Category Archives: Space

OK, I’ve Reconsidered

OK, I’ve gone back and taken a look at Jeffrey Bell’s Space Daily piece again.

In addition to the comments that Dwayne Day made on the previous post, he’s wrong about architectures. I was a little confused on my first read, and I thought I agreed with the following:

People who say that a manned moon mission could be assembled in LEO out of small pieces launched on existing boosters like the new EELVs are dead wrong. This option was never seriously considered by either the Red Team or the Blue Team back during the Moon Race. It vastly magnifies the chances of failure.

Both Delta 4H and Atlas 5H can lift about 20 tons to LEO, so many launches would be needed for each moon flight. The need to design the moonship in many small pieces increases its total weight. Rumor suggests that the actual number coming out of current studies of this option are in the range of 6 to 9 launches (120-180 tonnes). If any one of these launches were to fail, the whole mission plan would be disrupted.

Also, there is no way we could produce the number of Delta 4H or Atlas 5H boosters it would take to support a serious moon program on top of all other launch requirements. Since each Heavy EELV uses three core stages in parallel, 18 to 27 stages would be dumped into the Atlantic for one Moon landing.

I actually do agree with much of this–I don’t think that it’s sensible to use EELVs for the new space initiative. Of course, I don’t think that it’s sensible to use expendables in general. My biggest disappointment in the new space policy is that it seems to have thrown in the towel on the possibility of getting low-cost launch.

If we were to launch the pieces on a reliable, low-cost launcher (a highly reusable space transport), then the concerns about a missed launch would be vastly mitigated, the pieces themselves would be much cheaper, and there would be spares in the event of a launch failure. Unfortunately, this is an option that no one seems to be considering now, because NASA screwed the pooch so badly on X-33 that the agency (totally irrationally) really seems to believe that it’s not possible to build reusables, or lower launch costs significantly. And for the paltry goals that the agency has (even in the wake of the new space initiative), it’s probably not.

It will only happen when the nation (not NASA) decides that we have to have routine affordable access to space, and puts in place policies to achieve that goal (which involve much more activity than NASA’s space exploration goals). But once the goal is achieved, the trade space will become radically transformed, and articles like Jeffrey Bell’s will be irrelevant.

OK, I’ve Reconsidered

OK, I’ve gone back and taken a look at Jeffrey Bell’s Space Daily piece again.

In addition to the comments that Dwayne Day made on the previous post, he’s wrong about architectures. I was a little confused on my first read, and I thought I agreed with the following:

People who say that a manned moon mission could be assembled in LEO out of small pieces launched on existing boosters like the new EELVs are dead wrong. This option was never seriously considered by either the Red Team or the Blue Team back during the Moon Race. It vastly magnifies the chances of failure.

Both Delta 4H and Atlas 5H can lift about 20 tons to LEO, so many launches would be needed for each moon flight. The need to design the moonship in many small pieces increases its total weight. Rumor suggests that the actual number coming out of current studies of this option are in the range of 6 to 9 launches (120-180 tonnes). If any one of these launches were to fail, the whole mission plan would be disrupted.

Also, there is no way we could produce the number of Delta 4H or Atlas 5H boosters it would take to support a serious moon program on top of all other launch requirements. Since each Heavy EELV uses three core stages in parallel, 18 to 27 stages would be dumped into the Atlantic for one Moon landing.

I actually do agree with much of this–I don’t think that it’s sensible to use EELVs for the new space initiative. Of course, I don’t think that it’s sensible to use expendables in general. My biggest disappointment in the new space policy is that it seems to have thrown in the towel on the possibility of getting low-cost launch.

If we were to launch the pieces on a reliable, low-cost launcher (a highly reusable space transport), then the concerns about a missed launch would be vastly mitigated, the pieces themselves would be much cheaper, and there would be spares in the event of a launch failure. Unfortunately, this is an option that no one seems to be considering now, because NASA screwed the pooch so badly on X-33 that the agency (totally irrationally) really seems to believe that it’s not possible to build reusables, or lower launch costs significantly. And for the paltry goals that the agency has (even in the wake of the new space initiative), it’s probably not.

It will only happen when the nation (not NASA) decides that we have to have routine affordable access to space, and puts in place policies to achieve that goal (which involve much more activity than NASA’s space exploration goals). But once the goal is achieved, the trade space will become radically transformed, and articles like Jeffrey Bell’s will be irrelevant.

A Close Shave

A thirty-meter-diameter asteroid is going to pass within twenty-five thousand miles of the planet this afternoon (America time).

That is very close–about a fifth of the distance to the moon and well inside its orbit. A few thousand miles lower, and it could take out a geostationary satellite. If it were to hit land, it might leave a scar something like this.

And of course, like all bad things that happen, it will be Bush’s fault.

I took the picture Tuesday on a flight from Fort Lauderdale to LA, over Winslow, Arizona. The crater is almost a mile in diameter and about a two and a half miles in circumference. When it hit, back during the Pleistocene, it probably wiped out all life for many miles around. You can read more about it here.

Just another reminder that we have to start paying attention to these things.

[Update at 1:20 PM PST]

Clayton Cramer has more details.

Mystifying

At first glance, this didn’t seem like a very auspicious beginning for government-sponsored prizes in the modern era.

A $1 million race across a southern California desert by driverless robots ended Saturday after all 15 entries either broke down or withdrew, a race official said.

Two of the entries covered about seven miles (11 kilometers) of the roughly 150-mile (240-kilometer) course in the Mojave Desert while eight failed to make it to the one-mile (1500 meter) mark. Others crashed seconds after starting.

Color me confused. No, flabbergasted.

Were there some rules of which I’m not aware of in this contest? Like you couldn’t run the course, or some facsimile of it, ahead of time? You weren’t allowed to test your vehicle under actual course conditions?

I should start by saying that I’m not sure what the purpose of making it a real-time race was, unless they thought that this would generate more public excitement, or perhaps make it more challenging by having to deal with competitors as well as the course itself. If the goal is to get from Barstow to Vegas in a certain amount of time, then that’s the goal–why have everyone do it at the same time?

Why not do it like the X-Prize people, at least to start? Set a date that you’re going to make the attempt, have the judges show up to watch, and do the attempt. No need to have everyone go at once. Use graduated prizes–a million for the first, half a million for the second, a quarter million each for the next four. Once you’ve got some vehicles that can demonstrate their ability to do it, then you put them on the same course and actually have them race each other in real time.

But what amazes me is that, given that it was a real-time race (you had to beat not just the clock, but other competitors), wouldn’t you want to test and see if you could do it at all first, let alone in the allotted time period?

I mean, if I had a Formula I car, I don’t think I’d enter it in a race with other Formula I cars, or even with the pace car or a bicycle, until I’d at least seen if it could make it around the track once or twice. In fact, you know, I think that I’d drive the course the requisite number of times to win, and even see if I could at least approach some course records before I actually put it in competition.

Yet somehow, not a single one of these team’s vehicles were capable of making it five percent of the distance without some kind of breakdown. What’s up with that? Could it really be just an unfortunate set of circumstances, lousy luck all around?

Does anyone have an explanation?

Boost Phase Intercept Talk

There was a talk at the University of Maryland today by Daniel Kleppner, one of the co-chairs of the American Physical Society’s Boost Phase Missile Defence Study Group. The report is summarized here, and the whole thing is available here.

Anyway, the talk was very well presented, and it’s clear that if you accept the initial assumptions the conclusions follow logically. It’s the input assumptions that are somewhat problematic. I’ve seen people complain that the choice of initial assumptions is due to liberal bias, but Kleppner defended them quite well on the basis of the National Intelligence Estimate and the systems actually under consideration. Some of the parameters considered, such as the burn time, were skewed in favor of the defender, and they considered zero decision time cases, which also favor the defender. The minimum kill vehicle mass considered (90 lbs, including sensors, thrusters and fuel) seemed to me a little large, but I don’t have a basis to dispute it. This is a critically important parameter, since it scales all the other masses in the system.

Continue reading Boost Phase Intercept Talk

The Fall Of NASA?

Jeff Foust has a review of Greg Klerkx’ new book, Lost In Space (the title of this post is a subtitle of the book). I read it right after it came out a few weeks ago, and have been meaning to review it myself, but Jeff has mostly done it for me. He’s right in that there are some errors in the book that detract somewhat from its credibility. Here was a list that I made as I went through it.

He says that “…at their most basic, tethers are analogous to the wire that runs from a wall socket to a lamp.”

Errr, no. At their most basic, space tethers are a line that connects one object to another in orbit. He’s talking about a special category of space tethers–electrodynamic tethers, and an uninformed reader might believe that these are the only kinds of tethers that exist, and that their only use is for converting orbital energy to electrical energy and vice versa, when in fact that’s only one application.

He repeats the myth that “Even the paper plans for building the Saturns were gathered up and destroyed.” Not true. Well, perhaps it may be literally true–the plans exist on microfiche, but the implication is that they are beyond our reach. What really no longer exists is the tooling (at least not all of it), which was expensive to preserve and warehouse for a program that was considered part of the past. Should we choose, we could resurrect the Saturn program. It wouldn’t be wise, four decades on, but we have the plans, and there was no conspiracy to burn the bridge over the Rubicon to Shuttle, once across.

He says that “…two congressmen have flown, with little rationale other than their political status…” on the Shuttle. It’s wrong no matter how you define “congressman.” Two Senators (Garn and Glenn) have flown, and one congressman (now senator)–Bill Nelson. This is a particular perplexing error, because it should have been caught by an editor–later in the book, in discussing Senator Glenn’s flight, he writes, “To [Alan] Ladwig, this was Garn and Nelson all over again.”

In describing the Kistler K-1 vehicle (a project that recently got a new lease on life with a couple hundred million NASA contract to purchase flight data), he writes that it “would be a lot cheaper to use than the shuttle…because it will not be piloted and therefore will not have need of the extensive ‘human rating’ requirements that NASA employs for the shuttle.”

Here, he’s bought into (or at least is implictly endorsing) two myths of spacecraft design.

The first is that pilots add cost to vehicles (including space vehicles). There’s actually no evidence for this, at least in any vehicle other than space vehicles. There’s actually good reason to believe that piloted vehicles, properly designed, could be cheaper than unpiloted ones–a proposition that the X-Prize and commercial suborbital developers will test in the coming months and years.

The second is that the shuttle is human rated. In fact, it is not, and never has been, by the standards that NASA has established as human rated. For instance, it doesn’t have “zero-zero” abort capability (that is, the ability to abort from the pad all the way to orbit, the zeros corresponding to the velocity and altitude of the starting condition). I’ve discussed both of these aspects extensively in the past.

He states that Columbia wasn’t able to reach the ISS orbit. In fact, it was–but its payload would have been much less than that of the other orbiters, so it was designated mostly for non-ISS missions. It was in fact scheduled to go to the ISS had it not been destroyed a year ago.

On page 224, he expresses concern about sending nuclear waste into space that indicates a lack of understanding of the issues–he’s a little too prone to buy the scare mongering of some people about this. I do think that it might be financially feasible, and safe, to store nuclear waste in space, but this won’t happen until we develop much more reliable vehicles than are available at present. I discussed this a couple years ago in an early Fox News column.

Greg also has a higher opinion of Bob Park’s opinions than I do.

Overall, I agree with Jeff’s assessment of the book. It’s an interesting read, and will provide a lot of background in terms of NASA versus the private sector, but as Jeff says, it’s a little schizophrenic, in that he can’t quite decide whether the agency is an evil monolith, or a bunch of warring fiefdoms. Ultimately, while descriptive, it’s not very prescriptive, or well organized. It’s more a compendium of interesting stories than a coherent narrative, and it seems to peter out at the end, with no clear conclusion.

The world still awaits the book that lays out clearly the problems with our space policy, and viable recommendations to address them. This isn’t that book. Perhaps mine, if I ever get around to finishing it, will be.

SubOrbital Day

It’s fitting that my first post on Transterrestrial Musings is on suborbital industry lobbying – it certainly won’t be my last on this topic.

The Suborbital Institute has announced that it will be holding an event on May 17-18 to lobby congress on issues affecting the nascent suborbital spaceflight industry. If you are in the DC area or are able to travel to the area please join us. I’ll be there, as will various folks from the alt.space crowd. The date is chosen so that people planning to attend the May COMSTAC meeting can just come a couple of days early. I’ve been involved with the SubOrbital Institute since the beginning, and it’s a good bunch of people. SubOrbital days are interesting and fun, though there’s no doubt that it’s real work. I’ll post more on the institute and its agenda in the coming weeks.

On the topic of suborbital spaceflight, X-Rocket has revamped their website and they have some very interesting news. They have a working operational demonstrator for their planned vehicle, and they have test flights. Congratulations to X-Rocket and Ed Wright (who is one of the founders of the SubOrbital Institute). Link via HobbySpace.

That’s enough for now. I’ll post a formal introduction when the current family crisis has passed. I probably won’t be able to post more than occasionally until then.

Not About Space

I’ve often said that Apollo wasn’t about space, and that was one of the reasons that those who hope to resurrect the “space program” on an Apollo model are doomed to failure. The implication, of course, is that space activities that “aren’t about space” are a bad thing. My old friend (old in the sense that I’ve known him a long time, not that either he or I are old…) Jim Muncy has a different opinion:

Space exploration is not merely about the wonders of science and technology, although it produces countless discoveries and innovations. It is not merely about stunning images and daring adventures, although it has those aplenty. And to the disbelief of so many space professionals and aficionados alike, it is not even really about outer space.

Rather, space exploration is about strengthening and spreading the very essence of freedom: the magic of going and doing what you want, where you want, when you want and why you want. It is about the endless and innately human quest for a better, wiser and richer life, not just for yourself today but for generations hence. Freedom is as much about the creation and pursuit of new dreams, horizons and challenges as it is about achieving them.

RTWT

[via Mark Whittington]

Working Hand In Glove

Many of those enthusiastic about the president’s new space policy want to redo Apollo.

I pointed this out when it was first announced, but I didn’t really describe all the implications of it.

There are many, but I want to focus here on those aspects of it that affect our choice in launch systems to achieve the president’s goals, whether existing, or new.

There is an assumption that we cannot move humans beyond earth orbit without a heavy-lift vehicle, like the Saturn that first took men to the moon three and a half decades ago (and the fact that this July 20th will be the thirty-fifth anniversary of the first lunar landing makes me feel quite ancient). This assumption is based on the fact that it’s how we did it the first time, and some have too little imagination to conceive that it could be done in any other way.

But that was then, and this is now.

What are the differences between then and now, in terms of our ability to fling humans beyond earth’s orbit, and on to other worlds?

First, of course, we know much more now than we did then, if for no other reason than we’ve done it. But more importantly, technology has advanced over the past third of a century since we first went to the moon, in a time period in which technology has been generally advancing at a dizzying pace, with a seeming continuous acceleration.

Computers are much smaller and faster, materials are stronger with the ability to take higher temperatures, our ability to design is much greater, and our ability to get designs from a computer screen to functional hardware is phenomenal, compared to our capabilities in the 1960s.

Consider also that our goal then was not to open up space in any sustainable way, but to simply beat the Russians to the moon.

Under those conditions, our choice to launch a lunar mission on a single large rocket probably made sense. It wasn’t cheap, but it was low risk, since we knew how to build big rockets (we only had to scale up what we already had), and we didn’t know how to assemble things in space.

But there seems to be an assumption on the part of many that large launch systems are an intrinsic requirement of manned space travel. Accordingly, they’ve skipped past the part of the trade studies that would determine whether or not this assumption is valid, and gone straight to debating the best way to get heavy lift.

Of course, there’s another motivation on the part of many engaged in such debates–a large launch system means a large development contract that provides continued employment for many who may fear losing their jobs when the space shuttle is phased out.

There is a huge constituency for the Shuttle program–in Florida where they are processed and launched, in Utah where the Solid Rocket Boosters are manufactured, in Louisiana where the external tanks are built, and other places. The president’s announcement that we will no longer fly the shuttle after the end of this decade had to have cast a pall over many people in those places, because even if the new initiative blossoms, there’s no guarantee that it will benefit the communities that are currently supported by shuttle-based jobs.

So it’s not surprising that some are talking about building a new heavy-lift launch system that uses shuttle components. If they can’t keep the orbiters, there are certainly many parts of NASA and its contractors that will work very hard to maintain the rest of the (costly) shuttle infrastructure. Concepts for shuttle-based launchers have been around as long as the shuttle itself, and many will claim that this is the fastest and cheapest route to the capability that they insist we need.

But do we?

Most people are unaware that other options were considered for Apollo, including earth orbit assembly, but as I wrote above, this mode was ultimately rejected as being too risky in terms of the primary goal–beating the Russians to the moon.

But as the president said last month, this isn’t a race–it’s a journey, and we need to come up with modes of operation that recognize that, and make the journey an economically sustainable one. A heavy-lift vehicle, even a shuttle-derived one, will cost a lot to develop, and unless it flies enough, it will be difficult to amortize those development costs. Smaller vehicles, flown more often, will be more likely to reduce launch costs in the near term.

The objection, of course, is that orbital assembly carries its own risks. What few realize is that this is because NASA hasn’t really devoted the effort necessary to reducing them (particularly in developing space suits that don’t tire out the astronauts).

The current soft suit resists motion because bending a joint changes the volume of the air inside it, providing a force that wants to restore it to its original position. Think of a rubber glove, limp until inflated, but difficult to bend the fingers once under pressure.

In fact, the glove is the biggest problem in designing the high-pressure space suits necessary to avoid the bends (the same problem a diver has when she surfaces too quickly) when an astronaut goes out into the vacuum of space. Larger joints like shoulders and knees have special designs that are zero-volume change, but no one has yet miniaturized such a design to finger joints.

Because this is a critical technology, and one that has great leverage in influencing launch system trades, I would propose the following:

Build a vacuum glove box with a task box inside (perhaps an automobile engine that has to be dissassembled and reassembled). Put up a purse of a million dollars to the first person who can achieve the task working through gloves under a pressure differential of half an atmosphere, without a break.

Unlike many space activities, it’s a project that can be literally done in someone’s garage, and it may spur a great amount of innovation for very low cost. Accordingly, it would make an excellent candidate for the Office of Exploration’s new prize fund, and I hope they’ll strongly consider it. At very low cost to the taxpayers, one or more successful concepts could lay to rest myths about the intrinsic difficulty of working in space, opening up the options for how we will get to the planets beyond redoing Apollo, perhaps saving billions in dollars, and constituting a major step toward becoming a truly spacefaring nation.