SpaceX Falcon 9 Block 5 - Starlink L05 - Launching March 18, 2020
Screenshot from SpaceX Webcast of the launch of Starlink L05
Mission Rundown: SpaceX Falcon 9 B5 - Starlink L05
Written: July 20, 2021
Geoff Barreth makes poster like Mission views about Starlink L05, which is very informative
Your roof antenna needs to sit on a pole
SpaceX is targeting Wednesday, March 18 at 08:16 EDT, or 12:16 UTC, for its sixth launch of Starlink satellites. Falcon 9 will lift off from Historic Launch Complex 39A - LC-39A at NASA’s Kennedy Space Center in Florida. SpaceX will be launching 60 satellites on top of its workhorse Falcon 9 rocket.
This will be the 5th operational launch of SpaceX’s near-global satellite constellation – Starlink, which aims to deliver a fast, low-latency broadband internet service to locations where access has previously been unreliable, expensive, or completely unavailable.
After boosting the second stage along with its payload towards orbit, the first stage will perform an entry burn to slow the vehicle down in preparation for atmospheric reentry. The booster will then land 628 km downrange aboard SpaceX’s autonomous spaceport drone ship ‘Of Course I Still Love You.’ SpaceX will also attempt to recover both fairing halves with their humorously named fairing catcher vessels: ‘GO Ms. Tree‘ and ‘GO Ms. Chief.’
B1048 first flew on July 25, 2018 on the Iridium-7 NEXT mission. B1048 will, after having launched the fifth operational Starlink V1.0 L05 mission from LC-39A March 18, 2019, have completed its fifth mission thus becoming B1048-5.
This Starlink V1.0 L05 flight was also the first to reuse a fairing pair, which was recovered after the Arabsat-6A Falcon Heavy mission.
B1048 was set to again land on Of Course I Still Love You around eight minutes after liftoff. However, due to an engine failure in one of the engines involved with the reentry burns, it was lost at sea. Later it was determined that a cleaning fluid in a test pipe caught fire and destroyed the Merlins Thrust Vector Control - TVC actuator.
B1048 have launched from all three launch pads; SLC-4E twice, SLC-40 twice and LC-39A only once making this the third Falcon 9 “Hattrick” but with 5 launches.
The Payload
SpaceX plans to offer service in North America by the end of 2020 and estimates that once complete, its venture will make $30-50 billion annually. The funds from which will, in turn, be used to finance its ambitious Mars program.
To achieve initial coverage, SpaceX plans to form a net of 12,000 satellites, which will operate in conjunction with ground stations, akin to a mesh network. Furthermore, the company recently filed for FCC permission on an additional 30,000 spacecraft, which, if granted, could see the constellation amount to a lucrative 42,000. This would octuple the number of operational satellites in earth orbit, further raising concerns about the constellations' effect on the night sky and earth-based astronomy.
For more information on Starlink, watch the Real Engineering video listed below.
Each Starlink satellite is a compact design that weighs 260 kg. SpaceX developed them to be a flat-panel design to fit as many satellites as possible within the Falcon 9’s 5.2 meter wide payload fairing. 60 satellites fit into a dispenser affixed to the second stage. The entire Starlink payload weighs around 15,600 kg. That’s near the limit that a Falcon 9 can lift into LEO and still have enough propellant for landing.
For such small satellites, each one comes loaded with high-tech communications technology. There are six antennas, four high-powered phased-array and two parabolic ones that all support high-speed data throughput. Starlink also features a SpaceX built and designed star track navigation system to enable precision placement of broadband throughput.
Four inter-satellite laser links (ISLLs) allow high-speed communication between Starlink satellites. SpaceX placed two ISLLs on the front and rear of the satellite to talk with Starlink satellites in the same orbital plane. They remain fixed in position. Two ISLLs on the satellite’s sides track other Starlink satellites in different orbital planes. This means they have to move to track the other satellites.
The six launches of one testbed Starlink mission and five operational Starlink missions V0.9 L0 - V1.0 L05 brings the total number of launched Starlink satellites to 360. How many that still work, and are in orbit is no longer unknown thanks to this article.
SpaceX will assign 20 satellites to each of three orbital planes. Orbital planes are to satellites as tracks are to trains – they are orbits parallel to each other designed to maximize area coverage while minimizing the number of satellites required.
SpaceX plans to begin offering Starlink service to Canada and the northern United States later this year. Near global coverage is expected to start next year. Pricing has not been made public, but it has been hinted that speeds up to one gigabit may be possible.
Starlink’s low altitude also allows SpaceX to easily deorbit malfunctioning satellites, even if their engines fail. Although 100 km is commonly described as the upper limit of Earth’s atmosphere, there is no “hard barrier”.
Even at 550km altitude, there is still a slight amount of atmospheric drag pulling the satellites down. Each satellite’s onboard ion engine is powerful enough to keep it in orbit, but if the engine fails, it will fall back to Earth within about a year.
The miniscule atmospheric drag in low Earth orbit will help ensure that dead satellites don’t stay in orbit for long. This will help reduce the amount of space debris in orbit, which is rapidly becoming a major concern.
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