications Inc. 

The Iridium satellite constellation is a large group of satellites providing voice and data coverage to satellite phones, pagers and integrated transceivers over Earth's entire surface. The company Iridium Communications Inc. owns and operates the constellation and sells equipment and access to its services.

The constellation operates 66 active satellites in orbit to complete its constellation and additional spare satellites are kept in-orbit to serve in case of failure. Satellites are in low Earth orbit at a height of approximately 485 mi (781 km) and inclination of 86.4°. Orbital velocity of the satellites is approximately 17,000 mph (27,000 km/h). Satellites communicate with neighboring satellites via K_a band inter-satellite links. Each satellite can have four inter-satellite links: two to neighbors fore and aft in the same orbital plane, and two to satellites in neighboring planes to either side. The satellites orbit from pole to pole with an orbit of roughly 100 minutes. This design means that there is excellent satellite visibility and service coverage at the North and South poles, where there are few customers. The over-the-pole orbital design produces "seams" where satellites in counter-rotating planes next to one another are traveling in opposite directions. Cross-seam inter-satellite link hand-offs would have to happen very rapidly and cope with large Doppler shifts; therefore, Iridium supports inter-satellite links only between satellites orbiting in the same direction.