Octopus needs a cousin, is basically what i’m saying.

Low enough that some slightly nutso but quite brilliant philanthropist buys a Space Act licence from NASA, does a few years of development, and gets the ball rolling.

Said philanthropist may or may not have an undisclosed gentlemans agreement with another richer, geekier, music space and basketball obsessed philanthropist if said first philanthropist runs out of development funding. Said second, richer philantropist is friends with another, richer, geekier philantropist, who may at some stage be corralled into chiping in…

I’m expecting soon, is really what i’m saying.

Nah, use krypton. If you can get low leo equatorial launch costs down to less than ~$750/kg using an upscaled ‘aquarius style’ vehicle it’s heaps cheaper. Xenon’s only really worth the extra money if you’re paying $50,000 per kilo to GTO.

Grab it as low as you safely can given solar activity and atmospheric density with a tether for boost.

Proton is ~$1000 or $1200 per pound today. Without volume purchasing. How low does this market need to go before those materials scientists start spending money? How much might they pay for the R&D needed to deploy $100 per pound to LEO?

What efforts are being made to lower LEO to Luna transport costs? Lunar O2? Yup. One good example. But, an X Prize for tethers would be another. Toss 1000 kg from Earth to the Moon (crash landing?) with zero use of Earth launched propellant.

= = =

MXER tethers use solar power to re-boost and then transfer kinetic energy to payloads with lower orbital energy. The kinetic energy used to toss payloads to the Moon is harvested “out there” not lofted up from Earth. Solar ion propulsion does use Terran xenon for propellant but sunlight for energy.

Right now, its about 5 to 1 to soft land payloads on the Moon meaning 5 kg in LEO yields 1 kg on the lunar surface. Now, if we improve that ratio significantly with solar ion tugs or MXER tethers or lunar oxygen and r-LSAMs then the net Earth-to-Luna mass fraction ratios are very significantly increased even without lower cost Earth-to-LEO launch capability.

Then, lower cost lunar access will create demand for funding better Earth-to-LEO launch capabilities. There are zillions of good Earth-to-LEO ideas and right now little apparent ability for anyone to close the business case.

= = =

I’ve use the “golden spike” metaphor before. When the transcontinental railroad was built, we went west from St. Louis AND east from California.

Let work in parallel on lowering LEO to Luna costs AND on lowering Earth to LEO costs.

I know plenty of materials scientists who would be quite interested in cheap, frequent access to microgravity, if it were available.

Why would spending $100B to hit golfballs interest anyone?

Thanks, Bill — I’d been thinking of it entirely as a bracing aftershave, but darned if you aren’t right!

Total focus on Earth to LEO with little focus on LEO to Luna (or Mars, or NEOs) will result in [etc]

If I see anyone advocating such a focus, I’ll be sure to pass it on. To argue (as I did) that cheaper access to LEO is a necessary precondition for any other large-scale or self-sustaining activity, from LEO to Pluto, is very far from arguing that LEO is a sufficient destination in itself.

Propellant left in your tanks is actually a means to travel the second half of the journey. Forget ISS. Why would staying in LEO without the means to go further interest anyone? Robert Bigelow sure as heck isn’t interested in LEO-only space facilities.

Total focus on Earth to LEO with little focus on LEO to Luna (or Mars, or NEOs) will result in a situation where everyone whines for CATS and a re-useable RLV and no one can offer a business case for funding the R&D needed to build one.

With apologies to Janis Joplin: Oh Lord, won’tcha buy me a Mercedes RLV – – there are a zillion ideas for low cost Earth-to-LEO and no serious investors willing to fund them.

As for Elon Musk, he is an angel, not an investor. He is spending his PayPal money out of love for the prospect of humanity becoming spacefaring, NOT because he thinks he will earn as much as he could investing it elsewhere. And Musk himself isn’t too concerned about whether he personally ever gets to go.

Now, get to the Moon with LEO to Luna via MXER tethers, r-LSAMs and lunar oxygen to lower the cost of the 2nd half of the journey and that will help create business opportunities to encourage genuine investment in low cost Earth to LEO.

We can deploy innovative technologies in those arenas today – at lower costs that Musk promises with Falcon – just by buying Russian carrier rockets. And that runs us smack dab into ITAR.

Halfway to anywhere could be very interesting and useful… if you could get there often enough, with propellant left in your tanks (or waiting in a depot), and money left in your budget. That’s what we have yet to achieve.

Much of the bitching about ISS strikes me as learning the wrong lesson. It would be a very different story if we’d had a transportation system capable of building it faster, completing it (take your pick of the successive plans), and fully crewing it so that maintenance doesn’t eat up the majority of working hours.

ISS does not prove that a large LEO space station was an intrinsically bad idea. It proves that if you tackle such a project under the delusion that you have a “space truck” capable of building it cost-effectively, 22 years later you probably won’t be happy with the results.