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Comment Re: Rockets are too expensive (Score 1) 322

I think we were thrown off point by AC, who doesn't seem to grasp that physical systems can be described in alternative reference frames.

I think he is trying to say that there is no such thing as a geostationary orbit, because satellites in that orbit are actually tracing out a circular (or even more pedantically, spiral) path.

I believe the responder was trying to point out, using the example of a rocket ship travelling to geosynchronous orbit, that "stationary" is a kind trick of perspective when viewed from the frame of fixed stars.

Of course in the rotating frame of where we happen to be sitting on the Earth geostationary satellites are indeed actually stationary.

Comment Re: Rockets are too expensive (Score 1) 322

geosynchronous satellites: when the sun circulates over the north pole and it causes the satellite to exhibit the figure 8 orbit

geostationary : are fixed (fiction) stations , allegedly ground based

That is the most garbled explanation I've ever heard of geosynchronous orbits.

A geosynchronous orbit is one with a period that exactly matches the Earth's rate of rotation.

Geostationary orbits are a special case of geosynchronous orbits where the angle inclination of the orbit to the Earth's equator is zero.

So: a satellite in a geosynchronous orbit that is also geostationary appears to continually hover 22,236 miles above some point on the Earth's equator. If it is in a geosynchronous orbit that is not geostationary, it will appear from the earth to drift north and south of the celestial equator, tracing a figure 8 against the background stars over the course of one Earth rotation.

Of course in both cases the satellite would actually be following an elliptical (in fact almost perfectly circular) path around the Earth. The "stationary" or "figure 8" thing is simply a trick of perspective -- the way car in the next lane traveling at the same speed appears not to be moving.

Yeah, most of you knew all that. But insofar as there's an explanation here, it oughtn't be gibberish.

Comment Re:Poor on $100k? Sure (Score 1) 552

People can adapt to just about anything. If you live in a ditch, then a shack feels like a mansion. If the people around you live in mansions, a perfectly serviceable house seems like a shack.

It's the Red Queen's race:

"Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that!"

And once you've adapted to running twice as fast, you'll have to run twice as fast yet again to feel like you're progressing.

That's why I say the most important thing in your profession, once you have achieved enough income to live modestly and set a little aside for the future, is to find work that is in itself rewarding.

Comment Re:No surprise... (Score 5, Insightful) 210

But, it's a direct admission that they were basically gouging for want of competition.

How much are they gouging? What is the payback period on their R&D? What is the investment in the chip fab to make these things, and how far into the payback period are they now?

Will these price drops mean that they have to extend the payback period to recoup the costs of the smaller-feature fab? Will that delay the 7nm mass production they've announced for 2020?

I don't know the answers to these questions. I do know some of the questions to ask. Let's not jump to conclusions without understanding the data.

Comment Re:Rockets are too expensive (Score 5, Interesting) 322

And a space elevator, of course, would only cost about a Trillion, and there's this little problem of it hitting something (we'd have to make Earth Orbit absolutely pristine and keep it that way) and there's a problem with the kinetic energy if it falls down. Sort of like having many atom bombs go off.

Maybe someday. But right now making rockets as cheap as they can be is a better idea. It's only $200K to fuel up a Falcon 9. We don't get the whole thing back in working order yet, but that would be a lot easier than making a space elevator.

Comment No Dragon 2 Soft Landing Yet (Score 5, Informative) 322

Dragon 2 isn't built yet. The escape test was a boilerplate capsule more like a Dragon 1 than 2. Dragon 2 has not demonstrated a soft landing, because it's not built yet. That was the Falcon 9 first stage.

Also, you can't get Dragon 2 down to the Moon and back up on it's own. Not enough delta-V. You would need to have Dragon ride on top of something that can hold enough fuel. Like a larger version of the Apollo Service Module.

The Command/Service module was originally intended to land on the moon and return without the LEM, before NASA bought the LEM concept, and was overpowered for the mission it got. Dragon is larger and heavier, but a lunar landing one would probably look a lot like an Apollo Command and Service module, and legs.

And yeah, Orion: I'm Not on Board. Big expensive obsolete rocket with no mission that makes sense.

But good luck getting Elon Musk to focus on the practical and eminently desirable target of the Moon. He isn't interested. It's only Mars for Elon.

I try not to watch all of the Mars Colonial Transport speculation. Falcon 9 and Dragon are great, and they're here, and we could do so much with them.

Moon

How To Get Back To the Moon In 4 Years -- This Time To Stay (scientificamerican.com) 322

Scientific American describes "a way to get to the Moon and to stay there permanently...to begin this process immediately and to achieve moon landings in less than four years." It starts by abandoning NASA's expensive Space Launch System and Orion capsule, and spending the money saved on private-industry efforts like Elon Musk's SpaceX and Robert Bigelow's Bigelow Aerospace. schwit1 quotes their report: Musk's rockets -- the Falcon and the soon-to-be-launched Falcon Heavy -- are built to take off and land. So far their landing capabilities have been used to ease them down on earth. But the same technology, with a few tweaks, gives them the ability to land payloads on the surface of the Moon. Including humans. What's more, SpaceX's upcoming seven-passenger Dragon 2 capsule has already demonstrated its ability to gentle itself down to earth's surface. In other words, with a few modifications and equipment additions, Falcon rockets and Dragon capsules could be made Moon-ready...

Major segments of the space community want every future landing to add to a permanent infrastructure in the sky. And that's within our grasp thanks to Robert Bigelow... Since the spring of 2016, Bigelow, a real estate developer and founder of the Budget Suites of America hotel chain, has had an inflatable habitat acting as a spare room at the International Space Station 220 miles above your head and mine. And Bigelow's been developing something far more ambitious -- an inflatable Moon Base, that would use three of his 330-cubic-meter B330 modules.

The article calls Jeff Bezos's Blue Origin rockets "a wild car" which could also land passengers and cargo on the moon and suggests NASA would be better off funding things like lunar-surface refueling stations, lunar construction equipment, and "devices to turn lunar ice into rocket fuel, drinkable water, and breathable oxygen."

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