Disqus - Latest Comments for stockpotato

Re: The Most Lethal Animal in the World

stockpotato — Wed, 24 Feb 2016 14:47:24 -0000

Counting humans as animals, as some do, Mr. Gates is forgetting, of course, that pregnancy-related child homicide (codeword: abortion) is the number one cause of death by animal in the world.

Re: Students testing landing system prototype

stockpotato — Tue, 30 Aug 2011 17:10:40 -0000

Very impressive video. You guys look like you have something that is actually going to fly. Great presentation!

Re: Euroluna fully compliant with the Master Team Agreement

stockpotato — Tue, 30 Aug 2011 16:26:45 -0000

Should Romit-1 fans be concerned in the slightest that your launch provider, Interorbital Systems, has not had a website update for at least half a year or so? The website says, "Launches are expected to begin in 2011." But so far there is no sign of this happening.

Re: Response to The Launch Pad blog post “About the MTA . .”

stockpotato — Mon, 29 Aug 2011 03:07:37 -0000

What's most concerning about the XPRIZE is the lack of responsibility being shown toward children, whether in the form of exploiting them commercially, or exposing them to innuendo from drug culture. The XPRIZE knows how to play goodie-goodie and get people to trust its objectives socially. But closer examination shows other agendas--like when XPRIZE board member Elon Musk announced at the Google Zeitgeist conference that he had secretly named a NASA-funded spacecraft after a 60s reference to marijuana use, or when closer analysis revealed a "magic mushroom" look hidden in the MOON 2.0 logo being used by the Google Lunar X PRIZE. The XPRIZE needs to clean up its act and adopt the ethics of a drug-free culture.

Re: Posters

stockpotato — Fri, 26 Aug 2011 20:54:40 -0000

I still don't get what the "IL" part of SpaceIL is about? And now I'm seeing it in your education posters. I think you mean "YL" (Medinat Yisra'el) instead, don't you, at least according to the CIA World Factbook? So it should be SpaceYL. Otherwise, I have to wonder if it's properly authentic for a Yisraeli team planning to be the first to put a private rover on the moon, as compared to an American team. It would be a good idea to change it now before you have made too many posters.

Re: "Upgraded" Video of the previous one

stockpotato — Fri, 26 Aug 2011 02:09:00 -0000

Wear safety glasses. Wear face shield for pressurized tests.

Re: Moon Express Mini-Radar Takes Flight - The Prequel

stockpotato — Wed, 24 Aug 2011 19:15:52 -0000

"Radar provides autonomous landing spacecraft with crucial ranging information to the surface and has been one of the most challenging and high risk elements of all lander systems." This is very true. But a much, much more difficult challange for autonomous and manned landing lunar spacecraft is to get an accurate fix on trajectory while in orbit to orient the braking engines. Being a few degrees off in any direction will waste too much fuel to land and will leave the spacecraft way off course. Any idea how you will do this? Maybe you should ask NASA how Surveyor and Apollo did it? :)

Re: Testing of Mono Propellants

stockpotato — Wed, 24 Aug 2011 19:09:46 -0000

You guys need to be a little more careful. But it is good to see you starting from the ground up and working on your own engines. Engines for the lander are a key component of a successful mission. Another, I feel, is the problem of orienting the descent stage for braking, since it is hard to get a fix on your trajectory while in orbit around the moon. In contrast, to de-orbit the earth you have the aerodynamics of a dense atmosphere to orient your spacecraft in line with your trajectory, plus you also have a magnetic field.

Re: A new rocket fuel? Part 21

stockpotato — Tue, 23 Aug 2011 02:51:50 -0000

That is incredible! It went over 40 seconds. What do you think about refining the paper used? Would cotton paper, rice paper, or a particular paper stock work best? Now anyone can make their own engines to any size or length desired! You are getting to be a pro at this.

Re: Bringing an End to Conspiracy theories?

stockpotato — Sun, 21 Aug 2011 19:43:55 -0000

I didn't know those stories. Spooky.

Re: A new rocket fuel? Part 20

stockpotato — Sun, 21 Aug 2011 19:22:54 -0000

I was going to guess phenol. What does bromothymol blue do? :)

Try the phtalic anhydride by itself, which is one of the reagents (the other being phenol) used to make phenolphthalein. Perhaps this will work even better. Phtalic acid is another candidate. And remember, phtalate esters may harm your fertility!

Re: New Bucket-wheel for the Lunar Excavator

stockpotato — Fri, 19 Aug 2011 20:18:39 -0000

If you have been up-to-date about the moons hydrodynamics associated with my solar moisture theory, which was confirmed by Chandrayaan-1, and recently emailed to you, then you already know the regolith is wet. For this reason, your design is flawed because you have a high ratio of bucket surface area to bucket volume, which means the regolith you scoop is much more likely to stick to the sidewalls of the bucket. That will only work with dry, grainy stuff. Instead, you want the regolith to fall out and into the dump bed. Solution: Widen your buckets or at least lower the depth of the buckets, round the inside edges so they do not create sticking points, and don't forget an anti-stick coating like Teflon.

Remember, the Apollo and Luna samples only came back bone dry because at the time everyone thought they were supposed to be dry. I know that is hard to swallow, but if you are going to design stuff that will actually land on the moon, which means you will also have to be the first to solve the de-orbiting problem, then you will have to face reality. In fact, NASA had such a shortage of high-quality fakes (samples that could fool the geologists "testing" them) that they simply gave the Dutch a piece of petrified wood on a moon rock plaque, figuring that the legally blonde scientists in the Netherlands would never bother to test it. Eventually they did! (After displaying it in the museum for decades.)

Re: More Since Last

stockpotato — Fri, 19 Aug 2011 19:37:28 -0000

I checked your new website today and I like the look of your new lander/transit combo. I like it much better than your old one. It has more of a "Hollywood" look. (Although it looks to be slightly transparent (?) when it is landed on the moon, because the contour of the lunar horizon can be see through it.)

Re: A new rocket fuel? Part 18

stockpotato — Thu, 18 Aug 2011 19:46:29 -0000

Wow! A C6 engine normally only burns for 2 seconds. But your version is burning for 6 seconds.

Noting that your original test burned for 20 seconds, which weighed about the same as the combined weight as your quad version, I am wondering if you could lift off using a quad version of the 20 second engine (~160 g total). Also, it would be nice to see a lighter rocket lift off with a single 20 second hexaphenox engine (~40 g).

It looks like three of your 20 second hexaphenox engines in series, or one 60 second engine), would be enough to power my rocket rover 500 meters, the hexaphenox engine has comparable thrust.

Re: A new rocket fuel? Part 17

stockpotato — Wed, 17 Aug 2011 16:26:28 -0000

Great work!

That is over 20 seconds of burn time for such a small engine. But does it have any thrust? Because if it does, you have just invented the greatest model rocket engine in the world! (Assuming the combustion products are non-hazardous.) Long-lasting, high-thrust engines are exactly what is needed for lander development.
But I'm not sure you are getting a strong enough rate of burn for thrust. Otherwise, you will have to add coloring and show it to the fireworks manufacturers! When are you going to add a nozzle and see if it flies? Also, what about the toxicity? Is is hazardous?

Re: A new rocket fuel? Part 15

stockpotato — Mon, 15 Aug 2011 16:59:56 -0000

I like the way that burned. But I am confused about the formula. Was t his the test the hexamine/KClO3/catalyst=hexaphenox mixture or the hexamine/KClO3/KNO3/catalyst=hexaphenox mixture, and next time do you plan to test KClO3 + Epoxy by itself? I was unclear on that. Also, is it burning a bit hollow? It may be you are using a bit too much epoxy and the outer portion is hardening more than the inner. Maybe try more epoxy catalyst and less epoxy.

For your molding, try this to make a spiral grain geometry. Take a grain specimen as in your first image and roll it out with a rolling pin to 1-2 mm thick. Then place a layer of wax 0.5-1 mm thick on top of the specimen. Then roll it up into a spiral. Then cure the expoxy. Then heat in an oven to melt and remove the wax. This will leave you with a spiral grain geometry! You will need a bit more specimen for this. Also, try different thicknesses of the grain/wax.

Re: JURBAN is helping to "Connect a Million Minds "

stockpotato — Sun, 14 Aug 2011 22:23:16 -0000

The Million Mind March?

Re: Bob Richards @ NewSpace 2011: The NewSpace Approach to International Markets

stockpotato — Sun, 14 Aug 2011 19:15:32 -0000

Bob mentioned Orion. The scoop is that NASA was asked if it had finally solved the de-orbiting problem with enough confidence to guaranteed a safe manned landing. The answer was negative. (The problem is how do you determine your trajectory in lunar orbit, so as to orient your braking engines in the opposite direction using attitude controls, without a dense atmosphere for aerodynamic orientation or a magnetic field for magnetic orientation?)

The second question was whether a solution to the radiation problem (which does permanent damage to ovaries, unlike to testes which replace their gametes) had a solution in sight, or whether women meeting an age/parity requirement (too old for kids or already have them) would also be fit enough to endure lunar exploration. The answer was negative.

Hence, with no way to assure the safety of our astronauts or the feasibility of the mission, and given the social problem that would be posed by an all-male crew in today's gender-equality climate, the decision was made to pull the plug on Orion.

Re: The Lander Returns

stockpotato — Sat, 13 Aug 2011 15:48:08 -0000

I want to see a blog entry titled "The Lander Flies." When are we going to see that?

Re: Educationally Speaking

stockpotato — Sat, 13 Aug 2011 15:44:57 -0000

How am I supposed to understand the video when I don't speak Arabic?

Re: Moon Express Chairman Naveen Jain Interviewed on Bloomberg TV (12Aug11)

stockpotato — Fri, 12 Aug 2011 22:05:34 -0000

How do you land safely on the moon? There you go. That is the main question. Have you asked yourself: How exactly did Luna and Surveyor softly land on the moon? The problem comes down to this: How do you determine your trajectory in orbit, so that the descent stage engines can be pointed opposite the trajectory? With no dense atmosphere to provide aerodynamic orientation and with no magnetic field, the craft is left with as little sense of direction as Lisa with her eyes closed floating around in orbit around the moon. Without opening her eyes, how would she be able to point and tell you which direction she was traveling in, so that you can fire the braking engines in that direction to slow the craft for descent?

Re: A new rocket fuel? Part 14

stockpotato — Thu, 11 Aug 2011 18:55:34 -0000

I seems you're getting a much longer burn, but without a nozzle it is hard to make a comparison. You should be doing force measurements each time. You need to set up the proper testing apparatus for this to make it convenient so you do not lose this information each time you test. And what about your hexaphenox formula? Are you still working on it? It is impossible to know what formula you are testing if you don't mention it. But I have to say I look forward to this series of posts more than any other in the competition right now.

From the article you linked to: "I’ve long said that this isn’t a technical competition. Exploration of space is often pigeon holed into being called a technical problem, but it’s really a money and connections competition." Apparently, the author, Michael Doornbus, is unfamiliar with the attitude control problem of aligning the de-orbiting engine with the trajectory in orbit. But, alas, Luna, Surveyor, and Apollo all made it look so simple!

The moral of the story: Question authority. Except in China. :)

I'm still wondering about Bob Richards. He talks the talk, like a Peter Diamandis clone, but I haven't seen the lander he purchased from NASA make any real flight attempts yet. It looks like he's got the money. But if money could buy you a solution to the de-orbiting problem...

Re: JULT.tv

stockpotato — Mon, 08 Aug 2011 18:41:35 -0000

That is a very interesting project. I spent the next day thinking of what I would like to see highlighted in the field of view using "augmented reality" glasses. Good luck with that.

Re: Does the rocker bogie suspension work on the lunar surface?

stockpotato — Fri, 29 Jul 2011 22:52:15 -0000

Sorry, none of the above. To de-orbit a celestial body with a dense atmosphere (Earth, Mars, Titan, Venus, & Jupiter) NASA has relied on aerodynamics to orient the decent vehicle with respect to its trajectory. So how did Luna/Surveyor/Apollo orient their descent stages with respect to their trajectories in lunar orbit?

Re: Does the rocker bogie suspension work on the lunar surface?

stockpotato — Fri, 29 Jul 2011 22:48:18 -0000

Sounds a bit sophisticated for Luna/Surveyor/Apollo. Any guess how they may have done it?

Plus, with a startracker you are looking at attitude relative to the stars. But ultimately what you need for de-orbiting is attitude relative to the orbital trajectory.

With a startracker you need multi-point calculations to acquire a trajectory, and since good startrackers take about 60 s to acquire and identify stars, you are going to have some major complexities to deal with in a tight circumference such as lunar orbit. But perhaps you might acquire attitude and trajectory data before lunar orbital insertion, and then cross your fingers and rely on a MEMS motion reference unit from there on out.