The thread for space cadets!

[Cutlass]

Way to be late on a point that was already discussed, discarded, and moved on from.

Way to win friends and influence people.

 

[Symphony D.]

Yeah, I'm very concerned with the thoughts of people who hop in to say "cars don't work that way!" after I admitted cars don't work that way and that was one tiny sliver of a larger argument nobody has otherwise engaged since. You're right, my behavior is uncalled for. Carry on, Cutlass.

e: For content, have a short but interesting piece on the X-37. The origins of the Atlas V's first stage engines, the RD-180, in the N-1's NK-33 was particularly amusing to me.

 

[peter grimes]

That X-37 article was more informative than most that I've seen on it (tho' I haven't sought them out).

But I was surprised to hear that the payload is limited to 500lbs. Yet the vehicle itself measures in at 5.5 tons. So we have a ratio of 1:25 for payload to vehicle. That doesn't seem very high, but what do I know?

What sorts of satellites are less than 500lbs? I'm guessing a lot of them, otherwise this airframe (spaceframe?) would have been spec'd to different parameters. But I just sort of thought that most satellites were heavier than that. But as I said a moment ago, "what do I know?"

 

[Symphony D.]

500lbs is nearing what's commonly thought of as microsatellite territory, particularly for military equipment. Whatever it's up there doing, it's probably working with onboard labs and experiments, not acting as a satellite bus like the shuttle did.

 

[Winner]

Rabbit has landed!

(Softly, it seems.)

 

[Borachio]

Are the Indians going to be next? I doubt it, though. At least, not soon.

 

[Loppan Torkel]

Nearly 40 years since the last landing on the moon?

 

[dutchfire]

Good job China!

 

[hobbsyoyo]

Back from finals week! Sorry this is another wall of text. :\

Ultimately I think what you want is to refine this down to a standard storage package (the "cargo container" aspect), which you can fit a highly standardized guidance and orbital insertion package to; much the same way as a JDAM kit is fitted to an ordinary gravity bomb, only you don't want your payload to explode on impact. A lot of the rest would be working out how to pack these things as fully as possible and how to arrange the launches, but it would really just become a logistical challenge at that point.

I think you're probably right that you could develop some sort of delivery system that's *relatively* cheap and again I point to the Dragon or Cygnus systems. But as I've been saying all along, it's the payload that's going to drive costs.

Earlier, I tried to point out that now we're talking (essentially) about Oregon Trail in Space. What I meant is that Mars Direct envisions a limited number of launches, which is a more realistic assumption but doesn't offer a lot of opportunity for massive savings. However, if you are really sending dozens of modules to Mars, then you could definitely see some serious savings. But that's fundamentally different than Mars Direct as it's usually talked about and I think that difference has been driving a lot of the argument.

I do fundamentally agree with you that if a program could be put together on the scale you are talking about, you'd see all kinds savings from the boosters to the payloads.

While I'm by no means an expert at economics, I think this is actually very telling; a Lambo doesn't cost nearly as much to make as what it's sold for, either in terms of effort or materiel; even an ultra-high end supercar is not going to cost generally more than $10,000 to put together. Most of the price is for the badge and prestige. This applies to any given consumer product, whether it's Tide or a Cessna. The manufacturer, distributor, etc., are all getting their cut, and they want to keep their profit margins high. There are usually competitors, but they all essentially informally agree to keep prices within a certain range to keep these margins up (and because demand is limited and numerous other considerations). It's usually less "this is what it's actually 'worth'" though, and more "this is what someone is willing to pay," particularly for finished goods.

So I picked the wrong high-end car. Point still stands - until the volume goes up dramatically, you aren't going to see big savings because each rocket and certainly each payload are essentially one-off products. Moreover, they are high-end products that have to operate at the extreme limits of engineering in most cases. Particularly components meant to set up a colony on Mars. Sure, the supplies may be rather ho-hum, but all of the other equipment, from the living quarters, to the power generation facilities, to the atmosphere-cracking plants, to the rovers and so on are going to be extremely complex machines.

However, if you are sending dozens of these things at a time, then even the complex parts get to be ho-hum. But that's only after years and billions spent in development and initial tooling and of course rests on the assumption that a long-term and high-volume colonization program can be started and sustained long enough to see those savings. Unfortunately, I can't see the US government keeping things on track long enough for that kind of endeavor. Hopefully, the private space sector can develop enough in the near future to make this kind of program independent of massive government support.

ULA as an entity is particularly problematic because it's basically a cartel that has a monopoly on the (US) market and so it jacks up costs; it holds almost all the cards. When times are tough, it can basically set prices at whatever it wants. That SpaceX has so dramatically undercut them, from basically nothing reveals the degree to which they've been basically price-fixing. (For reasons which are understandable from a business perspective, sure, but true nonetheless.)

ULA doesn't hold all the cards - in fact, quite a lot of their high costs are driven by government ineptitude that's been going on for decades. They are also saddled with legacy costs due to the launch market implosion of the 90's, which saw Boeing and Lockheed massively overbuild capacity and drove out other competitors from the market. SpaceX came well after that and thus avoided that build-out. That, coupled with novel management practices means they do have an obvious cost edge. But it's not entirely the case that ULA has engaged in cost-fixing, it really does cost them a lot more to build rockets and in order to remain competitive, they are going to have to make some serious adjustments to how they build rockets and more importantly, how they manage their business. SpaceX is still relatively unproven but hopefully they will emerge as the market leader and drive down costs.

One area where SpaceX is having a tough time competing with ULA is for a share of the USAF launch manifest. The USAF prefers tried and true above all else and essentially wants to stick with ULA for that reason. Congress decided that wasn't fair and mandated that the USAF set aside 25% of their manifest for 'competitive bidding', which essentially means SpaceX/Orbital Sciences.

So there are huge scale effects, cool.

One-way. Costs went up, but they can't go down easily even if you bought more rockets.

So if you build more components, average cost comes down. That sounds like a scale effect.

No, average costs go up because they simply don't have capacity to build more components at a volume that would see big savings. So they would have to retool at great expense and since the government and private markets don't currently have enough demand of US boosters, they can't recap that massive-up-front cost by averaging out over a long production run. Instead, they pass the cost on to the few customers they get, which means even at higher volumes, costs go up because the volume is not large enough for scaling to kick in.

So at some stage government did manage to put in large enough orders to reduce average unit costs i.e. to achieve scale. With us looking at the results now in the cost competitiveness of older components over new stuff.

To your first sentence, the government didn't put in large orders - the private market did in the 90's and then imploded which left the rocket manufactures with an excess of components which has now run out.

The current private and government market does not provide enough demand to achieve good scaling, which is why costs went up with less orders but will also go up with more orders. Even then, there is serious question about whether or not many more additional orders can be had given the engine situation with respect to the Atlas V, which is ~half of the US launch capability.

So at some point along the curve average cost rises. That's, well, a scale effect too (see graph). Although, again, this could be overcome if the government put in a large enough order sufficient to spread the costs of retooling, retraining etc across more units. So why is it that scale doesn't work in rocketry again?

Because no has or can put in enough large orders! The one time things ever came close to that (in the 90's) the market imploded. Even with extremely optimistic projections about future launch demand, the projections don't even come close to what was projected in the 90's, when companies were talking about launching hundreds of satellites each.

So the scale works one way - lower volume increases cost. But increasing volume also increases costs and may not even be possible due to the engine shortage, shuttered production facilities, etc.

I haven't read nearly all of the immense walls of texts of doom in the previous pages, but just a comment on the notion that "economies of scale" will make "rockets cheaper" and thus manned space exploration will kick off.

Maybe. However, there is currently no demand which would stimulate such development. Everybody is hyping what SpaceX does, but in the end they're simply rationalizing the existing space launch business, which is (as Zubrin himself pointed out) extraordinarily conservative.

More fundamentally, I believe the physics of conventional space launch makes it extremely unlikely any kind of "big dumb booster" + "mass production" would bring prices of space travel back to Earth (pun very much intended).

What's needed are completely new, smarter approaches to the problem. Like *cough Skylon *cough*.

I agree. And while SpaceX can hopefully keep their own costs low, which will have a knock-down effect on providers like ULA, that's not because of scale. It's not the case that SpaceX can provide lower costs because of high demand, they have much lower management and fabrication costs relative to the older providers and that's where their savings come from.

Apparently there's huge scale effects as one moves from 26 to 23 units.

One way, one way, one way. Going back from 23 rockets to 26 rockets will not bring back the old costs.

That suggests that scale is a factor at current levels of production and that it does already help to significantly reduce costs.

No it doesn't, see above.

To that point: the CBO estimated in 1990 that the total program cost for 132 B-2 bombers would be $76.7 billion, or $581 million per bomber (in 1991 dollars). In 1997 dollars, this would be around $688.6 million per bomber; the actual total program cost for the 21 B-2s actually produced in 1997 dollars was $2.1 billion per bomber. For around 2x the cost, Congress could've bought 6x the bombers. (This has interesting implications for the constant reductions of F-22 and F-35 buys, but that's neither here nor there.)

Major aerospace items have absolutely horrendous cost-scaling. The previously cited evidence indicates it's no different for boosters, and I don't see any reason why it would be. Cost-savings of anywhere from a factor of 2 to 3 per purchased unit in extended production runs don't seem uncommon; that adds up tremendously over time. For something where you're doing continuous production (like boosters) instead of a limited run (like bombers), this is even worse due to the need to keep the plants, personnel, tools, etc., on hand and in working order instead of packing up the machinery for storage and reassigning the personnel (overhead and downtime become serious factors in costs). I would predict significantly larger cost savings for continuous production items by ramping up production.

Couple that with a competitive industry that isn't price-gouging its customers, and well... I can't tell you exactly how much money you'll be saving per unit capacity, but it'll be a helluva lot.

To the first bolded part - that's untrue. I've been pointing out over and over again that costs increased with lower volume but they don't decrease with increased volume. Particularly now that plants have been closed, their is an absolute limit to engine availability and older surplus parts have run out, etc etc.

To the second bolded part - rockets currently are much more of a limited run product like bombers. While yes, they are built on an ongoing basis instead of all at once with bombers, the volume at any given time is so low that costs are extremely high. That, coupled with all of the structural industry problems I've spoken about means that costs aren't going to go down due to scaling. ULA will have to rip-off pages from the SpaceX playbook and rethink management practices to really bring down costs and also rethink their engine situation.

However, the only way to get around the engine situation would be to open up a US production plant, which could provide the kind of volume that the Russians can't and won't due to tooling costs and political problems. But as I said before, opening up a US production plant for the RD-180 will lead to a 50% increase in unit cost, per a recent interview with the president of RD-Amross that provides the engine. Which is another example of why the economics of rocketry are so damn screwy.

About Skylon, to me their ridiculously low development and production cost looks like something pulled completely out of their ass, do they have specific plans that would explain their low price? Perhaps that low cost implies huge volumes of them being manufactured?

They claim that they can do a launch, land the vehicle and then turn it around to do another launch, I think I read they plan on doing something like 4 or 5 per week with the same booster. That would really bring down costs significantly. But there are a few caveats to consider:

The first version of Skylon can only carry a pretty small payload. Currently, the biggest market for launches (IIRC) is massive geostationary satellites. Skylon can't launch those on it's own to GEO, at best it could deliver a payload to LEO that then propels itself to GEO, but that would mean that the actual mass of the satellite that is delivered to GEO would be very, very small. Current communications providers can't work with such small masses, it just isn't useful for them to have tiny satellites at GEO as they couldn't (currently) provide much in terms of service.

-However-

Having a relatively cheap method to get to LEO could open up a lot of research opportunities for companies, universities and government entities. So that could open up currently untapped markets for small satellites that currently have to hope to piggy-back on other launches (which still costs a great deal). There is also the possibility that newer technology could make smaller satellites at GEO worthwhile, but that's a tall order.

But all of this rests on the assumption that Skylon can deliver on it's claims. Remember that the Space Shuttle was envisioned to launch at roughly the same frequency and it never even came close. While inherently the two systems are different, I personally will have to see Skylon deliver on it's promises before I fully believe it's possible.

e: For content, have a short but interesting piece on the X-37. The origins of the Atlas V's first stage engines, the RD-180, in the N-1's NK-33 was particularly amusing to me.

I posted a video here a while back called 'The engine that came in from the cold'. It's a documentary on that subject and it's really good and definitely worth checking out if someone has an hour to spare. It's on youtube.

That X-37 article was more informative than most that I've seen on it (tho' I haven't sought them out).

But I was surprised to hear that the payload is limited to 500lbs. Yet the vehicle itself measures in at 5.5 tons. So we have a ratio of 1:25 for payload to vehicle. That doesn't seem very high, but what do I know?

What sorts of satellites are less than 500lbs? I'm guessing a lot of them, otherwise this airframe (spaceframe?) would have been spec'd to different parameters. But I just sort of thought that most satellites were heavier than that. But as I said a moment ago, "what do I know?"

Well, the 'payload' in the case of the X-37B is actually the X-37B from the perspective of the launching rocket. What the X-37B carries into space in it's cargo bay is most likely equipment that helps the X-37B do it's primary mission, which, from what people can gather, is spying on other countries. I don't think it deploys satellites in it's own right but then again, no one really does as it's a secret project.

However, if they were dropping off satellites with the X-37B, they'd probably be experimental payloads to test novel hardware, as Symphony D says. But most likely it just carries fancy camera equipment and radars that it keeps with it and doesn't drop off into orbit.

 

[Glassfan]

Another damn thing to worry about...

Universe on the brink of collapse

The universe may one day collapse and everything in it - including the Earth - will be compressed into a small, super hot hard ball, scientists have warned.

The risk of a collapse is even greater than previously thought and the process may have already started somewhere in the universe, scientists claim.

New calculations from physicists at the University of Southern Denmark now confirm this prediction, suggesting sooner or later a radical shift in forces of the universe will cause every little particle in it to become extremely heavy.

This violent process is called a phase transition and is very similar to what happens when, for example water turns to steam or a magnet heats up and loses its magnetisation.

The phase transition in the universe will happen if a bubble is created where the Higgs-field associated with the Higgs-particle reaches a different value than the rest of the universe.

If this new value results in lower energy and if the bubble is large enough, the bubble will expand at the speed of light in all directions.

All elementary particles inside the bubble will reach a mass, that is much heavier than if they were outside the bubble, and thus they will be pulled together and form super-massive centres.

 

[dutchfire]

Science journalism at its finest.

 

[PlutonianEmpire]

God damn it! I only just got over my paralyzing fear of the Mayan 2012 apocalypse in the past year; I don't need a new debilitating, paralyzing fear already!

 

[peter grimes]

"Universe on the brink of collapse" =

"Maybe the collapse is starting right now right here or maybe it will start far away from here in a billion years. We do not know,"

I'm sorry I clicked the link.

 

[Symphony D.]

To me it seems like the issue basically comes down to ULA being basically uncompetitive and heretofore having had little reason to reform due to low demand and an installed client base (i.e., USAF).

To the first bolded part - that's untrue. I've been pointing out over and over again that costs increased with lower volume but they don't decrease with increased volume. Particularly now that plants have been closed, their is an absolute limit to engine availability and older surplus parts have run out, etc etc.

So it's down to, essentially, the industrial collapse of the industry? If that's the case, were 1. the required industry to be rebuilt to prevent bottlenecking (somehow), and 2. the demand for boosters to exist (somehow), would you expect cost-scaling to be possible and hold?

To the second bolded part - rockets currently are much more of a limited run product like bombers. While yes, they are built on an ongoing basis instead of all at once with bombers, the volume at any given time is so low that costs are extremely high. That, coupled with all of the structural industry problems I've spoken about means that costs aren't going to go down due to scaling. ULA will have to rip-off pages from the SpaceX playbook and rethink management practices to really bring down costs and also rethink their engine situation.

I don't think that we're really disagreeing here. My point is that having all the stuff on hand to make boosters is a big driver of expenses unless it is constantly being utilized; which as you point out, it's not. You have to keep it all in working order and then constantly start and stop production; a series of continuous limited runs, as it were. This overhead forms a large part of the ultimate program cost. Shifting to an actual constant production line (somehow) would defray this, and presumably allow cost-scaling to take hold (per above question).

You can see a similar issue with say, the US nuclear weapons industry, where a very large percentage of the expense is in maintaining the facilities, personnel with experience, etc., rather than the warheads themselves (which are, comparatively free). I wouldn't claim the booster industry is exactly the same, but it shows a lot of similarities in this regard, in addition to the other problems.

 

[peter grimes]

Well, the 'payload' in the case of the X-37B is actually the X-37B from the perspective of the launching rocket. What the X-37B carries into space in it's cargo bay is most likely equipment that helps the X-37B do it's primary mission, which, from what people can gather, is spying on other countries. I don't think it deploys satellites in it's own right but then again, no one really does as it's a secret project.

However, if they were dropping off satellites with the X-37B, they'd probably be experimental payloads to test novel hardware, as Symphony D says. But most likely it just carries fancy camera equipment and radars that it keeps with it and doesn't drop off into orbit.

I forgot this is not a single stage platform.

 

[hobbsyoyo]

I forgot this is not a single stage platform.

Something else I thought of -

One of the main capabilities of the X-37B is that it can do plane-change maneuvers, i.e. it can change the inclination of its orbit. This is an extremely costly (as far as deltaV) kind of maneuver that has a huge penalty as far as fuel requirements. So essentially, the spaceplane has to be loaded with fuel to do the maneuver and IIRC it can actually do at least 2 of these maneuvers if not more depending on how big they are. So it won't be able to carry much payload in its payload bay, which would explain the low mass it can carry because it has to carry so much fuel to do these maneuvers which help it spy on multiple countries/areas.

It may be able to dive into the atmosphere and use its wings to generate lift which would help it do these maneuvers without using nearly as much fuel. This kind of maneuver was studied in the late 50/60's for the Dynasoar (also a Boeing product) but they couldn't do it because the G load on the pilot was extreme and they didn't have the materials available to take the heat load at the time. With the unmanned X-37B (and decades of materials science R&D), it's conceivable that the X-37B could do this kind of maneuver. But I don't know that for sure and if it could I'm sure it's classified. It would be almost the perfect vehicle to do that kind of maneuver though...

So it's down to, essentially, the industrial collapse of the industry?

Yeah, I know I've beat that horse to death but things got super screwed up in the 90's. There was this massive build-out to launch all these expected satellite orders and then they were all canceled and half the launch industry went out of business and the other half that survived was loaded with massive legacy costs in the form of idled factories and a now-redundant workforce that obligated them with pensions, etc.

If that's the case, were 1. the required industry to be rebuilt to prevent bottlenecking (somehow), and 2. the demand for boosters to exist (somehow), would you expect cost-scaling to be possible and hold?

Great question. Short answer:

I think the industry is generally on track to recover and with companies like SpaceX entering the market, it's really driving everyone to bring down costs. That can be bad because it can reduce profit margins (particularly if you are ULA and are used to feasting on cost-plus contracts) but it can be great because reduced cost will drive up demand. I think a major tipping point will happen when launch costs get down to the point where groups of Universities can group together to buy piggy-back launches at affordable (i.e., less than a million dollars per small piggyback satellite) rates. Currently, even to piggyback on some rockets, it can cost millions or tens of millions of dollars. If that comes down then demand will go up dramatically as lots of institutions want to launch payloads but can't afford it, and that sudden demand could then further drive down costs.

On the other hand - if the US Government relaxes ITAR restrictions then honestly the American launch market could conceivably collapse. ITAR is this set of rules meant to keep US entities from transferring technology and it has generally meant that a lot of US satellites must launch on expensive US rockets. If the rules change overnight, a lot of entities might switch to Chinese/Indian/Korean/Japanese rockets that are cheaper and that would be bad unless companies like SpaceX can really bring down costs in a hurry.

I don't think that we're really disagreeing here. My point is that having all the stuff on hand to make boosters is a big driver of expenses unless it is constantly being utilized; which as you point out, it's not. You have to keep it all in working order and then constantly start and stop production; a series of continuous limited runs, as it were. This overhead forms a large part of the ultimate program cost. Shifting to an actual constant production line (somehow) would defray this, and presumably allow cost-scaling to take hold (per above question).

You can see a similar issue with say, the US nuclear weapons industry, where a very large percentage of the expense is in maintaining the facilities, personnel with experience, etc., rather than the warheads themselves (which are, comparatively free). I wouldn't claim the booster industry is exactly the same, but it shows a lot of similarities in this regard, in addition to the other problems.

That's a really good analogy and I think you're spot on.

 

[peter grimes]

One of the main capabilities of the X-37B is that it can do plane-change maneuvers, i.e. it can change the inclination of its orbit. This is an extremely costly (as far as deltaV) kind of maneuver that has a huge penalty as far as fuel requirements.

Inclination is the angle at which it crosses a given latitude, right? Why does changing that angle take a lot of energy? When they talk about changing the orbit of an asteroid they don't need massive amounts of energy, even very small amounts well-timed can be enough to avoid a collision with earth (so the thinking goes) - I would have thought it would be the same with something orbiting earth.

 

[hobbsyoyo]

Inclination is the angle at which it crosses a given latitude, right? Why does changing that angle take a lot of energy? When they talk about changing the orbit of an asteroid they don't need massive amounts of energy, even very small amounts well-timed can be enough to avoid a collision with earth (so the thinking goes) - I would have thought it would be the same with something orbiting earth.

The inclination is the angle at which it crosses the max/min latitude of that orbit. So for typical space station launches, the inclination will be about 55degrees, because the maximum and minimum latitude that the space station's orbit cross is 55 degrees above and below the equator.

To be completely honest, I'm not sure exactly why inclination changes are so costly from an orbital mechanics perspective (just finished Orbital Mechanics I and the last section we covered was inclination and 3D orbits, we barely touched on it and will pick it up in Orbital Mechanics II next semester).

If I had to guess, I'd say that it's more costly than other types of orbital maneuvers because you don't benefit much from the Oberth Effect. The easy way to explain the Oberth Effect is that you get 'free' energy from the planet you are orbiting. The lower your orbit, the bigger the effect, such that if you do a maneuver to raise your orbit by 100km from a low altitude, it will take much less energy to do that than if you were to raise your orbit by 100km from a high altitude. Most orbital maneuvers are performed in LEO, so you get a lot of energy/propellant savings from that alone.

I don't think inclination changes see any benefit from the Oberth Effect, so are therefore more costly from a propellant perspective. Also an inclination change can change your orbital altitude which is usually undesired. What that means is that when you burn to change your inclination, the high point/low point of your orbit will also shift by some amount (possibly a very big amount) that you don't want, then you have to do a second burn to correct that, which is also wasteful.


When people talk about changing the orbits of asteroids and how you can do that with relatively little deltaV, they are dependent on the fact that you would want to change the orbit years in advance. So if you change the orbit of an asteroid by just a few m/s, over time (and millions of kilometers), the net effect is that the asteroid is now thousands of kilometers from where it would have been if that very small deltaV was applied.

Here is a diagram that I hope explains what I'm trying to say:

Spoiler :

When you are orbiting the Earth, your orbit is confined to hundreds of kilometers, so you don't have the benefit of millions of kilometers to 'drift'. The asteroid, which is on a muuuuuuch larger orbit around the sun, can drift millions of kilometers 'off course' with a little nudge but it will take months and years to see a large change in the orbit.

 

[El_Machinae]

 

[hobbsyoyo]

Here are a couple of new diagrams that hopefully explain things better, Peter:

Spoiler :