Search found 1130 matches

by 93143
Tue Feb 04, 2014 9:45 pm
Forum: News
Topic: Reaction Engines
Replies: 37
Views: 5351

Re: Reaction Engines

No one wants to discover a discrepancy in the available data for a promising project. But this is about as innocuous as they come, isn't it? It appears someone writing publicity copy typed "per engine" without really thinking, or perhaps misunderstood a nebulous statement from someone bett...
by 93143
Tue Feb 04, 2014 7:26 am
Forum: News
Topic: Reaction Engines
Replies: 37
Views: 5351

Re: Reaction Engines

From the spread sheet it is hard to see how that could be right but the documents were both from late 2012 so that's not it. Actually, based on the metadata the spreadsheet looks like it was created in 2004. It describes the Skylon C1 configuration, meaning the engine is probably the SABRE 2. The S...
by 93143
Tue Feb 04, 2014 3:47 am
Forum: News
Topic: Reaction Engines
Replies: 37
Views: 5351

Re: Reaction Engines

I think the SR71 might be a good fit. Too small. SABRE 2 is twice the mass and between four and nine times the thrust of the J-58. And the SR-71 can't go much past Mach 3.6-3.7 or the windshield comes loose (so I hear). Have they done a full-engine computer simulation? Not sure if the technology is...
by 93143
Tue Feb 04, 2014 12:46 am
Forum: News
Topic: Reaction Engines
Replies: 37
Views: 5351

Re: Reaction Engines

Your reference title sounds better than Wikipedia but I don't find such a thing as a C1 trajectory spreadsheet. Would you give some guidance as to where to find that spread sheet beyond, it's on the REL web site? A link if possible. C1 trajectory spreadsheet presentation with C1 mass breakdown (pg....
by 93143
Mon Feb 03, 2014 6:19 am
Forum: News
Topic: Reaction Engines
Replies: 37
Views: 5351

Re: Reaction Engines

Ah... you might want to cut all those numbers in half. Skylon uses two SABREs, and their combined thrust and weight are similar to the figures you provided. Accurate numbers (for SABRE 2; the latest version is SABRE 4) can be had from the C1 trajectory spreadsheet. Static sea level thrust: <140,000 ...
by 93143
Mon Feb 03, 2014 3:22 am
Forum: News
Topic: Reaction Engines
Replies: 37
Views: 5351

Re: Reaction Engines

Why not fly a single engine test vehicle? A single engine should have enough push to get itself and enough fuel off the ground to then demonstrate a full transition cycle to rocket, then back to jet, and come in for a landing. This is about a full scale engine demonstrating its full flight regime, ...
by 93143
Sun Feb 02, 2014 11:56 pm
Forum: News
Topic: Reaction Engines
Replies: 37
Views: 5351

Re: Reaction Engines

If it's a boilerplate test vehicle you're after, a Skylon-like one would probably make a lot more sense. Is that what it would be, a boilerplate test vehicle? I don't know about the name but I want a vehicle with enough hydrogen/ lox capacity to reach the flight regime where the Sabre can transitio...
by 93143
Sat Feb 01, 2014 10:39 pm
Forum: News
Topic: Reaction Engines
Replies: 37
Views: 5351

Re: Reaction Engines

As for Skylon flight, that is more like 2025 IMHO. Maybe. They say the first prototype could fly in 2020 given ideal funding availability, but 2022 is more likely. A few slips could put them at 2025... In fact, maybe the Mach 5 LAPCAT airframe would work as a Sabre test bed. Unfortunately that airf...
by 93143
Sat Feb 01, 2014 9:36 am
Forum: News
Topic: Reaction Engines
Replies: 37
Views: 5351

Re: Reaction Engines

I am still skeptical of the landing gear and noted you're comparing against C1 and not D1. Are the numbers similar and are you sure those weights are of fully fueled craft? Well, we have no pictures of D1, so it's hard to say what exactly the landing gear looks like... And yes, those are fully-fuel...
by 93143
Sat Feb 01, 2014 7:19 am
Forum: News
Topic: Reaction Engines
Replies: 37
Views: 5351

Re: Reaction Engines

Paging Dr 93143 Uh... ...okay. Let's do this. They haven't even begun to work on anything but the engine, and the real work has all been in the heat exchanger. We discussed this a bit in this thread , but I suppose a little rehash never hurt anybody, and there were things that weren't said... REL h...
by 93143
Thu Jan 30, 2014 1:02 am
Forum: News
Topic: Recovery.Gov Project Tracker
Replies: 1822
Views: 866774

Re: Recovery.Gov Project Tracker

If this keeps going, maybe it does deserve its own thread - though I'm not sure it'd accomplish much. I feel like I'm trying to stop a river with a frying pan, but it had to be said. You do not get to declare your opponent's position unreasonable without saying why, and it doesn't much matter what t...
by 93143
Wed Jan 29, 2014 4:58 am
Forum: News
Topic: Recovery.Gov Project Tracker
Replies: 1822
Views: 866774

Re: Recovery.Gov Project Tracker

Yes, whatever you want to think. No, it's not whatever I want to think. We don't get a choice in whats true and reasonable and what isn't. That's true, but one of you has presented something resembling a case, and one of you hasn't. You do not get to declare your opponent's position unreasonable wi...
by 93143
Fri Jan 03, 2014 8:48 am
Forum: News
Topic: General Fusion in the news
Replies: 462
Views: 139259

Re: General Fusion in the news

mvanwink5 wrote:Given how cold Canadian winters are I wonder about how they can conduct these outdoor tests and who they get to conduct them (grad students? Eskimos? climate researchers?)

They're in southern British Columbia, aren't they? Winter is the rainy season.
by 93143
Wed Nov 06, 2013 6:03 am
Forum: News
Topic: General Fusion in the news
Replies: 462
Views: 139259

Re: General Fusion in the news

I thought it was D-T. Hence the molten lithium mixed in with the lead; that's where they get their tritium... You couldn't ask for a better neutron shield than a multi-metre layer of this stuff. If the compression event results in significant amounts of it transiently surrounding the entire fusion p...
by 93143
Mon Oct 28, 2013 8:55 pm
Forum: General
Topic: Engineering zero margin for error
Replies: 4
Views: 561

Re: Engineering zero margin for error

You guys have read "The Cold Equations", right?

No real-life system is ever engineered with zero margin. Ever.

Not deliberately, anyway...

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