SpaceX Starlink FCC Filing for Closer, Faster and Better Service

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SpaceX second-generation satellites have performed even better than expected so SpaceX has sent a request to the FCC to allow operation at about 350 kilometer instead of 530 kilometers.

This would be 68% of the height which would enable 68% latency. This would get latency from 28-35 milliseconds down to 15-20 milliseconds.

In 2022, the FCC cleared SpaceX to operate 7,500 second-get satellites in 525, 530, and 535 km altitudes or within the same region as the company’s first-ten satellites. China recently proposed a competing satellite network to operate at the 330 kilometer altitude.

The increased atmospheric drag would require ten times the fuel or more for the same satellite life. The fuel would not need to change as much if the satellite lasted 3 years instead of 5 years.

DARPA wants to fly satellites closer to the earth where there is more drag and resistance. The thermosphere (90 km or 56 miles) up to 500 and 1,000 km (311 to 621 miles) above our planet. DARPA wants Very Low Earth Orbit (VLEO) as orbits less than 450 km, or roughly 280 miles. The benefits of being in Very Low Earth Orbit are improved resolution for optical imaging, higher signal-to-noise ratios for radar and lidar systems, improved geospatial position accuracy. It is about ten to twenty times harder to maintain an orbit of 350-450 kilometers versus 550 kilometers. There have been Super Low Altitude Test Satellites (SLATS). Tsubame was a JAXA satellite intended todemonstrate operations in very low Earth orbit (VLEO, below 200 km), using ion engines to counteract aerodynamic drag from the Earth’s atmosphere. It had 4 newtons of thrust for its ion engine and stayed in orbit for about 2 years. Super Low Altitude Test Satellites were twice as close the where DARPA wants to fly.

This week SpaceX achieved peak download speed of 17Mb/s from satellite direct to unmodified Samsung Android phone.

If SpaceX has larger version 2 or version 3 Starlink satellites launched with Starship to the lower altitude this could increase bandwidth by 10 times. The larger satellites will have bigger antenna and being much closer will also increase the signal.

It would be reasonable to expect the current Gen 2 mini satellites to operate at 20-30 Mbps (faster than the proven download speed) for direct to unmodified cellphones.

The full Starship sized Gen 3 satellites to operate at 200-300 Mbps for direct to unmodified cellphones.

There will also be modified cellphones, attachable antennas or other means to boost the signal. The slightly modified cellphones could see 2-10X speed increases.

There will be a range of larger antennas up to lower power dishes that would provide a range of communication speeds.

The range of speeds would be the cellphone text communication speed at maybe 1-10 kbps and the 100 Mbps to 10 Gbps satellite services. There will likely be systems to fill in the gap from 30 kbps to 50 Mbps at the 30 kbps, 100 kbps, 300 kbps, 1 Mbps, 5 Mbps, 20 Mbps and 50 Mbps performance areas. The 10 kbps would be for basic voice calls, emails and minimum internet data service.

Altitude and Drag

Other Lower Altitude Satellites and Other Uses

New SpaceX argon Hall thrusters for on orbit maneuvering have 2.4x the thrust and 1.5x the specific impulse of SpaceX first gen thrusters. This will also be the first time ever that argon Hall thrusters are operated in space. SpaceX first gen ion thrusters were krypton ion drives.

Krypton is about one-sixth of the cost of xenon gas. It is about $500-1500/kg for krypton gas. It is $3000-10,000+/kg for xenon) has likely saved the company hundreds of millions of dollars. Argon gas is 1% of the cost of krypton gas. 99.999%-pure argon can be purchased in low volumes for just $5 to $17 per kilogram, and each Starlink V2 Mini satellite will likely need less than 80 kilograms. Per Satellite fuel costs drop from $40,000 to $120000 per satellite to $400-1600 each. Fuel costs for in space orbit keeping were about 20-40% of the cost of the satellite and now it is less than 1%.

Other options are fuel delivery, beamed power to long duration drones or satellites. SpaceX is just going to use a lot more fuel because they can deliver a lot more payload.

Powering the thrusters, improving aerodynamics of the satellite, lowering fuel costs. Ambient air for propellant. Tether power generation (using oxygen) are other options.

Startup Albedo has $48M in funding. They are lowering satellites for higher resolution imaging. They want 10 centimeter resolution. Maxar and Airbus currently sell 15 cm imagery, which they’re able to generate by algorithmically processing and upscaling resolution from 30 cm imagery.

6 thoughts on “SpaceX Starlink FCC Filing for Closer, Faster and Better Service”

  2. How about collecting the air and using that as reaction mass, like a little electric Bussard ramjet

    Impact speed must be 8 Km/s, ionize it, and push it out the back at 8,1, free forever. Well until it wears out.

    • There have been proposals to do that, yes. I don’t know that anybody has built a working prototype yet, though.

      It’s not as easy as a regular ion engine, as it’s mixed gas and not inert, either.

      • ESA/Thales are busy on a VLEO ABEP thruster demo related to Skimsat, supposedly there’s a DARPA project spinning up as well. Skeyeon allegedly is also working on ABEP but their primary focus is their first aerodynamic sat using compressed optics. JAXA in the past fiddled with ABEP inlet work.

  3. Google once had a moonshot called project loon that was trying something similar to starlink but with high altitude balloons. I wonder how high it’s possible to go with that approach.

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