Starlink: when can we expect Martian deployment?

[whvholst]

Apologies if this should be in the Starship section, but since Starlink threads are in this section, I thought it belongs here.

Anyway:

For Martian exploration a Starlink-like constellation would be a reasonable stepping stone. If I am not mistaken, this would already be doable with Falcon Heavy launches instead of Starship. What would be a reasonable timeline for such a thing starting to materialise?

[Robotbeat]

They prob Do have enough delta-v or could easily have it with the most minor of modifications. They have Hall effect thrusters. It doesn’t take that must to enter a high elliptical Mars orbit. Low thrust takes ~twice the delta v of hi thrust but even still. High thrust delta-v is just 0.9km/s to enter orbit. Isp of Starlink is 25km/s, and the low thrust delta-v would be less than 2km/s, so we’re looking at less than 10% of Starlink’s mass in Argon, a bit over 100 days with one thruster. (You need to do a weird trajectory to enter orbit with low thrust but it’s definitely doable.)

People always like to make the claims about how hard stuff is without actually checking the numbers. Check the numbers!!!

[intelati]

My dream intermediate Martian network is like a 20 starlink system (5 in four planes) all with a *single earth to system satellite* in a L2 point (Along that line)

I've *never* seen anyone suggest anything like that, so I don't even know if it's possible..

[jimvela]

For Martian exploration a Starlink-like constellation would be a reasonable stepping stone.

Nope.

Starlink SC are the wrong solution for Mars.  What Mars exploration needs right now are more and newer com relay spacecraft.

It may be centuries before there is enough presence on the ground for a high density of telecom spacecraft like starlink.

Even if you think I'm wrong, the starlink spacecraft are not able to close a link with Earth as-is, so you'd still need a telecommunications relay spacecraft to enable a starlink bus to function at mars.

Then there's the whole inability of a starlink to insert itself into Mars orbit. 
It's the wrong spacecraft, with the wrong telecom implementation, for Mars in the here and now.

If I am not mistaken, this would already be doable with Falcon Heavy launches instead of Starship.

You are mistaken.

What would be a reasonable timeline for such a thing starting to materialise?

Never.

Whatever goes to Mars to support exploration, it won't be anything like the current Starlink bus.  Perhaps some components and methodologies could be reused, but it would then be an all-new system.

[Robotbeat]

For Martian exploration a Starlink-like constellation would be a reasonable stepping stone.

Nope.

Starlink SC are the wrong solution for Mars.  What Mars exploration needs right now are more and newer com relay spacecraft.

It may be centuries before there is enough presence on the ground for a high density of telecom spacecraft like starlink.

Even if you think I'm wrong, the starlink spacecraft are not able to close a link with Earth as-is, so you'd still need a telecommunications relay spacecraft to enable a starlink bus to function at mars.

Then there's the whole inability of a starlink to insert itself into Mars orbit. 
It's the wrong spacecraft, with the wrong telecom implementation, for Mars in the here and now.

If I am not mistaken, this would already be doable with Falcon Heavy launches instead of Starship.

You are mistaken.

What would be a reasonable timeline for such a thing starting to materialise?

Never.

Whatever goes to Mars to support exploration, it won't be anything like the current Starlink bus.  Perhaps some components and methodologies could be reused, but it would then be an all-new system.

Way too dismissive and incorrect. Starlink can be used as relay satellites. Musk suggested it. Keep in mind Starlink includes multiple types of radios as well as laser links.

To zeroth order, Starlink satellites are free. So you can do things like multiple hop laser comms to Earth with some Starlink satellites at 1.1AU, some at 1.2AU, and so on. You can also compensate for lower gain with lower bitrate.

You’re also incorrect about inability to do insertion. High Isp on-board propulsion is sufficient; you can do low thrust insertions with the right trajectory.

Is it optimal? Maybe not, but it helps not to make technically incorrect statements to slap down an idea that is technically doable. If you want to correct something, you’d better actually be accurate in your statements.

[jimvela]

People always like to make the claims about how hard stuff is without actually checking the numbers. Check the numbers!!!

Check the conops.
It's not just about the Delta V, it's also about the impulse and trajectory design.

To insert at Mars with SEP, you need a trajectory that has a really low rate of closure with the planet because the thrust provided by the SEP thruster is so low. 

A conventional high-thrust insertion does all of its burn in minutes or tens of minutes, where the same delta-V from SEP takes days or weeks.

Then there's the whole power and thermal issue from being at 1.4 to 1.6 AU, and not being able to close a telecom link with Earth using the existing bus.

Starlink is not a Mars-capable bus without enough changes to make it an entirely new spacecraft.

[DanClemmensen]

Apologies if this should be in the Starship section, but since Starlink threads are in this section, I thought it belongs here.

Anyway:

For Martian exploration a Starlink-like constellation would be a reasonable stepping stone. If I am not mistaken, this would already be doable with Falcon Heavy launches instead of Starship. What would be a reasonable timeline for such a thing starting to materialise?

Use Aerosynchronous Mars (AMO) or medium height (MMO) instead. We used GEO for decades before launching LEO constellation. We need LEO constellations because we have millions of geographically-dispersed customers needing high bandwidth.  Until Mars has more than a few million people, most in cities, the higher satellites will be more than adequate. For AMO, three satellites and add four Molinyas if you insist on Polar coverage. For MMO, maybe 12 satellites.

[Robotbeat]

Apologies if this should be in the Starship section, but since Starlink threads are in this section, I thought it belongs here.

Anyway:

For Martian exploration a Starlink-like constellation would be a reasonable stepping stone. If I am not mistaken, this would already be doable with Falcon Heavy launches instead of Starship. What would be a reasonable timeline for such a thing starting to materialise?

In spite of the technically incorrect responses to your post, it is feasible. Not sure they’ll do it, though. FH launches cost real money and they’re focused on scaling out Starlink to meet regulatory deadlines plus readying Starship for Artemis.

[Robotbeat]

Apologies if this should be in the Starship section, but since Starlink threads are in this section, I thought it belongs here.

Anyway:

For Martian exploration a Starlink-like constellation would be a reasonable stepping stone. If I am not mistaken, this would already be doable with Falcon Heavy launches instead of Starship. What would be a reasonable timeline for such a thing starting to materialise?

Use Aerosynchronous Mars (AMO) or medium height (MMO) instead. We used GEO for decades before launching LEO constellation. We need LEO constellations because we have millions of geographically-dispersed customers needing high bandwidth.  Until Mars has more than a few million people, most in cities, the higher satellites will be more than adequate. For AMO, three satellites and add four Molinyas if you insist on Polar coverage. For MMO, maybe 12 satellites.

It only takes like 66 satellites to make a doable LMO constellation. One refueled Starship could launch that many Minis in a single go.

[Robotbeat]

People always like to make the claims about how hard stuff is without actually checking the numbers. Check the numbers!!!

Check the conops.
It's not just about the Delta V, it's also about the impulse and trajectory design.

To insert at Mars with SEP, you need a trajectory that has a really low rate of closure with the planet because the thrust provided by the SEP thruster is so low. 

…

Well yeah, that’s what I already said. “Oh well you have to use a differEnt trajectory.”

Is that even hard? No. Is it a showstopper, enough to claim it can’t be done and slap down someone’s post? Hell no!

[jimvela]

Well yeah, that’s what I already said. “Oh well you have to use a differEnt trajectory.”

Is that even hard? No. Is it a showstopper, enough to claim it can’t be done and slap down someone’s post? Hell no!

Again, the mission systems engineering can't be dismissed with a hand wave so easily.

Could you fling a batch of current generation Starlink busses to Mars as a dumbass publicity stunt? Yep.
Would they be useful? Nope.

Some further questions for you:
How do you close the link with earth?
After insertion to Mars orbit, what prop budget remains, and what mission life do you get out of the arrived vehicles?

What vehicles at Mars currently or in the near term future would be able to communicate with Starlink? (None.)
What planned spacecraft would be able to use the starlink? (None.)
What actual value is provided by this? (None.)


Now, if you want to talk about what would actually benefit Mars exploration in a way that actually helps science, exploration, and colonization- that's a whole different bird, and that's a good topic of discussion/debate. 

It still isn't a current generation starlink bird. I stand by my assessment.

[laszlo]

So we've moved on from LEGO rockets to LEGO comsats?

[waveney]

Well - I've considered this for a while (I am a retired telecoms consultant). 

Starlink for Mars will need beefed up optical links.   The protocols would need changing, to handle the delays, but not drastically.  Both are quite practical once they have it working well around the Earth.  It would offer significant bandwidth for about 10 months of the year (apart from when Mars is in Conjunction or Opposition - losing about a month each time).  The Sun's glare has a significant effect on optic links.

Its direct to cell use would be very applicable for smaller Mars equipment, not needing the complexity of the current transport via the current relay sats.

I predict that they will be deployed the first time a starship gets to Mars.

I have called it MarsLink in my Mars Book to be.

[Robotbeat]

Well yeah, that’s what I already said. “Oh well you have to use a differEnt trajectory.”

Is that even hard? No. Is it a showstopper, enough to claim it can’t be done and slap down someone’s post? Hell no!

Again, the mission systems engineering can't be dismissed with a hand wave so easily.

Could you fling a batch of current generation Starlink busses to Mars as a dumbass publicity stunt? Yep.
Would they be useful? Nope.

Some further questions for you:
How do you close the link with earth?
After insertion to Mars orbit, what prop budget remains, and what mission life do you get out of the arrived vehicles?

What vehicles at Mars currently or in the near term future would be able to communicate with Starlink? (None.)
What planned spacecraft would be able to use the starlink? (None.)
What actual value is provided by this? (None.)


Now, if you want to talk about what would actually benefit Mars exploration in a way that actually helps science, exploration, and colonization- that's a whole different bird, and that's a good topic of discussion/debate. 

It still isn't a current generation starlink bird. I stand by my assessment.

You ask a lot of questions as if to prove it's possible I need to give you a design document. The term for asking a lot of questions so when one objection is answered there are a dozen others behind it is called "Gish Galloping."

And you say "not a current generation starlink bird" as a very nice mobile goalpost that can be moved wherever you like once SpaceX demonstrates using Starlink for Mars in the future.

[DanClemmensen]

Well - I've considered this for a while (I am a retired telecoms consultant). 

Starlink for Mars will need beefed up optical links.   The protocols would need changing, to handle the delays, but not drastically.  Both are quite practical once they have it working well around the Earth.  It would offer significant bandwidth for about 10 months of the year (apart from when Mars is in Conjunction or Opposition - losing about a month each time).  The Sun's glare has a significant effect on optic links.

Its direct to cell use would be very applicable for smaller Mars equipment, not needing the complexity of the current transport via the current relay sats.

I predict that they will be deployed the first time a starship gets to Mars.

I have called it MarsLink in my Mars Book to be.

I think any AMO, MMO, or LMO constellation will be used to create the Mars-to-Mars internet. You need a separate link to Earth. Mars-to-Earth uses completely different protocols even if it uses some of the same hardware. The existing V.2 mini Starlinks already have 100Gbps laser ISL, and this will be more than adequate for the Mars Internet until the Mars population exceeds several million dispersed. I'm assuming that cities will use local fiber. The links back to Earth may either be on the ground or on separate satellites. A link back to Earth has very different physical and usage characteristics than an ISL.

[waveney]

Well - I've considered this for a while (I am a retired telecoms consultant). 

Starlink for Mars will need beefed up optical links.   The protocols would need changing, to handle the delays, but not drastically.  Both are quite practical once they have it working well around the Earth.  It would offer significant bandwidth for about 10 months of the year (apart from when Mars is in Conjunction or Opposition - losing about a month each time).  The Sun's glare has a significant effect on optic links.

Its direct to cell use would be very applicable for smaller Mars equipment, not needing the complexity of the current transport via the current relay sats.

I predict that they will be deployed the first time a starship gets to Mars.

I have called it MarsLink in my Mars Book to be.

I think any AMO, MMO, or LMO constellation will be used to create the Mars-to-Mars internet. You need a separate link to Earth. Mars-to-Earth uses completely different protocols even if it uses some of the same hardware. The existing V.2 mini Starlinks already have 100Gbps laser ISL, and this will be more than adequate for the Mars Internet until the Mars population exceeds several million dispersed. I'm assuming that cities will use local fiber. The links back to Earth may either be on the ground or on separate satellites. A link back to Earth has very different physical and usage characteristics than an ISL.

Agree on the total bandwidth.

Mars to Marslink - as Starlink today. 

Marslink to Earth orbit - New beefy optics (probably needs WDM), new highly delay tollerant protocols with handling for different routing, different ordering of packets, inverse muxing, differing procedures, switching between the satellites will have to change - lots of things, nothing a showstopper.

Earth obit to Earth - as Starlink today

[waveney]

The one month block out at conjunction and opposition can be worked around by placing a relay at Earth or Mars L4 or L5.   This would basically be a pair of Marslink sats back to back.   I don't expect those to be provided for quite while though.   

These links would be useful out side conjunction/opposition for slower than normal data transfers most of the time.

[DanClemmensen]

The one month block out at conjunction and opposition can be worked around by placing a relay at Earth or Mars L4 or L5.   This would basically be a pair of Marslink sats back to back.   I don't expect those to be provided for quite while though.   

These links would be useful out side conjunction/opposition for slower than normal data transfers most of the time.

A link at Mars L4 or L5 will more than double the transit delay. A link a Earth L4 or L will add at least 8 minutes. Three satellites in the same solar orbit, as near to the sun as the engineering easily allows, would be ideal. I have no idea how close that would be: maybe Mercury orbit?

[waveney]

The one month block out at conjunction and opposition can be worked around by placing a relay at Earth or Mars L4 or L5.   This would basically be a pair of Marslink sats back to back.   I don't expect those to be provided for quite while though.   

These links would be useful out side conjunction/opposition for slower than normal data transfers most of the time.

A link at Mars L4 or L5 will more than double the transit delay. A link a Earth L4 or L will add at least 8 minutes. Three satellites in the same solar orbit, as near to the sun as the engineering easily allows, would be ideal. I have no idea how close that would be: maybe Mercury orbit?

They would have long delays, but would be good for quantity of data and the ability to always have some link capacity.

Relays in a near sun orbit would not help.   Too close to the Sun and the glare ruins optic links.  Also there are large DeltaV requirements to get into inner orbits.  The Earth's L4/L5 are the easiest to reach.

Add a relay at one of the 4 points (Earth or Mars, L4 or L5) and you have comms most of the time. 

Add a relay at both L4 and L5  of either Earth or Mars and you have a comms link always, and two (or more) links 90+% of the time.

[steveleach]

The one month block out at conjunction and opposition can be worked around by placing a relay at Earth or Mars L4 or L5.   This would basically be a pair of Marslink sats back to back.   I don't expect those to be provided for quite while though.   

These links would be useful out side conjunction/opposition for slower than normal data transfers most of the time.

A link at Mars L4 or L5 will more than double the transit delay. A link a Earth L4 or L will add at least 8 minutes. Three satellites in the same solar orbit, as near to the sun as the engineering easily allows, would be ideal. I have no idea how close that would be: maybe Mercury orbit?

Does additional transit delay even really matter all that much, in practical terms?

When the best case delay is 15 minutes or so, your comms are already going to be more like email exchanges than phone calls or instant messaging. Without instant feedback, you are also going to want to spend more time crafting your message as well, and I can imagine that adding more delay than an L4/L5 relay does.