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Space Tug to the Moon and Beyond
An anonymous reader writes "Andrews Space and SpaceDev, a contributor to SpaceShipOne, are building a cargo transport called SmallTug to travel to the Lunar L1 point using a Hall Thruster and running off of solar power. The final craft will be capable of attaching to and transporting satellites 85 percent of the way to the Moon for use in interplanetary missions. The launch date is scheduled for 2008 and it is being designed to be quite inexpensive. The Inquirer has more details."
L1 is the first Lagrange point of the moon, the point between the Moon and the Earth where the perceived gravitation is negligable
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Andrews isn't, but SpaceDev is a publicly traded company.
Disclaimer: I own a few shares that I bought a little while after the SpaceShip One media blitz had died down. Scaled Composites is a private company, but SpaceDev builds their rocket engines. For me it's a long term bet - I may not win, but the sheer coolness of putting money in on this seemed like a good idea at the time.
Since I work in a completely unrelated field [entertainment], get horribly sick on a rollercoaster and would never see space willingly even if it was possible for me in my lifetime [I can get 30 minutes of me screaming, closing my eyes and being sick quite cheaply while in our atmosphere] - this is probably the only way that I can contribute to our expansion into space.
(Stocks go up and down and may become worthless and make your money explode, burn and you'll never see it again if you do anything I suggest, blah, blah, don't sue me for any of this).
"85% Why stop there? If it can get to 1.5 million km at L1 why can't it go all the way to 0.35 million km for the Moon? It seems to me that almost any spacecraft that can get to the 85% of the Moon in a finite period of time can make it all the way to the Moon" Because the purpose of this mission is to travel using the Interplanetary Superhighway. This is a very slow, but extremely energy efficient (almost energy free) way of travelling round the solar system. There are Lagrange points between any two bodies in the solar system, these are points where the gravitational forces balance out. Some of these are stable, but some are not and drift around. The Interplanetary Superhighway is the map of these drifting ones. Basically, you get to a drifting Lagrange point and you are on a highway which connects to any place in the solar system! It just takes ages to get anywhere though.
Seeing as how it's from the Inquirer and all... IF it's real
You DO know that the Inquirer site in question is NOT the American rag that prints things on the Sasquatch's illegitimate chilrden with Elvis and all that, but rather a British IT/Tech news site?
The fake news mag is spelled Enquirer, not Inquirer. And technically it's known as the National Enquirer.
Just tired of explaining this to people when they ask about an article from the Inq.
When somebody says "Space Tug", what comes to mind is a space version of the powerful little boats that haul barges around -- something compact which moves a lot of mass around.
The system, however, is called "Small Tug". It only costs $20 million becuase it's a technology demonstration. It's not meant to be practical, it's meant to show that it's principles of operation are sound and to get experience with the technologies involved. It's still a bargain, but if we could build something that would haul tons of cargo to L1 for 20 million, we'd be half way to Mars.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
The term in English for "cosmic speed" is, I believe, "escape velocity" - the speed required to escape from the Earth's gravity and go off into the cosmos, I suppose. The alternate term, however, is fascinating - what language is it from?
The World Wide Web is dying. Soon, we shall have only the Internet.
I will take a guess that the answer to your first question is implied by your second question.
Apollo, if it carried radiation instruments, only gave us 3-day samples. We still need to know likely worst-case values over the course of a year. Then there's enough data to correlate with sunspot numbers and whatnot, to make forecasts possible.
A PPT is a Pulsed Plasma Thruster. Usually a stick of somthing like Teflon is ablated by a big spark (i.e. the plasma part) and ejected out the back. The reaction force moves you in the opposite direction.
An MET is a Microwave Electric Thruster. You use microwaves to ionize a gas like Xenon and accelerate the ions out the back with a high-voltage electric field grid.
Here's a nice table of thruster technologies with specific impulse characteristics.
check out http://en.wikipedia.org/wiki/Interplanetary_Superh ighway
for an even longer transfer than Hohmann with lower energy