Author Topic: Star-Ship Mars' moon operations- is it part of the colony plan?  (Read 1202 times)

Offline 50_Caliber

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I was thinking how easy it would be for a Star Ship to go from the surface of Mars to the Martian moons. Perhaps Phobos would be the preferred moon for routine operations since it is much closer to Mars than Deimos. The question I have would be- has Elon Musk ever made any mention of utilizing the Martian moons as part of a colony? Is there a practical use for Phobos or Deimos in terms of supporting a Mars colony? Do you think if they wanted an orbital base around Mars, would one of the moons be preferable to building a base in a closer Mars orbit?

What would be the advantages or disadvantages of incorporating the Martian moons into plans for colony support?

Offline philw1776

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Elon has not mentioned the moons.
IF and a big IF the moons were found to be an unexpected source of propellant or other resource then yes, otherwise no.  Right now it's no.  A complication for what gain?

Offline AC in NC

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Just a few data points if I read the Delta V maps right..

Deimos and Phobos from Transfer Orbit are 29% and 34% of Landing Delta V (some reducible via aero-capture)
Deimos and Phobos from Mars are 85% and 94% of Transfer Orbit Delta V (most of that is initial Low Mars Orbit)

So I would gather than Mars Moon staging inbound might be reasonable but from Mars itself it's a lot of delta V comparatively.  Might make more sense to consider something else (eg: Orbital staging rather than Moon).


Real Solar System delta V Map from Garrst on a Kerbal forum:  https://forum.kerbalspaceprogram.com/index.php?/topic/131682-is-there-a-delta-v-chart-for-real-solar-system-mod/
« Last Edit: 01/20/2019 11:57 pm by AC in NC »

Offline 50_Caliber

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Just a few data points if I read the Delta V maps right..

Deimos and Phobos from Transfer Orbit are 29% and 34% of Landing Delta V (some reducible via aero-capture)
Deimos and Phobos from Mars are 85% and 94% of Transfer Orbit Delta V (most of that is initial Low Mars Orbit)

So I would gather than Mars Moon staging inbound might be reasonable but from Mars itself it's a lot of delta V comparatively.  Might make more sense to consider something else (eg: Orbital staging rather than Moon).


Real Solar System delta V Map from Garrst on a Kerbal forum:  https://forum.kerbalspaceprogram.com/index.php?/topic/131682-is-there-a-delta-v-chart-for-real-solar-system-mod/
I wonder what kind of Delta V budget does the StarShip have? Could it make it to Phobos from the surface of Mars?

Admittedly it's hard to find a rationale to incorporate the Martian moons into part of the operational activity of a Mars colony.

I'll throw out a few ideas:

1.A Phobos base would be a great tourist spot, not sure how much tourism there would be, but maybe...

2.Using tele-operated mining and 3d printing on Phobos, it could manufacture large solar panels for surface use or beamed power.

3.Potential fuel source?

4.NASA or another government pays for them to send expeditions there to explore the moons.

Do you think there would be any interest in sending an expedition to the moons of Mars once they get there, just to see what resources would be available?

Offline AC in NC

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I wonder what kind of Delta V budget does the StarShip have? Could it make it to Phobos from the surface of Mars?

Admittedly it's hard to find a rationale to incorporate the Martian moons into part of the operational activity of a Mars colony.

I'll throw out a few ideas:

1.A Phobos base would be a great tourist spot, not sure how much tourism there would be, but maybe...

2.Using tele-operated mining and 3d printing on Phobos, it could manufacture large solar panels for surface use or beamed power.

3.Potential fuel source?

4.NASA or another government pays for them to send expeditions there to explore the moons.

Do you think there would be any interest in sending an expedition to the moons of Mars once they get there, just to see what resources would be available?

Take my understanding of the numbers with appropriate caveats.  Others are far better numbers guys than I.

Starship is supposed to be just capable of SSTO with no payload.  Round that to 10km/s.  That's with no payload so payload upbound from Mars would would reduce that from the initial ~5km/s you spend getting there with the remainder to get somewhere else.  Inbound to Mars that 10km/s gets (A) reduced by payload and (B) reduced by Mars Transfer delta v (eg: ~3.5km/s starting from LEO).  My understanding is that what's left is NOT ENOUGH to land (5.7km/s) absent aero-capture.

So with that starting point, I'm left to suspect that WITH PAYLOAD ... you reach the moons from either direction without a great deal of spare fuel.

1)  You could probably stop by a moon (0.55-0.65km/s one-way; or double that as a stop off prior to landing on Mars) but I suspect you need to be refueled there or somewhere else (like Mars).  I don't know if that 1.1-1.3km/s makes landing impossible.  So I suspect visits require a depot or precise use of aerobraking to reduce the cost of getting there.

2)  As with the "glass" discussion, I suspect purity of raw material and other issues put this a long way off for practicality.

3)  Sort of the same -AND- I suspect the precursors aren't there.

4)  Certainly possible.

For my part, I'm just not aware of what the advantages or being there might or might not be.  As a layman I do wonder about a depot where you are perhaps shaded a lot and saved of the need for station-keeping.

I like to think about it though and would be pleased to hear from the experts.
« Last Edit: 01/21/2019 12:38 am by AC in NC »

Online Zed_Noir

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....
Real Solar System delta V Map from Garrst on a Kerbal forum:  https://forum.kerbalspaceprogram.com/index.php?/topic/131682-is-there-a-delta-v-chart-for-real-solar-system-mod/
I wonder what kind of Delta V budget does the StarShip have? Could it make it to Phobos from the surface of Mars?

Admittedly it's hard to find a rationale to incorporate the Martian moons into part of the operational activity of a Mars colony.

I'll throw out a few ideas:

1.A Phobos base would be a great tourist spot, not sure how much tourism there would be, but maybe...

2.Using tele-operated mining and 3d printing on Phobos, it could manufacture large solar panels for surface use or beamed power.

3.Potential fuel source?

4.NASA or another government pays for them to send expeditions there to explore the moons.

Do you think there would be any interest in sending an expedition to the moons of Mars once they get there, just to see what resources would be available?

Both option #1 and #2 seems redundant since you need a SX Starship to get mobile and static cargo to the Martian Moons. It will be a lot quicker and cheaper to outfit a Starship as a Mars orbital platform.

For option #3 and #4 brings up the issue of the SX Starship landing on either Mars Moons with their low escape velocity. Think one Raptor engine got too much thrust even at the lowest throttle setting. Maybe SX can do a hairy hover slam landing.

If anyone wants to go to the Martian Moons with people. A whole new set of vehicles and EVA gear is needed after you landed due to the low gravity.

Offline 50_Caliber

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Real Solar System delta V Map from Garrst on a Kerbal forum:  https://forum.kerbalspaceprogram.com/index.php?/topic/131682-is-there-a-delta-v-chart-for-real-solar-system-mod/
I wonder what kind of Delta V budget does the StarShip have? Could it make it to Phobos from the surface of Mars?

Admittedly it's hard to find a rationale to incorporate the Martian moons into part of the operational activity of a Mars colony.

I'll throw out a few ideas:

1.A Phobos base would be a great tourist spot, not sure how much tourism there would be, but maybe...

2.Using tele-operated mining and 3d printing on Phobos, it could manufacture large solar panels for surface use or beamed power.

3.Potential fuel source?

4.NASA or another government pays for them to send expeditions there to explore the moons.

Do you think there would be any interest in sending an expedition to the moons of Mars once they get there, just to see what resources would be available?

Both option #1 and #2 seems redundant since you need a SX Starship to get mobile and static cargo to the Martian Moons. It will be a lot quicker and cheaper to outfit a Starship as a Mars orbital platform.

For option #3 and #4 brings up the issue of the SX Starship landing on either Mars Moons with their low escape velocity. Think one Raptor engine got too much thrust even at the lowest throttle setting. Maybe SX can do a hairy hover slam landing.

If anyone wants to go to the Martian Moons with people. A whole new set of vehicles and EVA gear is needed after you landed due to the low gravity.

Hmm yeah, I hadn't thought of that, even one Raptor would be way over-powered for a landing on Phobos, but the directional thrusters could possibly be used to land, but it wouldn't be what their designed for.

Offline AC in NC

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Although it's absolutely correct that a different vehicle would be far better for the moons, I suspect there's enough RCS to do a landing if you wanted (but I think you'd really kind of prefer something to fire into the surface as an anchor).

The delta v map suggests that from Moon Capture orbit to landing is only 6 and 9 m/s.  In fact to put it in perspective, the final Low Orbit to Deimos delta v (2 m/s) is about the design spec for how hot the F9S1 can land.

Offline guckyfan

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Any mission profile that expends more delta-v in the vincinity of Mars than reserved for landing has a problem. The header tanks will be sized for landing only. So it would need a major redesign, seems not likely to me. That's assuming the steel version still needs header tanks, maybe not?

What they could do is land on Mars, refuel and then go to the moons and back to the surface. I have hoped for a long time that they could find the materials for propellant production. It would help a lot if they don't have to lift the propellant for trans earth injection from the surface of Mars. Besides that NASA or some other institution could do phantastic science missions. Not too expensive by NASA standards even if the Starship is no longer fit for earth return and needs to stay on Mars.
« Last Edit: 01/21/2019 07:44 am by guckyfan »

Offline Slarty1080

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As others have said I doubt that either moon would be of interest initially. In the more distant future I'm sure there would be sufficient interest for at least one expedition to investigate the moons. Beyond that in the far future I suppose they might pose an interesting location for some people.

A location where you could propel yourself into orbit by running might be an interesting if dangerous activity. It would probably need a prepared set of hard steps in the surface and a lot of practice. I imagine there might be a number of comical sub orbital flights with a lot of spinning. They would also probably need a computer controlled thruster pack to prevent crash landings and to deorbit.
The first words spoken on Mars: "Humans have been wondering if there was any life on the planet Mars for many decades well ... there is now!"

Offline 50_Caliber

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Any mission profile that expends more delta-v in the vincinity of Mars than reserved for landing has a problem. The header tanks will be sized for landing only. So it would need a major redesign, seems not likely to me. That's assuming the steel version still needs header tanks, maybe not?

What they could do is land on Mars, refuel and then go to the moons and back to the surface. I have hoped for a long time that they could find the materials for propellant production. It would help a lot if they don't have to lift the propellant for trans earth injection from the surface of Mars. Besides that NASA or some other institution could do phantastic science missions. Not too expensive by NASA standards even if the Starship is no longer fit for earth return and needs to stay on Mars.

The scenario you talk about of refueling on Mars and then going to to the moons was what I had in mind. It seems that if their fuel processing system on the surface of Mars could readily supply the fuel, then it would be a fairly easy and inexpensive prospect to go to the moons with a fully fueled StarShip. The entire Martian system would be readily accessible to the first colonists from the ability to go to any point on Mars clear out to the farthest Martian moon of Deimos.

Whether it's practical to utilize this access is another question, though it may be that the StarShip is so capable and the moons are readily accessible that practicality may not be the primary rationale for going to these locations when you have the fuel processing on Mars and a ship that can easily get there without even getting close to it's operational limits.

The idea that the first colonists would have routine and easy access across the entire Martian system appeals to me.

Offline Bynaus

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From the planetary science point of view it seems more and more likely that the moons of Mars are devoid of any volatiles (they are probably remnants of a big disk of devolatilized impact debris). As such, they are interesting in a scientific (and perhaps touristic) sense, but not much more. Sure, once there is a colony on Mars, they will be explored and they might find a local use, but I don't think they will play any critical role in the establishment of the colony on Mars.
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Offline mikelepage

Probably worth mentioning one of the conclusions we came to in a previous discussion was that any travel to Phobos/Deimos will almost certainly be from Mars surface, purely for orbital mechanics reasons.

Phobos inclination is 1.093 (to Mars' equator), but 26.04 (to the ecliptic).  Which means that if you were entering Martian planetary space on a hyperbolic (trans-planetary) trajectory, and wanted to aerobrake into a Phobos-inclination orbit, that would only be possible twice per Martian year - when Phobos' orbit's ascending/descending nodes align with that Sun-Mars axis. 

You're probably coming from Earth, so the Earth-Mars transfer windows (and corresponding Mars arrival times) will only align with these ascending/descending nodes on very rare occasions (i.e. decades apart).  So better to land on Mars first (get the extra fuel via ISRU) and then explore Phobos (and Deimos) separately.

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