By Douglas Messier

Managing Editor

Over the years, I’ve heard many speakers at various space conferences and events say all sorts of things that I felt…oh, comment on dit?…stretched the truth like Silly Putty. Yes, that’s a polite way to put it.

After a while, I’ve become quite numb to it all — the hype, promises, publicity stunts, optimistic schedules that get blown away like fallen leaves on a windy Mojave day. By this point, most of it just passes over me without meriting so much as a mention.

But, sometimes I hear something that stretches the rhetorical Silly Putty beyond the breaking point. I had just such an experience three weeks ago at the Space Tech Expo in Long Beach, Calif.

The speaker was Dream Chaser Co-program Director John Curry, who was giving conference attendees an update on Sierra Nevada Corporation’s (SNC) entry in NASA’s Commercial Crew Program.

It wasn’t Curry’s everything’s-going-great claims about Dream Chaser that caught my attention. That might well be true, although the company is running about 17 months behind schedule in completing a crucial series of drop tests of its mini-space shuttle. Other than that, I suppose, all is well.

It was when Curry veered off into describing Sierra Nevada’s work on a hybrid motor for Virgin Galactic’s SpaceShipTwo suborbital space plane that I really saw the Silly Putty begin to break. Work on that engine project was going “very well,” Curry insisted, as pictures of the vehicle in powered flight appeared on the screen. In fact, the SpaceShipTwo hybrid engine is a commercial “spin in” for the smaller set of hybrids on Dream Chaser, he said.

I gasped. Out loud. I looked around to see if anyone had noticed my reaction; apparently no one had. Nor had they seemed to have reacted at all. Curry’s claims simply floated out there as so many others had in the past, with little notice and no challenge. Perhaps everyone else was even numb than I was to these assurances. Or they believed them. Maybe they didn’t care.

That’s astonishing given that everyone involved in the program has been making essentially the same claim for years despite all evidence to the contrary. Explosions, lengthy program delays, powered flights that ended well short of space, a lack of technical details, long unexplained gaps in the flight test program, and still….everything is always going “very well.” Seriously?

Even as Virgin Galactic confidently predicts it will send its founder, Sir Richard Branson, and his two children into space by the end of the year and then promptly begin commercial service, the reality behind the scenes is quite a bit less certain. And it’s a great deal more interesting.

The following is what I know about SpaceShipTwo’s engine progress, based on reliable sources and what I have witnessed personally here in Mojave where SpaceShipTwo is undergoing tests.

The Flights

SpaceShipTwo has flown under power three times using SNC’s nitrous oxide-rubber hybrid motor. The engine firings were 16, 20 and 20 seconds each. The ship reached a peak altitude of 71,000 feet on its third and most recent powered flight in January.

The burn times and altitudes were far short of getting SpaceShipTwo anywhere near suborbital space. The reason is that the SNC engine produces such severe oscillations and vibrations that they dare not fire it to full duration. That would have literally ripped the ship and the crew to pieces.

Scaled Composites, which is conducting the flight test program, took SNC’s engine as far as it could. That enabled the company to expand the flight test envelope, give the pilots flight experience, demonstrate progress to customers and investors, and buy time to find a better solution.

And they did find a better solution. Sort of….

The Modified Engine

In December, SNC performed a 55-second static firing of a nitrous oxide-rubber hybrid with modifications that improved the thrust of the engine and dampened out the oscillations and vibrations. A jubilant Virgin Galactic released a video of the test, which it labeled as a full-duration burn, just in time for the holidays.

So, that was good news, right? Yes. It was a breakthrough in a very troubled engine development program. It should allow Scaled Composites to proceed with much longer burns in flight. However….

SNC’s modified engine requires significant changes to SpaceShipTwo, which engineers are now making in Mojave. This explain the three-month gap in flights the program is now in, a period that could stretch into June or later.

The specific changes are a well-guarded secret, but some things are known. For one, it won’t be possible to fully replicate the exact conditions used in that December ground test on SpaceShipTwo. So, nobody really knows just how much better the engine will perform in actual flight. Or whether a 55-second “full duration” burn will be sufficient to get the vehicle to space.

SpaceShipTwo will be heavier and possess a different center of gravity (CG), both of which have significant implications. First, the modifications mean that Scaled Composites can’t just pick up where it left off during the last powered flight in January. They will need to start with unpowered drop tests before lighting the engine.

Second, sources say that the ship can’t reach the 100-km (62-mile) and above altitudes that Virgin Galactic has been promising its customers for nearly a decade. (The 100 km boundary is the international definition of space.) The ship might exceed 80 km (50 miles), which is the definition of space used by the U.S. Air Force to award astronaut status to X-15 pilots in the 1960’s.

From a legal standpoint, Virgin Galactic would be fulfilling its customer agreement if the ship reaches 50 miles and above. However, ticket holders who have relied on the company’s public promises and failed to read their agreements carefully are likely to be disappointed if they can’t get to 100 km and enjoy the same interval of microgravity they were promised.

Third, SpaceShipTwo will take an unspecified hit in its payload capacity. The vehicle is designed to fly with two pilots and six passengers, or two pilots and a flight engineer and the equivalent in scientific experiments. The spaceship will not be able to carry that large of a load with SNC’s engine.

That’s not going to be good for Virgin Galactic’s bottom line, which depends upon maximizing per flight revenues for what is a very expensive vehicle to operate. The cost of the non-reusable hybrid engine has reportedly risen sharply since the program began in 2004, sources say.

Fourth, any modifications made in SpaceShipTwo to improve its engine performance could lead to unexpected problems in other areas. Engineers could be faced with a new set of problems, which could stretch out the flight test program and move Branson’s flight into 2015. (We’ll discuss the significance of that later.)

In short, SNC’s engine development for SpaceShipTwo doesn’t seem to be going all that well even though the company was brought into the project nearly six years ago. Lest you think I’m picking on SNC, it was Scaled Composites that designed and built SpaceShipTwo before figuring out how to scale up the hybrid motor. This reverse approach to spacecraft development has resulted in years of delay.

In any event, SNC’s modified hybrid engine does not appear to be a viable long-term solution for SpaceShipTwo. If it was, engineers wouldn’t be working on….

The Alternate Engine

Scaled Composites has been actively testing an alternative hybrid engine that uses nitrous oxide and nylon. The tests — two of which I have personally witnessed — are reportedly going very well. And they are continuing. Engineers conducted a successful 50-second test on Wednesday, April 9, on a test stand at the Mojave Air and Space Port.

However, the engine won’t be ready for installation on the first SpaceShipTwo, which Virgin Galactic plans to fly Branson and his children on later this year. Instead, the nylon engine would be installed on the second SpaceShipTwo, which is still under construction. Assuming, of course, that the engine tests continue to go well and provides the levels of thrust and safety required.

This raises a couple of questions. If the nitrous-nylon engine development is going well, why not move right into building a second SpaceShipTwo? Why fiddle around with extensive and expensive modifications to the current ship to make use of SNC’s engine?

Well, this is where things get really interesting.

The Investors. Building a second SpaceShipTwo and testing it would take a significant amount of time and money. And Virgin Galactic doesn’t have much of either at this point. The company has eaten through an enormous amount of funding over the past nine years without flying a single paying customer. Virgin Galactic needs to start showing results and flying people to space.

There is a more serious problem, however. Waiting until a second SpaceShipTwo would almost certainly delay Branson’s flight to at least 2015. And that could be a disaster for Virgin Galactic because of how the company has been funded.

Instead of financing SpaceShipTwo himself, Branson followed his usual practice of getting a partner to put up the bulk of the funds. In this case, the government of Abu Dhabi invested $390 million through aabar Investments for a 37.8 percent share in the company and the development of a small satellite rocket called LauncherOne.

The agreement, which was signed at the Oshkosh airshow five years ago this July, expires at the end of 2014. Multiple, reliable sources says there is a provision that requires Virgin Galactic to fly Branson into space by the end of the year.

If the company fails to reach that milestone, there are significant claw backs in the agreement. It’s not clear precisely what the claw backs are, but it could involve repayment of some of the original $390 million investment or an increase in aabar’s 37.8 percent share of the company.

Virgin Galactic is denying reports that aabar would pull out of the project. In an email obtained by Parabolic Arc that was sent to a group of ticket holders last month, Commercial Director Stephen Attenborough wrote

“There are a couple of other points that I discussed with some of you, firstly concerning rumors of an end of the year deadline for commercial operations/Richard’s flight which, should it be missed, would see aabar withdraw its funding. This is completely unfounded. “Second, while it is absolutely true that the hybrid rocket motor has been a long and complicated engineering challenge and one that has been subject to many design iterations, we believe we now have what we need to start commercial service. That will be demonstrated in what we expect to be a rapid sequence of progressively longer and higher powered flights over the summer. Once completed to our satisfaction, Scaled will formally hand over the vehicle to Virgin Galactic in preparation for Richard’s flight and commercial operations.”

The Schedule

So, to get Sir Richard, Sam and Holly on a flight by the end of this year, what precisely has to happen? A lot, and in a short period of time.

It’s already late April, and SpaceShipTwo hasn’t flown in three months. It’s not clear when flights will begin again, but one informed estimate says that could occur in June or possibly as late as August. There will be a series of unpowered flights followed by powered flights until SpaceShipTwo reaches its maximum speed and altitude. How long that will take is unknown.

After Scaled Composites finishes with the flight test program, it will turn SpaceShipTwo over to its customer. Virgin Galactic will then have to move the ship and flight operations to its commercial base at Spaceport America in New Mexico.

Ideally, Virgin Galactic would conduct SpaceShipTwo test flights in New Mexico before placing Branson and his family aboard. Whether it will do so is unclear, but there are good reasons to undertake additional flights at Spaceport America before the boss and his children fly.

To date, test operations have been under the control of Scaled Composites. Virgin Galactic needs to gain experience in flying SpaceShipTwo safely into space and turning it around for another flight. They will want to practice until they get it right.

Virgin Galactic also needs to learn how to operate effectively in Spaceport America’s airspace. This is not trivial. SpaceShipTwo flight tests involve close coordination between the pilots, mission control, air traffic controllers, spaceport personnel, and emergency services. The folks in Mojave are pros at it by now. Virgin will be starting fresh in New Mexico, so it will take some time to get that process operating smoothly.

Ultimately, the question is whether Scaled Composites and Virgin Galactic can accomplish all these tasks this year, and do so without unnecessarily rushing the flight test program. Virgin Galactic says safety is the North Star of its operation, so in theory they won’t cut any corners to meet a deadline. However, if the company’s survival is at stake…



The one wild card in this equation is the possibility of Virgin Galactic securing additional outside investment in the months ahead. An infusion of cash from a deep pocket investor or partner could relieve some of the financial and schedule pressures the company is under.

The Future, Unvanquished

Ten years ago this September, Branson announced the SpaceShipTwo program, confidently predicting that he would fly into space by 2007. As he prepares to mark that anniversary, his company finds itself in a race. Not with a competitor, but with itself and time. How the company got here will make a great book someday.

With just over 8 months left in the year, Virgin Galactic has a long way to go and a short time to get there. Will it soar triumphantly, or fall back to Earth? It will be interesting to see what happens.

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Correction: The original version of the article indicated that aabar could end up not providing additional funds if Richard Branson does not fly into space this year. It is more likely that the claw backs would involve a repayment of funds or increased equity in Virgin Galactic.