Boeing's Delta IV Heavy Gets Ready for its Close-Up

www.space.com ^ | Monday, December 6, 2004 | Jason Bates

[hopespringseternal]

I'm talking about structure mass, not fuel cost. The fuel mass (and related tankage) is governed by whatever mass has to be placed into orbit.

But for expendables, you are just throwing away all that structure to save fuel (or boost payload). That makes sense only within the framework of our current dead end space program.

If we are going to meet our goals for space development, we are going to have to design our launchers around those goals.

If we are going to return to pointless, one-and-off missions to say we did it, then expendable heavy lift will work.

But if we are going to establish ourselves in space with industry and mining, operational cost has to be minimized. That is simply impossible with expendables. Aerospace hardware is expensive and there is no good reason why it can't be reused.

[Lazamataz]

Boeing's Delta IV Heavy Gets Ready for its Close-Up

Thanks for flying Delta!

[r9etb]

But for expendables, you are just throwing away all that structure to save fuel (or boost payload). That makes sense only within the framework of our current dead end space program.

First off: I'm not impressed by comments such as "dead end space program." That sort of terminology suggests that you have a partisan, and perhaps even an ideological, position in addition to a technical interest in the topic at hand. Please let us limit our discussion to technical issues.

And on the technical side of the ledger, reusable boosters are prey to the dreaded mass fraction. The more stuff you bring home, the less actual payload you can actually place into orbit, and the more mass you waste (in fuel and tankage) taking it up to orbit in the first place. That's the mathematical basis for staging.

But if we are going to establish ourselves in space with industry and mining, operational cost has to be minimized. That is simply impossible with expendables. Aerospace hardware is expensive and there is no good reason why it can't be reused.

If we're going to establish ourselves in space with industry and mining, it will be because we need the products of space industry and space mining in space. For terrestrial uses, it's FAR cheaper to do mining and manufacturing on the ground, and it's likely to remain that way for a long, long time.

If you're going to establish yourself in space, the best way to get low-cost space travel is to free yourself from Earth-based launchers ASAP. You can establish the infrastructure using ground launches -- and the economics for that seem to favor a relatively small number of very heavy launches (on expendables), as opposed to the larger number of small payloads that a reusable system would seem to offer.

[hopespringseternal]

That sort of terminology suggests that you have a partisan, and perhaps even an ideological, position in addition to a technical interest in the topic at hand.

I do have a partisan, ideological position. We are either moving forward, expanding our capabilities and presence in space or we are stagnating. While we seem to have ambitions in space, we are paying little attention to the foundation necessary to achieve our ambition.

And on the technical side of the ledger, reusable boosters are prey to the dreaded mass fraction. The more stuff you bring home, the less actual payload you can actually place into orbit, and the more mass you waste (in fuel and tankage) taking it up to orbit in the first place. That's the mathematical basis for staging.

And so you throw away tens or hundreds of millions in expensive aerospace hardware to save a few hundred thousand in fuel plus a few million more in (non recurring) structural costs (that you are going to throw away anyway.)

First of all, we have to ask just how big a payload we really need to accomplish our goals. But wait, before that, we have to decide what our goals are.

What exactly do you want to accomplish? Maximum mass fraction? No, that isn't the end goal. Maximum payload? No.

What our space program will look like will determine what our launchers look like. But when we start debating efficiency of our launchers, we are putting the cart before the horse. Our current architecture is optimized for our current situation. Unfortunately, this is the mindset most aerospace managers are locked into. They have worked in the industry for their entire lives with this paradigm and cannot envision anything else.

Right now, heavy lift, reusables, SSTOs, are all big losers. Large gross liftoff weight and high flight rates are useless right now. If you are only launching ten times a year, you will never pay back reusable development.

But the flip side is also true. For any meaningful (long term) space development, our current architecture is useless. We are going to need big boosters and small, high flight rate vehicles. We will never be able to fly more than ten times a year or launch millions of pounds with our current architecture, and we will need a lot more than that.

[Paleo Conservative]

But that also points out the problem: there's simply no market right now for anything close to that sort of launch rate. These days the Atlas and Delta guys are lucky if they get 6 launches per year. You just can't get economies of scale when your launch rate is so low.

There's a glut of fiber optic capacity. There's much less need for geostationary communications satellites.

[RightWhale]

The mission also marks the debut of Boeing's 5-meter fairing

Hard to keep up with movies. Will wait for the DVD.

[Moonman62]

We didn't "cut our own throats." The unpleasant truth is that there was no market for such a heavy-lift booster once Congress shut down the moon program. Nor is there even a significant market for the Delta IV -- and that includes no commercial market for that much throw weight.

Thank you. The article clearly states that there is very little market for the Delta IV. So what do former small government conservative Republicans want? That's right, an even larger, taxpayer funded rocket for which there is no market whatsoever.

[jscd3]

Excellant market oriented observations

[Moonman62]

That's the bitter truth. It would almost be worth giving the plans of the Saturn V to China and let them knock off a couple hundred copies...

The answer is in your post. As long as we have the knowledge, we don't need to waste money building it. In fact, we have the knowledge to build an even better rocket than the Saturn V. What we lack is a viable reason to use it.

[hopespringseternal]

That's right, an even larger, taxpayer funded rocket for which there is no market whatsoever.

The whole thing is the classic chicken or egg problem. There is no launch market because there is no launcher capable of supporting any reasonable market activity. There is no economically viable launcher because there is no market.

Efforts to rectify this through government funding of a viable launcher have fallen flat on their face. The shuttle could have been a viable launcher in its earliest incarnations, but by the time the Air Force and Nixon administration finished working it over it was useless as anything but a waste of money.

In all likelihood, NASA will flounder along barely meeting mission objectives until someone like Burt Rutan manages to build a launcher with a measure of economic reality.

[Gekko The Great]

Money, markets, bucks, money, markets, taxes, economics, money, bucks. It's all about bucks, kid. Hey, you're all guys after my own heart. Oops, I almost forgot, I don't have one.