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Starlink Satellite Constellation of SpaceX

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Starlink is a satellite constellation development project underway by SpaceX, to develop a low-cost, high-performance satellite bus and requisite customer ground transceivers to implement a new spaceborne Internet communication system.

SpaceX has said it will offer speeds of up to 1 Gbit/s, with latencies between 25 ms and 35 ms. Those latencies would make SpaceX's service comparable to cable and fiber, while existing satellite broadband services have latencies of 600 ms or more, according to FCC measurements.

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Figure 1: Starlink constellation logo (image credit: SpaceX)

Some background: In November 2016, SpaceX filed an application with the FCC (Federal Communications Commission) for a license to operate a constellation of 4425 non-geostationary satellites (NGS) in orbits ranging from 1100 and 1300 km. However, when they issued their regulatory filings in 2017, the plan called for the deployment of nearly 12,000 satellites in Low Earth Orbit (LEO). 1)

However, competition from other satellite internet providers forced SpaceX to expedite their plans. By the Fall of 2018, the company announced a new plan to deploy their first batch of 1600 satellites to a lower altitude at 550 km. The development team also introduced a simplified design so that the first batch would be ready to go no later than the June of 2019.

Rather than broadcasting in two bands ("Ku" and "Ka"), the simplified design of the first batch will broadcast only in the "Ku" band. At present, SpaceX hopes to launch 2200 satellites in the next five years, which will act as a sort of prototype while the company develops an improved design for full-scale production.

Eventually, this will result in a constellation that offers the kinds of performance outlined in the company's original plan. This presents numerous challenges, not the least of which is the fact that they will need to conduct launches every month for the next five years, averaging 44 satellites per launch.

Second, there's the matter of attrition, as satellites will begin to deorbit after a few years and SpaceX will need to replace them regularly in order to maintain its constellation. In fact, Hugh Lewis – the UK Space Agency's representative on the Inter-Agency Space Debris Coordination Committee – recently stated that in order to maintain a constellation of just 4425 satellites, SpaceX will have to launch that many every five years.

However, SpaceX intends to use this to their advantage by gradually replacing inactive satellites with ones that offer superior performance. In this way, the constellation will gradually be upgraded with the addition of heavier satellites that are capable of transmitting more information, and which are placed in longer-lasting, higher orbits.

SpaceX will also need a lot of production space if they are going to meet even the more modestly-sized constellation of 4425. While the company has commenced converting one of their Starlink buildings into a prototype production facility that will assemble the first few dozen satellites, this is merely a fraction of what they will need in the long run.

Starlink is also going to be seeing competition in the coming years thanks to companies like OneWeb and Telesat, which plans to create smaller constellations that will offer service by 2021. Tech giants like Amazon and Samsung have also announced plans to deploy their own constellations, which would consist of 3,236 to 4600 broadband satellites, respectively.

 

Spacecraft

Designed and built upon the heritage of Dragon, each spacecraft is equipped with a Startracker navigation system that allows SpaceX to point the satellites with precision. Importantly, Starlink satellites are capable of tracking on-orbit debris and autonomously avoiding collision. Additionally, 95 percent of all components of this design will quickly burn in Earth's atmosphere at the end of each satellite's lifecycle—exceeding all current safety standards—with future iterative designs moving to complete disintegration. This mission will push the operational capabilities of the satellites to the limit. SpaceX expects to encounter issues along the way, but the lessons learned here are key to developing an affordable and reliable broadband service in the future (Ref. 10).

The satellite description will be added when it becomes available.

 


 

Development status of Starlink

• May 11, 2019: SpaceX CEO Elon Musk has published the first official photo of the company's near-final Starlink design and confirmed that Falcon 9 will launch a staggering 60 satellites into orbit. 2)

- Known internally as Starlink v0.9, this mission will not be the first launch of operational satellites, but it will be the first internal SpaceX mission with a dedicated Falcon 9 launch. Additionally, the payload will be the heaviest yet launched by SpaceX, signifying an extraordinarily ambitious first step towards realizing the company's ~12,000-satellite Starlink megaconstellation.

- Put simply, SpaceX's Starlink v0.9 launch is extremely unique for several reasons. Aside from the unprecedented step of launching 60 spacecraft weighing ~13,000 kg on a developmental mission, both the form factor of each satellite and the style of dispenser/payload adapter has never been seen before. SpaceX appears to have settled on a square dispenser with four separate quadrants for satellites. The satellites themselves look truly bizarre – it's actually difficult to discern where one spacecraft stops and the next begins.

- Nevertheless, it appears that each Starlink satellite is a relatively thin rectangle, possibly with a squared top and bottom. It's also possible that they are all around rectangular and that the dispenser instead has two main sections. Either way, the very fact that the Starlink v0.9 payload can scarcely be parsed into recognizable satellites is thrilling. Aside from the rise of smallsats and cubesats, satellite design and engineering has been relatively stagnant for decades, particularly with respect to form factors and structural layouts. Most modern satellites are simply squarish boxes with electronics inside and payloads bolted on the outside.

- Despite using the same exact Falcon fairing that has been standard for years, SpaceX has managed to cram 60 spacecraft – each weighing around 227 kg into just the bottom two-thirds of the fairing, leaving a considerable amount of unused volume for future expansion.

- According to President and COO Gwynne Shotwell, Starlink v0.9 satellites are extremely close to SpaceX's true final design. However, they are still considered by SpaceX to be a "test batch" of satellites and do not have the optical (laser) interlinks that will be a critical part of Starlink's unique constellation design.

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Figure 2: The second phase of Starlink testing – 60 advanced satellites – stacked in a single fairing (image credit: SpaceX)

• April 30, 2019: The FCC has granted a request by SpaceX to begin launching spacecraft for the company's Starlink broadband network to a lower orbit than originally planned, overruling protests by competitors and clearing a major regulatory hurdle before the launch of the first batch of Internet satellites from Cape Canaveral in May. 3)

- The regulatory commission approved SpaceX's proposal Friday to fly more than 1,500 of its Starlink satellites at an altitude of 550 km, instead of the 1,150 km orbit originally planned.

- "This approval underscores the FCC's confidence in SpaceX's plans to deploy its next-generation satellite constellation and connect people around the world with reliable and affordable broadband service," said Gwynne Shotwell, SpaceX's president and chief operating officer. "Starlink production is well underway, and the first group of satellites have already arrived at the launch site for processing."

• April 8, 2019: SpaceX has announced a launch target of May 2019 for the first batch of operational Starlink satellites in a sign that the proposed internet satellite constellation has reached a major milestone, effectively transitioning from pure research and development to serious manufacturing. 4)

- R&D will continue as SpaceX Starlink engineers work to implement the true final design of the first several hundred or thousand spacecraft, but a significant amount of the team's work will now be centered on producing as many Starlink satellites as possible, as quickly as possible. With anywhere from 4400 to nearly 12,000 satellites needed to complete the three major proposed phases of Starlink, SpaceX will have to build and launch a minimum of ~2200 satellites in the next five years, averaging 37 high-performance, low-cost spacecraft built and launched every month for the next 60 months.

- Despite the major challenges ahead of SpaceX, things seem to be going quite smoothly with the current mix of manufacturing and development. As previously reported on Teslarati, SpaceX CEO Elon Musk forced the Starlink group through a painful reorganization in the summer of 2018, challenging the remaining leaders and their team to launch the first batch of operational Starlink satellites no later than June 2019. As a consequence, a sort of compromise had to be reached where one additional group of quasi-prototype satellites would be launched before settling on a truly final design for serious mass-production.

- According to SpaceX filings with the FCC, the first group of operational satellites – potentially anywhere from 75 to 1000 or more – will rely on just one band ("Ku") for communications instead of the nominal two ("Ku" and "Ka"), a change that SpaceX says will significantly simplify the first spacecraft. By simplifying them, SpaceX believes it can expedite Starlink's initial deployment without losing a great deal of performance or interfering with constellations from competitors like OneWeb.

• On 16 November 2018, the US Federal Communications Commission (FCC) announced it had authorized SpaceX to launch 7,518 satellites, adding to 4,425 satellites it has already approved. 5)

- None of the satellites has launched yet. SpaceX has six years to put half in orbit, and nine years to complete the satellite network, according to FCC rules.

• On 1 April 2018, SpaceX received US approval to launch 4,425 LEO (Low Earth Orbit) satellites, a key milestone in its plan to offer broadband with high speeds and low latency around the world. 6) 7)

- The FCC (Federal Communications Commission) issued an order approving SpaceX's application with some conditions. SpaceX intends to start launching operational satellites as early as 2019, with the goal of reaching the full capacity of 4,425 satellites in 2024. The FCC approval just requires SpaceX to launch 50 percent of the satellites by March 2024, and all of them by March 2027.

- "Grant of this application will enable SpaceX to bring high-speed, reliable, and affordable broadband service to consumers in the United States and around the world, including areas underserved or currently unserved by existing networks," the FCC order said.

- SpaceX's network (known as "Starlink") will need separate approval from the ITU (International Telecommunication Union). The FCC said its approval is conditioned on "SpaceX receiving a favorable or 'qualified favorable' rating of its EPFD (Equivalent Power Flux-Density) limits demonstration by the ITU prior to initiation of service." SpaceX will also have to follow other ITU rules.

• February 22, 2018: SpaceX has launched with the debuting of an upgraded payload fairing for the Falcon 9 rocket during Spain's PAZ satellite lofting from Vandenberg Air Force Base. The launch carried the first two demonstration satellites for SpaceX's own satellite internet constellation. The launch occurred at an instantaneous launch opportunity at 06:17 Pacific Time (14:17 UTC) on 22 February 2018. 8)

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Figure 3: SpaceX's first two Starlink prototype satellites are pictured here before their inaugural launch, showing off a thoroughly utilitarian bus and several advanced components. They were launched as secondary payloads with the Spanish radar observation satellite (PAZ) on a Falcon 9 rocket from Vandenberg Air Force Base, California. SpaceX called these two prototype Starlink satellites, Tintin-A and Tintin-B (image credit: SpaceX)

 

Launch: The first flight of SpaceX's Starlink satellite constellation launched on 24 May ,2019 (02:30 UTC) with the twice-flown Falcon-9 rocket from SLC-40 (Space Launch Complex-40) at Cape Canaveral Air Force Station, Florida. The Falcon vehicle contained a payload of 60 minisatellites, each with a mass of 227 kg. 9) 10)

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Figure 4: Image of the first launch of SpaceX's Starlink satellite constellation on 24 May 2019 at 2:30 UTC (image credit: Satnews Daily)

Today's launch is a major step towards the final goal of launching and operating 12,000 satellites in orbit to beam internet to the ground by the 2020s, reaching those who are not yet connected, with reliable and affordable broadband internet services. It's estimated that 4 billion people in the world remain unconnected to the internet.

Eight minutes after the launch, the first stage of the rocket successfully landed on the drone ship Of Course I Still Love You (OCISLY) in the Atlantic Ocean. This was the third flight for the first stage booster, having flown on the Telstar 18 VANTAGE mission in September 2018, and the Iridium-8 mission in January 2019.

With a flat-panel design featuring multiple high-throughput antennas and a single solar array, each Starlink satellite has a mass of ~227 kg, this is SpaceX's heaviest launch to date at about 13,620 kg, thus allowing SpaceX to maximize mass production and take full advantage of Falcon- 9's launch capabilities. To adjust position on orbit, maintain intended altitude, and deorbit, Starlink satellites feature Hall thrusters powered by krypton.

An hour later, the Falcon-9 rocket began to release the satellites at an altitude of 450 km. The satellites then had to separate and use their thrusters to take up their positions in a relatively low orbit of 550 km. 11)

"Successful deployment of 60 Starlink satellites confirmed!", the company said on its official Twitter account.

 


1) Matt Williams, "SpaceX's Starlink Constellation Construction Begins. 2,200 Satellites Will go up Over the Next 5 years," Universe Today, 16 April 2019, URL: https://www.universetoday.com/141980/spacexs-starlink-constellation-construction-begins-2200-satellites-will-go-up-over-the-next-5-years/

2) Eric Ralph, "SpaceX CEO Elon Musk reveals radical Starlink redesign for 60-satellite launch," Tesla Rati, 11 May 2019, URL: https://www.teslarati.com/spacex-starlink-satellites-tease-revolutionary-design/

3) Stephen Clark, "FCC approves SpaceX's plan to operate Starlink satellites at lower altitude," Spaceflight Now, 30 April 2019, URL: https://spaceflightnow.com/2019/04/30/fcc-approves-spacexs-plan-to-operate-starlink-satellites-at-lower-altitude/

4) Eric Ralph, "SpaceX's first dedicated Starlink launch announced as mass production begins," Tesla Rati, 8 April 2019, URL: https://www.teslarati.com/spacex-starlink-first-launch-date/

5) "SpaceX gets nod to put 12,000 satellites in orbit," Phys.org, 16 November 2018, URL: https://phys.org/news/2018-11-spacex-satellites-orbit.html

6) "SpaceX Receives FCC's Stamp of Approval to Launch 4,425 Broadband Satellites," Satnews Daily, 2 April 2018, URL: http://www.satnews.com/story.php?number=1759391214

7) Jon Brodkin, "FCC approves SpaceX plan to launch 4,425 broadband satellites," ars Technica, 30 March 2018, URL: https://arstechnica.com/information-technology/2018/03/spacex-gets-fcc-approval-to-build-worldwide-satellite-broadband-network/

8) "SpaceX launches Falcon 9 with PAZ, Starlink demo and new fairing," NASA Spaceflight.com, 22 February 2018, URL: https://www.nasaspaceflight.com/2018/02/spacex-falcon-9-paz-launch-starlink-demo-new-fairing/

9) Chris Gebhardt, "Falcon 9 launches first Starlink mission – heaviest payload launch by SpaceX to date," NASA Spaceflight.com, 23 May 2019, URL: https://www.nasaspaceflight.com/2019/05/first-starlink-mission-heaviest-payload-launch-spacex/

10) "Sixty Launched ... 11,940 Left to Go ... as SpaceX Successfully Sends Off Their First Batch of Starlink Satellites," Satnews Daily, 24 May 2019, URL: http://www.satnews.com/story.php?number=179808724

11) "SpaceX launches first satellites of its internet network," Space Daily, 24 May 2019, URL: http://www.spacedaily.com/reports/SpaceX_launches_first_satellites_of
_its_internet_network_999.html

 


The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: "Observation of the Earth and Its Environment: Survey of Missions and Sensors" (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (herb.kramer@gmx.net).

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