From Carolyn Porco.
No, we don't need "big" rockets. We need affordable rockets.
[Update a couple minutes later]
The perennial question: why do reporters (even science and technology reporters) think that scientists are a good source for technology policy advice?
A decent source of the arguments for heavy lift is this article. But all of the applications boil down to one thing. You have a high delta v application (for example, sample return from Io deep in Jupiter's gravity well). You need an Ares V to deliver both the propellant mass and initial velocity for a mission that fits within a couple of decades. Unless you can use electric propulsion or other high ISP engine, aerobraking and aerocapture, and can assemble your space probes in LEO. If that holds, then you don't need an Ares V.
why do reporters (even science and technology reporters) think that scientists are a good source for technology policy advice?
They don't. They know scientists like to talk a lot, and in all the endless jibber-jabber will undoubtably say something that can be used to support whatever point of view the reporter wants to push. Furthermore, being academic, they (1) probably won't mind the reporter's point, and (2) wouldn't know how to push back even if they wanted to.
Someone in the policy area -- or even a management/entrepreur type -- would be a lot more media-savvy, and the reporter would be much less in control of what the source was "saying."
The perennial question: why does Rand think that reporters are looking for good technology policy advice?
They're not. Actual policy advise is bland and boring. It doesn't move ad inventory.
I've also noticed that reporters seem to think that scientists are the ones to ask about space business. Why that should be so is beyond my ken. I certainly don't ask my scientist friends for business advice, unless it's about some particular technology with which they might be familiar by virtue of their position in the science field. It's why I don't put much credence in articles that draw their business info from science sources.
Scientists are smart... or they wouldn't be scientists, would they! :P
I browsed some of the other futurists on the Wired list. I hope none of them gets anywhere near the Oval Office.
BBB
I don't even think it's good space science policy advise, because I suspect the Ares rockets will be very expensive to build and (if they get that far) operate. In the budget I suspect NASA will have when/if Ares V gets finished, there won't be much money left over for science missions that are big enough to justify an Ares V launch. It could make sense if we develop a line of huge but simple (thus cheap) robotic spacecraft, but I doubt that's going to happen.
Here's an old, but related, thread:
www.spacepolitics.com/2007/02/21/heavy-lift-and-space-science/
A Delta IVHeavy with orbital propellant rendezvous can do anything a Ares V can do and more. NASA would just have to contract to Spacex or OSC to fill the tanks. However, in this day and age Systems Engineering does not trump the political engineering the system.
In her case I think you can call it "rocket envy".
It would be cheaper still to pretend that we're sending probes to the planets and just rerun the same ". . . very surprised and excited at the results we're seeing .. " JPL scientist tape every time.
BBB, you wrote:
I browsed some of the other futurists on the Wired list. I hope none of them gets anywhere near the Oval Office.
I'm starting to think that Wired is really more of a glitzy cross between Weekly World News and Candid Camera. People must read this solely to laugh at the pretentious clowns contained therein. I can't believe anyone takes it seriously. The only Wired I'll buy is the one that has me in it. ;-)
A lot of scientists are stupid and parochial, but no more so than many engineers and managers. Everybody in this business has their own axe to grind.
Porco's reasons for wanting Ares V are clearly derived from her desire to get big payloads to Jupiter and beyond. That's her principal interest. How's that rationale fundamentally different from Mike Griffin's wanting Ares V to deliver a million pounds in LEO to do the Mars Design Reference Mission?
Asking a given space scientist about rockets may or may not be informative, but it's a refreshing change from the usual "space policy" talking heads that the media always go to.
As a long time Wired reader I usually explain the magazine as similar to Playboy only with the women etc. replaced with technology. It is a techno-fetish gossip magazine (and it's proud of it!) and some do read it for the articles... ^_^
Yes it has a fold out, it's called info porn and consists of graphs/data eye-candy. They don't choose "Chart of the Year" but that's likely just because they haven't thought of it ^_^
Wired and Slashdot were on the curriculum of the bachelors degree* I started on (before getting ill, had to quit) and not without reason as in their own ways they used to be very influential (just like old Byte but in different ways). Wired still is in many ways. Plenty of big/important debates have rolled through their pages including the very start of some ("Why the Future Doesn't Need Us" comes to mind as a prime example --first published in Wired).
Important in the way that many might (now or in the future) consider RLVnews, The Space Review, The Space Show, and others to be in relation to, and for those interested in, the current second major push for independent private space access.
* I'm not even sure how I should translate the name of the bachelors degree but it was a combination of computer science/informatics, media knowledge, and law.
How's that rationale fundamentally different from Mike Griffin's wanting Ares V to deliver a million pounds in LEO to do the Mars Design Reference Mission?
It's not. Mike is wrong, too, Paul.
If you have to deliver a million pounds to LEO (particularly when most of it is propellant) a heavy lifter that hardly ever flies is the least cost-effective way to do it.
If you have to deliver a million pounds to LEO (particularly when most of it is propellant) a heavy lifter that hardly ever flies is the least cost-effective way to do it.
I don't disagree. My point was that each of us has a perspective, an expoerience base, and a bias. I cheerfully admit to mine.
Well, I cheerfully admit to mine, too, Paul. Mine is a space-faring civilization, as soon as possible with available funding, to allow everyone (or at least as many as possible) who has goals in space to affordably accomplish them, including Carolyn Porco. But hers is much more parochial, and I think that it would be a disaster for the next president to take policy advice from her, particularly if she is the only one offering it (and I didn't see any other "space policy experts" listed in the Wired article).
No, we don't need "big" rockets. We need affordable rockets.
OK, you guys just can't see the forest for the trees! Bigger rockets do have huge economies of scale - we just haven't built them large enough yet. For example, an optimization of $/kg:
Consider a rocket, massing about 5.9 x 10^21 tons. When it takes off, it only has to fight against less than 1% of G - so higher Isp engines can be used. In addition, LEO velocities will be greatly reduced, almost eliminating the required burn time - and that size of rocket can definitely carry an entire ecosystem and society!
;-}
They need to replace NASA with one office filled with desks and a phone on each. Not a very big office.
Proposals get collected. Cost estimates are made. X-prizes from 10% to 50% are posted. An organization is only entitled to one x-prize per year. Full visibility is required and the public can contribute ideas.
Then business can make their own business case and the government stays out of it.
Government is the problem - RR.
Take the goals (not the implementation) of the 90 day report as an example. A prize of 10% it's estimated cost would have allowed the Mars Society working with other companies to already have a base on Mars.
Or pick your prize... a fuel station in orbit.
"OK, you guys just can't see the forest for the trees! Bigger rockets do have huge economies of scale - we just haven't built them large enough yet."
Big rockets are like big airplanes. If you expect to fly them often (and the demand that implies for major traffic to specific destinations and/or frequent transport of stuff that isn't practical to break down into smaller parts for assembly at their destinations) and profitably (in the case of people, that means comfortably over the breakeven number of seats, most of the time) you build and use them.
Espically if it's an RLV, but even if it's not.
Unmanned science projects most certainly can benefit from their availability, but they aren't going to be nearly enough of a market by themselves. And the bigger they are, the more you'd better have payloads/passengers to nearly fill them, nearly every time.
As a modern wide-bodied jet would be unprofitable back when a DC-3 was adequate (not enough people on enough routes with enough frequency for one of them), we don't 'build [rockets] large enough yet' because the demand for that capability isn't large enough yet. Economies of scale only help when there's a need to scale up to meet.
We're still waiting for that space equivalent of a DC-3, you know. The shuttle wanted to be it, but wasn't.
OK, you guys just can't see the forest for the trees! Bigger rockets do have huge economies of scale - we just haven't built them large enough yet. For example, an optimization of $/kg:
No, they don't. Sure there are modest economics of scale associated with bigger payloads than the current level, but this is dwarfed IMHO by launch frequency and degree of reusability. And it strikes me that for chemical rockets they're probably in the region of diminishing but positive returns due to the noise issue.
Economies of scale only help when there's a need to scale up to meet.
The problem is, when people talk about economies of scale, they frequently choose the wrong scale.
Space transportation (like air transportation) scales weakly weakly with vehicle size, but it scales strongly with flight rate.
Yes, to get costs down we need economies of scale, but you have to pick the right variable to scale!
Even the 'best' sci-tech reporters are more often than not people who can write, not people who have a sci or tech background. Look at how the culture throws around 'science' and 'technology' as interchangable. You've got your answer right there. People don't know the differences between the professions and attitudes, or they just don't have the time to bother to find out. Even if it would take only 5 minutes, or 5 seconds.
Not to mention the ongoing effects of referring to rocket engineering as 'rocket science,' which so far as I know is the product of the valley girl school of English - and perhaps the _only_ product of that which has really stuck.
Ugh. Gag me with a spoon.
OK, Karl and Frank - WHOOSH.
Please check the mass of said rocket. Then check the mass of planet Earth...
Edward Wright wrote:
"The problem is, when people talk about economies of scale, they frequently choose the wrong scale. [snip] Yes, to get costs down we need economies of scale, but you have to pick the right variable to scale!"
I'm in complete agreement with everything Edward Wright wrote (and he wrote it damn well, nails the issue head on).