On Monday, January 8, the Starlink team successfully sent and received our first text
messages using T-Mobile network spectrum through one of our new Direct to Cell satellites
launched six days prior. Connecting cell phones to satellites has several major challenges toovercome. For example, in terrestrial networks cell towers are stationary, but in a satellite
network they move at tens of thousands of miles per hour relative to users on Earth. Thisrequires seamless handoffs between satellites and accommodations for factors like Doppler
shift and timing delays that challenge phone to space communications. Cell phones are also
incredibly difficult to connect to satellites hundreds of kilometers away given a mobile phone’s
low antenna gain and transmit power. Starlink satellites with the Direct to Cell payload areequipped with innovative new custom silicon, phased array antennas, and advanced softwarealgorithms that overcome these challenges and provide standard LTE service to cell phones
on the ground. As the global leader in rocket and satellite launch and manufacturing, SpaceX
is uniquely positioned to rapidly scale our Direct to Cell network and will rapidly launch aconstellation of hundreds of satellites to enable text service in 2024 and voice, data, andInternet of Things (IoT) services in 2025.

On January 2, 2024, we launched to orbit our first six Starlink satellites with Direct to Cellcapabilities. Launch and early tests of the technology were all completed without issue. On
Monday, January 8, less than 6 days after launch, we sent and received our first text messages
to and from unmodified cell phones on the ground to our new satellites in space using TMobile network spectrum. This validates that our link budget closes, and the system works!
The Direct to Cell network will expand Starlink’s vision by
providing ubiquitous connectivity and seamless access to text,
voice, and data for LTE phones and devices across the globe.
Text service begins this year, followed by voice, data, andInternet of Things (IoT) services in 2025.
Developing a satellite network that connects to unmodified cell
phones presents several new technical and regulatory
challenges beyond those Starlink has already overcome in
deploying a 5,000+ satellite constellation in a few years, servingmore than 2.3 million customers across the globe.
The top six Direct to Cell Satellites
stacked and ready for launch

The first challenge is transmitting sufficiently strong radio
signals to and from cell phones that were not designed toconnect to satellites, with very low gain antennas and transmit

power (max 0.2 Watts). Our team developed custom silicon onboard the satellite that is
optimized for this application and reduces power and cost on the satellite. We also developed
large 2.7 m x 2.3 m advanced phased arrays that use extremely sensitive radio receivers andhigh-powered transmitters for communicating with cell phones from space. The antennas
were designed to ride on the Starlink v2mini satellites and are reliably launched and deployed
to low-Earth orbit every few days by the Falcon 9 rocket. SpaceX is uniquely positioned torapidly scale out our first Direct to Cell constellation in mere months, due to our unique andunprecedented vertical integration controlling both launch and satellite production in addition
to operations. In the future, we will launch Direct to Cell satellites on Starship to improve theservice even further and increase our launch cadence.
Since our vision is to connect everyone using their existing phones without needing a newphone, upgrades, or a special app, we decided to use standard LTE/4G protocols. Our satellites
orbit hundreds of kilometers above the Earth’s surface at speeds of 7.7 km/s. As a result,compatibility with LTE timing, Doppler, and latency constraints are extremely challenging. For
the vehicles to perform like a true cell tower in space, handoffs between vehicles and on theground must be completely seamless to the user. To accomplish this, we architected thesystem including satellite altitudes, beam size and placement, elevation angles, and number ofsatellites, such that we are just at the edge of physics where LTE is achievable and reliable. We
fly an advanced LTE modem onboard each satellite that operates like a cell tower in space.

Direct to Cell satellites act like cell towers in space, sending traffic to partner operator’s cores using Starlink's spaceand ground systems

The Direct to Cell network leverages the infrastructure we’ve built for Starlink over the pastseveral years. Direct to Cell satellites plug into the existing Starlink satellite constellation via
laser backhaul; meaning even our early satellites can provide services anywhere withregulatory approvals without requiring dedicated ground infrastructure. We also leverage all
the existing networking, ground stations, and Points of Presence (PoPs) Starlink hasdeveloped. The Direct to Cell data travels over Starlink’s core directly to the operator’s core,providing a seamless integration.
In August 2022, we announced our first partnership with T-Mobile, and have since announceddeals with Rogers in Canada, Optus in Australia, One New Zealand, KDDI in Japan, Salt in
Switzerland, and Entel in Chile & Peru. The operators provide critical LTE spectrum in the 1.62.7 GHz range that we use to transmit our satellite signals. This allows Starlink to integrate
like a standard roaming partner with operators, and together we provide services directly andseamlessly to their customers. Operators in our network have access to reciprocal global
access that allows their users to access the service when they travel to one of our partnercountries. There is incredible demand and high interest in this program, and handset providers
and mobile operators alike are eager to test and participate in a successful rollout.
We worked closely with the Federal Communications Commission (FCC) to obtain initialauthority to launch and test our satellites in record time, and we will continue to work withthem to find innovative ways to connect people and save lives in emergencies. We are working
closely with regulators around the world to bring this service to their countries as soon as
possible.
This year, we look forward to expanding our testing to include greater coverage; launching
hundreds of satellites to enable our text constellation; working toward our voice, data, and IoT
constellation in 2025; and expanding our global footprint. If interested in joining us feel free tocontact us here or look for opportunities to join the team here.