Virgin Galactic Clarifies Status of SpaceShipTwo Engine

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Hybrid engine test at the Mojave Air and Space Port on Jan. 23, 2013. (Credit: Douglas Messier)

The latest edition of The Lurio Report includes an update on Virgin Galactic’s testing of SpaceShipTwo. I’m reproducing the relevant excerpt from it with the original bold emphasis included:

Around the same time stories were again heard that the present engine design would not be able to attain space altitude – at least not with a full compliment of six passengers and two crew.  Will Pomerantz, VP of Special Projects for Virgin Galactic, said in response to my query that, “Mojave’s certainly full of rumors, so it’s good to have a chance to clarify.  On the basis of the great results from PF01 and PF02 [the first two powered flights], coupled with continued ground testing, we do expect the present hybrid motor to be capable of carrying passengers into space.  As always, we’ll continue to look at a variety of ways to improve the motor’s performance and cost-effectiveness.”  (Later Pomerantz confirmed that he was referring to a full complement of passengers and crew when using the hybrid motor.)

He added that while Scaled is not working on any liquid engines Virgin Galactic is, though only for the LauncherOne orbital rocket which will be released from the WhiteKnightTwo (WK2) aircraft.

This is really interesting. Let’s dissect this statement one clarification at a time.

Around the same time stories were again heard that the present engine design would not be able to attain space altitude – at least not with a full compliment of six passengers and two crew.

Those are my stories.1 I am, as near as I know, the only one writing about it.2

Will Pomerantz, VP of Special Projects for Virgin Galactic, said in response to my query that, “Mojave’s certainly full of rumors, so it’s good to have a chance to clarify. 

These are not rumors. They are accurate reports. They have been persistent and consistent for more than four years. My confidence in the sources and the accuracy of their information has only increased during that time.

On the basis of the great results from PF01 and PF02 [the first two powered flights], coupled with continued ground testing, we do expect the present hybrid motor to be capable of carrying passengers into space….” (Later Pomerantz confirmed that he was referring to a full complement of passengers and crew when using the hybrid motor.) 

This is an interesting statement. Note that he says they “expect” the present hybrid motor to reach space with a full load of passengers. I would think that after 9 years of development and with a flight into space now reportedly set for February, there would be a more definite statement that this on the status of the engine and its capabilities. (I’ll note the February spaceflight estimate came from Richard Branson, who’s consistently overly optimistic about such things.)

I would think that the engine would have been fully tested on the ground at full thrust and for full duration by now. And further, that Virgin Galactic would have released a video showing such a test and released details of it. My sources say the nitrous oxide-rubber hybrid has never had a full duration hot fire at full power. Further, they say the engine isn’t powerful enough to get the ship all the way to space.

As always, we’ll continue to look at a variety of ways to improve the motor’s performance and cost-effectiveness.”

Another rather vague statement. I’m not really sure what that means.

I can tell you what I have seen and heard here in Mojave over the past 10 months. My sources indicate that a number of alternate engines have been tested by Scaled Composites, Virgin Galactic and contractors. I have first-hand knowledge about the tests of three of these engines. I saw two of them personally, and viewed the aftermath of a third one a few hours after the engine blew itself apart on the test stand.

1.  On Dec. 5, 2012, George Whittinghill of Whittinghill Aerospace conducted a test of an alternative engine design at a test stand at the Mojave Air and Space Port.

The test was conducted after dusk. Due to the darkness and nature of the camera, the video is not very clear. The test actually went a lot better than it looks in the video. It’s hard to tell, but the actual hot fire lasted about 20 to 30 seconds.

2.  A second contractor — whose name I’m not sure of — tested a different engine on the same test stand on Jan. 23, 2013.

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Hybrid engine test at the Mojave Air and Space Port on Jan. 23, 2013. (Credit: Douglas Messier)

That was a memorable test because the engine burned for maybe 30 seconds and then it wouldn’t shut off. It kept burning for quite a long time, sending a column of black smoke over the test stand and drifting southeast toward the spaceport. Emergency personnel could be heard discussing what to do over the radio; they decided not to approach the site until after the nitrous oxide in the tank burned itself out. It was the right call. The test crew was in no danger; they were safely inside a bunker, so there was no danger to them.

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A hybrid engine continues to burn after its shutoff time. (Credit: Douglas Messier0

3. Scaled Composites destroyed a nitrous oxide/nylon engine during a hot fire at a different test site on May 17, 2013. The accident blew out the nozzle and engine casing; they ended up on the desert floor far from the test article. The test stand was wrecked. And a cloud of nitrous oxide appeared over the test area.

He added that while Scaled is not working on any liquid engines Virgin Galactic is, though only for the LauncherOne orbital rocket which will be released from the WhiteKnightTwo (WK2) aircraft.

That’s might well be true. My information about the work on liquid propulsion is far less clear. They do seem determined for the time being to get the hybrid to work.

The more interesting question is why. Replacing a hybrid engine after every flight is expensive. It’s time consuming. It prevents the spacecraft from being refueled, serviced and sent back into space quickly.

If Virgin Galactic is serious about flying frequently and reducing the highest ticket prices in this emerging industry (now up to $250,000 without having flown anyone yet), why is it not pursing a liquid-fuel replacement?

Notes

1.  The issue has been discussed in a number of previous posts, including:

2. I’m not sure why The Lurio Report failed to cite either me or Parabolic Arc as the source of these stories. The rest of the report — which covers a variety of other commercial space news — is meticulous about citing other sources. It’s odd, but frankly speaking, this is the least important aspect of the story — hence it being relegated to a footnote here. There is far more at stake than any hurt feelings.