There’s very little news in Virgin’s announcement today, except for the pretty picture and the schedule. Many more questions are left unanswered than answered. There’s a little more, but not much more info at the New York Times (registration required). The Times piece has an error, calling SpaceShipTwo SpaceShipOne.

Are they really claiming that they’re going to start SS2 flights in June? Or just White Knight 2? And if SS2 flies in June, how many flights will there be with ballast for the propulsion system (i.e., simply drop tests) and at what point will it first fire the rocket motor? I ask because, despite Scaled’s fine for not properly training its employees in the handling of nitrous oxide, there has been no announcement as to the cause of last July’s accident. Do they know? If not, have they moved forward with engine development anyway? Or have they switched gears and gone to a different propulsion system? Seems like a pretty tight schedule, if so.

I think that they could learn a lot and start test flying the airframe this summer, assuming it’s well enough along, and perhaps they’re betting on the come when it comes to the powerplant to meet that schedule. Finally, I wonder what Burt thinks about the announcement?

Jeff Foust has more thoughts. The dual cabin design of WK2 is interesting. I wonder if that’s for additional passenger revenue?

[Update a little later]

A lot of posts and links over at Clark Lindsey’s place (not a permalink).

[Update at 5 PM EST]

Alan Boyle has more details, with some comments from Virgin. But none on propulsion. As I suspected, the initial flights for SS2 will be drop tests (naturally), which can go forward without engines.

And Alan has pretty mixed response from his commenters, some of whom sound like morons. At least I don’t have to worry about that until I get my comments fixed, which is turning out to be a much bigger deal than I thought it would. Again, if there’s an MT doctor in the house, email me at the address in the upper left corner.

[Evening update]

Clark Lindsey has more info. As I was guessing, the flight tests this summer will be WK2, not SS2, and Burt still says they don’t know what happened or what they’ll do about propulsion. That’s not good if they want to be in operations in ’09. He surely must have some options in mind. I’d recommend going with a liquid, from XCOR or someone else, and dumping the hybrid, which adds ops cost, and whose safety is overrated. But we’ll see.

OK, CalOSHA has fined Scaled Composites for not training its employees properly in the handling of nitrous oxide. But there’s still no explanation of what caused the explosion, or really, how to prevent it in the future. At least, not in this story.

This can’t be good news for the SS1 propulsion system.

ESMD has finally responded to Keith Cowing’s questions to NASA PAO.

One bit of explanation is required, I think. When Keith refers to a “five-by-five” matrix, he’s talking about the standard risk assessment tool that NASA (and ARES Corporation, for whom I casually consult, and others) use to track program risk.

Here’s an example from the Mil Standard, but it’s a five by four (five levels of probability, four levels of consequence). Anything that is in one corner (low likelihood, low consequence) can be ignored, and anything that is in the opposite corner (high for both) should be receiving the bulk of the program resources. Things that are in between are tracked, and measures are taken to move them down to the 1,1 corner of the matrix. Though I can’t find an example of one at my fingertips, the five by five is a little more fine grained in consequence level.

It can be used either for safety issues (in which case, “catastrophic” corresponds to loss of mission or crew), or for programmatic issues, in which case “catastrophic” would probably be complete program failure. It’s a little harder to evaluate in this case, though, because that depends on how “program failure” is defined. Does it mean that the program is cancelled? Or does it mean that the program is restructured beyond recognition? Ares 1 seems to me to be vulnerable to either one.

What exactly is the issue? The problem is that any structure has a resonant frequency at which it naturally vibrates. If you excite the structure at that frequency, you can develop a positive-feedback system that will literally shake it apart (the Tacoma Narrows Bridge is the classic example).

Solid rocket motors don’t run particularly smoothly (compared to well-designed or even poorly designed liquids) and large solid motors provide a very rough ride. Everyone who has ever ridden the Shuttle to orbit has commented on how much smoother the ride gets after staging the SRBs.

Now, one way to mitigate this is to damp it out with a large mass. The Shuttle does this by its nature, because even though it has two of the things, they are not directly attached to the orbiter–they are attached to a large external tank with one and a half million pounds of liquid propellants in it, and it can absorb a lot of the vibration. Moreover, the large mass has a frequency that doesn’t resonate with the vibration.

As I understand it (and I could be wrong, and I’m not working Ares, but this is based on discussions, many off the record and all on background with insiders on the program), there is a very real concern that the upper stage on top of the SRB in “the Stick” will be excited at a resonant frequency, but that even if not, the stage will be too small to damp the vibrations of the huge SRB below.

If this is the case, there is no simple solution. You can’t arbitrarily change the mass of the upper stage–that is determined by the mission requirement. Any solution is going to involve damping systems independent of the basic structure that are sure to add weight to a launch vehicle that is already, according to most reports, underperforming. Or it will involve beefing up the structure of the upper stage and the Orion itself so that they can sustain the acoustic vibration loads. In the case of the latter, it is already overweight, with low margins.

So this constitutes a major program risk, that could result in either cancellation, or a complete redesign (that no longer represents the original concept, because the problem is fundamentally intrinsic to it).

Now, let’s take apart the response a little:

Thrust oscillation is…a risk. It is being reviewed, and a mitigation plan is being developed. NASA is committed to resolve this issue prior to the Ares I Project’s preliminary design review, currently scheduled for late 2008.

The problem is that NASA can “commit” to resolve it until the cows come home, but if it’s not resolvable, it’s not resolvable. They can’t rescind the laws of physics, and we’re approaching a couple of anniversaries of times when they attempted to do that, with tragic results.

Now this next part is (to put it mildly) annoying:

NASA has given careful consideration to many different launch concepts (shuttle-derived, evolved expendable launch vehicle, etc.) over several years. This activity culminated with release of the Exploration Systems Architecture Study in 2005. Since then, the baseline architecture has been improved to decrease life cycle costs significantly.

NASA’s analysis backs up the fact that the Ares family enables the safest, least expensive launch architecture to meet requirements for missions to the International Space Station, the moon and Mars. NASA is not contemplating alternatives to the current approach.

The problem is that NASA didn’t give “careful consideration” to the previous analyses after Mike Griffin came in. As far as can be determined, all of the analysis performed under Admiral Steidle’s multiple CE&R contracts, performed by major contractors, was ignored, and put on the shelf to collect dust while NASA decided to build what the new administrator, along with Scott Horowitz and Doug Stanley, were predisposed to build. I have never seen “NASA’s analysis” that supports this statement. Steve Cook made a valiant attempt to justify it at the Space Access Meeting last March, and was given kudos, at least by me, for having the guts to come in and defend it to a hostile audience, but no one was convinced, or even saw convincing data. He simply stated the conclusions, but didn’t show the numbers.

But the most troubling thing to me is the end:

Thrust oscillation is a new engineering challenge to the developers of Ares – but a challenge very similar to many NASA encountered during the Apollo Program and development of the space shuttle. Every time NASA faces an engineering challenge – and it faces many – agency engineers examine all the options for addressing the issue. NASA has an excellent track record of resolving technical challenges. NASA is confident it will solve this one as well.

The problem is that, in reality, despite its confidence (or at least its stated confidence) NASA’s record on this score is, at best, mixed. For instance, think about (as just two examples) the X-33. Or the OMV (I did a Google on it, and couldn’t come up with any good histories of it–one needs to be written). Or many of the original space station concepts, which required complete redesigns. Sometimes engineering challenges are just too great to overcome, and a new approach is required to overcome a flawed concept. I don’t know whether that’s the case with Ares 1 or not, but this response doesn’t instill in me any confidence that it’s not.

Jeff Manber writes that we should be inviting China to participate in the ISS program, and space in general.

I have a hard time getting worked up about it, either way. I don’t consider either NASA or China relevant to the future of space at this point, though if they actually start flying this thing, I may start to take them more seriously.

Clark Lindsey talks some more about Steven Weinberg’s space and science budget opinions in reply to my interview of him.

I interviewed Steven Weinberg who has replaced James Van Allen as the most prestigious and eloquent direct critic of human spaceflight (unlike Barack Obama who may be the most effective passive-aggressive de-funder of space activities since Nixon).

I faced a fundamental media ethics issue. Weinberg’s opinion on the likelihood of nuclear war with Russia in the next twenty years (“more likely than not”) puts him in a tiny minority. By publicizing his view on this, it delegitimizes him as a spokesman against human spaceflight without discrediting directly his arguments against human spaceflight on the merits. I chose to carefully transcribe his words on this point, confirm that he stood by them, then released them.

What would you have done?

Continue reading Debating Human Spaceflight →

Four years ago, President Bush announced a new direction for the nation in space, perhaps the biggest space policy change since the end of Apollo, in that it forthrightly declared that there was now a national goal to send people beyond low earth orbit, where they had been stuck since 1972, a situation that was cemented with the onset of the Shuttle era, because it was our only crewed space vehicle, and it could go nowhere else.

Unfortunately, four years later, the program is bogged down with an unnecessary new launch system that will do little to improve safety and nothing to reduce costs, and for this and other reasons, it seems unlikely to survive the next administration, almost regardless of who wins. My primary hope is that at least the goal remain in place, and perhaps some fresh thought will be given to how it will be best achieved, with a lot more emphasis on the commercial sector and tying it in to national security, as the Aldridge Report advised, and NASA has completely ignored. And no, COTS doesn’t count, both because it’s inadequately funded, and because it has nothing to do with VSE–it’s simply a way to replace Shuttle logistics for ISS.

Jeff Foust has some thoughts over at The Space Review today. Here’s what I wrote as I live blogged the speech at the time, from a motel in Lauderdale-By-The-Sea.

Glenn at Instapundit points to a UPI story that says JPL thinks the odds of a 4,000 km flyby for 2007 W(M)D5 or less is 99.7%. If it’s not going to hit Mars, that increases the chances that it will slingshot around Mars toward Earth. Odds are likely in the 1 in a million range or less, but what if it did? I wouldn’t say “probably“, but let’s have some transplanetary musings!

Jesse Londin has a roundup. I’d like to go to the one in Arcachon, France.

She also has a year-end space linkfest that I’d missed.