The SpaceX satellite constellation is a development project underway by SpaceX to develop a low-cost, high-performance satellite bus and requisite customer ground transceivers to be used to implement a new space-based internet communication system.
SpaceX has plans to also sell satellites that use the same satellite bus, satellites that might be used for scientific or exploratory purposes
Development began in 2015, initial prototype test-flight satellites are expected to be flown in 2017, and initial operation of the constellation could begin as early as 2020.
By October 2016, SpaceX had developed test-flight satellites that they hope to launch in 2017 and they are focusing on a significant business challenge of achieving a sufficiently-low-cost design for the user equipment, aiming for something that can ostensibly install easily at end-user premises for approximately US$200.
The internet communication satellites are expected to be in the smallsat-class of 100-to-500 kg (220-to-1,100 lb)-mass, which are intended to be orbiting at an altitude of approximately 1,100 kilometers (680 mi). Initial plans as of January 2015 are for the constellation to be made up of approximately 4400 cross-linked satellites, more than twice as many operational satellites as are in orbit in January 2015
SpaceX plans to begin flight testing of their satellite technologies in 2017, with the planned launch of two test satellites, MicroSat-1a and MicroSat-1b. The satellites will orbit in a circular low Earth orbit at 625 kilometers (388 mi) altitude in a high-inclination orbit for a planned six to twelve-month duration. The sats will communicate with three testing ground stations in Washington and California for short-term experiments of less than ten minutes duration, roughly daily. Both microsats will be launched into 625 km circular orbits at approximately 86.4 degrees inclination, and will include panchromatic video imager cameras to film image of Earth and the satellite
SpaceX expects its own latencies to be between 25 and 35ms, similar to the latencies measured for wired Internet services. Current satellite ISPs have latencies of 600ms or more, according to FCC measurements.
SpaceX promises that its satellites will boast impressive bandwidth, the amount of data that can be delivered each second. That could potentially reduce or eliminate the need to impose strict limits on consumers.
“Once fully optimized through the Final Deployment, the system will be able to provide high bandwidth (up to 1Gbps per user), low-latency broadband services for consumers and businesses in the US and globally,” SpaceX told the FCC. “Subject to additional development work, SpaceX plans to design and manufacture its own satellites, gateway earth stations, and user terminals.” Home Internet customers would receive a “low-profile user terminal that is easy to mount and operate on walls or roofs.”
Each satellite will provide aggregate downlink capacity of 17 to 23Gbps, the application said. “With deployment of the first 800 satellites, the system will be able to provide US and international broadband connectivity; when fully deployed, the system will add capacity and availability at the equator and poles for truly global coverage,” SpaceX said.
Upgrades will follow
SpaceX said per-satellite bandwidth should increase periodically as the company deploys improvements. “The system leverages phased array technology to dynamically steer a large pool of beams to focus capacity where it is needed,” the company said. “Optical inter-satellite links permit flexible routing of traffic on-orbit. Further, the constellation ensures that frequencies can be reused effectively across different satellites to enhance the flexibility and capacity and robustness of the overall system.”
SOURCES – Spacex, Ars Technica, Wikipedia