Posted on 01/16/2006 9:53:39 AM PST by Paul Ross
Aviation Week & Space Technology
Griffin Tells Astronomers To Lower Expectations
By Frank Morring, Jr.
01/14/2006
LOOKING TO THE STARS
Astronomers in the U.S. can still look forward to a human servicing mission to the Hubble Space Telescope next year, and perhaps to big observatories on the far side of the Moon some day.
But for the most part, the funding outlook at NASA for space science is tight as the agency shifts its focus to sending humans back to the Moon, meaning near-term priorities like searching for Earth-like planets around other stars will slip, and it will take longer to begin answering new questions like "What is dark energy?"
"NASA simply cannot accomplish everything that was on our plate when I took office last April," Administrator Michael Griffin told the American Astronomical Society (AAS). "In space-based astronomy, as in other areas, we will have to make tough trade-offs between maintaining current missions--of which there are 14 ongoing--and developing new capabilities."
Griffin drew applause when he reminded his audience that he reversed a decision by his predecessor not to send another space shuttle mission to service the Hubble telescope, which continues to produce important new discoveries.
But he cautioned that the final Hubble servicing mission, tentatively scheduled before the end of next year, will be launched only "if at all possible." And he said bluntly that there is no way from an engineering standpoint to mount a robotic servicing mission, as former Administrator Sean O'Keefe opted to do, that could do more than deorbit the telescope safely before it is expected to become uncontrollable.
The fate of the Hubble--and a lot of NASA's other programs--will depend on White House funding decisions due for public release with the Fiscal 2007 budget next month. Griffin conceded, "I do not know in all its details what it will contain," which suggests a debate is still underway within the Bush Administration on how to cover a shortfall of at least $3 billion in the shuttle program (AW&ST Nov. 7, 2005, p. 40).
"By any measure, one would have to say that the growth of science in NASA has been in the 5-7% range, annualized, over the last decade or so, and that's all been great," Griffin said. "We're in a budget environment now where that level of growth can't be maintained, although science at NASA will still have growth."
SOME OF THAT GROWTH will be absorbed by the James Webb Space Telescope, the top space mission in the U.S. National Academies' decadal list of astronomy priorities. Terming the $1.5-billion shortfall in available funding for the mission "under-costing" rather than an overrun, Griffin said his agency has a better handle on the cost of the deep-space infrared observatory. Launch of the Webb telescope has been slipped from 2011 to 2013 to cover the extra cost without hampering its ability to peer back to the earliest galaxies in the Universe, and penetrate closer dust clouds to watch star formation within.
Under questioning from AAS President-elect J. Craig Wheeler of the University of Texas, who collected queries from members, Griffin said the problems with the Webb observatory will force a delay in starting the Space Interferometry Mission (SIM) and its successor, the Terrestrial Planet Finder, both National Academies priorities designed to find Earth-like extrasolar planets.
Griffin noted that President Bush's human-exploration directive has raised concerns in all of the communities of scientists who use NASA systems in their work, and vowed to do what he could to keep the disruption to a minimum.
"Our cost estimates for returning astronauts to the Moon are conservatively structured to achieve our goals within budget," he said. "Also, while we certainly are not claiming cost savings that have not been proven, we very much intend to find ways to reduce the cost of the exploration program through improved technology, commercial involvement and international partnerships."
And in the long term, he said under Wheeler's questioning, astronomers may some day find the Moon a better place to conduct their business than Earth orbit or the L-2 Sun-Earth Lagrangian point where the Webb observatory is bound. The Moon's far side offers a much quieter environment for radio telescopes, and many types of sensors could be laid out in arrays on the Moon for higher-resolution imaging than is possible on Earth.
"I would argue strongly with those who assert that human spaceflight is inimical to science," he said. "Our scientific initiatives go hand in hand with our extended reach into the Solar System. It is not our desire to sacrifice present-day scientific efforts for the sake of future benefits to be derived from exploration.
"A stable platform like the Moon offers advantages in the engineering aspects of astronomy that are hard to obtain in space."
His views on using the Moon as an observatory notwithstanding, Griffin ducked a question from Wheeler on whether it would be worthwhile for U.S. astronomers, working through the National Academies, to reconsider their priorities in light of the new possibilities raised by the exploration initiative, or by recent discoveries.
"I think the astronomy community has to decide for itself whether the priorities have changed enough to warrant doing a decadal survey in an off year," Griffin said.
One thing pushing astronomers to change their priorities is the discovery of a mysterious force driving the expansion of the Universe at a rate that appears greater than can be explained by what is visible to telescopes like the Hubble and the most advanced ground-based instruments. The force, dubbed dark energy, was confirmed after the astronomy priorities for this decade were set. A National Academies panel created for the job stopped short of recommending that new priorities be drafted.
INSTEAD, THE PANEL called for "balanced" planning of future astronomy missions, with a greater role for the U.S. Energy Dept. and greater use of Explorer-class space missions. And it cautioned that slips in programs growing out of the exploration initiative could "adversely affect NASA's ability to generate the kind of transformative science that is the hallmark of the past decades."
NASA is already working with the Energy Dept. to draw up a Joint Dark Energy Mission, for which concepts are due in March. Among them is the SuperNova/Acceleration Probe (Snap), a two-meter space telescope (see artist's concept) that would continue detailed measurements of the Type Ia supernovae that provided evidence the Universe is expanding more rapidly than thought.
But with the science budget already squeezed, and the possibility of more budget cuts in the offing, it is unlikely that new starts like Snap will be funded, regardless of the science they produce. Indeed, senior astronomers like Wheeler, are worried they won't be able to fund graduate students today who will be called on in the future to make sense of dark energy and other new questions.
"We're all holding our breath, waiting to see what the budget's going to be," Wheeler said. "The budget for NASA is probably not going up. The budget for the science division is almost certainly not going up. The question is whether it will go down."
> The overwhelming reason space elevators are (in theory) far less expensive than rockets is because rockets have to accelerate their propellant with them. That's it.
Tell me: how does the payload get up the elevator? Seems to me that a beamed-energy system is needed to power the climber. Where does the energy come from? Who builds and maintains the laser, and how much do they get paid? How much energy *total* is required to climb up to GEO, and how does that compare to the energy requirements for a rocket?
You're the only one I've seen making the argument that lifting will be just as expensive with a space elevator as with the controlled explosions burning up chemical rocket fuel propelling things to orbit. I've read a great deal about the concepts to include items from NASA engineers and other engineers and no one makes the argument you're making. Given what I've gathered I must disagree with your assessment. The whole reason that NASA and others are looking at space elevators is the reduced cost of getting material to orbit.
Read the rest of the Wiki entry. I also urge you to read up on the subject. A simple Google search will lead you to several papers from NASA and other organizations.
The beamed energy system is one proposed method of powering a crawler. There are other methods. The amount of energy is simply the amount needed to mechanically pull the weight the distance required. Are you putting forth the argument that it would cost the same to move a certain amount of weight by train as it would to by rocket launch? That is really the comparison here.
> You're the only one I've seen making the argument that lifting will be just as expensive with a space elevator as with the controlled explosions burning up chemical rocket fuel propelling things to orbit.
I'm not makign that arguement. I'm simply pointing out that this technology is not a panacea, and has definite limitations. It is, for example, *worthless* for quick-response systems or military applications and the transportation of heavy items.
I never proposed that it could be used for quick-response systems. However, it is far more efficient at moving heavy objects to orbit to include weapons platforms for the military.
>> Tell me: how does the payload get up the elevator? Seems to me that a beamed-energy system is needed to power the climber. Where does the energy come from? Who builds and maintains the laser, and how much do they get paid? How much energy *total* is required to climb up to GEO, and how does that compare to the energy requirements for a rocket?
>Read the rest of the Wiki entry.
Non-responsive. I was hoping to see if *you* have in fact studied up on the topic, and were able to consider the plusses and minuses.
> A simple Google search will lead you to several papers from NASA and other organizations.
No need. I have a big fat binder at home with numerous Air Force, AIAA, NASA and other technical papers and conference proceedings on the topic.
> I never proposed that it could be used for quick-response systems.
Then if you want to do away with rockets... what exactly were you planning on using?
> it is far more efficient at moving heavy objects to orbit to include weapons platforms for the military.
Incorrect. The payloads that an elevator will be able to carry will be fairly small, at least for the foreseeable future.
> The amount of energy is simply the amount needed to mechanically pull the weight the distance required.
Ahhh... no. It is that *plus* the numerous efficiency losses. Consider:
1) Your energy production facility (say, a nuke plant) produces X megawatts.
2) Your laser is, say, 20% efficient at converting electricity to light.
3) You lose 10% of that due to atmospheric scattering.
4) Your crawler converts 80% of the incident laser light to electricity.
5) The onboard motors are 75% efficient at converting electricity to motive power.
6) You lose (handwave) percent to mechanical losses.
7) You lose a *lot* to gravity losses, as you're goign straight up the whole time.
In the end, you are *maybe* a couple percent efficient at turning nuclear power into payload kinetic energy. But lets say you don't care, because nuke plants are a dime a dozen and electricity is too cheap to meter. Woo! But...
Rocket engines are routinely above 90% efficient at turning the chemical energy into kinetic. Gravity losses are at most 25 or so percent, drag losses even less. So if electricity is cheap, then production of chemical fuels (LOX and LH2, LOX/kero, LOX/CH4, whatever) is also cheap, even without petrochemcial feedstocks. I myself built a suitcase-sized machine that made methanol out of water, carbon dioxide and electricity... not that hard.
>Are you putting forth the argument that it would cost the same to move a certain amount of weight by train as it would to by rocket launch?
Are you putting forth the arguement that a train going horizontally has anything to do with a train going *vertically,* while grabbing onto some of the slipperiest materials yet devised by Man?
Did I say I want to do away with rockets? I only said that they were inefficient, impractical, and expensive to do heavy lifting on any reasonable scale into orbit to support the construction of large space stations and adequately shielded and equipped interplanetary vehicles and to get heavy construction, fabrication, and other equipment up there to construct a lunar colony. The long traversal time on the elevator and its pass through the Van Allen belt may make it somewhat impractical or dangerous for humans to use for transportation. I repeat, MAY. Supplemental rocket launches may be necessary and chemical rockets will certainly be needed to propel ships and payloads to and from the moon and within the solar system.
> it is far more efficient at moving heavy objects to
orbit to include weapons platforms for the military.
Incorrect. The payloads that an elevator will be able to carry will be fairly small, at least for the foreseeable future.
Those who are familiar with the space elevator concept predict costs of around a couple hundred dollars per pound. The Space Shuttle can lift 25 tons, once in a blue moon, dangerously, for about $40,000 per lb given what I could gather via Google. One space elevator concept would lift 20 tons at $200 per lb. Once you get one elevator constructed, the construction of others would be relatively elementary and multiple elevators would be in use simultaneously. The cost, per lb, to get an item to orbit would drop with each new elevator. Lifting material to orbit would become relatively safe and economical and routine. And that is the point.
> I only said that they were inefficient, impractical, and expensive to do heavy lifting on any reasonable scale into orbit to support the construction of large space stations
Yes, that's what happens when you *never* *friggen* *launch*. But the sort of market that would support a space elevator would also support more versatile heavy lifters.
> Those who are familiar with the space elevator concept predict costs of around a couple hundred dollars per pound. The Space Shuttle can lift 25 tons, once in a blue moon, dangerously, for about $40,000 per lb given what I could gather via Google.
Trust me, son, if you want to win an arguement regarding the potential costs of space transportation systems with someone who works with space transportation systems, bringing up the Space Shuttle as the benchmark of rockets will only get you laughed at. It's like using an armor-plated, jet-powered Italians sport concept car to prove that automobiles are inefficient means of transportation. The Shuttle does not show what rockets are like; it shows waht *bad* rockets are like.
> One space elevator concept would lift 20 tons at $200 per lb.
Uh-huh. And this is based on what actual engineering? I seem to recall that the Space Shuttle would cost $50 million per flight and woudl require no more than two weeks to turn aroudn for the next flight. And then reality hit. What makes you think that a space elevator which, unlike the Shuttle, is *right* *at* the edge of what is physically possible, would be able to attain the lowest possible prices?
That's correct. Just a lot of expensive engineering.
I noticed that you ignored my questions and changed the subject, but here is one more that you'll ignore. If you have $100,000 in research money to spend, where do you think you will get more for it, putting it into private industry as buying stock in a company or paying it as tax to government?
You space heads are all alike in one regard. You all want someone else to foot the bill for your grandiose pipe dreams. You, like all statists, think that you know best how to spend the money that other people busted their buns for. In that regard you are no different than some "homeless advocate" or some militant welfare queen or Hillary Clinton and her tax based "health care" or any other government looter who has some hair brained scheme that no one would pay for except when forced at gunpoint by the government.
> If you have $100,000 in research money to spend, where do you think you will get more for it, putting it into private industry as buying stock in a company or paying it as tax to government?
A piddly $100,000? Private industry. But a billion? Government R&D. FOr the simple fact that the government has the capability to carry out or direct research projects that private industry would *not* tackle.
> You, like all statists, think that you know best how to spend the money that other people busted their buns for.
Blah, blah, blah. Do you get this twitchy when someone suggests that DARPA or an Air Froce or Army research lab should study such-and-such? Are you still cheesed off about the billiosn spent on the Manhattan project? Couldn't private industry have done it better?
You make my case for me. Government R&D is typical Marxist central planning. Use up a vast quantity of money and you might get something good and you might not, but you don't have any way to tell because there aren't any price signals attached. Further you will never see the true costs. Like I said pay for your own fantasies or if there is so much value in space, form a company to exploit it and get rich.
> Government R&D is typical Marxist central planning.
Blah, blah, blah. Do you get this twitchy when someone suggests that DARPA or an Air Froce or Army research lab should study such-and-such? Are you still cheesed off about the billiosn spent on the Manhattan project? Couldn't private industry have done it better? What about the DARPAnet? Shouldn't you be boycotting the Internet in protest? Or are you just a hypocritical Marxist?
Do you always bray this much when someone suggest that you pay for your own toys?
... internet ... Look at the difference in the government internet and the current version. Do you seriously contend that we wouldn't have had the internet without the government or your hero Al Gore?
Or are you just a hypocritical Marxist?
Me = libertarian/conservative want the space heads to pay for their own space fantasies
You = statist/marxist want someone else to pay for your unworkable fantasies
> your hero Al Gore?
Go back to DU, you dishonest troll. You serve no purpose here.
You're the DU troll and a rude dishonest ass as well. Let's see YOU
As you said in so many words a while back, the real difference between liberals and some self-described "conservatives" boils down to little more than the shape and size of their unconstitutional special interests.
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