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."
> if you're going to persist in calling me a liar
Facts are facts.
> liberal douche bag who wants to spend other people's money on something that he just "knows" is good for the collective.
Have fun in delusion-world.
> in order to accomplish this we need the right tool - a space elevator.
And in order to get that, we need cheap space launch. And once we get cheap space launch, the need for an elevator will be minimized.
>> Hydrogen-3
s/b
Helium-3
http://www.freerepublic.com/focus/keyword?k=helium3
Chemical rocketry will never achieve cheap space launch. The necessity to lift one's own fuel out of the gravity well establishes that. The space elevator can be started with a single rocket launched mission and completed with less launches than it took to complete the utterly useless ISS.
You wouldn't know a fact if it bit you in the ass.
Have fun in delusion-world
wooo wooo a space head thinks I'm deluded. LOL
> Chemical rocketry will never achieve cheap space launch. The necessity to lift one's own fuel out of the gravity well establishes that.
No, it does not. LOX and kerosene are *cheap*.
> The space elevator can be started with a single rocket launched mission and completed with less launches than it took to complete the utterly useless ISS.
Speculative in the extreme.
All you have are insults and falsehoods. Not even a decent comeback, much less a well-formulated arguement.
Not in terms of heaving lifting. To lift the kinds of structures into space that we need to exploit the moon, inner planets, and asteroids we must lift large and heavy structures. The radiation shielding alone will be heavy let alone the food, water, and other supplies required by humans. The larger and heavier the ship to carry everything, the more rocket fuel you need. Do some math.
Besides, once the first space elevator is constructed it becomes somewhat elementary to begin constructing more from that base of operations.
Because, of course, we all know that no real science is required at all to put a permanent manned settlement on the surface of the moon.
And, that, my friends, sums up why we aren't going back. We don't have the will or desire.
The national pride that would have Americans holding their head up high at the prospect of a US flag waving over the Tycho-1 Complex on the moon is now considered psychotic, jingoistic, imperialistic, wasteful, etc.
If Kennedy were to say today: "We do these things not because they are easy, but because they are hard," Americans would riot.
That's funny, That's exactly what I was thinking about you. Here's a little true or false quiz for you:
> The larger and heavier the ship to carry everything, the more rocket fuel you need. Do some math.
Pssst: Hey, Spiff: I design these things for a living. I've done the math. I'm a rabid collector of launch vehicle design documentation. I've seen the math others have done. Propellant costs... hardly even show up. When you get to the point where propellant costs are an important pricing factor in space launch vehicles... you've just made space launch cheap enough for everyone to go to orbit.
> Besides, once the first space elevator is constructed it becomes somewhat elementary to begin constructing more from that base of operations.
You make the mistake of assuming that once this elevator becomes operational it'll be simple and cheap to operate with minimal upkeep. If history has shown anything, it's that that sort of thinking is tragically flawed.
And there's this: with a reusable and matured launch vehicle design, there's no reason in the world why you couldn't launch the same vehicle to LEO two or three times a day. But an elevator can only take one climber at a time, moving at... what? 20 miles per hour? How long to climb to GEO, and then climb back down? How much propellant - and the associated rocket stage, engines, controls, structures - will be needed to maneuver the payload from the drop-point to the final orbit?
As you say... do some math.
> But then your delusion won't let you see the limitations and the WASTE OF MONEY that this is.
Uh-huh. So... if you are opposed to government-directed technology R&D... how far back in technological time do you want to go? Clearly, you need to give up the Internet and electronic computers and satellite-based communications systems. What else?
Ah, but never mind. People with small minds and narrow vision and no desire to leave a better world for future generations bore me.
> We don't have the will or desire.
While the Indians and the Chinese do. This could well be *their* century... and if it is, the rest of the future belongs to them. Just look at this thread to find Freepers who would gladly hand over the keys of the universe to the Red Chinese just so's they wouldn't have to worry about the five bucks some mission is costing them.
> If Kennedy were to say today: "We do these things not because they are easy, but because they are hard," Americans would riot.
Well, they'd certainly panic. "AAAHHHH!!! Zombie Democrats!!!"
You want to throw your money at your hobby, go right ahead. Have a blast. Just keep your more-patriotic-than-thou hands to yourself.
The national pride that would have Americans holding their head up high
That "national pride" was to prove to the friggin' Russkies and their commie friends that we're best. Been there. Done that.
Now, if there's something preventing you from holding your head up high today, it seems to me that's likely your problem and not a national problem. Otherwise, let us know how throwing money at your fantasies is in the best interest of this nation.
If Kennedy were to say today: "We do these things not because they are easy, but because they are hard," Americans would riot.
No, we'd wonder why someone hasn't told him The Cold War is over and we won.
Somebody should tell the Chinese. I don't think they got the message. But, hey, we proved 40 years ago that we can beat the Commies to the moon, so now we can just sit on our fat ****** and remind them how much better we are.
You have every right to sit on yours if you like.
But, if you honestly believe we have need to beat the Chinese in space, feel free to state your case.
OK. Educate me. Why is it so darned expensive right now, per pound, to lift things to orbit?
operational costs compared to rockets
It is unavoidable that it takes 57e6 N*m = 16 KWh of energy, per kilogram, to move any mass from the ground to geosynchronous orbit (allow me to call this "orbit energy"), no matter how you do it.
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.
Other reasons (such as
propulsion is more efficient with a larger reaction mass. Rockets use tons of reaction mass to get pretty good efficiencies. The "reaction mass" of the space elevator is planet Earth.
The "reaction mass" of rockets burns up. The "reaction mass" of the space elevator (planet Earth) can be used over and over again.
rockets have to travel at high speeds -- some kinetic energy is lost to air resistance loss
because SE can spread out orbit energy over a longer period of time (days instead of minutes) means don't need to pay (at $10,000 per pound) for padding you otherwise would need to protect fragile cargo from launch vibration. ) are much less significant.
> Why is it so darned expensive right now, per pound, to lift things to orbit?
The standing army of tens of thousands, for starters. Secondly, and very importantly... space launch just ain't that common. The usual analogy is to compare space launch to a 747. Right now, flying on a 747 isn't all that expensive. But imagine if there were only five of them and they each flew once a year, and they each had thousands of people tearign them apart and measuring everything after each flight and holding meetings and issuing quality reports and argueing and...
And you can bet your keister that a space elevator will suffer from the same issues. Especially given the potential (real or percieved) for global disaster from a structural failure, you'll have the EPA, OSHA, NSA, CIA, FBI, MI6, NID, FAB and Knights Templar crawling all over you every hour of every day.
If you want cheap space flight... fly *often.*
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