SpaceX and OneWeb internet satellite comparison

[oldAtlas_Eguy]

Here is my take on the business cases comparisons.

	SpaceX	OneWeb
No of Sats	4000	650
Uplink/Downlink Gbs per Sat	24/24	8/8
Available Bandwidth to Customer Mbs/user	1000	50
Average real max bandwidth usage Mbs	10	2.5
No of Subscribers /network capability	10%	10%
Yearly Revenue $M at $100 per subscriber/month	$1,152	$249.6
Yearly Revenue $M at $300 per subscriber/month	$3,456	$748.8
Cost to implement $B	$10-15	$2-3

Analysis of business cases:
- Revenue to costs ratio is the same for both.
- SpaceX offers 4 times or more the real bandwidth than OneWeb. Could be as high as 20 times more.
- SpaceX costs for maintain remote ground stations is $0. But for OneWeb system to work it must have remote locations ground stations. SpaceX can place ground stations interconnects into the Internet backbone at most economical locations on the various continents due to sat to sat links.

The SpaceX data is based on a ~200kg sat launched 32 at a time by F9R.
If a FHR is used and a complete ring is populated at a time ~64 sats, the sat weight is 340kg sat. A much heavier sat means a lot more power which means more spots which mean more data bandwidth per sat or nearly 64Gbs for the FHR scenario vs F9R scenario of 24Gbs per sat.  Also cost of launch per sat is actually lower for the FHR case and since scaling up nearly twice the weight will not cost twice as much to produce the sat. So a much more capable constellation could be built for only slightly more cost than the lighter weight one.

[Zed_Noir]

Just some minor nits @oldAtlas_Eguy.

The F9R can lift 72 Sats per flight if the Sat is less than 182 kg/400 lb each (similar in size to the Orbcomm-2 sats). Base on the weight limit of the EELV Secondary Payload adapter ring Sat mounts Also the Sats will fitted in a standard SpaceX PLF.

The FHR requires a longer PLF to carry 64 Sat that is 340 kg each.

[docmordrid]

Its more than just mass, you need deployment adapters. Going with ORBCOMM size satellites and the Moog rings that deployed them, my M1 Eyeball puts the rings at 1-1.5 meters high. With 4 birds per ring and 5-6 rings that's only 20-24 satellites per launch in the 5.2m fairing. Maybe 28 of you can shoehorn 7 rings.

We need a bigger boat. Maybe FH's BA-330 fairing from the Bigelow GATE 2 study.

[Zed_Noir]

Its more than just mass, you need deployment adapters. Going with ORBCOMM size satellites and the Moog rings that deployed them, my M1 Eyeball puts the rings at 1-1.5 meters high. With 4 birds per ring and 5-6 rings that's only 20-24 satellites per launch in the 5.2m fairing. Maybe 28 of you can shoehorn 7 rings.

We need a bigger boat. Maybe FH's BA-330 fairing from the Bigelow GATE 2 study.

The Moog ESPA rings are 28 inches high with 6 mounting points for Sats 400 lbs or less. A stack of 12 rings will fitted in the SpaceX PLF. This adapter ring is commonly use for secondary payloads on all major US LVs.

You are referring to the Moog EPSA Grande which is 38.8 inches high with 4 mounting points for Sats 660 lb or less.

Moog ESPA brochure

[Ludus]

Here is my take on the business cases comparisons.

	SpaceX	OneWeb
No of Sats	4000	650
Uplink/Downlink Gbs per Sat	24/24	8/8
Available Bandwidth to Customer Mbs/user	1000	50
Average real max bandwidth usage Mbs	10	2.5
No of Subscribers /network capability	10%	10%
Yearly Revenue $M at $100 per subscriber/month	$1,152	$249.6
Yearly Revenue $M at $300 per subscriber/month	$3,456	$748.8
Cost to implement $B	$10-15	$2-3

Analysis of business cases:
- Revenue to costs ratio is the same for both.
- SpaceX offers 4 times or more the real bandwidth than OneWeb. Could be as high as 20 times more.
- SpaceX costs for maintain remote ground stations is $0. But for OneWeb system to work it must have remote locations ground stations. SpaceX can place ground stations interconnects into the Internet backbone at most economical locations on the various continents due to sat to sat links.

The SpaceX data is based on a ~200kg sat launched 32 at a time by F9R.
If a FHR is used and a complete ring is populated at a time ~64 sats, the sat weight is 340kg sat. A much heavier sat means a lot more power which means more spots which mean more data bandwidth per sat or nearly 64Gbs for the FHR scenario vs F9R scenario of 24Gbs per sat.  Also cost of launch per sat is actually lower for the FHR case and since scaling up nearly twice the weight will not cost twice as much to produce the sat. So a much more capable constellation could be built for only slightly more cost than the lighter weight one.

For SpaceX you project a bit less than a million subscribers yielding 1.1to 3.4 billion dollars in annual revenue ($100/$300 per month fee estimate)Musk's projection of 10% of local internet traffic seems to imply a number at least 100X that high. Gigabit/s capacities are about 1000X less than fiber backbone yet he expects to carry more than 50% of long distance traffic which now flows through fiber.

Do you think Musk is wildly overstating the capacity?

[MP99]

Its more than just mass, you need deployment adapters. Going with ORBCOMM size satellites and the Moog rings that deployed them, my M1 Eyeball puts the rings at 1-1.5 meters high. With 4 birds per ring and 5-6 rings that's only 20-24 satellites per launch in the 5.2m fairing. Maybe 28 of you can shoehorn 7 rings.

We need a bigger boat. Maybe FH's BA-330 fairing from the Bigelow GATE 2 study.

The Moog ESPA rings are 28 inches high with 6 mounting points for Sats 400 lbs or less. A stack of 12 rings will fitted in the SpaceX PLF. This adapter ring is commonly use for secondary payloads on all major US LVs.

You are referring to the Moog EPSA Grande which is 38.8 inches high with 4 mounting points for Sats 660 lb or less.

Moog ESPA brochure

From Elon's Seattle talk:-

"This would be not using cubesats. Satellites we have in mind are to be quite sophisticated. They'd be a smallish satellite but with big satellite capability. By smallish I mean, in the few hundred kilogram range."

Possibly going to need a bigger Moog than the Grande's 300 kg limit.

Cheers, Martin

[Robotbeat]

I'd be surprised if they didn't build a custom dispenser.

[A_M_Swallow]

Ships and isolated farms need internet access. These are natural customers for satellite services.

[Avron]

I for one will be taking SPx service over my local monopoly or oligopoly - the man said $100 or $300 for the terminal that used phase array antenna, and a crazy small switch time from sat to sat.. the cost pre user per month would be affordable world wide.. think sub $10 / month, anything higher will allow the ground based folks and other providers to crush SPX and that is not going to happen..  look at your internet bill and reduce that by an order of magnitude.. that's Musk talk. Innovation requires bold steps

[WmThomas]

Don't you all realize that Elon thinks that by the time his satellites are ready, so will the BFR, his super-heavy reusable rocket system?

He has thought up a brilliant way for SpaceX to bring business to itself.

Custom dispenser: you bet! And how many 300 KG satellites could one BFR launch? 200? 300?

Sorry if I'm repeating what someone else has pointed out.

[MP99]

Don't you all realize that Elon thinks that by the time his satellites are ready, so will the BFR, his super-heavy reusable rocket system?

He has thought up a brilliant way for SpaceX to bring business to itself.

Custom dispenser: you bet! And how many 300 KG satellites could one BFR launch? 200? 300?

Sorry if I'm repeating what someone else has pointed out.

That appears to be more than the number of sats required in any one plane.

Cheers, Martin

[guckyfan]

I don't understand why more than max. 3 inclinations would be necessary. The ISS with its inclination covers much of the total surface of the earth. Just phase them so they cover it all at the same time.

Two inclinations might be more efficient but not many, or am I missing something?

One inclination to include the polar regions. That would be the third.

[MikeAtkinson]

I don't understand why more than max. 3 inclinations would be necessary. The ISS with its inclination covers much of the total surface of the earth. Just phase them so they cover it all at the same time.

Two inclinations might be more efficient but not many, or am I missing something?

One inclination to include the polar regions. That would be the third.

These are planes, not inclinations. Think of the Earth in inertial space, if it were a non-rotating ball, the satellites that cross the equator at longitude 0, cross it going the other way at longitude 180. These satellites would continue to pass over the same ground track, and much of the Earth would never see a satellite. So you add more planes which cross the equator at different longitudes. About 20 planes are needed to cover the whole Earth. Rotate the Earth and the same situation still applies.

All the planes may be at the same inclination, or some might be at different inclinations to give a more even distribution of satellites.

[guckyfan]

These are planes, not inclinations. Think of the Earth in inertial space, if it were a non-rotating ball, the satellites that cross the equator at longitude 0, cross it going the other way at longitude 180. These satellites would continue to pass over the same ground track, and much of the Earth would never see a satellite. So you add more planes which cross the equator at different longitudes. About 20 planes are needed to cover the whole Earth. Rotate the Earth and the same situation still applies.

All the planes may be at the same inclination, or some might be at different inclinations to give a more even distribution of satellites.

OK then, I am not too familiar with the terms, it is planes then. You can get satellites to any plane  with the same inclination with one launch. Just keep them elliptical for some time and the plane will change.

[denis]

These are planes, not inclinations. Think of the Earth in inertial space, if it were a non-rotating ball, the satellites that cross the equator at longitude 0, cross it going the other way at longitude 180. These satellites would continue to pass over the same ground track, and much of the Earth would never see a satellite. So you add more planes which cross the equator at different longitudes. About 20 planes are needed to cover the whole Earth. Rotate the Earth and the same situation still applies.

All the planes may be at the same inclination, or some might be at different inclinations to give a more even distribution of satellites.

OK then, I am not too familiar with the terms, it is planes then. You can get satellites to any plane  with the same inclination with one launch. Just keep them elliptical for some time and the plane will change.

It all depends how much time you have and how much of the satellite propellant you want to spend on this.

The rate of precession of the nodes depends on the orbit semi-major axis and inclination and to a lesser extent to the eccentricity (because we can assume roughly circular orbit in this context, with eccentricity < 0.1).

At 500km and 45deg inclination, you get a precession of about 5.4deg/day and at 1100km, about 4deg/day.

This means that you could launch all your satellites on a 500km circular orbit, directly raise the orbit of some of them to 1100km and wait some time before raising the orbit of the other ones. The planes will drift from each other at 1.4deg/day, so about 4 months if you want up to 180deg shift between the planes (for 45deg inclination).

The rate of precession decreases mostly linearly with increasing inclination down to about zero at 90deg. So at 67deg, it would take about twice the time. At lower inclination, it's higher, but not linear (with max at 0deg).

However, all this assumes quick orbit altitude changes. As they mentioned Hall thrusters, this is more complex as the orbital raising is more progressive. I guess this means more time required to get the required relative plane shift.
In terms of delta-V, we are talking 311m/s to go from 500km to 1100km, so assuming 1500s Isp (seems conservative for Hall thruster), that's about 2% of the total mass to be consumed as propellant. Assuming 300kg spacecraft, that's 6kg, and with a 50mN thruster, it also means 21 days of continuous thrust for orbit raising.

So, if you can wait some months to get your satellites in the correct orbits and accept the additional fuel, maybe it's possible.
On the other hand, it would be an operational nightmare to manage all these satellites on continuously changing orbits when going from their initial orbit up to 1100km, especially that you'll be crossing the orbital path of all the sats in sun-synchronous orbits (mostly in the 600 to 900km range).
Finally, launching a large number of satellites together from the same launcher increases the risk of collisions just after separation, so the separation mechanism and sequence needs to be very carefully designed.

[MP99]

OK then, I am not too familiar with the terms, it is planes then. You can get satellites to any plane  with the same inclination with one launch. Just keep them elliptical for some time and the plane will change.

It all depends how much time you have and how much of the satellite propellant you want to spend on this.

The rate of precession of the nodes depends on the orbit semi-major axis and inclination and to a lesser extent to the eccentricity (because we can assume roughly circular orbit in this context, with eccentricity < 0.1).

At 500km and 45deg inclination, you get a precession of about 5.4deg/day and at 1100km, about 4deg/day.

This means that you could launch all your satellites on a 500km circular orbit, directly raise the orbit of some of them to 1100km and wait some time before raising the orbit of the other ones. The planes will drift from each other at 1.4deg/day, so about 4 months if you want up to 180deg shift between the planes (for 45deg inclination).

The rate of precession decreases mostly linearly with increasing inclination down to about zero at 90deg. So at 67deg, it would take about twice the time. At lower inclination, it's higher, but not linear (with max at 0deg).

However, all this assumes quick orbit altitude changes. As they mentioned Hall thrusters, this is more complex as the orbital raising is more progressive. I guess this means more time required to get the required relative plane shift.
In terms of delta-V, we are talking 311m/s to go from 500km to 1100km, so assuming 1500s Isp (seems conservative for Hall thruster), that's about 2% of the total mass to be consumed as propellant. Assuming 300kg spacecraft, that's 6kg, and with a 50mN thruster, it also means 21 days of continuous thrust for orbit raising.

So, if you can wait some months to get your satellites in the correct orbits and accept the additional fuel, maybe it's possible.
On the other hand, it would be an operational nightmare to manage all these satellites on continuously changing orbits when going from their initial orbit up to 1100km, especially that you'll be crossing the orbital path of all the sats in sun-synchronous orbits (mostly in the 600 to 900km range).
Finally, launching a large number of satellites together from the same launcher increases the risk of collisions just after separation, so the separation mechanism and sequence needs to be very carefully designed.

AIUI, each plane will need to orbit at a discrete altitude. 4,000+ sats could be ~64 planes of ~64 each.

If you need to deliver a sat to whichever is the highest plane, would it be practical to have the thruster raise it through the lower 63 planes to reach its destination? Or, does one minor error, like a thruster failure, put you at risk of setting off your own Kessler Syndrome? I know "Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space."

I just can't picture how dangerous this is, or if the chances of collision are negligible even in such a "crowded" space.

Cheers, Martin

[denis]

AIUI, each plane will need to orbit at a discrete altitude. 4,000+ sats could be ~64 planes of ~64 each.

If you need to deliver a sat to whichever is the highest plane, would it be practical to have the thruster raise it through the lower 63 planes to reach its destination? Or, does one minor error, like a thruster failure, put you at risk of setting off your own Kessler Syndrome? I know "Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space."

I just can't picture how dangerous this is, or if the chances of collision are negligible even in such a "crowded" space.

Cheers, Martin

My conclusion is "maybe it's possible", not "it's a very good and practical idea"

It think the operational difficulty and the collision risk is probably too high to do it that way.
The main reason being that if you want to do it that way in a realistic amount of time (i.e. a few months), then you need to start from quite low (like 500km) compared to the final orbit. Then you end up crossing the path of all the satellites in SSO, which is too risky (for the sats in SSO, not for the "1 in 4000 sats which we don't care to lose").

Even if your 64 planes are in 64 different altitudes, they will be close to each other, so this natural shift in orbital plane is not practical (takes too long). Maybe there is an efficient way of actively changing the orbital plane with the Hall thruster (for reasonable propellant consumption), but I don't know much about this type of orbit manoeuvres.

In any case, I think this question is a bit rhetorical: if we are talking 64 satellites per plane, it's more than enough to launch in one go, it's going to be hard enough to deploy so many of them on a single launch (+ the difficulty of the launch campaign and the LEOP).
Going for an even heavier launcher to launch more in one go sounds a bit mad (and might be more expensive than using 2 smaller launchers; launch cost is not just the cost of the launcher)

[Zed_Noir]

Its more than just mass, you need deployment adapters. Going with ORBCOMM size satellites and the Moog rings that deployed them, my M1 Eyeball puts the rings at 1-1.5 meters high. With 4 birds per ring and 5-6 rings that's only 20-24 satellites per launch in the 5.2m fairing. Maybe 28 of you can shoehorn 7 rings.

We need a bigger boat. Maybe FH's BA-330 fairing from the Bigelow GATE 2 study.

The Moog ESPA rings are 28 inches high with 6 mounting points for Sats 400 lbs or less. A stack of 12 rings will fitted in the SpaceX PLF. This adapter ring is commonly use for secondary payloads on all major US LVs.

You are referring to the Moog EPSA Grande which is 38.8 inches high with 4 mounting points for Sats 660 lb or less.

Moog ESPA brochure

From Elon's Seattle talk:-

"This would be not using cubesats. Satellites we have in mind are to be quite sophisticated. They'd be a smallish satellite but with big satellite capability. By smallish I mean, in the few hundred kilogram range."

Possibly going to need a bigger Moog than the Grande's 300 kg limit.

Cheers, Martin

For a 5 year lifespan Sat. It should as light as possible. I take Musk's comment to meant between 100 and 200 kg per Sat.

By comparison the Orbcomm-2 Sats are only 172 kg each.

I'd be surprised if they didn't build a custom dispenser.

Only if is a lot cheaper than the Moog ESPA rings, which is basically a monbloc forged aluminum cylinder. Any new dispenser system have to be developed and get certified plus manufacturing infrastructure set up.

[guckyfan]

I'd be surprised if they didn't build a custom dispenser.

Only if is a lot cheaper than the Moog ESPA rings, which is basically a monbloc forged aluminum cylinder. Any new dispenser system have to be developed and get certified plus manufacturing infrastructure set up.

They would need thousands. I am sure there will be a new development designed for mass production. Internal or Moog we will see.

Or there will be no dispenser at all. Just a stack of satellites, 9 in each layer, with layers stacked above each other as many as the fairing or launch vehicle capacity allows. It would be a stack much more stable than dispensers with minimal structural mass. That also allows for more satellites per volume.

They just must make sure the disconnecting mechanism is reliable.

[MP99]

Its more than just mass, you need deployment adapters. Going with ORBCOMM size satellites and the Moog rings that deployed them, my M1 Eyeball puts the rings at 1-1.5 meters high. With 4 birds per ring and 5-6 rings that's only 20-24 satellites per launch in the 5.2m fairing. Maybe 28 of you can shoehorn 7 rings.

We need a bigger boat. Maybe FH's BA-330 fairing from the Bigelow GATE 2 study.

The Moog ESPA rings are 28 inches high with 6 mounting points for Sats 400 lbs or less. A stack of 12 rings will fitted in the SpaceX PLF. This adapter ring is commonly use for secondary payloads on all major US LVs.

You are referring to the Moog EPSA Grande which is 38.8 inches high with 4 mounting points for Sats 660 lb or less.

Moog ESPA brochure

From Elon's Seattle talk:-

"This would be not using cubesats. Satellites we have in mind are to be quite sophisticated. They'd be a smallish satellite but with big satellite capability. By smallish I mean, in the few hundred kilogram range."

Possibly going to need a bigger Moog than the Grande's 300 kg limit.

Cheers, Martin

For a 5 year lifespan Sat. It should as light as possible. I take Musk's comment to meant between 100 and 200 kg per Sat.

By comparison the Orbcomm-2 Sats are only 172 kg each.

If he meant that small, then a better word would have been "couple", rather than "few".

I would take his comment to mean 300 to 400 kg, but we may need to agree to differ over a minute analysis of a single phrase until we get another quote.

Cheers, Martin