SpaceX for Moon Base

[Dave G]

Lunar landings are fine, but even SpaceX has no idea how to really do ISRU there, so it's limited to touch-and-go.

Not quite sure what you mean here.

Yes, Elon mentioned that there would be no methane/oxygen fuel production on the Moon, but he also mentioned that the space ship can make the return trip to Earth without it, due to the Moon's lower gravity.

As for other consumables, note that the Moon does have lots of water ice in permanently shaded areas of craters.  For this reason, many have proposed a Moon base at the South Pole.  This would also provide a constant source of sunlight for power.

• Constant sunlight unobstructed by any atmosphere
• Huge supply of water, which can be used to make oxygen
• 24/7 communications with Earth, with only a 1-second delay
not so bad...

[John Alan]

Lunar landings are fine, but even SpaceX has no idea how to really do ISRU there, so it's limited to touch-and-go.

Other than graphics, there was no declaration of intent either.  IF some one pays them, they might take him/her/them there.

The intent is to colonize Mars, and that hasn't changed.

I agree with you.
EM basically outlined this...
"Hey everyone... I'm going to build a space transport system that can lift 150 tons to LEO...
Max payload size about 8m dia and about 15m long... (if cone shaped 8.5m dia and 20m long is possible
And using tankers I can put that payload anywhere in the inner solar system for a fee...
With this slide... I show I can put 150 tons of crane able crates delivered to The Moon Surface... 
Call SpaceX if you have a need for such a delivery service..."

No mention of a SpaceX need to do this... He just intends to start a space trucking company for hire... 
And the folks that need crates and people delivered to the Moon... will help him get to Mars via cash flow... 

[MikeAtkinson]

Lunar landings are fine, but even SpaceX has no idea how to really do ISRU there, so it's limited to touch-and-go.

Not quite sure what you mean here.

Yes, Elon mentioned that there would be no methane/oxygen fuel production on the Moon, but he also mentioned that the space ship can make the return trip to Earth without it, due to the Moon's lower gravity.

O2 is available everywhere on the moon, and is much easier to obtain than the water ice in polar cold traps.

They can increase the landed payload by only loading enough O2 to land from the tankers, then filling up with the missing O2 on the moon. Direct 1-to-1 replacement of O2 with payload. It is also possible to use the same technique to increase the returned payload, though the benefit is not as great.

[oldAtlas_Eguy]

Lunar landings are fine, but even SpaceX has no idea how to really do ISRU there, so it's limited to touch-and-go.

Other than graphics, there was no declaration of intent either.  IF some one pays them, they might take him/her/them there.

The intent is to colonize Mars, and that hasn't changed.

I agree with you.
EM basically outlined this...
"Hey everyone... I'm going to build a space transport system that can lift 150 tons to LEO...
Max payload size about 8m dia and about 15m long... (if cone shaped 8.5m dia and 20m long is possible
And using tankers I can put that payload anywhere in the inner solar system for a fee...
With this slide... I show I can put 150 tons of crane able crates delivered to The Moon Surface... 
Call SpaceX if you have a need for such a delivery service..."

No mention of a SpaceX need to do this... He just intends to start a space trucking company for hire... 
And the folks that need crates and people delivered to the Moon... will help him get to Mars via cash flow... 

Worst case price for a Moon mission: 1 SC + 5 Tankers at a extremely pessimistic price each of $60M ->$360M for >25mt. Just how much more payload for the no-prop-needed on Moon scenario was unclear. Best case $120M for 150mt. In $/kg on Moon surface from <$1,000/kg to as high as $14,400. I believe it will be much closer in reality to the $1,000/kg value.

The lowest $/kg just to LEO is $3,000/kg and that is also from SpaceX with a F9.

Moon base here we come. It would be within ESA budget to develop palatalized Moon hardware and pay for its transport 2 times a year with a 6 month Lunar crew change-out. A <$1B annual program for a fully 365 day manned "Moon Village".

[oldAtlas_Eguy]

Lunar landings are fine, but even SpaceX has no idea how to really do ISRU there, so it's limited to touch-and-go.

Not quite sure what you mean here.

Yes, Elon mentioned that there would be no methane/oxygen fuel production on the Moon, but he also mentioned that the space ship can make the return trip to Earth without it, due to the Moon's lower gravity.

O2 is available everywhere on the moon, and is much easier to obtain than the water ice in polar cold traps.

They can increase the landed payload by only loading enough O2 to land from the tankers, then filling up with the missing O2 on the moon. Direct 1-to-1 replacement of O2 with payload. It is also possible to use the same technique to increase the returned payload, though the benefit is not as great.

A question is there is an unknown and that is how much frozen CO2 is also in the cold traps with the water ice? The BFR would a little more than 100mt of prop to return to Earth. 50mt of H2O and 50mt of C02 to make 100mt of Methalox prop. But any amount of CO2 recovered would help. The same hardware used on Mars to make prop would work here with little to no modification.

Not only would this definitely enable without question the delivery 150mt of payload but could also reduce number of tankers needed by 1. A nominal savings of $20M per mission. A 17% price reduction as well as the likelihood of a payload increase.

Get stuff there. Open mine. Produce water and CO2 (if possible). Produce methalox. Produce HydroLox (for other space transport users and even for fuel cell "buggies"/mining equipment. Build more habitats and infrastructure:landing pads, cargo handling, personnel transfer, prop manufacture, power systems, cooling systems, refining, smelting, etc.

[CuddlyRocket]

As for other consumables, note that the Moon does have lots of water ice in permanently shaded areas of craters.  For this reason, many have proposed a Moon base at the South Pole.  This would also provide a constant source of sunlight for power.

• Constant sunlight unobstructed by any atmosphere
• Huge supply of water, which can be used to make oxygen
• 24/7 communications with Earth, with only a 1-second delay
not so bad...

it's more difficult to get to the lunar poles, and if you also need to land on permanently lit areas, you're restricting yourself to a very small portion of the Moon - a portion that may not include areas you're interested in for other reasons.

You can produce oxygen from regolith anywhere on the Moon; it's a technology that has been demonstrated in the lab and just requires power. More power than required to electrolyse water, but you have to get the water in a form ready to be electrolysed in the first place! We don't know how to mine mixtures of ice and rock at super-cryogenic temperatures and then purify the water; and what are the power requirements for all those processes?

As for intermittent sunlight, I doubt that's going to faze the CEO of Tesla even if a fortnight of darkness is 28 times longer than half a day! Especially if you switch off your oxygen production when it's dark.

(And 24/7, 1 second delay, communications with Earth is possible over all the near side. )

[meekGee]

Didn't mean to start a general "how to build a moon base" argument.

As per the thread title, I was noting that Musk A) didn't show any intended flights to the moon, and B) only spoke about earth originated propellant.

In short, they showed that if someone (else) is interested, they can take them there.

Musk is smart to put it out there, and then let nature take its course.

[rakaydos]

Lunar landings are fine, but even SpaceX has no idea how to really do ISRU there, so it's limited to touch-and-go.

Other than graphics, there was no declaration of intent either.  IF some one pays them, they might take him/her/them there.

The intent is to colonize Mars, and that hasn't changed.

I agree with you.
EM basically outlined this...
"Hey everyone... I'm going to build a space transport system that can lift 150 tons to LEO...
Max payload size about 8m dia and about 15m long... (if cone shaped 8.5m dia and 20m long is possible
And using tankers I can put that payload anywhere in the inner solar system for a fee...
With this slide... I show I can put 150 tons of crane able crates delivered to The Moon Surface... 
Call SpaceX if you have a need for such a delivery service..."

No mention of a SpaceX need to do this... He just intends to start a space trucking company for hire... 
And the folks that need crates and people delivered to the Moon... will help him get to Mars via cash flow... 

Worst case price for a Moon mission: 1 SC + 5 Tankers at a extremely pessimistic price each of $60M ->$360M for >25mt. Just how much more payload for the no-prop-needed on Moon scenario was unclear. Best case $120M for 150mt. In $/kg on Moon surface from <$1,000/kg to as high as $14,400. I believe it will be much closer in reality to the $1,000/kg value.

The lowest $/kg just to LEO is $3,000/kg and that is also from SpaceX with a F9.

Moon base here we come. It would be within ESA budget to develop palatalized Moon hardware and pay for its transport 2 times a year with a 6 month Lunar crew change-out. A <$1B annual program for a fully 365 day manned "Moon Village".

I would increase your worst case by 50%, rendevusing with a half-refilled tanker in elliptical orbit in addition to the LEO tank fill.

Your overall point still stands, though... it is easilly within the reach of single-administration space program projects now.

[ciscosdad]

How do we balance the elliptical orbit with exposure to the Van Allen belts?
Do it all on Auto (unmanned) and  add crew at the last minute?
Set so apogee lower than VA belt?
Put in a Prop Depot so refueling can be manned and of Minimum duration?
Better to use L1 or L2?
Some combination of these?

[envy887]

Given Elon's recent comments and obvious interest in "Moon Base Alpha": Is anyone willing and able to do some calculation on what could be accomplished using an elliptical tanking earth orbit instead of circular?

My calculations show that the elliptical orbit is 200 km x 3600 km LEO, and 7.85 tanker flights are required. This assumes 150 tonnes delivered to the lunar surface and the ship returns to Earth empty.

There are some tricks that can improve this, such as lunar orbit rendezvous and fuel transfer between a full ship going down and an empty ship returning home.