Category Archives: Space

Space, Space Education, Space History

Remembering Challenger

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This weekend, I met a young woman, now attending law school in Ann Arbor, who was in diapers when it happened. To her, it’s ancient unremembered history, just as the Eisenhower administration is to me (though I at least study it, unlike most of my age cohorts). It made me feel old. We have a generation, though, about ten years older than her, now in their thirties, for whom it was probably the most traumatic event of their young lives. The comments are closed on my post from six years ago, but anyone who wants to post remembrances can do it here, with the caveat that I still haven’t completely recovered from my recent MT upgrade (still hoping that someone who knows it will volunteer to help), so you can use them, but they will time out. Don’t expect to get a response after submitting the comment. Just back up after a while, and refresh the page to see it.

I’m particularly interested in how the event changed your perception of the Shuttle, and the space program in general, if at all, per my previous thoughts.

Space, Space History

Twenty-Two Years

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This is a week of space anniversaries. Yesterday was forty-one years since the Apollo fire that killed three astronauts on the launch pad as horrified technicians watched during a ground test. Thursday will be the fiftieth anniversary of the launch of the first US satellite, Explorer I. Friday will be five years since the Columbia disintegrated over the otherwise quiet morning skies of Texas.

But today is the twenty-second anniversary of the destruction of the Space Shuttle Challenger, an event that traumatized the nation as millions of schoolchildren watched the first “teacher in space” go up in a fireball on live television. I’ll never forget the date because it was then (as it remains) coincident with the anniversary of my birth.

It wasn’t obvious to many at the time, but that event was the beginning of the end of the Space Shuttle program, then less than five years old, with its first flight having occurred on April 12th, 1981. Prior to that flight, there had still been plans (that some thought fantasies, due to budget restrictions and ongoing problems of turnaround time) of twenty-four flights a year (including a couple per year out of Vandenberg AFB in California). The catastrophe was a splash of cold water in the face of those who had held out hopes for the Shuttle in terms of meeting its original promises of routine, affordable, safe access to orbit. Those promises had caused people (like those in the L5 Society) to dream of space stations, and space manufacturing, and ultimately, space colonies.

After the disaster, many realized that if those dreams were to come true, they would have to be by some means other than the Shuttle (a realization that some later took one step further and decided that NASA itself was unlikely to be of much help in achieving the goals, particularly since it continued to flout the law, and had no interest in them whatsoever). But the program went on, because it was all NASA had for manned spaceflight, and it maintained jobs in the districts of politically powerful congressmen and senators. Though there had been disillusionment about the promise of the program, there was no political will to replace it. The few (misguided) attempts (NASP, X-33, SLI, OSP) to replace it all floundered or failed. The latter two morphed from one to the other. The program thus struggled along with four orbiters, and a low flight rate, with occasional fleet stand downs due to endemic problems, such as hydrogen leaks at the interface, or other concerns.

But the final blow was struck five years ago this coming Friday, with the loss of Columbia. The fleet was down to three birds, and unlike the case after the loss of Challenger, no structural spares had been procured with which to build a new one, and the tooling for them had long since been scrapped. So the decision was finally made, almost seventeen years after the loss of the first orbiter, to end the program.

Unfortunately, what is planned to replace it, Ares 1/Orion, will be little improvement, and in some ways a major step backwards. It will launch even fewer crew than Shuttle, and while the Shuttle was a heavy-lift vehicle capable of delivering twenty tons to the space station, the new system will deliver little payload other than crew. It will have minimal ability to return payloads and no ability to return the types of payloads that the Shuttle could. It will likely cost as much or more per launch, particularly when having to amortize the development costs, which had been long sunk for the Shuttle, and it’s unlikely to launch much, if any, more often. We will go from a system that could deliver a few government employees (along with a couple dozen tons of paylad) into space a few times a year, at a cost of hundreds of millions of dollars per flight to a system that can deliver fewer government employees (with essentially no paylad) into space a few times a year, at a cost of hundreds of millions of dollars per flight. The only saving grace is that, in theory, it can also deliver people to the moon, and it may be somewhat safer.

But the Shuttle started out with a dream: of dozens of flights per year, of low costs per flight, of many flights for many purposes, some of which would be privately funded for private purposes. In canceling most launch vehicle technology development, and returning to a horrifically expensive concept from the 1960s, NASA has in essence officially declared that dream dead.

Fortunately, investors don’t take NASA as seriously as they used to, and the dream now lives on in the form of new private companies, determined to open up the heavens to all of us, and not just a few civil servants. If we hadn’t lost the Challenger over two decades ago, the Columbia loss might have been seen as an anomaly in an otherwise-successful program. As in 1986, it might have simply been replaced (albeit at great expense) with the structural spares that were earlier used to build Endeavor, and the program might still be lumbering on, keeping us trapped in low earth orbit, and continuing to crush the dreams of those who believe that we can do better. If that loss back then was a necessary catalyst to ultimately end the program and spur on efforts to do better privately, even if delayed, then perhaps the sacrifice of the Challenger crew will, in the long run of history, be viewed as not for naught.

Space, Technology and Society

The Radiation Problem

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A solution?

They started with two common food preservatives–the same stuff, BHA and BHT, that keeps Wonder Bread fresh for weeks–as a means to carry away free radicals before they can cause harm.

But for the food preservatives to become effective, the scientists needed a way to get them inside cells.

That’s where carbon nanotubes, single layers of carbon atoms curved into tiny cylinders, came in handy. The research team attached the food preservatives to the nanotubes, which, because of their size, provided a perfect vehicle for traversing the body’s arteries and entering cells.

Tour said he began his research with the goal of finding a drug to protect astronauts on long-duration space missions from the radiation to which they are exposed outside Earth’s atmosphere.

But the test results in mice, which were given the drug 30 minutes before a blast of radiation, were so impressive that Tour thought the drug might have much broader potential.

I hope that the real promise is for deep space travel, not for a nuclear war. We need to do everything we can to avoid the latter, but if not, this will help as well.

Political Commentary, Space

What I’d Like To See A Presidential Candidate Say About Space

Of either party.

“I fully support the president’s Vision for Space Exploration. I believe that we should expand our presence beyond low earth orbit, and establish a human civilization into the solar system, going to the moon, the asteroids, Mars and points beyond, which is what the vision was in its essence. However, I’m extremely disappointed in the implementation of it to date by NASA, and if elected, I pledge to revisit the Aldridge Report, which required that the vision be fully integrated with the commercial sector and that it support national security goals, and restructure it in order to do so.”

One could obviously expand on it in detail, but that’s what’s missing from the debate, in my opinion.

Political Commentary, Space

What I’d Like To See A Presidential Candidate Say About Space

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Of either party.

“I fully support the president’s Vision for Space Exploration. I believe that we should expand our presence beyond low earth orbit, and establish a human civilization into the solar system, going to the moon, the asteroids, Mars and points beyond, which is what the vision was in its essence. However, I’m extremely disappointed in the implementation of it to date by NASA, and if elected, I pledge to revisit the Aldridge Report, which required that the vision be fully integrated with the commercial sector and that it support national security goals, and restructure it in order to do so.”

One could obviously expand on it in detail, but that’s what’s missing from the debate, in my opinion.

Political Commentary, Space

What I’d Like To See A Presidential Candidate Say About Space

Of either party.

“I fully support the president’s Vision for Space Exploration. I believe that we should expand our presence beyond low earth orbit, and establish a human civilization into the solar system, going to the moon, the asteroids, Mars and points beyond, which is what the vision was in its essence. However, I’m extremely disappointed in the implementation of it to date by NASA, and if elected, I pledge to revisit the Aldridge Report, which required that the vision be fully integrated with the commercial sector and that it support national security goals, and restructure it in order to do so.”

One could obviously expand on it in detail, but that’s what’s missing from the debate, in my opinion.

Space

The Unveiling

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.

Space

Boy, Does This Need A Follow Up

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.