* Posts by Marduke

7 posts • joined 30 Jun 2009

Discovery (finally) good to go on 24 Feb

This post has been deleted by a moderator

Neil Armstrong renews attack on Obama space vision

Marduke

"Human Rating" existing design = total redesign

"The Human Rating is just minor adjustments of the flight profile, so that the rocket doesn't exceed human G force maximums during the flight to orbit. To declare that it would be a complete redesign of either the Delta IV or the Atlas V doesn't know what they're talking about. "

That is completely and utterly WRONG. For one, you simply can't "make minor adjustments" to the flight profile to significantly change it. Rocket science doesn't work that way... The entire structure was designed and built around the specific loading of the flight profile it was designed to fly. You just can't "slow it down". You get your flight profile FIRST, then you get your loads, then you can BEGIN to design your structure AFTER you know it's loading profiles. Going backwards is pushing rope.

Also, the strength and fracture margins are COMPLETELY different for man-rated structures. I know EXACTLY what I'm talking about, it's what I do for a living. By the time you add enough weight to have the required margins and safety factors for manned flight, your payload on the Delta IV and Atlas V go to ZERO. Redesign and reanalysis time alone would be LONGER than starting a brand new program from scratch, which is EXACTLY why we didn't go that way when the new programs started 4-5 years ago.

BTW, the vehicles of the Mercury and Gemini program were NOT man-rated by current standards. They weren't even close.

Just think about new building construction vs complete renovation of an old house. Any person who has done it will tell you that renovation to update a house and bring it up to code is MUCH more expensive and time consuming that just plowing it under and starting from scratch.

Marduke

Fuel transport

And exactly how do you propose we get that fuel up there to begin with? You fuel fraction goes up with larger structures, meaning it is MORE efficient to launch it up with big vehicles, not lots of small ones.

The reason it's not done is because people who still have some basic math skills know not to listen to those who do not.

Marduke

"Human Rating" existing design = total redesign

If you human rate the Atlas or Delta, you don't have the Atlas or Delta anymore. They would have to be COMPLETELY redesigned and would be NOTHING like what they are now. It would be like "tweaking" the design of a minivan to become a Formula 1 racecar.

Missing Soviet nuclear electrocar FOUND ON MOON

Marduke
FAIL

shadows

The shadows are correct. Craters (depressions) have shadows on the side closest to the sun. Projections above the surface (hills and missing landers) have shadows on the side furthest from the sun.

Jumbo-jet ray cannon in missile-vape success

Marduke

solid fuel

"There was never any chance, nor any intention, of taking out the second test target entirely."

It most certainly could have.

It IS entirely possible to take out a solid fuel rocket. It already destroyed an identical solid fuel rocket in flight 8 days earlier.

http://www.mda.mil/news/10news0002.html

Rogue knob could ground space shuttle Atlantis

Marduke

why no cut

They can't cut it out because any sawing/cutting/grinding action will impart high frequency vibrations directly into the window, causing more damage. It would be no different than taking a vibro-etch pen to the window pane.

It is a huge ordeal because this is the INNER pressure pane, not the outer window that is routinely replaced after missions due to debris impacts. This component is not designed to be replaced at the Cape. The only facility with the tools has been shut down over 6 years. To even access the pane to replace it requires extensive disassembly, hence the long timeframe.

Also, the manufacturer of the window has been out of business for about 20 years, so a new vendor would have to be qualified, and the window also requalified. The spare pane was used to build Endeavour.

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