Thursday, February 24, 2022

SpaceX is testing Starlink roaming

A failed roaming test
Last April, Elon Musk tweeted that Starlink "should be fully mobile later this year, so you can move it anywhere or use it on an RV or truck in motion." It is good to know that mobility with a standard dish is in the works, but it's not yet available.
David Lang had been able to connect his Starlink terminal about fifteen miles from his home in Simi Valley, California, but when he brought it to my place in Carpinteria California, about forty-three miles away and in a different coverage cell, it failed to connect.

David's experience is not unique -- others have reported similar inconsistency on social media, but if one is willing to change the registered address of their terminal, it can be moved -- if there is available capacity at the new location.

Consider the experience of Marcus and Julie Tuck, who have been digital nomads for eight years and Starlink users since April 2021. As of December 16, 2021, they had registered at one hundred different addresses and had service at 157 locations. 

The Tucks and their truck
They experienced a significant roaming change while driving in central California. On February 11, 2022, they noticed they could move into a new cell and retain Starlink service without registering an address change. Later, when they crossed from California to Nevada, they had to enter a new address, but when they returned to California, they did not have to change it back. They have not changed it subsequently but will have to when they enter Mexico.

When David Lang brought his terminal to my home, he would have risked losing the ability to connect when he returned home if he had temporarily registered his terminal at my address. When the Tuck's experience becomes available, users will be able to leave home for a trip and return without risking the ability to reconnect at home.

David's visit was a week after the Tuck's experience, so roaming has not yet been rolled out. Perhaps the Tucks were in a limited test area or were selected by SpaceX because of their frequent address changes.

The Tucks had fixed roaming, not the in-motion connectivity Elon Musk promised, but it is a first step and there are still unanswered questions about roaming like:

  • Will terrestrial roaming while in motion require a different terminal? (It will at least have to be mounted differently). Planes, ships, and military vehicles will surely use different terminals. 
  • Since capacity must be reserved for roaming, the service will cost SpaceX. Will they charge for roaming and, if so, how -- by the month, the cell transition, the ground-station transition?
  • Will the roaming fee be less in low-demand, unsaturated areas? 
  • Will it be different for transitions into or out of high-demand areas? A function of the number of open slots at the time of transition?
  • Because of capacity limitations, they will not be able to guarantee 100% roaming success. Might we see a collective service-level guarantee like "99% success globally each month"?
  • How long will it be before a Starlink terminal is offered as an option on Tesla cars and trucks? 
  • How long will it be before a Geely Holding Group terminal is offered as an option on Volvo, Mercedes and other Geely brand autos?
  • SpaceX has begun launching satellites with inter-satellite laser links and the other LEO broadband operators will follow -- how will that affect roaming?
  • Eventually, I expect we will have optical links to ground stations with climate and weather-aware routing -- how would that affect roaming?
Elon missed his target date, but he seems confident that we will eventually have "full mobility" -- let's hope he is right.

Update 2/25/2022

This map shows the Tuck's most recent travels. Note that they did not have to re-register during the stops marked with green push points. They re-registered after crossing the state line into Nevada but did not re-register after returning to California.



Star = registered address

A. First of five locations after registering
B. First of seven locations after re-registering
C. First of fourteen locations after crossing the state line and re-registering
D. Fourteenth location after registering, 2/23/2022

Update 3/3/2022

SpaceX has enabled fixed and mobile roaming in Ukraine and reduced peak power consumption.

Update 3/12/2022

The Tucks mounted the Starlink dish horizontally on the top of their RV and used it while in motion. They have reported on a 101-mile drive at an average speed of 45 miles per hour and a top speed of 54. During the test, they live-streamed a video, and Marcus' wife listened to a live UK radio broadcast while doing a range of general Internet surfing, social media, etc. Below is a snapshot from a video log of the entire trip, speeded up to run in 2 minutes.










Update 3/13/2022

When the Tucks crossed into Mexico, they feared roaming would fail, but roaming and in-motion connectivity continued working.













Thursday, February 03, 2022

Update on China SatNet's GuoWang broadband constellation -- can they do it?

In 2020, China applied to operate GuoWang, a constellation of 12,992 low-Earth orbit (LEO) broadband Internet satellites, and in 2021, it became clear that it was intended to become China's global LEO broadband constellation. Can they do it? Maybe, but it will take a long time.

Launch capability

Chinese launch startups (source)
China does not have the capacity to launch 12,992 satellites today. I don't know the mass of their planned satellites, but GuoWang is informally referred to as China's answer to Starlink. Starlink's version 1 satellites were 262 kg each and version 2 is said to be between 800 and 1,250 kg. If, say, the GuoWang satellites turn out to weigh 500 kg, the constellation would require 260 launches using China's most powerful rocket, the Long March 5, assuming no failures and ignoring replacement, and it would be 867 launches using the forthcoming, reusable Long March 8.
But times are changing. In a recent DongFang Hour podcast, Jean Deville said there are about twenty new commercial launch companies in China, and they were raising an unprecedented amount of money. While none of these is in the class of SpaceX's Starship, which they say will be able to launch >100 tons to LEO, China's forthcoming Long March 9 is being designed to launch 150 tons to LEO. (Elon Musk tweeted that they might be able to get it up to ~150 tons in a reusable Starship).
Launching and maintaining a constellation of 12,992 satellites would require a coalition of commercial startups and/or the Long March 9. (In an idealistic, united world one could imagine iconoclastic Elon Musk offering to launch GuoWang satellites using Starships).

Satellite manufacture

GalaxySpace satellite "super factory" (source)
As of last September, China only had 431 satellites in orbit. Chinese state-owned enterprises clearly do not have the capacity to produce and maintain satellites for a mega constellation. As with launch, one or perhaps a coalition of private companies could be called upon to manufacture GuoWang satellites. 

As Deville put it, "2022 could be year one of the significant if not massive deployment of Chinese small satellites." He cited the example of the completion of the GalaxySpace satellite production line at their "super factory" in Nantong and showed the first six broadband communication satellites that were just completed. He also described several other satellite manufacturing companies including auto manufacturer Geely, which has a factory capable of producing 500 satellites per year and deep mass production experience.

Optical links and ground infrastructure

Inter-satellite optical links are a priority for LEO constellations -- they will reduce latency and the need for ground stations -- and China has relatively poor access to global ground infrastructure. As with launch and satellite manufacture, there are promising optical communication start-ups, but China lags established companies like Mynaric and Tesat and is precluded from using their products by the current technology cold war and Xi's Made in China 2025 policy. 

Optical links between satellites and the ground could compensate in part for a lack of radio-frequency ground stations and China's recently released Five-year Perspective white paper says they have tested satellite-ground laser communication. Ground station load can also be reduced by relaying data through geostationary satellites and the Five-year Perspective includes a commitment to a coordinated multi-orbit communication system.

Amazon offers ground-station serviceAWS Aerospace and Satellite Solutions offers space/terrestrial systems consulting service and Microsoft offers Azure Orbital ground station service, which enables satellite access to its Azure cloud services. Will Chinese Web services and terrestrial infrastructure companies integrate with GuoWang?

Politics

Belt and Road nations, January 2021 (source)
GuoWang is behind SpaceX Starlink and nearly as far behind the OneWeb, Telesat, and Amazon Kuiper constellations, but the political division between China and the US may protect it enough to survive. Starlink service will not be allowed in China, and they will discourage it in nations that participate in their Belt and Road infrastructure initiative, and GuoWang service will not be allowed in the United States or nations with which we are closely allied. 

This division shields GuoWang from competitive market pressure and it locks in global waste and economic inefficiency by ensuring that LEO constellations will be able to route traffic but will otherwise be idle while orbiting over "enemy" nations. 

I've reviewed three areas in which GuoWang needs to catch up, but GuoWang, Starlink and the other would-be broadband Internet service providers also face joint constraints like LEO debris and spectrum scarcity, (Note that SpaceX has also applied to launch 30,000 more broadband satellites). Optical links between constellations and the ground may relax the spectrum constraint if inter-satellite routing algorithms are climate-sensitive but global collaboration is needed to deal with debris, collision avoidance, and spectrum scarcity.

GuoWang is facing an uphill battle. If SpaceX and the others do not go bankrupt, they will have been operating for years before GuoWang completes a 12,992-satellite constellation. On the other hand, the Chinese government has given GuoWang high priority, their lunar, Martian, and space station programs started long after ours, and China plans to "build a satellite communications network with high and low orbit coordination" within the next five years.

Update 2/22/2022

GuoWang got political affirmation recently when China Satnet signed a strategic cooperation agreement with the Shanghai Municipal Government. (Like state governments in the US, Chinese municipal governments often support commercial efforts). Satnet is a state-owned enterprise, but its executives visited commercial satellite constellation operator Guodian Gaoke signaling openness to cooperation with Chinese commercial space firms. 

It seems clear now that GuoWang will be China's global broadband provider, not Hongyun and Hongyan, less ambitious broadband constellation projects of powerful state-owned enterprises CASC and CASIC.

Update 3/13/2022

The Dongfang Hour reports that the Long March 9 will not be ready to launch for 8-10 years. How many satellites will GuoWang's competitors have in orbit by then? They also reported that the six broadband communication satellites mentioned above were launched. The satellites have a mass of 190kg and a throughput of 40 Gbps.

Several companies are ramping up to build satellites, so a coalition may be able to equip GuoWang, but launch capacity seems to be an even more significant constraint. Either way, they have a long way to go. Here's a wild dream -- SpaceX could launch GuoWang satellites. Elon Musk has been known to help competitors -- he put 249 Tesla patents in the public domain in 2014.

Update 7/22/2022

As we saw earlier, the Long March 9 was expected to be ready for launch in 8-10 years, but a revised design is being considered. Andrew Jones reports that Long Lehao, a veteran chief designer of the Long March rocket series, presented plans for a new reusable methane-liquid oxygen launch vehicle to be ready in 2035. He described a two-stage rocket capable of launching 150 tons to low-Earth orbit. That sounds a lot like SpaceX Starship, but without mention of the launch/land pad with "chopstick" arms to capture a returning booster.


Presentation on the revised Long March 9 (source)

There is no doubt that China is paying attention to and is way behind SpaceX's Starship development. If Starship succeeds, Elon Musk may have an apartment on Mars by 2035 :-).
Update 1/25/2023
Here is confirmation of the 2035 target date for the Long March 9. By that time, several LEO broadband providers hope to have been serving customers for several years. Note the emphasis here is on deep space exploration, not Internet service. 
"Around 2035, China will implement a one-time configuration flight verification mission of heavy rockets, and after the successful mission, heavy rockets will become one of the main forces of China's deep space exploration."
Update 4/18/2023
The 14th Central Inspection Team
China Satnet is undergoing a comprehensive political "physical" (on-site?)  examination by the 14th inspection team of the Central Committee and a new General Manager has been appointed They plan to work on the investigation for about two and a half months. 
The focus of the visit is to report and reflect on violations of political discipline, organizational discipline, integrity discipline, mass discipline, work discipline, and life discipline in addition to assessing progress toward strategic goals.
To an American, that sounds a bit like 1984 but it may be routine for China. (This update was based on a Google translation).
Update July 12, 2023
The seventh test satellite was launched three days ago. The first production satellites will be launched in the third quarter of this year