Become a fan of Slashdot on Facebook


Forgot your password?

Comment: splashdown (Score 1) 113

by Jookey (#49490229) Attached to: An Engineering Analysis of the Falcon 9 First Stage Landing Failure
Why don't they just use a splashdown? It seems that corrosion resistance is relativly easier to solve than landing a rocket on a platform thats swaying in the ocean. You could even have it splashdown in a freshwater lake or a barge half filled with fresh water. You would also save the weight penalty of landing gear.

Comment: splashdown (Score 1) 81

by Jookey (#48619963) Attached to: SpaceX To Attempt Falcon 9 Landing On Autonomous Spaceport Drone Ship
I don't know why they just don't land the thing in the water. It seems like waterproofing and preventing corrosion is a lot easier to solve than the controll problem of landing on a barge. Unlike landing on the moon, landing on a barge you have to deal with wind gusts, currents, and waves. A splashdown would leave a larger margin of error and neglect the need for landing gear.

Comment: Programming is all about abstraction (Score 1) 876

by Jookey (#46194539) Attached to: Ask Slashdot: Why Are We Still Writing Text-Based Code?
Richard Feynman: "Thinking is just like having a conversation with yourself." Friend: "Oh yeah(sarcasticly). Do you know what a crank shaft looks like?" RF: "Of course." Fr: "Than describe it's shape to me" RF: "..." Some concepts are better understood visually and some are better understood with text. Most textbooks have pictures and text. Can you emagine giving a contracter a set of plans written in text? One of the main obsticles to visual programming is it is currently used to teach coding. This is a terrible idea. In order to understand code you must have at least some basic concept of whats going on in the background. Visual programming abstracts this away. That being said, visual coding could be extremly usefull if you could use several paradigms at once, text and visual(s). For example you could start out your code with text, then insert picture that describes a controll loop. Inside one of the controll loop boxes there could be more text. Another box might contain a graph that in conventional programming would require a table or a seprate data file. Another box could contain a spreadsheet. Another box could contain a differential equation written in standard mathematical notation. Another box would be a visual layout of the GUI. etc... If you stick to one visual paradigm your going to make certain abstractions harder or impossible while making others easier.

Comment: Use plugin hybrids (Score 1) 734

by Jookey (#46056325) Attached to: Will Electric Cars and Solar Power Make Gasoline and Utilities Obsolete?
The main problem with purely electric vehicles is long recharge times, low battery energy density and lack of backward compatibility with current infrastructure. Plug in flex fuel hybrids seem like the way to go. The best option seems to be a Brayton cycle turbo-electric drive-train with a battery backup. The advantages of having the US car and truck fleet switch to this include: - It has a backward compatibility with current infrastructure. - Power to weight ratio of the drive-train is comparable to conventional cars. - Regenerative braking allows for better efficiency. - Brayton cycle engines run on just about any liquid or gaseous fuel without modification. This allows an easy transition to alternative fuels. - It is an established technology that is used on excavation dump trucks and locomotives. - There is an advantage over purely eclectic vehicles. Apartment dwellers who cannot run an extension cord to there car can still use it. It can still be used for long trips. - Regenerative breaking reduces fuel consumption - The drive-train has fewer moving parts and is much more reliable. Cars with a disabled turbine can still function as purely electric vehicles. - The turbine and battery pack can be made to be easily removable and upgradeable. - It increases elasticity in oil demand thereby reducing oil price spikes.

Comment: Here is something to look for (Score 1) 247

by Jookey (#42500587) Attached to: Teenager Makes Discovery About Galaxy Distribution
There is a theory that antimatter is gravitationally repulsive to matter but attractive to itself. There is also a possibility that some galaxies are made up of antimatter. If this were true and the distribution of matter and antimatter were fine enough so that antimatter galaxies were in the observable universe then a pattern should emerge in the large scale structure of the universe. The pattern of filaments and voids would have two sets of filaments that would never connect. In other words: if you modeled galaxy clusters as nodes and filaments as edges there would be two separate graphs that would never be attached. This would be relatively easy to find (or rule out) in current survey data. Has anyone done this? (In hopes of not sounding like a crank; I am aware of the counter evidence of antimatter galaxies. Namely the lack of gamma radiation caused by annihilation. But that's no reason more counter evidence could not be added to that pile.)

Comment: Re:Another reason we're stuck on this blue planet (Score 1) 505

by Jookey (#42458735) Attached to: Trip To Mars Could Damage Astronauts' Brains

The problem is not the atmosphere. Getting to space is relatively easy. Getting to orbital velocity is the hard part. The crux of the problem is the exponential nature of the rocket equation.

The way I see it there are three hurdles to getting a self sufficient colony going. Any solution will probably require combination of advancement in several of the following areas.

1. Funding. Anyone who has seen "The right stuff" knows it's funding that makes the rockets go up. In this category there are two options for this.
    1a. Government funding. This requires political will. The only way I see this happening is if two large powers are competing like in the cold war. Until that happens people would rather devote there production possibilities frontier to penis enhancing sports cars and episodes of jersey shore. But if we really wanted to we could probably make a colony in the next 15 years for about 10% of an Iraqi invasion.
    1b. Philanthropy. Lets face it the funds of the private sector pale in comparison to government funding. This might work however with substantial improvements in the other two categories.

2. Lowering the mass necessary for self sufficiency. According to a NASA study "Advanced Automation for Space Missions" A semi-self sufficient moon colony could be started with 100 tons. (This would still require supply missions of hard to manufacture items like microprocessors and tool heads.)

3. Lowering the cost to orbit. There seems to be several solutions to this.
    3a. Conventional chemical rockets: The big improvement that needs to be made here is re-usability. Rocket fuel accounts for less than 1% of the cost per launch.
Space X is making some headway in this department. There current quoted price is in the $3.7million/ton to LEO range. With reusable designs an improvement in cost by a factor of 10 seems plausible. This puts a colony in the $10billion range within reach.
    3b. Other more exotic orbital launch systems(nuclear light-bulb, launch loop, space elevator ..etc) would require fairly large R&D budgets/infrastructure investments but could bring down costs to the $10k/ton range quite feasibly.

Comment: M.U.L.E. (Score 4, Funny) 210

by Jookey (#42356709) Attached to: DARPA's Headless Robotic Mule Takes Load Off Warfighters

The competing agency FARPA is developing competitor to the LS3 technology. The name for this project is the Military Utility Logistics Engine. The stats are about the same except:
MULE has a payload of only 200lbs
MULE is quieter
MULE is capable of in situ resource utilization simplifying logistics
MULE is capable of doubling as a food source.
MULE's per unit cost is .01% of LS3 technology.

FARPA is also working on a more advanced project known as DONKEY, that will have self replicating abilities. Unfortunately this project is still in the early development stages.

When asked about the cost discrepancy between the $5,000,000,000 LS3 project vs the much more cost effective $500 MULE project, Congressmen Porkbarrel, R, MA replied: "I'm sorry I cant hear you over the sound of all this bribe money"

Here is a link to an early prototype of LS3:

"You show me an American who can keep his mouth shut and I'll eat him." -- Newspaperman from Frank Capra's _Meet_John_Doe_