Love it or hate it, Starlink might be the biggest space undertaking ever once completed. The combined mass of the Starlink satellite constellation exceeds any prior space endeavor. The SpaceX network provides global satellite Internet access will weigh in more than any other prior space program. The constellation consisting of thousands of mass-produced small satellites in low Earth orbit adds up quickly. Each Falcon 9 launch gets packed full of sixty Starlink satellites. The satellites neatly fit in both size and mass limitations of the Falcon 9.

November 11 at 9:56 a.m. EST, 14:56 UTC, SpaceX launched 60 Starlink satellites from Space Launch Complex 40 (SLC-40) at Cape Canaveral Air Force Station, Florida. Credit SpaceX

In 2018, The Federal Communications Commission granted SpaceX approval to launch up to 4,425 low-Earth-orbit satellites at several different altitudes between 1,110km to 1,325km. The following year, the FCC approved a license modification to cut the orbital altitude in half for 1,584 of those satellites. The lower altitude for the Starlink satellites reduces the latency of the Starlink. Yeah initial Starlink will be nearly the mass of the ISS.

NameKgQtyTotal Kg
Starlink2601                                    260
Starlink launch26060                               15,600
Initial Starlink2601,584                             411,840
ISS419,7251                             419,725
Partial Starlink2601,614                             419,725
Starlink full thrust2604,425                          1,150,500
Big freak’n Starlink26012,000                        3,120,000
Some Back of the napkin calculations about Starlink… give or take a little.
The Starlink constellation, phase 1, first orbital shell: 72 orbits with 22 each, 1,584 satellites at 550 km altitude. Credit Lamid58 

Other companies planning large constellations of internet satellites fall short to SpaceX in mass and qty. The fate of OneWeb’s 1,980 satellite network remains uncertain while the company works through bankruptcy. Amazon’s 3,236-satellite constellation and Telesat’s roughly 300-satellite broadband network also are planned but not yet launched. Elon Musk has shared that he plans to expand Starlink to reach roughly 12,000 in-orbit satellites. 

A satellite constellation consists of a group of artificial satellites working together as a system. A constellation can provide permanent global or near-global coverage where a single satellite provides limited coverage. With a network of satellites, possible for at least one satellite to provide coverage at any time everywhere on Earth. The satellites are typically placed in sets of complementary orbital planes and connect to globally distributed ground stations. Some, like Starlink, also use inter-satellite communication.

Starlink to exceed the mass of the ISS. 

Comparing to other major projects completed in space, Starlink surpasses them all in mass. Putting aside the complexity of assembling the ISS, the Starlink network already contains 1/4th of the mass of the ISS and only has 10% of the initial constellation in orbit. 

According to the Guinness World Records website, The International Space Station, measures in as the single largest human-made object in space with an orbital mass of roughly 419,725 Kg. The ISS follows an inclined orbit of 51 degrees to the equator. The altitude ranges from 360 km to 347 km above the Earth. It measures roughly 109 m x 51 m x 20 m and can be seen from the ground with the naked eye during darkness. ISS orbits the Earth once every 91 minutes.

ISS in Nov 2018 Credit NASA
(Oct. 4, 2018) — The International Space Station photographed by Expedition 56 crew members from a Soyuz spacecraft after undocking. NASA astronauts Andrew Feustel and Ricky Arnold and Roscosmos cosmonaut Oleg Artemyev executed a fly-around of the orbiting laboratory to take pictures of the station before returning home after spending 197 days in space. The station celebrated the 20th anniversary of the launch of the first element Zarya in November 2018. Credit: NASA/Roscosmos

It would take roughly 27 Falcon 9 rockets to launch the equivalent mass into orbit. Getting to the ISS requires more fuel than just getting into orbit. To launch the components of the ISS using a Falcon 9 requires more than 27 rockets. The final number depends partially on the orbital inclination as well as the altitude.

To complete SpaceX’s communication network, SpaceX requires a minimum of 73 launches. Similar to the ISS, the number represents the minimum since some satellite launches require sub-optimal planes(from a launch perspective). To complete the initial Starlink constellation, the required trips to space increases to something like 90-100.  

The SpaceX Starlink on-orbit mass in orbit mass exceeds the ISS even before Starlink completion.  

Starlink will far exceed other orbital constellations.

Although the ISS qualifies as the single largest manmade object to orbit the Earth, Starlink will be more massive. What about other satellite constellations? By quantity, SpaceX already passed the prior largest in orbit network. What about the mass comparison to other satellite constellations?

Let’s compare two other satellite networks to Starlink. The first constellation you should know, GPS.

VersionYearQty luanchedFailedIn PrpepPlannedOperationalKG total
I1978–19851010007597590
II1989–199090000166014940
IIA1990–1997190000181634504
IIR1997–20041210012237028440
IIR-M2005–200980007237018960
IIF2010–20161200012166319956
IIIAFrom 20182053238807760
IIIF000220  
        132150
Approximate summary of mass

The GPS network, or Global Positioning Network, represents one of the oldest satellite networks. Started in the 1970s, GPS expanded from the initial satellites into the current day network. Different from Starlink, GPS provides location triangulation.   

A representation of the US GPS network

More than 70 satellites launched since the begging of the program. The total GPS satellites launched since the 1970s add up to be over 130,000 kg. With a few more Falcon 9 launches, the total mass of Starlink also surpasses GPS total past and current satellite mass in orbit. About 150 satellites remain active.

Planet Labs represents a different segment in the Space market. Leveraging standardized satellites, Planet lab provides high-frequency Earth Observation data to companies. Since the beginning of the company in 2010, Planet Labs launched about 300 satellites.

Some benefits cited by Planet include:

  1. Small and easier to design, build & test (esp. in large quantity)
  2. Standardized launch interface, lots of launch opportunity
  3. Advances in commercial electronics allow smaller cheaper

Planet Labs and SpaceX have a similar approach to utilizing smaller satellites. Both are considered smallsats. Planet Labs satellites are much smaller and less massive.   

Planet focused on 3U CubeSats weighing 5 kg. The satellites equipped with a 90 mm aperture optical payload and RGB imaging with commercial-grade CCD. Each satellite includes fold-out solar arrays and antenna flap.  

Planet Labs results? Planet provides 3 – 5 meter resolution.   

About The Author


Bill D'Zio

Bill D’Zio

Co-Founder at WestEastSpace.com

Bill founded WestEastSpace.com after returning to China in 2019 to be supportive of his wife’s career. Moving to China meant leaving the US rocket/launch industry behind, as the USA and China don’t see eye to eye on cooperation in space. Bill has an engineering degree and is an experienced leader of international cross-functional teams with experience in evaluating, optimizing and awarding sub-contracts for complex systems. Bill has worked with ASME Components, Instrumentation and Controls (I&C) for use in launch vehicles, satellites, aerospace nuclear, and industrial applications.

Bill provides consulting services for engineering, supply chain, and project management.

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