XCOR and the Lynx rocket

[Moe Grills]

Article says Lynx is coming together, but no mention of when flight testing will start. It is probably a good thing not to give timelines, VG do and are always having to change them.

Not just that, but the workers have to do their job carefully.
Mistakes can kill, as we have learned from NASA, Soviet and commercial space history.

I luv seeing people actually working with their hands and brawn as well as brain.
It's wonderful seeing something like this actually come together.

[Elmar Moelzer]

I might be misinterpreting the pictures, but it looks to me like the first prototype will look quite different from the renderings that we have seen...

[QuantumG]

I might be misinterpreting the pictures, but it looks to me like the first prototype will look quite different from the renderings that we have seen...

maybe.. what makes you say that?

The skeleton rarely looks like the skin.

[john smith 19]

New(?) pictures of LYNX at SpaceRef: http://spaceref.biz/company/lynx-spacecraft-development-in-pictures.html

EDIT: these images show the 'Wing Strake' components built by FiberDyne: http://www.aero-news.net/getmorefromann.cfm?do=main.textpost&id=040f7855-abd6-45f9-a515-ceed142ca150

EDIT 2: I replaced the images with the full resolution ones from http://www.xcor.com/pressimages/ - the image names now indicate when the fuselage pictures were taken. (Aug 11 2014)

That shot of the front of the vehicle seems to show a "bubble" windscreen. IIRC Greason was saying making a transparency for high temperature flight that's not flat was very tough.

This will fly up to M3? M5?

[QuantumG]

It's a double pressure vessel. The inside of the wind shield is curved but the outside isn't.

[Lars-J]

It's a double pressure vessel. The inside of the wind shield is curved but the outside isn't.

Which seems slightly counter-intuitive, for a supersonic aircraft. I would not be surprised if the final version of the "outside windshield" is more rounded.

[Elmar Moelzer]

It's a double pressure vessel. The inside of the wind shield is curved but the outside isn't.

Ahh, got it and now that I look closely, I can see the same thing in the renderings!
I think I kinda understand why they are doing that.  I assume that a pressure vessel is easier with rounded shell and high temperature windshield is easier when it is flat?
 

[docmordrid]

It's a double pressure vessel. The inside of the wind shield is curved but the outside isn't.

Ahh, got it and now that I look closely, I can see the same thing in the renderings!
I think I kinda understand why they are doing that.  I assume that a pressure vessel is easier with rounded shell and high temperature windshield is easier when it is flat?

IIRC the main issue was cost - curved high temp/strength glass isn't cheap.

[Elmar Moelzer]

IIRC the main issue was cost - curved high temp/strength glass isn't cheap.

Understood.

[john smith 19]

IIRC the main issue was cost - curved high temp/strength glass isn't cheap.

Yes. That's the reason why it's so tough.   

Producing bespoke curved glass transparencies is expensive even with window glass. Dealing with a much higher melting point material, even in fairly small parts,  calls for specialized equipment used by a limited number of suppliers.  IIRC that's why Virgin Galactic went with the small portholes.

[Rocket Science]

It's a double pressure vessel. The inside of the wind shield is curved but the outside isn't.

Which seems slightly counter-intuitive, for a supersonic aircraft. I would not be surprised if the final version of the "outside windshield" is more rounded.

Look at the SR-71/YF-12 or X-15 all supersonic to hypersonic

[simonbp]

Plus, an optically flat windshield provides a less distorted picture for a space tourist's eyeball or a scientific instrument (XCOR's two markets).

[Lars-J]

Plus, an optically flat windshield provides a less distorted picture for a space tourist's eyeball or a scientific instrument (XCOR's two markets).

Not if you have two windshields, now you get the worst of both worlds. I see some practical reasons for it, but it strikes me as very... inelegant? None of the other examples listed have two windshields stacked of such different spacing and shape.

I know the holy works of "Saint Greason" should not be questioned lest you open yourself for attack , but curious minds do wonder sometimes.

I look forward to seeing it fly - sometime soon, I hope. Two months of progress should have been done since the latest pictures.

[QuantumG]

I've never seen the point of it. When you consider that they're also going to have pressure suits on, it's like belt and suspenders wasn't enough so they're also going to tie a rope around their hips (yah, metaphor!)

I can't remember when it was, but someone was talking this up as being a very safe design and a questioner innocently asked if the crew were going to have ejector seats, or at least parachutes, and there was an uncomfortable pause before the speaker tried to claim that the crew were safer without a bailout capability.

Whenever people make "safety innovations" they seem to forget that actually flying is an important prerequisite. Lack of safety is not the reason why no-one is flying on suborbital hops today - lack of flights is. If you want to make version 2 of your operational vehicle 10x safer because you have strong market demand for such a vehicle, go for it, but version 1 should just fly.

[Zed_Noir]

Plus, an optically flat windshield provides a less distorted picture for a space tourist's eyeball or a scientific instrument (XCOR's two markets).

Not if you have two windshields, now you get the worst of both worlds. I see some practical reasons for it, but it strikes me as very... inelegant? None of the other examples listed have two windshields stacked of such different spacing and shape.
...

Well, there were the F-102 Delta Dagger & F-106 Delta Dart jet fighters with their flat panel front windshields comes to mind.

As for un-distorted view from the cockpit, there is always the overhead and side windshields.

[Lars-J]

Plus, an optically flat windshield provides a less distorted picture for a space tourist's eyeball or a scientific instrument (XCOR's two markets).

Not if you have two windshields, now you get the worst of both worlds. I see some practical reasons for it, but it strikes me as very... inelegant? None of the other examples listed have two windshields stacked of such different spacing and shape.
...

Well, there were the F-102 Delta Dagger & F-106 Delta Dart jet fighters with their flat panel front windshields comes to mind.

As for un-distorted view from the cockpit, there is always the overhead and side windshields.

You missed my point. Read it again. None of the examples listed (including your two new ones) has a rounded windshield inside a flat windshield.

[baldusi]

Plus, an optically flat windshield provides a less distorted picture for a space tourist's eyeball or a scientific instrument (XCOR's two markets).

Not if you have two windshields, now you get the worst of both worlds. I see some practical reasons for it, but it strikes me as very... inelegant? None of the other examples listed have two windshields stacked of such different spacing and shape.

I know the holy works of "Saint Greason" should not be questioned lest you open yourself for attack , but curious minds do wonder sometimes.

I look forward to seeing it fly - sometime soon, I hope. Two months of progress should have been done since the latest pictures.

The other's examples either didn't went to vacuum or the diameter of the pressure vessel wrt the window sized was much smaller. The inner glass has to be curved because it is part of the pressure vessel . The external is straight because doing glass heat shields curves is terribly expensive.

[Robotbeat]

I wonder, exactly how expensive?

[jongoff]

I've never seen the point of it. When you consider that they're also going to have pressure suits on, it's like belt and suspenders wasn't enough so they're also going to tie a rope around their hips (yah, metaphor!)

You do know that Randall Clague likes using the phrase "belt, suspenders, duct-tape" to describe his approach to safety, right?

~Jon

[Zed_Noir]

Plus, an optically flat windshield provides a less distorted picture for a space tourist's eyeball or a scientific instrument (XCOR's two markets).

Not if you have two windshields, now you get the worst of both worlds. I see some practical reasons for it, but it strikes me as very... inelegant? None of the other examples listed have two windshields stacked of such different spacing and shape.
...

Well, there were the F-102 Delta Dagger & F-106 Delta Dart jet fighters with their flat panel front windshields comes to mind.

As for un-distorted view from the cockpit, there is always the overhead and side windshields.

You missed my point. Read it again. None of the examples listed (including your two new ones) has a rounded windshield inside a flat windshield.

Looking through the HUD gun sight in the F-106 would be similar to the looking out Lynx's front windshields. IMO