Tuesday, October 24, 2017

Will low-Earth orbit satellite Internet service providers succeed?

Teledesic animation: a satellite
constellation that would cover
the planet -- routers in space.
In 1990, Teledesic was formed to deliver satellite-based Internet service. Cellular pioneer Craig McCaw, Microsoft co-founder Bill Gates and Saudi Prince Alwaleed bin Talal were early investors and Boeing was both an investor and the prime contractor. Teledesic hoped to offer global Internet connectivity using a constellation of 840 satellites in low-Earth orbit (LEO) at an altitude of 700 km. (The plan was scaled back to 288 satellites in 1997).

Teledesic failed.

Twenty seven years later three companies SpaceX, OneWeb, Boeing and Leosat are trying to do what Teledesic could not do. Will they succeed?

Good news -- a lot has changed since Teledesic tried and failed.

Launches have gotten cheaper -- SpaceX has made landing a 549,054 kg rocket that is 70 feet long and only 3.66 meters in diameter and has reached an altitude of 247 km and fallen at a speed of up to Mach 7.9 within .7 m of the target on a drone barge at sea almost routine. They have had 18 successful soft landings and their next-generation rocket, the BFR is designed for reusability and will be able to launch many satellites per flight.

Satellites are now cheaper, smaller and lighter. OneWeb and their manufacturing partner Airbus say automation and re-design will enable them to manufacture three satellites per day at a cost of less than $1 million each and launch cost per satellite will be low since they are small and light. In a talk at the opening of the SpaceX satellite engineering office in 2015, CEO and Lead Designer Elon Musk expressed confidence that they would be able to mass produce satellites and also pointed out that the failure of one or a few satellites in a constellation of thousands was relatively unimportant. If a satellite fails, the remaining satellites will route around it and increased tolerance of failure reduces manufacturing cost.

Consumer ground-stations will also be small, cheap and easy to install "pizza boxes." Since the signals will be weak, the antennae will have to be outside, but end users will be able to install them because, unlike today's TV and Internet dishes, they will not have to be aimed precisely at a single, geostationary satellite. Modern phase-shift array antennae will follow a satellite as it moves and switch to another in microseconds or a few milliseconds when it goes out of site. Similarly, satellites will be able to transmit a beam that is fixed on one area on the ground as it moves over it.

Communication technology has improved dramatically. Today's radios are smart -- rapidly changing power, frequency, modulation scheme, etc. under program control. Teledesic belonged to an era of dedicated spectrum allocation, but smart radios are ushering in an era of unlicensed spectrum and spectrum sharing. This is a fundamental shift -- like the introduction of packet switching -- and it will lead to efficient use of spectrum (on Earth and in space).

The terrestrial fiber network has grown exponentially since the time of Teledesic. making Internet gateways attractive targets. Satellites may compete favorably with long undersea and terrestrial cables. Elon Musk says SpaceX satellites will communicate optically among themselves, forming a low-latency, highly interconnected mesh that will carry the majority of our long-distance traffic. Google, a billion dollar SpaceX investor, might be their first long-haul customer.

The market for Internet connectivity is larger today than it was at the time of Teledesic because more people are aware of the Internet and many are trained to use it with mobile devices. Furthermore, applications are varied and powerful today. The Teledesic project was during the Web 1.0 era when the Web consisted of static sites with text and small, compressed images. Today, the U. S. Federal Communication Commission (FCC) defines "broadband" as at least 25 Mbps download speed and some fortunate people have gigabit connections in their homes. The low latency of LEO satellites is well suited to interactive applications that require error checking.

While increasing numbers of people are online with mobile devices, the digital divide has widened. A slow connection using a phone is not the same as a fast connection that can support modern applications on a computer. I can consume content, make purchases and chat with friends using a mobile phone, but I could not have written this post or done the research that went into it without a laptop and a fast Internet connection. High-speed connectivity to homes, schools, libraries, clinics, etc. will be in demand and narrow the qualitative digital divide.

Today's satellite company executives have different backgrounds than Teledesic's. Bill Gates had built a software company, Craig McCaw a cellular phone company and Boeing had experience with the technology of the time. I know nothing about Boeing's people today, but they have the benefit of the lessons the company has learned since Teledesic. OneWeb CEO Greg Wyler created a successful satellite-based company, O3b, which provides Internet service using a constellation of 12 mid-Earth orbit satellites. (O3b is now owned by SES).

Given his track record, Elon Musk deserves special mention. For a start, he is CEO and Lead Designer at SpaceX -- actively involved in engineering decisions -- Jobs and Wozniak in one package. He is also unfettered by outside investors, giving him more latitude and the ability to reassign personnel -- relatively free of shareholder's pressure to pursue their applications or maximize short-run profit. (Of course, he needs to make money in order to continue his business and invest in journeys to the Moon and Mars). While I hope the market is large and varied enough to support others, SpaceX will succeed if anyone does.

Unknowns and possible glitches

The above changes improve the outlook for today's satellite projects, but there is still uncertainty. For example, it is hard to know what the true capacity of these systems will be -- the number of users and the user mix they will support. They speak of serving individual users, local area networks like schools, libraries or public-access hotspots, Internet gateways, cell phone backhaul, ships, airplanes, automobiles, Internet of things (IoT) devices, etc. One can even imagine a space-based content-delivery network using solid-state drives.

An Internet gateway requires more bandwidth than an IoT sensor that is read every hour and, during the day, a school needs more bandwidth than a home. Will the companies end up with different customer mixes? For example, SpaceX has singled out long-haul Internet exchanges and home connectivity as target applications and, given Elon Musk's other interests, we can imagine him targeting autonomous vehicles and power distribution. OneWeb is also going after homes and buildings, but a key investor, Softbank, is focused on the Internet of things. OneWeb CEO Doug Wyler's first satellite service, O3b, serves mobile network operators, ship lines, governments, and enterprises. Perhaps OneWeb will focus on large customers.

A related question -- how will these companies handle sales and service? Will they have online sales, global offices, dealers, partner with ISPs and mobile companies, etc.? (OneWeb backer Softbank tried to merge with Intelsat, but the merger, which would have provided OneWeb with global offices, failed).

There are regulatory as well as technical challenges. The FCC has delayed acting on SpaceX's launch application pending negotiations on spectrum-sharing techniques between them and other satellite companies using the same range of radio frequencies. These will be global networks and they will have to satisfy the spectrum regulators of all nations they wish to serve as well as the International Telecommunication Union. At the very least, that means dealing with a lot of bureaucracy.

Standards also come to mind. SpaceX, OneWeb, Boeing, and others are working on methods of spectrum sharing. The Ethernet standard grew out of joint work by Intel, DEC and Xerox -- will SpaceX, OneWeb and Boeing create satellite spectrum standards one day?

Regulators also worry about falling debris. These satellites have a useful life of about five years after which they are de-orbited and burn up in the atmosphere. SpaceX hopes to launch over 4,000 satellites in their first constellation and they are in discussion with the FCC over the likelihood of human injury from falling debris. SpaceX eventually hopes to be able to economically recapture spent satellites using the BFR.

There are also political and cultural barriers. Will nations like China or North Korea allow citizens to install home ground stations and connect to the Internet? Will Saudi Arabia tolerate access to pornography? Cuba will not allow citizens to connect to expensive, slow geostationary satellites -- allowing connections to fast, cheap Internet satellites would require a political shift.

(That being said, Cuba would be a prime candidate for this service if the government would allow it. They have very little infrastructure, an educated population and since it is an island, the constellation "footprint" would not be densely populated).

There may also be a need for international anti-trust and consumer-protection regulation. What if one or all three of these companies succeed in establishing global networks that become monopolies or oligopolies in some nations or regions -- for example in central Africa. That could have significant consumer protection and political implications.

Teledesic planned to offer service through local service providers, but OneWeb and SpaceX plan to sell services and easily installed ground-stations directly to consumers. Will terrestrial Internet service providers fight them by lobbying governments and in court the way they have fought publicly-owned terrestrial Internet service providers?

Manufacturing, launching and operating these constellations seems like an immense engineering task. It is hard to imagine an organization capable of such a feat, but let's put these efforts in perspective. If humans can manufacture, launch, deploy and operate the James Webb Space Telescope or the flood-control and water-distribution system in ancient Petra, a constellation of "low-tech" satellites in low-Earth orbit seems like a piece of cake -- the question is whether the business model will work out.

Will these companies succeed?

Sorry to disappoint, but I don't know enough about their coverage and business models to say "yes" with certainty, but I am hopeful because smart, experienced business people, entrepreneurs, and investors are betting they will succeed.

More remarkable -- last year, Tom Wheeler, President Obama's FCC chairman, summed up a talk on the impact of improving technology, saying:
The pace of innovation is accelerating, and with new technological advances, satellites now have the opportunity to play a much more important role in bringing broadband to underserved and unserved areas around the world.
This year, Trump's FCC chairman Ajit Pai stated:
Today, the FCC updates the framework that will govern non-geostationary-satellite orbit satellite systems. And it’s high time: It’s been over a decade since we first adopted rules for these types of constellations. In the years since, innovation has brought exciting potential to connect consumers across the nation, especially in rural, remote, and tribal areas. The rules we adopt will promote the next generation of non-geostationary satellite systems, which could expand broadband access where it’s needed most.
Do Obama and Trump's appointees agree on anything other than this? Let's hope all the projects succeed and we have some decent competition.

Saturday, October 14, 2017

The BFR and its role in SpaceX's satellite Internet service

Elon Musk is CEO and Lead Designer at SpaceX.

SpaceX started with their Falcon 1 booster followed by several versions of the Falcon 9. The Falcon Heavy will fly later this year and the rocket that will take the first person to Mars is called, for now, the Big F***ing Rocket or BFR.

The Falcon1, Falcon 9, Falcon heavy and the BFR (source)

The 150-ton BFR payload will be 10 times that of the Falcon 9. It will have an have an extra landing-guidance engine for reliable reusability and SpaceX also expects to be able to soft-land and reuse the second-stage payload rocket as well as its protective nose cone, substantially reducing cost per launch. (Note that Boeing is also planning a Mars mission so they may be planning their own BFR).

The following is speculation, but I think the BFR will play a significant role the SpaceX satellite Internet service.

SpaceX applied to launch their 4,425 satellites in two phases -- an initial deployment of 1,600 satellites and a final deployment of 2,825. That is a lot of satellites and the FCC has required licensees to deploy their full constellations within six years of their grant, but last month they relaxed that constraint, establishing milestones of launching 50% of a constellation within six years and allowing another three years to complete the constellation. The FCC has delayed licensing SpaceX's plan until spectrum sharing agreements are reached by satellite operators, so the clock has not yet started running on their six and nine-year milestones.

SpaceX plans to send a BFR to Mars in December 2022, and they won't give me any details, but they will surely be used "locally" before that. They plan to begin launching operating Internet satellites in 2019 and those will be launched by Falcon 9 or Falcon Heavy rockets, but the BFR should be available to launch many of the planned 4,425 satellites before the FCC deadline and it will be used for replacement satellites when they are eventually required.

SpaceX estimates the satellite mass as 386 kg and the BFR can carry a 150-ton payload so, if they fit perfectly, a BFR could launch about 350 satellites at a time, but they won't fit perfectly, so let's say 300 per launch. SpaceX Senior Director Tom Ochinero says they will be capable of up to six launches per month. Using the BFR, 4,425 satellites in nine years sounds feasible and relatively cheap. (Elon Musk has estimated that future versions of the BFR may carry up to 1,000 tons).

The BFR may also play a role in debris mitigation. When they are taken out of operation, satellites are de-orbited and they burn up in the atmosphere, but there is some risk of debris hitting the Earth. Bloomberg reported that the FCC had challenged SpaceX's assessment of risk of human casualty from falling debris and SpaceX responded the following month. Recently two Senators have also asked the FCC to investigate the risk of collisions and debris.

The BFR may render the debate moot. In a recent presentation, Elon Musk speculated that the BFR might be used to capture orbiting satellites and return them to Earth, as illustrated here:

SpaceX hopes to recapture satellites in the future (source)

I will conclude with the following image that illustrates how the BFR got its name -- it is a BFR. If you are interested in the BFR and its role in Elon Musk's plan to colonize Mars, you should definitely read the post this illustration is taken from.

Still not sure how big it is? Check out this view of a BFR in Boston:

Update 10/20/2017

In a talk at the 2017 International Astronautical Congress in Australia last month, Elon Musk summarized SpaceX's technology progress, including 18 successful booster landings, and described the BFR design and economics and its applications -- launching satellites, shuttling to the International Space Station and travel to the Moon, Mars and between distant cities on Earth. It is a terrific talk, well worth watching:

On October 15, Musk followed up his talk with an “Ask Me Anything" (AMA) discussion about the BFR on Reddit. You can read a good summary of the AMA discussion, which includes video excerpts from the IAC talk and a concept video on terrestrial travel here. if you have time on your hands to geek out, you can see the entire AMA session here.

Last, but not least, SpaceX has posted a terrific 39-slide presentation on the project. It's a "Steve Jobs" kind of presentation -- long on images illustrating a concept and short on words. (I'm a big fan of that presentation style and try to force it on my beleaguered students). The presentation also includes links to a couple of animations and a video illustrating a hypothetical terrestrial travel scenario. Here are four of the slides to whet your appetite:

Update 12/9/2017

The much-delayed test launch of the Falcon Heavy rocket is scheduled for January 2018. The payload capability of the Falcon Heavy is about 2.5 times that of the Falcon 9 and around one-third of that of the BFR -- "well over 100,000 pounds to low-Earth orbit" according to Elon Musk.

(The Falcon Heavy test payload will be a Tesla Roadster destined for solar orbit -- a good publicity stunt and a near-permanent symbol of our transition to alternative energy sources).

The Falcon 9 will be used to launch SpaceX's first two prototype satellites next year, but in 2019, when SpaceX will begin launching operational Internet-service satellites, the Falcon Heavy will be available. The BFR will be available before the first Internet constellation is complete in 2024.

Update 12/20/2017

SpaceX has released photos of the first Falcon Heavy rocket. It is expected to launch next month, putting a Tesla Roadster in solar orbit. When asked why he wanted to put the car in orbit, Musk said he loves "the thought of a car drifting apparently endlessly through space and perhaps being discovered by an alien race millions of years in the future," and so do I. That reply is even cooler than Mallory saying he climbed Mount Everest "because it's there."

They hope to retrieve and reuse the three booster rockets.

Wednesday, October 11, 2017

Non-terrestrial spectrum sharing

Will we have global standards for Internet satellite spectrum sharing one day?

Four companies, SpaceX, OneWeb, Boeing and Leosat have announced ambitious plans to put thousands of Internet-service satellites in non-geostationary low-Earth orbit (NGSO) and other companies like ViaSat and SES are currently operating hundreds of communication satellites in medium-Earth and higher, geostationary orbits.

With so many satellites orbiting in different planes and at different altitudes, there are bound to be frequent "inline events" when two satellites are simultaneously above an area both are communicating with -- causing potential radio interference.

Terrestrial radio interference has historically been handled by setting limits on transmitter power and granting exclusive rights to organizations, so, for example, in the Los Angeles area radio station KPCC has the exclusive right to broadcast at 89.3 MHz. Since transmitter power is also regulated, KPCC does not interfere with stations broadcasting at the same frequency in distant cities.

Technology has improved since the early days of radio and we are entering an era when smart radios can be programmed to cooperatively share the same spectrum (range of frequencies) by quickly changing frequencies, power levels, antenna focus, etc. (You can see a quick overview of the frequency ranges these companies wish to use here).

Last month, the US Federal Communication Commission (FCC) voted to delay SpaceX's application to launch satellites, saying they would defer to the International Telecommunication Union (ITU) on how these new satellite systems should coordinate and share spectrum. Since OneWeb had already been granted permission to launch their satellites, Bloomberg and others speculated that the issue of potential interference might pose a significant problem for SpaceX.

It would have been a problem in the past, but today's regulators recognize that we need new rules for the spectrum-sharing era. In 2015, the ITU came out in favor of coordination between operators stating that they did not intend "to state an order of priorities for rights to a particular orbital position and the coordination process is a two way process" and last month FCC chairman Ajit Pai agreed, saying "given recent trends in the satellite industry and changes in satellite technology, the Commission began a review last year of the rules governing NGSO fixed-satellite service operations to better accommodate this next generation of systems."

What this means is that OneWeb and other early applicants who have been approved by the ITU and FCC as having priority access to frequency bands do not have exclusive rights to that spectrum, just that SpaceX will have to negotiate and define a sharing mechanism that satisfies them.

OneWeb technique to avoid inference
with geostationary satellites (source)
That process has begun. For example, OneWeb has a patent pending on progressive pitch technology, a technique to avoid interference between their low-Earth orbit constellation and geostationary satellites, which orbit around the equator at relatively high altitudes. Their satellites will automatically change orientation and power level as they pass over the equator to avoid interference with geostationary satellites orbiting above them.

SpaceX has proposed that NGSO operators share data to indicate the steering angle of each beam within a satellite's footprint. As shown below, they assert that this data sharing would drastically reduce the occurrence of inline events between their 4,425 satellites and a ViaSat geosynchronous satellite.

Inline events (red dots) without and with information sharing

This effort to enable efficient spectrum sharing by OneWeb, SpaceX, Boeing and operators of other satellites (and one day perhaps balloons, drones and other high altitude platforms) reminds me of the proposal for the Ethernet standard for local area networks by three companies -- DEC, Intel and Xerox. A major difference, in this case, is that the Ethernet standard was adopted by a professional engineering organization and a satellite communication standard would be approved by the ITU, a United Nations agency. It may be too soon, but might engineers from OneWeb, Boeing and SpaceX one day define global standards for non-terrestrial spectrum sharing?