Space Ship Two - General Thread

[QuantumG]

Ok, so a play on words with regards to "cracks" which I took literally. SS2 *doesn't* have spar cracks to add to its woes.

Understood.

Ya know, no-one ever accused me of being subtle.. but maybe I am?

Let me be clear: hybrids vibrate a lot, and they get worse the bigger you make them and the longer you burn them. Carbon fiber vehicles fall apart if you vibrate them too much. The bigger the vehicle, the more of a problem this is (depending on how you do your layups). SS2 has this problem. They measure the vibrations before they put the rocket on the vehicle. They've yet to do a full duration burn because it would crack the vehicle.

Clear?

[banjo]

did snc tell scaled composites that the hybrid would scale up without problems?
or did scaled build ss2 without consulting snc?

[QuantumG]

did snc tell scaled composites that the hybrid would scale up without problems?
or did scaled build ss2 without consulting snc?

I expect neither.. Scaled knew about the problems going in and SNC never claimed their hybrids defy the laws of physics. When it comes to working through these problems there may have been various amounts of undue optimism on either side.

[Ric Capucho]

Ok, so a play on words with regards to "cracks" which I took literally. SS2 *doesn't* have spar cracks to add to its woes.

Understood.

Ya know, no-one ever accused me of being subtle.. but maybe I am?

Let me be clear: hybrids vibrate a lot, and they get worse the bigger you make them and the longer you burn them. Carbon fiber vehicles fall apart if you vibrate them too much. The bigger the vehicle, the more of a problem this is (depending on how you do your layups). SS2 has this problem. They measure the vibrations before they put the rocket on the vehicle. They've yet to do a full duration burn because it would crack the vehicle.

Clear?

Clearly spelt out now that you're using a sharper crayon.

Ric

[docmordrid]

Wonder of PatanolicArc has acquired any more info on this since 3 days ago?

http://www.parabolicarc.com/2014/05/15/spaceshiptwo-reach-100-km-boundary-space/#disqus_thread

Douglas Messier xxxxx xxxxxxx 3 days ago

Mixed signals on that. At one point last year, they were looking to adapt the liquid Newton engine for SS2. Then that seems to have been taken off the table. But, more recently VG's Mark Butler was down in Las Cruces and seemed to imply their were going to do that .

Edit: found the quote,

http://www.lascrucesbulletin.com/index.php?pSetup=lascrucesbulletin&curDate=20140502&pageToLoad=showFreeArticle.php&type=art&index=04&title=Officials+share+plans+for+Spaceport

“We are developing rocket motors from scratch,” he said. “It is no mean feat. We know that type of engine has limited capabilities so we are also developing our own liquid rocket engines as well. That is what takes time. We have to get through the development stage happening now in California.”

[meekGee]

did snc tell scaled composites that the hybrid would scale up without problems?
or did scaled build ss2 without consulting snc?

I expect neither.. Scaled knew about the problems going in and SNC never claimed their hybrids defy the laws of physics. When it comes to working through these problems there may have been various amounts of undue optimism on either side.

I thought SSNC was only brought in after the accident, no?

If that is the case, then Scaled committed first

[parabolicarc]

did snc tell scaled composites that the hybrid would scale up without problems?
or did scaled build ss2 without consulting snc?

I expect neither.. Scaled knew about the problems going in and SNC never claimed their hybrids defy the laws of physics. When it comes to working through these problems there may have been various amounts of undue optimism on either side.

I thought SSNC was only brought in after the accident, no?

If that is the case, then Scaled committed first

After SSOne ended, Rutan & company decided to bring engine development in house. They had been working with SpaceDev, but Rutan and Jim Benson hated each other. So, Scaled worked away until July 2007 when the accident happened and three employees died. About a year later, SNC was brought into the project. SNC had in the interim purchased SpaceDev.

They've stuck with the rubber hybrid despite all the development problems and the fact that it's not remotely clean like Branson says it is (burning rubber in the upper atmosphere -- why could that be bad)? God knows why they didn't go with a liquid one years ago.

[parabolicarc]

Here is a more detailed piece on what's going on with SpaceShipTwo:

http://www.parabolicarc.com/2014/05/15/spaceshiptwo-reach-100-km-boundary-space/

The engine they flew with would have torn the ship to pieces if they had gone anywhere near full duration.

All the assurances over the years about how well engine development was coming along....not true.

[meekGee]

did snc tell scaled composites that the hybrid would scale up without problems?
or did scaled build ss2 without consulting snc?

I expect neither.. Scaled knew about the problems going in and SNC never claimed their hybrids defy the laws of physics. When it comes to working through these problems there may have been various amounts of undue optimism on either side.

I thought SSNC was only brought in after the accident, no?

If that is the case, then Scaled committed first

After SSOne ended, Rutan & company decided to bring engine development in house. They had been working with SpaceDev, but Rutan and Jim Benson hated each other. So, Scaled worked away until July 2007 when the accident happened and three employees died. About a year later, SNC was brought into the project. SNC had in the interim purchased SpaceDev.

They've stuck with the rubber hybrid despite all the development problems and the fact that it's not remotely clean like Branson says it is (burning rubber in the upper atmosphere -- why could that be bad)? God knows why they didn't go with a liquid one years ago.

Yup - I was just responding to the original question of: "did snc tell scaled composites that the hybrid would scale up without problems? or did scaled build ss2 without consulting snc?" - in that SC decided on their course of action before SNC was in the picture, and so consulting (or not) with SNC was not an option - this was SC's choice of direction.

[banjo]

thank's for the history lesson everyone.  wow, what a mess.   how do we see this panning out?     

[dougkeenan]

Here is a more detailed piece on what's going on with SpaceShipTwo:

http://www.parabolicarc.com/2014/05/15/spaceshiptwo-reach-100-km-boundary-space/

The engine they flew with would have torn the ship to pieces if they had gone anywhere near full duration.

All the assurances over the years about how well engine development was coming along....not true.

Could they fly one via remote control and purposefully blow it up? 

I'm asking as a technical and flightpath question.

eta: empty obviously

[Jim Davis]

...but Rutan and Jim Benson hated each other.

Not to hijack the thread but this is the first I've heard of this. What was the source of enmity between the two?

[HMXHMX]

http://www.nbcnews.com/storyline/virgin-voyage/virgin-galactic-makes-switch-spaceshiptwos-rocket-motor-n113216

[Lar]

http://www.nbcnews.com/storyline/virgin-voyage/virgin-galactic-makes-switch-spaceshiptwos-rocket-motor-n113216

Thanks for finding that. Interesting that they are saying "it won't be much of a delay"

[Jarnis]

http://www.nbcnews.com/storyline/virgin-voyage/virgin-galactic-makes-switch-spaceshiptwos-rocket-motor-n113216

Thanks for finding that. Interesting that they are saying "it won't be much of a delay"

Virgin Galactic is good at PR.

I'd call the years they've spent on the vehicle so far "a delay" and engine issues have definitely been a factor.

[catdlr]

Virgin Galactic Hybrid Rocket Motor Test - May 8 2014

Published on May 23, 2014
Footage from Virgin Galactic's recent Hybrid Rocket Motor Test

[Elmar Moelzer]

Great video!
Looks like the quality of the burn is slowly getting less stable and clear after a while, or is that just my personal impression?

[savuporo]

Why the fade out at the end ? Ran out of VHS tape ?

[ChrisWilson68]

Here is a more detailed piece on what's going on with SpaceShipTwo:

http://www.parabolicarc.com/2014/05/15/spaceshiptwo-reach-100-km-boundary-space/

The engine they flew with would have torn the ship to pieces if they had gone anywhere near full duration.

All the assurances over the years about how well engine development was coming along....not true.

Could they fly one via remote control and purposefully blow it up? 

I'm asking as a technical and flightpath question.

eta: empty obviously

Each copy of SpaceShipTwo is quite expensive.  They're only planning on building five of them, at least for a while.  Why destroy one?  Boeing didn't destroy any 787s in its test program for that craft, and it is planning to build far more than five of them.

[Lars_J]

Great video!
Looks like the quality of the burn is slowly getting less stable and clear after a while, or is that just my personal impression?

Yes. The burn does not look very stable, the flame seems to "oscillate" a bit. But the combustion looks cleaner than the previous hybrid engine.