Water Found Deep Inside the Moon • Hacker News Board

Re: Water Found Deep Inside the Moon

#281

Post by computerex » Mon, Aug 28, 2017, 12:17 PM UTC

lorenzhs wrote: post #247

computerex wrote: post #212

Earlier quoted context omitted.

The space elevator even on Earth in GEO is a hopeless, fool's dream.

A lunar space elevator is feasible with today's materials (just a whole lot of them, way too much for current technology to transport to the moon). Here's a nice talk by Markus Landgraf, a mission planner at ESA, at 33c3: https://media.ccc.de/v/33c3-8407-an_elevator_to_the_moon_and...

It's not just about the tensile strength of the materials. The dynamics of a lunar elevator necessitates and extraordinary amount of weight to be used as a counterweight nevermind the length of the cables themselves.

Just because something ticks the checkbox of being theoretically possible doesn't mean it's practical or feasible to build.

Maybe in a few hundred years we'll have the means to build something on that scale. It still takes $10k to put 1kg in LEO, imagine the cost of transferring to the Lagrange points.

Re: Water Found Deep Inside the Moon

#282

Post by lorenzhs » Mon, Aug 28, 2017, 2:29 PM UTC

computerex wrote: post #281

lorenzhs wrote: post #247

Earlier quoted context omitted.

A lunar space elevator is feasible with today's materials (just a whole lot of them, way too much for current technology to transport to the moon). Here's a nice talk by Markus Landgraf, a mission planner at ESA, at 33c3: https://media.ccc.de/v/33c3-8407-an_elevator_to_the_moon_and...

It's not just about the tensile strength of the materials. The dynamics of a lunar elevator necessitates and extraordinary amount of weight to be used as a counterweight nevermind the length of the cables themselves. Just because something ticks the checkbox of being theoretically possible doesn't mean it's practical or feasible to build. Maybe in a few hundred years we'll have the means to build something on that sc…

Sure, the amount of materials needed exceeds what current technology can get even into LEO by several orders of magnitude. Nobody's proposing to actually build a lunar space elevator. All I'm saying is that a super-advanced civilisation could theoretically build one from the materials available to us today, which is not true for a space elevator from the Earth's surface.

Re: Water Found Deep Inside the Moon

#283

Post by Abishek_Muthian » Tue, Aug 29, 2017, 3:55 AM UTC

bb611 wrote: post #253

Abishek_Muthian wrote: post #210

"In 2009, NASA crashed a rocket and a satellite into a crater on the moon’s south pole, in the hopes of picking up additional watery evidence. " NO, In 2008 ISRO crashed Moon Impact Probe (MIP) into lunar surface as part of Chandrayaan-I mission. MIP didn't have any specific role, other than political agenda. The NASA's Moon Minerology Mapper M3 onboard of the Chandrayaan spacecraft was instrumental in providing the…

I think you're right to ask for credit where it's due, but this is not such a place - the event being referenced is the 2009 LCROSS mission: http://www.cnn.com/2009/TECH/space/10/09/probe.moon.crash/in... I discovered this with a very quick google search of the terms "2009 NASA crash moon"

You are right,the specific case about 2009 crash could be of NASA spacecraft. But what about the entire context of the article ?

Re: Water Found Deep Inside the Moon

#284

Post by quotha » Wed, Aug 30, 2017, 3:50 PM UTC

hutzlibu wrote: post #105

quotha wrote: post #89

Earlier quoted context omitted.

Adj. 1. bone dry - without a trace of moisture; as dry as a weathered bone

metapher - something not allways meant to be literal in a scientific sense. Bone dry is a very good description for a desert for a ordinary human beeing, as it means you wont find water you can use

For a desert on a planet, but not for an entire planet. You sound ridiculous claiming Mars is bone-dry. It is not a "very good description". It is false.