Slashdot is powered by your submissions, so send in your scoop

 



Forgot your password?
typodupeerror
For the out-of-band Slashdot experience (mostly headlines), follow us on Twitter, or Facebook. ×

Comment: Re:It's called Rocket Science for a reason ... (Score 2) 316 316

The cameras pulled back to show the launch facility, which was not of interest as the failure occurred at altitude.

Well, what else are you going to show, if you've lost your video feed from the vehicle and the tracking camera shows nothing but blue sky? Patch-in a feed from Sesame Street?

My concern is, how long is this going to put SpaceX out of commission? How many months (or years) will it take to track down the source of this failure and bring the Falcon family of rockets back online?

Comment: Re:Water for people (Score 1) 599 599

Desalination produces water for hundreds of times the cost that farmers are charged for the water they squander.

Then clearly the "market" is not performing well here. Whether that is due to over-regulation or unfettered monopolies is a separate issue, the question is, how can we make the market reflect the true cost of water? And how can we find cost-effective solutions to the water problem?

In a nutshell: raise the price of almonds.

If everybody paid an extra nickel for their snack-pack of mixed nuts at the pub, farmers could invest more in their water handling infrastructure, such as terracing the landscape to retain rain water and allow it to slowly soak into the ground. There are lots of tricks like this in the field of permaculture which is the art and science of sculpting and tweaking the ecosystem to become inherently over-productive. (If you are lucky enough to live near a mature permaculture "food forest", you only spend a few hours a week on subsistence, and most of that time is just gathering the harvest.) Suffice to say, most of California's drought problems could be greatly alleviated by better management.

As for the cost of desalination... why is it so damned expensive? According to my Boy Scout Handbook, a few sheets of plastic and a couple of pots and/or cups is enough to distill fresh water on the open sea, so surely with space-age materials and techniques we ought to be able to engineer a high-volume "passive solar" desalination design that can be replicated with backyard tools in third-world countries.

What if California spent 0.2% of its budget on passive desalination plants for the next ten years? How much of a dent would that make?

Comment: Re:Money pit. (Score 2) 98 98

You're right and wrong. He wants a system that covers both Earth and Mars, but he also wants to run a satellite internet service. As he said at the Seattle announcement a few weeks ago, we don't know exactly what we'll need to build a city on Mars, "But one thing's for sure, it'll take a whole lot of money." So he intends to use the ISP satellite network to fund the overall Mars mission.

Comment: Re:4000 (Score 4, Informative) 98 98

I saw a video of the announcement in Seattle a few weeks ago, and I'm pretty sure he mentioned the number 1,100 km when asked about the altitude. But since then I've heard 6~700 km from another source. Anyway, the idea is to be high enough so that you can join any two points on the globe in only 3~5 hops. He said this would be faster than terrestrial backbone, where you typically have 15 or 20 hops between A and B, each of which adds latency in the form of processing time, not to mention that light travels almost twice as fast in vacuum as it does in fiber.

+ - SpaceX Dragon V2 passes pad-abort milestone w/ NASA

taiwanjohn writes: NASA has approved a $30 million milestone payment to SpaceX under the agency’s Commercial Crew Integrated Capability (CCiCap) agreement with the company following a recent and successful pad abort test of its Crew Dragon spacecraft.

“The reams of data collected provide designers with a real benchmark of how accurate their analyses and models are at predicting reality. As great as our modern computational methods are, they still can’t beat a flight test, like this, for finding out what is going on with the hardware,” said Jon Cowart, partner manager for NASA’s Commercial Crew Program.

The next milestone will be an in-flight abort test, scheduled for this fall.

Comment: Re:Yeah (Score 1) 100 100

The way SpaceX is trying to recover the booster is like catching a bullet in your teeth. They have only a second or two of usable thrust, since the Merlin engines don't have enough throttle range to land at a nice gentle pace. But what if they developed a "Merlin DT" (Deep Throttle[TM]) and used that for the center engine? Even if the Merlin-DT was less efficient, it's only one of nine, so you could optimize it quite easily over the whole flight profile.

If you had that one center engine with enough throttle range to burn at very low thrust for 10 or 12 seconds, that would be ideal for landing.

I know, I know.... that's just what you guys need right now, another new engine design... But maybe you could find a way to add a tweak to allow greater throttle range, even at the expense of some efficiency. You only need the deep-throttle thrust for a few seconds at the end of the flight, and only on one engine, so it would be worth having a separate engine class devoted tho this use.

Comment: Re:"without coming close" is false (Score 2) 100 100

""The DC-X, short for Delta Clipper ... was an unmanned prototype of a reusable single-stage-to-orbit launch vehicle built by McDonnell Douglas in conjunction with the United States Department of Defense's Strategic Defense Initiative Organization (SDIO) from 1991 to 1993. Starting 1994 until 1995, testing continued through funding of the US civil space agency NASA.[1] In 1996, the DC-X technology was completely transferred to NASA, which upgraded the design for improved performance to create the DC-XA."" [wikipedia]

The DC-X was a prototype intended to develop a SSTO vehicle.

Comment: Re:Very "original" (Score 2) 100 100

Yes, that's why it's nickname is the "Senate Launch System". ;-)

The tragedy is, most of the people working at those jobs are really smart, highly skilled professionals who could do a lot of good for the amount of money we'll spend on them. Instead, we're going to waste both the money and their talents on a project that will at best enable an asteroid mission before it gets mothballed.

Comment: Re:"without coming close" is false (Score 2) 100 100

I wrote that it was the first PRACTICAL return stage. Different thing, man.

No, you said they were first to "operate on the principle that it was practical," which allows both of you to be right on this point. Surely the folks at McDonnell were operating on the principle that it was practical, they just couldn't find a way to make it work, because single-stage-to-orbit is really f-ing hard, perhaps not even possible with chemical rockets. It was the shuttle era, and they were trying to make what everyone wanted the shuttle to be, a SSTO "space plane" just like Buck Rogers.

Elon had the insight that Von Braun's Saturn V was pretty close to an ideal design for its time, and upgrading it to modern technology would provide enough extra payload capacity to make reusability possible. You didn't need a new kind of vehicle, just an evolution of the tried and true, with legs.

In the near term, major players like ULA and Arianespace will stay afloat on long term contracts already in the pipeline, and political inertia will keep them going after that. But the best news for them is that SpaceX simply can't make rockets fast enough to meet the demand. On the down side, once they figure out how to reuse them, they'll start to decouple their launch capacity from their production capacity. And they're not the only ones. There are several dozen other companies offering launch services in the next few years. Most are still in development, but many have already built and tested engines and other components.

There are basically 4 or 5 launch providers on the open market (depending on how you count, more if you include India, Iran, NK, etc). That number is likely to double or triple in the next five years or so. And they will serve a wide range of needs. Several are focusing on small payloads in the few-hundred Kg range, while some others offer heavy-duty versions of the Spaceship One/White Knight configuration, emphasizing the convenience of launching from high altitude: "Any orbit, anytime!" is the slogan of one of them (Stratolaunch, I think). And there are others focused on various niches of the market.

Point is, the space market is going to get a lot busier in the next few years, and the dinosaurs like ULA are going to be in a heap of trouble if they don't start adapting right quick. They are not stupid. They can see this too, which is why we see this shiny new concept from Arianespace and the recent Vulcan announcement from ULA. They know if they want to still have a meal ticket in 10 years, they'd better stay in the game.

Question is, can they pull it off, or is their inherent bureaucratic structure impervious to change because it's joined at the hip with the political establishment? Only time will tell.

365 Days of drinking Lo-Cal beer. = 1 Lite-year

Working...