Dissecting Starlink’s V3 Constellation Application
On Oct. 11, SpaceX filed with the U.S. Federal Communications Commission (FCC) requesting to modify Starlink’s architecture and establish what it calls “SpaceX V3.” The filing pertains to SpaceX’s plans for a 30,000-satellite constellation (specifically, 29,988 satellites), of which the FCC has authorized an initial 7,500 satellites.
The filing showcases the incredible speed at which Starlink has moved, having launched nearly 3,000 Gen-2 satellites in less than two years. It also showcases a bit of Starlink's competitive thinking and geopolitical posturing. SpaceX is urging the FCC to approve the new architecture to “remain globally competitive amidst the rise of state-owned and state-backed satellite systems that have been deploying at a rapid clip.” This is most likely a reference to Chinese constellations like Spacesail, GuoWang, and Honghu-3, each of which aims to have more than 10,000 satellites.
SpaceX requested several changes, with the end goal of delivering “gigabit” speeds to end users (apparently to consumers, not just higher-paying enterprise and mobility customers) and improving coverage of high-demand areas. The following short analysis examines four key changes that Starlink is requesting now and in recent filings, along with their implications as understood at this time.
Key modifications:
A potentially dramatic increase in spectrum use. Today, Starlink mainly uses Ku-band for customer-facing services and Ka-band for gateway links. Starlink's modification discusses using Ku-, Ka-, V-, and E-band “for either mobile- or fixed-satellite use cases” where regulations and technology allow.
Implication: Starlink may need user terminals in these new bands, not just Ku-band or multi-band terminals. The latter is a rarity today, not that unfamiliarity has ever stopped SpaceX before, in launch or in broadband hardware.
A drop in orbital altitude. SpaceX wants to lower its three orbital shells by 45 to 60 kilometers each, shifting from the current 525-km, 530-km, and 535-km shells to 480-km, 485-km, and 475-km altitudes, respectively.
Implication: The change would reduce Starlink’s latency slightly, improve de-orbit times slightly, and provide other benefits. SpaceX says the reconfiguration will enable it to “deliver better broadband coverage and service quality for American consumers in areas of high demand” and be more responsive to consumer demand changes. Notably, the change would also give Starlink more wiggle room since the FCC sided with Amazon in requiring a minimum separation distance, meaning Starlink satellites aren’t allowed to go above 580 kilometers (Kuiper begins at 590 kilometers).
Lower elevation angle by five degrees. Starlink wants user terminals to scan down to 20 degrees above the horizon (versus 25 today) after the altitude drop. This makes sense because satellites at lower altitudes will zip across the sky even faster, so widening the aperture gives more time for connections.
Implication: Not only would a wider scan range offset the lower orbits, but it should (per SpaceX) increase data rates by increasing the number of satellites in simultaneous view at any given time. It's worth noting, however, that this won’t always be possible. The closer the elevation angle gets to the horizon, the greater the likelihood of blockages from structures like buildings, trees and mountains.
A change in orbital inclination. By shifting the inclination of future launches by one to five degrees, SpaceX says it can better launch future satellites on Starship from Boca Chica, Texas.
Implication: In the past, SpaceX had outlined two different LEO architectures, one based more heavily on Falcon 9 launches, the other more heavily reliant on Starship. The new paperwork suggests Starship is taking a firmer role in Starlink’s go-forward plans.
It's worth noting that FCC filings give a window into a company’s future vision but are not a guarantee of near-term actions or actions at all (the FCC’s dockets are filled with V-band constellations that have remained nothing but paper, for example). Therefore, the above conclusions should be taken with a healthy grain of salt.
SOURCE: https://licensing.fcc.gov/cgi-bin/ws.exe/prod/ib/forms/reports/swr031b.hts?q_set=V_SITE_ANTENNA_FREQ.file_numberC/File+Number/%3D/SATMOD2024101100224&prepare=&column=V_SITE_ANTENNA_FREQ.file_numberC/File+Number