Posted on 12/12/2004 7:52:14 AM PST by snopercod
Rescue missions expensive, ineffective.
CAPE CANAVERAL, Fla. (AP) - Trying to save the famed Hubble Space Telescope with a robot would cost $2 billion with just a 50-50 chance of success, an aerospace research group is advising NASA in the coming days.
And that thumbs-down is likely to be preceded by another potentially negative finding from the National Academy of Sciences, due to report on Wednesday.
Both reports could spell doom for the popular, aging Hubble, whose fans have heavily lobbied to get it repaired to prolong its life and continue its stream of stunning and revealing pictures from space.
NASA requested the reviews of the National Academy and the Aerospace Corp., a California-based not-for-profit research group, in hopes that a robotic repair could be made.
An Aerospace Corp. summary provided to the academy estimates a robotic Hubble mission would cost $2 billion and would take at least five years to be ready for launch. By then there would be a less than 40 percent chance Hubble still would be functioning.
Less than three years would be needed to launch a shuttle mission to Hubble, for no more money and with the usual medium risk of mission success, the company said.
The full 100-page report is expected to come out this week or next, a company spokesman said.
In an interim report over the summer, a National Academy panel of scientists, aerospace experts and astronauts who have worked in orbit with Hubble urged NASA to keep its options open for one last service call by space shuttle astronauts. The panel did not rule out a robotic mission but noted its complexity and the technical challenges.
But NASA Administrator Sean O’Keefe has stuck by his guns that regardless of what the academy or the Aerospace Corp. says, no people will risk their lives to fix Hubble.
On Wednesday, the National Academy of Sciences will issue its final report on the subject.
"These reviews have tended to reinforce NASA’s sense that although" a robotic mission "is feasible, it will be extremely challenging and will require very disciplined management," the space agency said in a statement Tuesday.
NASA will spend the coming year evaluating the robotic rescue plan and decide next summer whether to proceed. If nothing else, the space agency promises to launch a deorbit tug to guide Hubble down over the ocean - and not over populated areas - well before it would tumble in on its own during the next decade.
Sorry. They would have no way of repairing or even getting to the Hubble.
The "trojan points" are the L4/L5 LaGrange points. They are so called because the Jupiter-Sun trojan points are populated by asteroids named after heros of the Trojan war.
BTW, LaGrange points are a two-body concept, - with one body orbiting the other. You have to be careful which two bodies you mean. In this case, the Earth (actually Earth-Moon system) and Sun, although there are Earth - Moon Lagrange points as well.
LOL!
Actually I am very glad it is not true. We now have an idea of Venusian soil composition. :-)
L1 is between E and M.
L2 is on the far side of M.
L3 is on the far side of E (other side from M).
L4 leads M in its orbit about E by 60 degrees.
L5 lags M in its orbit by 60 degrees.
Note: There are L points for the Earth Sun as well.
Sorry. They would have no way of repairing or even getting to the Hubble.
I know not immediately, but with their resources and know how, it might be a start of something. Just a thought.
Indeed there is potential there. However, not enough time to save Hubble.
Could a Soyuz dock with HST? I'm not learned in the tech side of it all. It will be a shame to lose this instrument.
So much for "empty" space.
There's also gravity waves which slowly decay orbits. The decay of orbits caused by gravity waves is measurable in binary pulars.
The tidal drag of the moon on the earth will eventually lead to the earth becoming locked into a gravitional resonance with the moon, so that the earth will always keep the same face pointed at the moon. The moon is already locked into such a gravitional resonance with the earth. Then the moon's orbit will decay until it approachs with the Roche limit and tidal forces break it up and it turns into a ring circling in the Earth.
You're correct, but the write-ups for the Web Space Telescope indicates that it will occupy the L2 point 1.5 million km from earth, so I'm pretty sure this is the Earth (actually Earth/moon system)-Sun L2 point. The earth-moon L2 point would be more wicked tricky because of the effect sun's gravity would cause enormous perturbations.
Nope. Run the numbers.
There's also gravity waves which slowly decay orbits. The decay of orbits caused by gravity waves is measurable in binary pulars.
Think of just how little this effect would be on a tiny satellite.
The tidal drag of the moon on the earth will eventually lead to the earth becoming locked into a gravitional resonance with the moon, so that the earth will always keep the same face pointed at the moon. The moon is already locked into such a gravitional resonance with the earth. Then the moon's orbit will decay until it approachs with the Roche limit and tidal forces break it up and it turns into a ring circling in the Earth.
I agree with everything here except the Moon falling back towards the Earth.
The reason the Moon keeps one face to the Earth (its rotation on its axis matches the period of its orbit) is it is tidally locked to the Earth. This tidal locking will eventually cause the Earth and Moon to keep one face to each other.
Note: The Sun will go Nova long before this can happen.
Here is a more in depth explanation. The total angular momentum of the earth moon system, which is spin angular momentum plus orbital angular momentum, is constant. (The Sun plays a small part as well, which will be ignored for this discussion.) Friction of the oceans caused by tides is causing the Earth to slow down a tiny bit each year. This is approximately two milliseconds per century, and amazingly this causes the moon to recede by about 4 centimeters per year. As the Earth slows down, the Moon must recede (this is an increase in orbital momentum) to keep the total angular momentum a constant. In other words as the spin angular momentum of the earth decreases, the lunar orbital angular momentum must increase. Here is an interesting side note: the velocity of the moon will slow down as the orbit increases.
Another example of tidal locking is the orbit period and rotation of the planet Mercury. What is interesting about this one is that instead of a 1:1 synchronization where Mercury would keep one face to the Sun at all times, it is actually in a 2/3:1 synchronization. This is due to the High eccentricity of its orbit.
There also can be more than one body "locked" to each other. Lets take a look at the moon Io. Io is very nearly the same size as the Earth’s moon. It is approximately 1.04 times the size of the moon. There is a resonance between Io, Ganymede, and Europa. Io completes four revolutions for every one of Ganymede and two of Europa. This is due to a Laplace Resonance phenomenon. A Laplace Resonance is when more than two bodies are forced into a minimum energy configuration. There is also the thought that Venus and the Earth are also tidally "locked" as well.
And finally a look at the asteroid belt:
The asteroid belt has an estimated total combined mass of less than 1 tenth of the Earth’s moon. Jupiter also has a profound effect on the asteroid belt. Since Jupiter has a semimajor axis of 5.2 AU (I AU is the distance from the Sun to the Earth) it has an orbital period of 11.86 years. Since the asteroids are not all at the same distance from the sun, some of them have an orbital period of one half of Jupiter. This puts that asteroid in a 2:1 orbital resonance with Jupiter. The result of this resonance is gaps called Kirkwood’s gaps. So here is the rub; why did not these asteroids for a planet? The reason is the gravitational force of Jupiter. It perturbs the asteroids giving them random velocities relative to each other. Another effect of both Jupiter and the Sun on the asteroid belt is a group of asteroids that both precede and follow Jupiter in its orbit by 60 degrees. These asteroids are known as the Trojans.
It is not designed to do that or hold it while repairs are being accomplished. I am afraid it is Shuttle or nothing. :-(
Some would like to put a big-a$$ radio telescope on the dark side. Next to no artificial radio interference.
We think alike! :-)
See post #76
Well, of course. Sound science is sound science.
excellent post! i knew I'd enjoy this thread if I came back to it later!
Thanks! :-)
This is the king of "suff" I do for a living.
58 - Sorry, but you miss the main qualifications for a man of your age - you must get elected to the Senate and control some NASA appropriations. All your other skills and talents are not important.
The Hubble should be 'preserved', not 'replaced'. Because if it is 'replaced', then we still only have one telescope in space, and as such, very limited 'time'. Two telescopes, we will have twice as much 'time' for discovery available.
I understand the Hubble is booked now, years in advance, so we are missing out on a lot, because of this 'time' limitation.
Not when you are in a property rights fight. I actually detest that phrase. The liberal butts trying to take your land and rights are the same ones doing the "sound science". I sat and listened to the "scientists" talk about there studies that made Klamath necessary. It was the biggest load of horse manure I have ever heard. And all of it "sound science".
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