Virgin Galactic Suddenly Very Chatty About Engine Progress

35 Comments
Newton engine (Credi: Virgin Galactic)

Newton engine (Credi: Virgin Galactic)

The exclusive, multi-platform partnership that Virgin Galactic has forged with NBCUniversal has begun to bear fruit over the past two months. The media giant has signed on to chronicle Sir Richard Branson’s flight aboard SpaceShipTwo and all the events leading up to it.

In November, Sir Richard Branson phoned into CNBC from his Necker Island retreat in the Caribbean to announce that Virgin Galactic would begin accepting the virtual currency Bitcoin for SpaceShipTwo reservations.

A month later, NBC News got into the act, with Science Editor Alan Boyle and a film crew trekking out to Mojave for a powered flight of SpaceShipTwo. They went away disappointed when the test was scrubbed due to a rare patch of bad weather in the High Desert.

But, no matter. Boyle has been giving Virgin Galactic blanket coverage ever since, in a manner reminiscent of the Life Magazine coverage of the American space program during the 1960′s. Life forged a similar exclusive arrangement with NASA and its early astronauts.

Boyle’s latest article is an in-depth look at Virgin’s development of its Newton engines, which will power the company’s LauncherOne small satellite rocket. Aside from giving too much credence to Virgin Galactic’s far-in-the-future plans for point-to-point passenger service, it’s a well-written story chock full of interesting details. And that’s precisely what makes the piece so very strange.

You want details? Oh, Boyle’s got details. The Virgin folks were quite chatty. How many Newton engines are under development? Three. How many have been tested? Two. How many rounds of testing have been conducted? Dozens. What do the engines burn? RP-1 kerosene and supercooled liquid oxygen. How much thrust does the NewtonOne engine produce? 3,500 pounds. And the first stage NewtonTwo?  47,500 pounds. And how long will that burn? Two and a half minutes.

So, what’s so unusual about all this? Nothing. These are precisely the sort of details that most companies will happily release about their rocket engines. Providing, of course, that development is going well. And therein lies the rub.

While Virgin Galactic is free with specifics about a small, unmanned rocket that won’t fly until 2016, it has not been very forthcoming about the RocketMotorTwo engine it plans to use later this year on SpaceShipTwo to fly Branson and his family on a suborbital joy ride.

How much thrust will RocketMotorTwo produce? How long will it actually burn? What will it burn, rubber or nylon? How high can it propel SpaceShipTwo?

All very good questions — with few answers. Virgin Galactic has been very reluctant to describe the capabilities of the most important engine in the entire program, the motor upon which the company’s fate depends.

Boyle’s story adds little to our understanding of it. He discusses RocketMotorTwo briefly, but in the place of specifics we get a curious and carefully worded email response from Virgin Galactic Vice President for Special Projects William Pomerantz.

“We and our contractors at Scaled Composites and Sierra Nevada are continuing to develop ways to improve the motor design by making them easier to manufacture and install, or by further improving their handling characteristics and performance,” Pomerantz wrote.

Translation: we’re still working on it. But, we’d be happy to tell you more about these Newton engines. They’re pretty awesome, huh?

The truth is that nearly a decade into the SpaceShipTwo program, RocketMotorTwo remains a work in progress even as Branson has been running around the world telling everyone that his flight to space is mere months away.

SpaceShipTwo has flown three times under power using nitrous oxide-rubber engines that have fired 16, 20 and 20 seconds apiece. Although it appears the slow progress is based on a desire to carefully expand SpaceShipTwo’s flight envelope, the reality behind the scenes is different.

Sources tell me that is probably as far as they can go with that version of the hybrid engine. If it was fired longer, the oscillations the engine produces would increase to the point where they would be bad for the pilots, passengers and ultimately the ship.

Efforts to dampen out the oscillations on the nitrous-rubber engine are continuing, sources say. Engineers also are working on alternative engines that could replace it. An engine that uses nitrous oxide and nylon was tested in Mojave two weeks ago. That test reportedly went very well.

Nitrous nylon engine test on Jan. 16, 2014. (Credit: Ken Brown)

Nitrous nylon engine test on Jan. 16, 2014. (Credit: Ken Brown)

How well any of these approaches will work is uncertain at this point. Nor is it clear how long they might take to implement. Much additional testing and work lies ahead before engineers will have clear answers.

If the engineers are successful, there is a good chance that SpaceShipTwo could reach some definition of space this year. It’s not clear whether the ship will reach the international standard of 100 km (62.1 miles) that Virgin Galactic has promised its 700 customers, or the 50-miles (80.47-km) standard the U.S. Air Force used for X-15 pilots in the 1960′s. The lower limit would probably be sufficient for Virgin Galactic to say it has reached space.

If they fail to find a solution, the SpaceShipTwo program and the company itself could be in real trouble. The months ahead will be crucial to determining the future of this nearly decade-old venture. It will be interesting to watch.

35 Responses to “Virgin Galactic Suddenly Very Chatty About Engine Progress”


  1. 1 Hemingway

    Do you think that Virgin Galactic will get a FAA license with this questionable nitrous-rubber engine in 2014?

  2. 2 Robert Clark

    Thanks for the usual insightful analysis. BTW, I’ve combined my comments about the benefits of a liquid fueled engine on the SS2 that I’ve been discussing here to a post to my blog:

    Transitioning SpaceShipTwo to liquid fueled engines: a technology driver to reusable orbital launchers.
    http://exoscientist.blogspot.com/2014/01/transitioning-spaceshiptwo-to-liquid.html

    Bob Clark

  3. 3 Douglas Messier

    That’s a good question. I initially thought they wouldn’t get a license witthout demonstrating the ability to safely reach space, but now I think they probably will.

    I believe Jeff Foust is right about the informed consent regime. The rules seem to only focus on dangers to the uninvolved public. It seems like companies can go out and do whatever they want as long as they can make a reasonable case they won’t kill people on the ground.

    It’s sobering. The launch of a bunch of high net-worth billionaires will be little different from that of a commercial satellite launch. The FAA doesn’t care if a Falcon 9 fails; it just doesn’t want the thing crashing into Cocoa Beach. Early space tourism will be little different.

  4. 4 Eric Weder

    It should be sobering. You are talking about risky things. Just like back in the early 20th century when barnstormers used to get killed pretty regularly, along with lots of their customers. The space travel industry must grow and evolve if you expect it to eventually become as safe as a well-developed system like the airline industry. In the meantime, the informed consent model is just what is needed.

  5. 5 Douglas Messier

    I’ve always found the comparisons with early aviation and barnstormers to be misleading. Aviation prospered not because people did stunt flying, thrilled crowds and periodically killed themselves and their passengers. Or because Charles Lindbergh managed to make it across the Atlantic while others died trying.

    It evolved because it could take people and cargo from place to place. Aviation could advance at its own pace, capturing market share along the way in markets that were already served by thriving ground, rail and water-going transportation systems.

    The suborbital market has nowhere to go at present. It will go up, it will come down and land at the same place. Point-to-point across any significant distance is beyond current technologies. In that way, I guess, it is like barnstorming, but without the ability to tap into an existing point-to-point market. If early aviation was forced to rely simply on barnstorming and stunts, it would have quickly died.

    I think the successful suborbital companies are the ones that will be able to operate safely, create markets for more than just tourism (micro-g research and tech demos, for example), and/or develop technologies that are a precursor to either orbital or long-distance point-to-point travel.

    XCOR’s Lynx is designed to prove out technologies and operational practices for a planned orbital vehicle. I’m hopeful they can pull all that off. If they do, it’s a game changer.

  6. 6 Carl Pham

    Tourism is a major economic activity. There are cities, counties, and even entire (small) nations that count tourism as one of their major moneymaking “products.” Do not underestimate tourism as a major driving force for a niche industry. Otherwise, why are there still ocean liners? What builds all those fancy weird buildings in Las Vegas? Etc.

  7. 7 Douglas Messier

    Those are good points.

  8. 8 df

    A few more questions: How much heritage does RocketMotorTwo inherit from the American Rocket Corporation IP that Sierra Nevada acquired with SpaceDev? Did AmRoc ever test an engine with the same thrust as RocketMotorTwo, and if so, did it also have issues with combustion instability?

  9. 9 Douglas Messier

    Tom Bower is the author.

  10. 10 Iain

    I believe AMROC tested a LOX/HTPB engine called the H-500 which had a thrust of 312,000N (70,000lbf) and burnt for 70sec and later the H-250F which had a thrust of 1,100,000N (250,000lbf), burning the same propellant combination. Not sure of the burn time for the later one. As for the rest, my books just say additional work is needed to better understand the issues at a larger scale.

    Interesting pdf article in this link though.
    http://forum.nasaspaceflight.com/index.php?topic=6026.0

  11. 11 Carolynne Campbell

    Well, I’ve read the book. It does open with details about the fatal accident and Virgin Galactic is one thread that runs through the entire book, but it is but no means the sole subject matter. From spaceships to formula one cars to bio-fuels and airlines, it is a tale of dodgy deals, criminal conspiracy, broken promises and technological incompetence.

    It’s light on the sort of technical details that we rocket enthusiasts love. But then, it’s aimed at a much wider audience who would simply get lost and bewildered in that kind of stuff.

    It does detail the birth and evolution of Virgin Galactic. So it does give insight into how we got to where we are now. Some of the content is pretty damning, especially the revelations about the aftermath of the accident. Missing evidence, misleading the investigation, and the fact that the three people who were killed were not ‘gathered at the fence’ with all the other spectators (as is reported in the Cal/OSHA accident report), they were inside the perimeter.

    One very funny and revealing line is in the chapter about Branson’s foray into Formula One. Two of his key people were at the first race. When the cars first rolled out of the pits, one of them said, “Fuck me, I didn’t realise we had TWO cars!” These guys had put $30,000,000 into it.

    I’m told Sir Richard has flown into London and is about to go on the counter-attack, although nothing has yet surfaced in the media. His lawyers will doubtless be considering if a libel action might be brought. Branson has sued Bower twice
    before and lost, so we’ll see about that one.

    If they can’t show that anything in the book is defamatory, then the fight-back will come as a media campaign. The second part of the serialisation will be in the Sunday Times (London) at the end of this week.

    It’s a big book with a load of stuff in it. I recommend it as a good, fast-paced read that is something of an eye-opener.

  12. 12 Robert Clark

    I don’t blame Branson for the explosion at Scaled since he is not a tech guy. I have understanding also for Scaled for how it could have taken place. If I blame anyone it would be SpaceDev for promoting the idea that hybrids “can not explode”. Even if you accept the idea the combustion chamber can not explode, and there is some doubt about that, it is HIGHLY misleading to state this when the oxidizer tank under high pressure can explode. The passengers on a flight for example would not care very much if there was an explosion in the engine compartment that resulted in loss of flight if it was actually in the oxidizer tank compared to the combustion chamber.
    By making that blanket statement also it would have the effect of strongly influencing those working on such a hybrid propulsion system that it was safe.
    I did a Google search on: hybrid engines can’t explode. Several promoters of hybrids made that claim including SpaceDev prior to the Scaled accident. So this idea unfortunately was wide spread. A notable dissenter to that claim I found was Rand Simberg. On his blog in 2005, he noted that he himself witnessed an earlier hybrid engine explode. In this case it was combustion chamber itself that exploded:

    The Hybrid Myth Continues.
    http://www.transterrestrial.com/?p=5757

    Bob Clark

  13. 13 Carolynne Campbell

    Bob, The book doesn’t blame Branson, It does say that Scaled were warned of the dangers. Perhaps one should worry about what it says about hybrids in the safety section of the Virgin Galactic website:

    “Hybrid motors offer both simplicity and safety. This is the type of motor that SpaceShipTwo will employ and that was used by SpaceShipOne. It means that the pilots will be able to shut down the SpaceShipTwo rocket motor at any time during its operation and glide safely back to the runway. The oxidizer is Nitrous Oxide and the fuel a rubber compound; both benign, stable as well as containing none of the toxins found in solid rocket motors.”

  14. 14 Robert Clark

    Thanks for the correction. I fixed that in my blog post.

    Bob Clark

  15. 15 Stuart

    It’s a bit more information than was originally given which will satisfy some, I do suspect somebody is reading Parabolic Arc though at Virgin/NBC.

  16. 16 Michael Vaicaitis

    “XCOR’s Lynx is designed to prove out technologies and operational practices for a planned orbital vehicle. I’m hopeful they can pull all that off. If they do, it’s a game changer.”
    What do you mean? What exactly would be a “game changer”?.

  17. 17 Dave Salt

    XCOR envisage a fully reusable system capable of placing small payloads (1-2 tonne?) into low Earth orbit using rockets evolved from those used on Lynx, which will enable a flight every few days. Moreover, this would be an air-launch concept, adapting an existing aircraft as the “first stage” launch platform for a two-stage pure rocket… ideal for operating from conventional airfields and enabling very wide launch windows.

  18. 18 Douglas Messier

    Bob:

    Scaled dumped SpaceDev and had brought the hybrid motor project in house prior to the explosion. It became Scaled’s responsibility to conduct testing in a safe manner. They didn’t. You can’t blame SpaceDev for a lack of safety protocols during a test they had nothing to do with.

    One of the reasons the companies split is that the founders of them couldn’t get along. Burt Rutan couldn’t stand Jim Benson of SpaceDev. The feeling was mutual. There’s a story of them screaming at each other in public during a conference.

    Burt was naive about the complexities of rocket development. He had come off a highly successful SpaceShipOne project and thought he knew more than he did. He was also sick during that period with a condition that eventually led to heart surgery. My sources tell me he wasn’t thinking clearly. And for decades, he had been the smartest guy in the room. It was a very toxic mix.

    The book is accurate. Scaled was warned of the danger. I know someone who tried. They ignored the warnings, and three young men died and three others were injured. Unnecessarily.

    Explosions are par for the course in this industry. But, how many people die? Very few, because there are established safety protocols for tests.

  19. 19 Douglas Messier

    The Lynx is focused on low-cost access to suborbital space. The engines are designed to be reusable like today’s jet engines. The idea is to fly into space, land back at the airport, refuel, and fly again the same day. Once they get to operational pace, they would be able to do that four times per day. Aircraft style operations, only on a ship headed to space.

    Plans call for a fully-reusable. multi-stage orbital system that would be able to fly on a regular basis. Also low cost using engines that could be fired over and over again. The Lynx would pioneer those technologies.

    Think daily, low-cost access to space by multiple systems operating from any airport equipped to support them. That’s not just game changing, that’s life changing.

  20. 20 windbourne

    Close on aviation.
    Aviation took off because us gov. Spent a fortune helping it out. War dept. Bought planes. USPS bought flying service( air mail was a BIG to do ). Then when airlines started, it was gov ppl along with wealthy that helped them.
    That is why I keep saying that BA is so important. Plenty of gov WANT to send ppl into space. They can fund INEXPENSIVE trips to space. But once a base is on the moon, every gov will cough up money to join. Same with mars.

    But to be effective, we need multiple destinations with multiple purposes. The other day we argued about passengers willing to go anywhere on moon. I stick by that. But the main buyers, gov and corps, will not.

  21. 21 windbourne

    Tourism to orbit will be less than 10% of all revenue for space travel. It will increase, but gov for Leo, lunar, and mars and corps for lunar and asteroids will matter much more.

  22. 22 lopan

    If they have to develop an entirely new engine, there is no way they’re going operational this year or even next year, and probably not the year after that either. The story of Virgin Galactic will be pretty much as it’s been since the beginning – hysterical, almost defensive hype coupled with barely any forward motion as months drag into years, with planted stories every six months or so about some silly-ass gimmick they’re doing to deflect attention from their lack of progress.

  23. 23 windbourne

    Hopefully, you are wrong.
    Besides, they could pick up an engine from SpaceX quickly.

  24. 24 delphinus100

    In their size range? Competitor or not, it would make more sense to try to cut a deal with XCOR for propulsion…

  25. 25 windbourne

    it would, but will they? Probably not.
    Interestingly, the Merlin D is 3x the thrust of RM2. I wonder if it could be done if needed? Probably not.

  26. 26 Michael Vaicaitis

    Oh Douglas, what are you thinking? (and you Dave Salt).

    To lift a spacecraft to orbit that is worth taking and reusing, it would have to be capable of carrying at least in the region of 6 passengers and/or 2-3 tonnes of cargo. So we’re either talking about a second stage and spacecraft or the second stage is the spacecraft. In either case the additional mass required for the second stage propulsion system to lift is likely to be in the region of at least 4-5 tonnes plus payload. For the sake of argument let’s call it 6 tonnes to LEO. Given that the second stage must get a payload of 6 tonnes to LEO, the whole launch-system will likely be in the region of 300 tonnes on the runway (perhaps less if it uses LH2, but then you got to deal with LH2). It will then need sufficient lift to take off and fly, boost to perhaps 80km and probably in the region of 4,500mph, then perform a separation of the second stage, re-enter and boost/fly back to the launch runway. Now if we’re assuming that this first stage booster is some sort of winged vehicle, then we need to envision some way that it could carry the second stage when fully fuelled, re-enter at 4,500mph and then fly back to a runway landing, whilst in both flight phases have a centre of mass that remains conducive to its centre of aerodynamic lift.
    Now if the second stage is also going to return to a runway landing then that will require either wings or a lifting-body shape, all of which adds structure and mass and drag that the first stage will have to carry.

    I recall reading that xcor have said that their piston pumps become less mass efficient than turbo pumps at about 95,000lbs (that may not be accurate, my memory is a little vague on the exact number). Now it could be that piston pump engines may provide increased longevity and so perhaps they could consider a mass efficiency hit, made up for by extra propellent and a larger first stage (and perhaps second stage). I’m assuming throughout that with LOX/RP1 or LOX/CH4 the cost of fuel would be negligible compared to amortising the cost of hardware (the same may also apply to LH2 and perhaps I exaggerate the issues with using LH2).

    Perhaps xcor are hopeful of scaling up their piston-pumps to orbital class engines, but will a 2 seat suborbital Lynx be providing any useful data towards that?, possibly may be. But with regards to airframes, heat-shields, etc., the suborbital Lynx system is not really testing any of the technologies that will be required for a meaningfully useful and thus “game changing” orbital vehicle.

    In any case, widened launch windows and taking off from and/or landing on runways are not advantages that really matter, they are no more than airy-fairy whimsies of convenience. The only variable of any importance is $/kg to orbit.

  27. 27 Douglas Messier

    I’ll pass your analysis along to my friends at XCOR. I’m sure they will be amused.

  28. 28 Michael Vaicaitis

    My comments were not intended as a slur on xcor, quite the opposite, their approach looks to be more promising than most – with particular emphasis on the piston-pump tech. I was simply attempting to point out the glaring gap between the Lynx suborbital and a useful payload, runway launched and landed, fully reusable, orbital system that would “change the game”.

    Perhaps I am mistaken, but the tone of of your response implies that I may have erred in some obvious and/or significant way. If I am indeed in error, I would be delighted to be corrected.

  29. 29 Douglas Messier

    It’s more your tone at the beginning (what are Dave and I thinking?) that sounded very sarcastic toward us. And you seem to discount the utility of Lynx providing useful data and experience for the orbital program. Perhaps I misread these parts.

    XCOR has done a great deal of analysis and given a lot of though to the design of the orbital system. That includes the applicability of the Lynx to the follow-on vehicle. Some of the details of that are public. I know some details that are not public. And there are parts of it that I don’t know.

    Not having a technical background, and not knowing precisely what is public and what is not, it would not be helpful for me to address any of the specifics of your analysis. I guess the most I can say is they have thought through all the things you mention above, with all the benefits and trades involved. It would be best for them to answer, if they feel they can at this point.

  30. 30 Robert Clark

    In that report by the Knight Arrow propulsion group on the Scaled accident I cited it quotes Scales after the accident:

    “The body of knowledge about nitrous oxide (N2O) used as a rocket motor oxidizer did not indicate to us even the possibility of such an event.”

    This would seem to indicate either a lack of due-diligence in researching the hazards surrounding N2O (negligence) or a wilful disregard of the truth.

    You say they were warned. I’d like to know in what way they were warned. They were claiming after the accident they knew of nothing in the literature that said N2O could explode.

    Bob Clark

  31. 31 Carolynne Campbell

    Bob,
    Some of the sources listed in that commentary do pre-date the accident. If you want to send your email address via the knights arrow website, I’ll arrange for the actual documents to get to you You are one of the few who has the patience and diligence to do that kind of digging..They were warned verbally, in terms just prior to the test by people whose expertise should have been recognised. Symptoms of problems had already surfaced, concerns had been expressed and they were ignored.

  32. 32 Douglas Messier

    I’ve talked with someone who tried to warn them. I believe the source, the person is credible, and the story has been confirmed by others. I can’t go into details due to confidentiality, but efforts were made, advice was ignored, and people died.

  33. 33 Robert Clark

    Thanks for that. Lack of expertise no doubt contributed to the accident. To paraphrase an old saying, ‘hubris goeth before the fall’. Or said another way, you’re never as smart as you think you are.
    I still do think that the false claim that “hybrids can not explode” being so widely repeated contributed to the accident. VG is still committed to using nitrous as the oxidizer, with either rubber or nylon as fuel, whereas it might not in fact be safe for this use according to Knights Arrow.
    You earlier suggested I search under nitrous explosions. One of the first Youtube video’s I turned up was of a drag race car where a nitrous bottle exploded. I was struck by a comment to the video in the comments section. It said the nitrous being rapidly vented was a sign it was about to go.
    Really? The N2O was being rapidly vented due to the built in safety feature and the bottle STILL exploded?

    Shakedown at E-town Huge Nitrous EXPLOSION Jeff Rodgers.
    http://youtube.com/watch?v=5Kht95C3vO4

    Bob Clark

  34. 34 Carolynne Campbell

    Nitrous is tricky stuff. We still don;t fully understand all the ways it can misbehave. A small burst disc will only provide protection for a slow and relatively small over -pressure. It can’t vent fast enough to deal with a big pressure-spike. In big tanks the solution that seems to have been applied is to use large burst-plates. Unfortunately this can make things worse. The liquid nitrous in a tank is kept liquid by the vapour pressure of nitrous gas in the free space. If a large breach happens, such as a burst-plate departure or tank rupture, all the liquid tries to boil at once, releasing huge amounts of high-pressure gas. This results in another kind of explosive event known as a ‘BLEVE’ (a Boiling Liquid Vapour Explosion) – a well known phenomenon among engineers. Remember Nitrous Oxide is a mono-propellant. Mono-propellants need to be treated with the same respect as any explosive. The mono-propellant reaction can be initiated in a variety of ways, especially with gas at high temperatures and pressures

  35. 35 Robert Clark

    The speed with which these two liquid fueled engines were developed supports the idea that if VG had chosen liquids they would already be flying suborbitally. NewtonTwo already has sufficient thrust for such a flight. How long has VG been working on these two liquid engines? Two years? And after ten years of work on the hybrids they still do not have sufficient thrust.
    We now know that hybrids can be as dangerous as liquids, and even more so using nitrous oxide. The real reason VG continues to use them is because nitrous oxide is a room temperature oxidizer and it is easier for VG to work with than cryogenic LOX.
    That will not be considered a valid reason when passenger flights are first being initiated.

    Bob Clark

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