Category Archives: Space

Space

Unmitigated Risks

10 Comments

Ares 1 marches (or staggers) on:

Thrust Oscillation is specifically named in relation to end of the first stage burn of Ares I-X, which requires mitigation – proposed to be in the form of high strength fasteners.

“Preliminary results show lower axial loads and higher lateral loads during thrust oscillation at the end of the FS (First Stage) burn (T+120sec). Proposed mitigation (high strength fasteners in impacted hardware) in work, needs to be presented at ERB (Engineering Review Board).

Afraid it will shake apart? Use bigger screws!

I love this, too.

While beefing up the structure is a mitigation for the hardware, Ares I-X’s components are also in the TO firing line, with the most concerning element referencing the Flight Termination System (FTS) – which may require a range waiver due to the potential TO could exceed the components certification, and the threat of vibrating them out of action.

“Requirement – Range Safety: multiple waivers. Lack of dual S&A device. Lack of initiation of LSC at both ends. Lack of “CRD Self-test” capability. Minimum separation of FTS components,” added the presentation.

We may massage the thing so hard that we won’t be able to blow up the vehicle if something goes wrong (e.g., it starts blasting toward the VAB). Can we have a waiver, please?

NASA’s unending ability to waive itself from its own requirements is one of the reasons that the notion of “human rating” is nonsensical.

[Early evening update]

Link to NASA Space Flight was bad before. It’s fixed now. I’m kind of surprised that it took all day for someone to point it out. Just more evidence that most people don’t follow the links, at least if I post significant excerpts and/or commentary on them.

[Update a couple minutes later]

Rob Coppinger has Ares 1, then and now. That upper stage has really grown. I also hadn’t realized that it had a common bulkhead for the tanks. Well, at least it’s not hypergolic.

Space

Sad Anniversary

1 Comment

Clark notes that tomorrow will be a time of remembrance in Mojave.

And one year later, they still don’t seem to know for sure what happened. And we haven’t heard what’s going on with SpaceShipTwo propulsion development, though it won’t fly before late next year (at least two years behind the original schedule, with some of that slippage no doubt due to last year’s incident).

Political Commentary, Popular Culture, Space

Not This Again

20 Comments

The “rocks have rights” crowd are worried again about vandalizing space:

Edward O Wilson has suggested that biophilia, our appreciation of Earth’s biosphere, is a by-product of evolving in this environment. If he’s right, we might find we don’t care about other worlds in the same way. This raises the alarming prospect of rapacious lunar mining altering the view from Earth.

Maybe our biophilia will kick in here: after all, our view of the Moon is one of Earth’s natural vistas. Surely we can agree that we don’t want that changed? It is an awesome thing to look up and remember that human footprints once marked the Moon’s surface. It’s quite another to imagine the moon looking like an abandoned quarry.

No, we can’t agree. Note that this was in the context of a discussion on “eco issues” on the moon.

Here’s the “eco issue” on the moon (and in the rest of the universe, as far as we know right now). There is no “eco” there. There is also no “bio” for our “biophilia” to kick in about. Ecology and biology are about life, something that exists only on earth. It’s one thing to want to preserve an ecosystem, but when one simply wants to preserve the entire universe in its current “pristine” state, there’s something unsettling and misanthropic going on.

Why is it all right for a meteroid to slam into the lunar surface and leave a crater (which has happened billions of times throughout history, and continues today) which is how the moon got to look the way it is, but a pit for mining is verboten? Would he object to seeing the lights of a lunar city up there? Does he have any idea how far away it is and how much mining one would have to do to see it from earth, even with a telescope?

What is this worship of entropy? What is this loathing of humanity? What is this apparent loathing of life itself?

Political Commentary, Science And Society, Social Commentary, Space

Can Women Be Explorers?

9 Comments

Of course they can, despite this misreading of my exploration piece on Monday. History is replete with them, though there are far fewer of them than men (more now, with more opportunities for them). For instance, the “mountain men” who explored much of the west were, pretty much to a…man, men.

I recently received an email from someone who made an analogy between what I wrote and saying that a “white” boy could be an explorer as long as the school system didn’t “blacken” him. I find the analogy completely spurious. Briefly, race is not gender.

This was my point, and one that will no doubt set off a crowd of angry blank slaters who think that gender is purely a social construct charging up the hill to my mansion with pitchforks and torches.

There are such things as masculine and feminine traits. All people have some of both–they are androgynous to one degree or another. We define the two by noting that most men are (by definition) more masculine, and most women are more feminine, and viva la difference. So things that most men do, and few women do, are called masculine, and vice versa for feminine (and of course there is a wide range of things that are neither). When men cook, garden, sew, etc., (as I do, though I don’t sew much) they are indulging in their feminine side, and when women explore, go shooting, chainsaw trees, drive Indy cars (among other things) they are being sort of manly. And there’s absolutely nothing wrong with either doing either. There’s plenty of femininity to Danica Patrick, from what I can see.

There are a number of evolutionary psychological reasons to think that an urge for exploration is more of a male trait, and the Economist piece gives one more. If such an urge is an attention-deficit issue, it’s indisputable that (at least as it’s currently diagnosed) the preponderance of occurrence of it is in boys. At least, it is they who are being medicated the most for it in the schools. There may be some girls who are being similarly abused who would also be good explorers, but girls can be good explorers even when they act like girls in the classroom, because it’s a lot easier for them to act like girls in the classroom (even if they have some male characteristics) because they are, well…girls. They still learn, but aren’t having their exploratory urges browbeaten out of them. So to the degree that we are inhibiting budding explorers with a misguided educational system which defines good behavior as feminized behavior, the boys are taking the brunt of it. I could have, when referring to the future Neil Armstrong, said “her,” instead of “him,” but it would have seemed a little strained in political correctness, not because Neil was a man, but because not that many girls are being diagnosed ADHD and getting Ritalin.

Political Commentary, Space

The Cause Of The Ares 1 Problem

23 Comments

Well, actually there are multiple causes, but this is one of them. The launch escape system is very heavy. And it’s heavier than it needs to be because of the inherent inefficiency of the engines resulting from the cant outward (necessary to avoid blasting the capsule with the exhaust). Note that each opposed pair are fighting each other with the horizontal components of their thrust, contributing nothing whatsoever to the mission. This is called a cosine loss because the effective amount of vertical thrust is the total thrust times the cosine of the angle they’re canted at. Since the lost thrust is the sine of the angle, you need more thrust overall (and hence a heavier engine) to compensate, making a bad problem worse.

People have considered putting the escape motor underneath the capsule for this reason (I think that Mike Griffin even drew a napkin sketch of it–we looked at it in OSP as well), but that complicates jettisoning, since it goes between the capsule and the service module. That would mean that you’d have to carry it all the way to orbit on each mission, and then separate, jettison, and redock with the SM, which carries performance and safety risks in itself. Or if it goes under the service module, then the motor has to be a lot bigger, and then you have to do a CM/SM separation after motor burnout but before rotation for entry. So they stuck with the Apollo tractor configuration, in which the capsule is pulled away in an abort.

The other solution, which would give them a ton (actually, literally tons) of margin would be to get rid of the damned thing. It’s only there as a backup in case something goes wrong with the launch vehicle, and then only if specific things go wrong (for instance, a loss of thrust wouldn’t require it). The weight and design is driven by the extreme case in which the upper stage is exploding beneath you and you have to try to outrun the flying debris. This is an extremely unlikely failure mode, but politically, they have to have the system there, because no one wants to take the chance that they’ll have to testify before Congress that they killed astronauts because they didn’t have it. With it, the estimate is a one in five hundred chance of losing a crew. Without it, it’s much higher (though there are no doubt many astronauts who would accept the risk regardless, since they’re already doing so now on the Shuttle).

Also, as Jon Goff has pointed out in the past, they’re putting a lot of effort into safety during ascent, when this is actually one of the lesser hazards of a total lunar mission.

But that’s the way that politics drives a government space program, and why it is so horrifically expensive.

[Update a while later]

It just occurs to me that the other case where you need it is an on-pad, or shortly-after-liftoff abort, when there is insufficient altitude for safe chute deployment.

But the thing to keep in mind is that it made a lot more sense in Apollo, because in the early sixties, “our rockets always blew up.” The technology is much more mature now, and the failure modes for which it would be needed are much less likely, even in an expendable.

Media Criticism, Science And Society, Space

Rolling My Eyes

6 Comments

…at Keith’s brief “review” of my exploration piece:

The author of this article makes some odd, borderline misogynist, and mostly unsupportable claims (mixed with some valid points) as he rambles along trying to explain why people do or not explore. “Empirically obvious“? – Where’s the data to support this?

Where the support for the claim that it is “misogynist,” “borderline” or otherwise? Is he claiming that Cristina Hoff Sommers is misogynist?

What is “odd” about my claims?

And as for the data to support my claim, I provided it in the piece. Things for which there is an “innate human urge” are done by most, if not all humans. Most people don’t explore.

[Update a few minutes later]

One of the commenters over there gets it:

I didn’t see anything misogynist in Simberg’s piece – he’s just pointing out a potential cost of browbeating and drugging boys into behaving more like girls in school.

Exactly. If my piece was (mis)interpreted to imply that women cannot or should not be explorers, that’s absurd, and I would hope obviously so.

Space

The Problem With Ares

7 Comments

Henry Spencer (whose wisdom is finally becoming available on the web, apparently) explains:

An experienced designer with more freedom to act might have realised that there was just too much optimism in the Ares I concept, that a shuttle SRB was simply too small as a first stage for a rocket carrying the relatively heavy Orion spacecraft. There were several ways to handle the situation, but in my opinion the best was to just forget about Ares I entirely: build Ares V, or something like it, right away and use it for all the launches.

With a big launcher, there would be plenty of margin for weight overruns in development. Using the big launcher for Earth-orbit missions would obviously permit much heavier payloads there. Moreover, the lunar missions would get greater margins too, because they’d be done with two big launches rather than a big one and a little one, so they could weigh almost twice as much.

There is also an important pragmatic issue: the biggest threat to NASA’s return to the Moon is the possibility that Congress will delay or cancel development funding for Ares V. Doing Ares V right away, and using it for the Earth-orbit missions as well as the ones to the Moon, would have ensured that this crucial element of NASA’s plans actually gets built.

Of course, better yet would have been a focus on in-space infrastructure, drawing on ISS assembly experience, to allow us to use existing launchers. That would have also freed up money for earlier development of injection stages and landers, and made lunar missions much more of a fait accompli by now.