Tankers. A new price category?

[pathfinder_01]

I'm interested in the assertions about labor costs.

The trick for tankers will be to examine the flow of vehicles (reusable or expended) through the system and minimize the (mostly labor) costs to maintain that flow.  Personally I would target a system that launches every two weeks, where the staff for pad and control room operations consisted of only 10 workers and 4 managers working 40 hour work weeks. 

Another way and the best way in the short term is to use a rocket that has other users/uses. Say Atlas, Detla, Falcon 9, ect.  That way you don't need to build pads, ect.

For instance a propellant verions of Dragon or more likely Cgynus. Only trouble is that in the case of Cgynus the most it could deilver would be about 3 tons or so(enough for a SEP system maybe).

[Cherokee43v6]

Why talk about converting Cygnus or Dragon or building a dedicated tanker craft.

Why not come up with an RCS and a multiple restart system for the second stage on an F-9 or Taurus2 and stretch the tanks?  Instead of a payload, the nose fairing would cover a docking mechanism.  You would save weight all around, thus maximizing propellant delivered.  Right?

[douglas100]

In other words, the ACES approach (but not necessarily with cryogenic propellants.)

[pathfinder_01]

Why talk about converting Cygnus or Dragon or building a dedicated tanker craft.

Why not come up with an RCS and a multiple restart system for the second stage on an F-9 or Taurus2 and stretch the tanks?  Instead of a payload, the nose fairing would cover a docking mechanism.  You would save weight all around, thus maximizing propellant delivered.  Right?

Depends on what propellant you plan to use. Taurus II 2nd stage is solid. F9 uses Lox/Kerosene. While LoX/kerosene is a possible propellant for a depot so are Lox/methane, lox/Loh, Aragon, Xenon, Hydrizine and lots of others.

[sdsds]

the best way in the short term is to use a rocket that has other users/uses. Say Atlas, Detla, Falcon 9

Yes but none of those launch systems are willing to tolerate the loss of a vehicle.  So for any payload including a tanker they must charge at least the marginal cost of a fully reliable launch.  That eliminates the "new price category" premise of this thread.

[douglas100]

Something along the lines of the Beal BA 2 might be feasible. Fairly low tech but with a reasonable payload to LEO. All of this is dependent on a viable market emerging, of course.

[savuporo]

Why plan to build "unreliable" launchers?  I'm not sure how making a launch vehicle less reliable would save money.  I'm not even sure how to save money by making a launch vehicle less reliable! 

..really ? You could make any launch vehicle in existence today much cheaper by simply removing half of the people working on it, and skipping a ton of procedures ( not testing, verifying, or checklisting any bit of hw that goes on a rocket )

However, your reliability vs cost curve is going to hit a very bad spot, as the launch vehicles have not been designed for that.

If you design from the outset for mass manufacturing, regular mass manufacturing QA methods, low personnel overhead costs you could, in theory, have a rocket that starts out being 80% reliable and improves as you improve your manufacturing process.

That, by the way, is how a lot of new consumer tech enters the market. The yields on the first generation products are often crap.

WRT rockets, there is a historical precedent : V2 started out very unreliable, but they did improve it later on.

[charliem]

Why plan to build "unreliable" launchers?  I'm not sure how making a launch vehicle less reliable would save money.

It's not so much planning "unreliable" as not going the extra mile to maximize reliability.

If to increase it from, lets say, 80% to 98%, you have to double the price, that only makes economic sense when there are other costs beyond the launcher.

With 80% you get 80 payloads up for a cost of 100. Average cost 1.25

With 98% you get 98 payloads up for a cost of 200. Average cost 2.04

[edkyle99]

You could make any launch vehicle in existence today much cheaper by simply removing half of the people working on it, and skipping a ton of procedures ( not testing, verifying, or checklisting any bit of hw that goes on a rocket )

However, your reliability vs cost curve is going to hit a very bad spot, as the launch vehicles have not been designed for that.

If you design from the outset for mass manufacturing, regular mass manufacturing QA methods, low personnel overhead costs you could, in theory, have a rocket that starts out being 80% reliable and improves as you improve your manufacturing process.

I'm not sure I buy into this theory, at least not precisely as described.  In practice, any real rocket that proves unreliable, and by unreliable I mean 80% or less after a few launches, is quickly dropped from service.  Consider, for example, Altas Able, Juno's I and II, Vanguard, Europa, H-II, Delta III, Falcon 1, and soon probably Taurus.  Why not design the rocket to succeed from the outset?   

 - Ed Kyle

[93143]

Private space companies SpaceX and Blue Origin seem to think that recovering the LV is the best way to reduce cost. Not dropping millions of dollars worth of hardware into the ocean is the best way to save millions of dollars!

Sea Dragon was fully reusable, despite dropping into the ocean.  Nothing fancy, just built like a battleship...  and equipped with an inflatable drag enhancer on the tail...  Independent studies indicated extremely low cost to orbit.

[sdsds]

Why not design the rocket to succeed from the outset?   

I think the idea is to design a rocket that succeeds every time, on paper.  When fielded, though, the real-world manufacturing, assembly and launch processes might "fail" occasionally.  That is, they might let through an article that fails to meet its specification or that is exposed to environments outside what it is specified to tolerate.

Just one tiny example:  how many high altitude weather balloons are needed to give 99% confidence the flight will get through any wind shear, vs. the number of balloons needed to give 95% confidence of that?  (I suspect the number of balloons needed for 95% confidence is zero!)

[savuporo]

In practice, any real rocket that proves unreliable, and by unreliable I mean 80% or less after a few launches, is quickly dropped from service.  Consider, for example, Altas Able, Juno's I and II, Vanguard, Europa, H-II, Delta III, Falcon 1, and soon probably Taurus

All examples of rockets not following minimum cost design principles, and thus when working unreliably, hitting a really bad spot in cost vs reliability curve.
So in context of this discussion, really worthless.

[baldusi]

Why plan to build "unreliable" launchers?  I'm not sure how making a launch vehicle less reliable would save money.

It's not so much planning "unreliable" as not going the extra mile to maximize reliability.

If to increase it from, lets say, 80% to 98%, you have to double the price, that only makes economic sense when there are other costs beyond the launcher.

With 80% you get 80 payloads up for a cost of 100. Average cost 1.25

With 98% you get 98 payloads up for a cost of 200. Average cost 2.04

Now do your numbers again considering that the launch cost is just 20% of the whole mission cost.

[Jim]

(I suspect the number of balloons needed for 95% confidence is zero!)

Nope, it is in the 70's

[pippin]

Private space companies SpaceX and Blue Origin seem to think that recovering the LV is the best way to reduce cost. Not dropping millions of dollars worth of hardware into the ocean is the best way to save millions of dollars!

Sea Dragon was fully reusable, despite dropping into the ocean.  Nothing fancy, just built like a battleship...  and equipped with an inflatable drag enhancer on the tail...  Independent studies indicated extremely low cost to orbit.

Paper rockets have a habit of having extremely low cost to orbit, ESPECIALLY with "independent" studies which are usually made by consultants who don't actually have to fly the thing.

[pippin]

All examples of rockets not following minimum cost design principles

SpaceX would disagree.

From looking how all projects trying to reduce cost through what is deemed to be good practice in design-to-cost, I suspect that it's not as simple as it sounds to make a minimum cost design rocket.

I believe the problem is that margins have to already be very, very low to make it to orbit at all (or the rocket has to be really, really large which incurs i's own expenses) which kill a lot of your design-to-cost strategies, especially all these which try to eliminate processes for QA and testing  through e.g. standardization.
I've only followed it more closely with SpaceX but you could clearly see that while getting to actually launch they learned a lot about the weaknesses of their original KISS approach, from ablative nozzles, over pintle injectors, simple tanks without slosh baffles, in-the-loop control and simple staging to corroded nuts...

[charliem]

Why plan to build "unreliable" launchers?  I'm not sure how making a launch vehicle less reliable would save money.

If to increase it from, lets say, 80% to 98%, you have to double the price, that only makes economic sense when there are other costs beyond the launcher.

Now do your numbers again considering that the launch cost is just 20% of the whole mission cost.

Should we renounce to decrease that 20% to, say, 10%, just because it's too little?

To thrive in space we need find ways of cheapen every aspect of our missions, launch costs included.

I saw the first human step on the Moon live when I was a child. I'd very much like to see the first human step on Mars before I pass away. To achieve that we need: 1) A lot more money that we can afford right now, or 2) A much cheaper way to go there.

[edkyle99]

In practice, any real rocket that proves unreliable, and by unreliable I mean 80% or less after a few launches, is quickly dropped from service.  Consider, for example, Altas Able, Juno's I and II, Vanguard, Europa, H-II, Delta III, Falcon 1, and soon probably Taurus

All examples of rockets not following minimum cost design principles, and thus when working unreliably, hitting a really bad spot in cost vs reliability curve.
So in context of this discussion, really worthless.

"Minimum cost design", if you are talking about the classic "Big Dumb Booster" idea, has never been employed.  There are several reasons.  One reason is because the payloads cost more than the rocket - sometimes multiple times more than the rocket.  The Dumb rocket might be able to tolerate an above-average failure rate, but the payloads cannot.  Even if the payloads are propellant tankers, they still have great value in the context of a complex, costly mission buildup sequence.

Rather than developing a BDR, just fly Atlas 15 times per year instead of 5, year after year for decades.  The per-launch cost would drop by one-third or one-half, probably, and 98 percent of the payloads would get where they're supposed to go.

 - Ed Kyle

[baldusi]

You could get a lot better economics if you could slash the costs of transponders, avionics, thrusters, satellite buses, integration and testing. Let's put for example the WGS satellites. Those are fully developed, the factory is working, so an additional unit is almost pure cost. Yet, the participating countries have to spend over USD500 on each bird, plus LV. And then they will have to operate it. So the LV is about 20% or less of the project cost. If you have to add development it's closer to a 5%. So unless you can find a way to radically lower the cost of the mission, a LV that was free would mean a 20% discount. Interesting, but nothing that would explode a new industry.

[pippin]

Well, at _that_ extreme the assumption is obviously wrong. If a flight was close enough to free there are a lot of things _I_ would want to launch so there would indeed be a new industry exploding.
It's a bit of a chicken-and-egg: If you are at 200 M$ a shot you will only develop payloads that are worth that investment and if they should really pay offf they will likely be more expensive and so on...

The point is that I doubt that built-to-cost really gets you there, I don't think current rocket engineers are that dumb to let go for a massive cost reduction potential and while it may give you some savings to let go on reliability a bit I suspect that it will require more than that for _massive_ reductions.

It's just a feeling but I believe the real potential might lie in mass production as Ed writes - after all we've seen it when LVs were ICBMs and if you _know_ you have a case for massive mass-production you might also be able to get some economies of scale by investing in more scalable production facilities, do more automation and all these things that make planes and card affordable.