Category Archives: Space

Political Commentary, Space

“Not Silent”

21 Comments

As usual, Doug Cooke defends ESAS:

The “direct” variation fails to meet NASA’s needs on several grounds. It is vastly over-capacity and too costly to service the International Space Station, but worse, its lift capacity would not be enough for NASA to maintain a sustained presence on the moon.

Advocates for the “direct” variation are touting unrealistic development costs and schedules. A fundamental difference is that the Ares I and Orion probability of crew survival is at least two times better than all of the other concepts evaluated, including “direct”-like concepts.

Also as usual, he provides no evidence for his assertions. We are simply supposed to accept them because Doug Cooke says so. Have we ever seen the actual report that came out of the sixty-day study, with a description of methodology and assumptions? I haven’t.

I’m not necessarily a big fan of “Direct,” but his statement raises more issues than it answers. Why doesn’t the “lift capacity allow a sustained presence on the moon” in a way that ESAS does? Why should it be assumed that NASA’s new launch system will service space station? I thought that this was what COTS was for? What are the marginal costs of an additional Jupiter launch versus Ares 1?

Give us some numbers, and provide a basis for them, and we might take this seriously.

[Wednesday morning update]

More thoughts and comments at NASA Watch, and from Chair Force Engineer.

Political Commentary, Space

“Not Silent”

As usual, Doug Cooke defends ESAS:

The “direct” variation fails to meet NASA’s needs on several grounds. It is vastly over-capacity and too costly to service the International Space Station, but worse, its lift capacity would not be enough for NASA to maintain a sustained presence on the moon.

Advocates for the “direct” variation are touting unrealistic development costs and schedules. A fundamental difference is that the Ares I and Orion probability of crew survival is at least two times better than all of the other concepts evaluated, including “direct”-like concepts.

Also as usual, he provides no evidence for his assertions. We are simply supposed to accept them because Doug Cooke says so. Have we ever seen the actual report that came out of the sixty-day study, with a description of methodology and assumptions? I haven’t.

I’m not necessarily a big fan of “Direct,” but his statement raises more issues than it answers. Why doesn’t the “lift capacity allow a sustained presence on the moon” in a way that ESAS does? Why should it be assumed that NASA’s new launch system will service space station? I thought that this was what COTS was for? What are the marginal costs of an additional Jupiter launch versus Ares 1?

Give us some numbers, and provide a basis for them, and we might take this seriously.

[Wednesday morning update]

More thoughts and comments at NASA Watch, and from Chair Force Engineer.

Business, Space

Where Is The Money Coming From?

2 Comments

And where is it going, in commercial space?

I have to say, I thought this was pretty funny:

Virgin Galactic has already been watching its back with the EADS suborbital space plane (pictured above), set to make its first flight by 2012. But now there’s cash across the pond. “We have invested substantial money into this project,” Auque said without citing exact figures. “The problem is that we need to create this market.”

I doubt very much that Virgin Galactic is worried that EADS Astrium is going to raise a billion dollars to build a suborbital tourist vehicle. There’s a reason that Auque didn’t cite “exact” (or even approximate) figures. He expects to do it mostly with someone else’s money, if he can find a sucker (like ESA?).

Business, Economics, Political Commentary, Space

The Rough Road To Space

2 Comments

I have a new piece up over at Pajamas Media on space transportation and the Interstate Highway System.

Hey, it was Mike Griffin who made the analogy, not me.

I should also note that while the title is mine, the subheadline is theirs.

[Late afternoon update]

Only Mark Whittington would have the native talent to so misread this piece as to think that I was “expressing astonishment.” Of course, it’s not the first time that he’s fantasized about my views.

[Another update]

Now Mark is fantasizing that I actually want, or expect NASA to build the Interstate to space.

Well, it’s totally in character for him.

I sure wish he’d learn to read for comprehension.

Political Commentary, Space

Nothing New About That

Keith Cowing thinks that the Coalition for Space Exploration is asking the wrong questions.

If the Coalition for Space Exploration really wants to further the notion of a robust taxpayer-funded program of space exploration – one based on a solid footing of public support – then they need to start paying attention to what their polls actually say and stop trying to skew the results to say something that the numbers do not support. If, however, they want to support space exploration – regardless of how it comes about – then they need to re-examine their motives – and ask different questions.

People might not want to pay more taxes for space exploration, but they might be interested in buying a ticket.

Indeed.

As usual (and perhaps inevitably), an organization ostensibly set up for the purpose of supporting space exploration in general ends up being a NASA cheerleader. That’s partly because a lot of the funding for it comes from the space industrial complex. In any event, these polls should always be taken with a grain, if not a whole shaker of salt. They’re based on public ignorance, and once again demonstrate that support for the current plans are a mile wide and an inch deep.

Space

Glide Back

17 Comments

Jon Goff has put up the fourth installment of his survey on space transport concepts. As he noted earlier, it could be the basis of a useful textbook on the subject, with a lot more work and analysis (and accompanying graphs and figures). When I was on The Space Show the other day, David got a chat from an aerospace engineering student about when he’d learn how to design low-cost launchers, because he hadn’t seen anything about that in any of his course work. This would be the text for such a course.

As Jon notes, TPS is a common thread in making reusable entry vehicles practical and cost effective. The Shuttle tiles are too high maintenance, and risky (as we saw with Columbia). However, a lot of these issues go away if the vehicle “swallows the tank” (as Rockwell and others proposed in their X-33 concepts). No external tank dramatically reduces the risk to damaging the tiles, and containing a hydrogen (or even hydrocarbon, though to a lesser degree) fuel tank makes the vehicle much more “fluffy”* on entry, considerably reducing the heat load. Because of the ET, Shuttle had unique TPS issues that future vehicles are less likely to have to worry about. And also, as Jon notes, XCOR is in the process of building exactly the type of “X-vehicle” that will be useful to start to prove out both trajectory and TPS concepts, something that NASA should have done years ago, and probably would have had it still been NACA.

[Update late afternoon]

Notwithstanding the silly microkerfuffle in comments, I should add that when I came up with the term “fluffy,” it didn’t occur to me to apply it to a vehicle. I really intended it to apply to something that actually is fluffy (i.e., homogeneously undense, e.g., liquid hydrogen), rather than something that has low average density, but very high local density with vast volumes of low or zero density. We should probably come up with some other word to describe a large empty tank, to distinguish between the homogeneous and heterogeneous cases.

*A word I came up with years ago at Rockwell to mean the opposite of “dense.” Others may have come up with it independently.

Space, Technology and Society

Thoughts On The Number Six

11 Comments

Over at Rockets and Such.

So, it goes from Ares 5 to Ares 6, and it still doesn’t satisfy the mission requirement. And now it has outgrown the MLP.

There’s a concept in the development of a space vehicle known as “chasing your tail,” in which the need to add something to the vehicle (like adequate structural strength, with margin) results in more weight, which results in the need for bigger or more engines to push it, which results in the need for more propellant capacity to accelerate the added mass, which results in…

And the design won’t close.

Now in fact, it is probably possible to get this design to close–bigger vehicles are easier in that regard than small ones. But regardless of the size of the vehicle, mission needs are always going to grow (and they still don’t really have solid numbers on the EDS/Altair/cargo requirements). So it won’t be able to get the mission concept (one and a half launch) to close, particularly as we move beyond the moon, even if it can be done for the moon.

The rationale for the heavy lifter has always been to avoid the complication of orbital assembly (apparently, the false lesson learned from our success with assembling ISS is that we should throw away all that experience, and take an entirely different approach for VSE). But it’s already a “launch and half” mission, needing both Ares 1 and Ares 56, so they’re not even avoiding it–they’re only minimizing it. And even if the lunar mission doesn’t outgrow the Ares 6, it won’t be able to do a Mars mission in a single launch. So if we need to learn to do orbital assembly (and long-term propellant storage) anyway, why postpone it? Why not take the savings from not developing an unneeded heavy lifter (and new crew launch vehicle), and invest it in orbital infrastructure, tools and technology to provide a flexible system that can be serviced by a range of launch vehicles, without the single-point failure of Ares? These are the kinds of issues that a new administrator will have to consider next year.

And don’t get me started on the Ares 1 problems:

The currently favored mitigation approaches – still undergoing a trade study – for thrust oscillation will add around 500 lbs to Orion for shock mounting on the crew seats and vital components.

So, because the geniuses behind this concept decided to put the crew on top of the world’s biggest organ pipe, they’ll add a quarter of a ton to an already-overweight vehicle with no margin, so that the astronauts will (might?) be able to survive watching the rest of the capsule being vibrated even more intensely around them.

There is a word for this. It starts with a “k” and ends with “ludge.” And then there’s this.

Thrust oscillation is now categorized as a 5×4 risk for the upper stage.

I’m not sure which axis is which in that formulation, but it either means that there is a very high likelihood of a catastrophic outcome, or that that it is probable that there will be a near-catastrophic outcome. And no mitigation has yet been found.

They really need to consider going from one and a half launches to (at least) two launches of a single medium-sized vehicle type. Two launches is two launches, it would save them a huge amount of development costs, provide much better economies of scale in operation and production, and get completely around the “stick” idea, which is proving to be a programmatic disaster waiting to happen, if it hasn’t already. Let us finally end the cargo cult of Apollo, and develop real infrastructure.

[Late morning update]

Here’s more discussion over at NASA Space Flight.

[Update a few minutes later]

In a post from a week ago, Chair Force Engineer has some related thoughts as well, on the wisdom of choosing solids at all:

The solid-liquid trade study is one that couldn’t have been adequately analyzed during the 60 days of the ESAS study, and will likely end up as an interesting footnote in the Ares story. The question is whether the Ares story will fall into the genre of historical nonfiction, or fantasy and tragedy. If the latter is true, perhaps liquids were the answer after all. But the decision to not cap the weight of Ares V (even at the expense of payload) is one that taxpayers shouldn’t forget if the massive rocket, and its shiny new infrastructure, ever get off the drawing board.

It seems pretty clear (as it did at the time) that the decision to build “the Stick” was pre-ordained, and that the sixty-day study was a rationalization, not a rationale, and that none of the CE&R recommendations were seriously considered. An Administrator Steidle would no doubt want to revisit it.

Space, Space History

Len Cormier’s Final Flight Plan

3 Comments

I just got the sad news from Pat Kelley:

Len took his final journey this morning, passing peacefully. His family is going to have his ashes interred at Arlington cemetery, but I have no schedule. For those who wish to express condolences, you can reach his life partner, Anne Greenglass via email, [email me for the address if you want to do so–rs].

I tried to address this notice to all the people on my list, but I’m sure there are others I may have missed, so please forward this to anyone else you feel would want to know. I do intend to continue trying to get backing for Len’s last design (Space Van 2010) as a tribute.

Len was a truly unique man, and a rare breed these days. Always the gentleman, honest to a fault, and always ready to give credit where it was due (and sometimes even allowing the unworthy to take credit for his work, for the sake of an important effort). He is unreplaceable, and will be sorely missed.

Ad astra, cum laetitia, Len.

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