NASA Considers Sending Telescope To the Outer Solar System 152
Nancy_A writes "A mission that astronomers and cosmologists have only dreamed about — until now. A team at JPL and Caltech has been looking into the possibility of hitching an optical telescope to a survey spacecraft on a mission to the outer solar system. Light pollution in our inner solar system, from both the nearby glow of the Sun and the hazy zodiacal glow from dust ground up in the asteroid belt, has long stymied cosmologists looking for a clearer take on the early Universe."
Earth's orbit and slingshots (Score:5, Informative)
Why couldn't they just send one upwards out of the plane of the solar system? Wouldn't that be quicker?
Costs. And time.
We already have a certain velocity in the plane (earth is going around the sun, and we have to escape the sun's gravity well). We have practically zero velocity in the upwards direction. This is also who rockets are launched from near the equator.
Add to that possible slingshots around other planets, and you have your whole answer.
Re:not a good idea with current technology (Score:5, Informative)
Well then it's a good thing they're only hoping to go as far as Jupiter, where "the zodiacal light is 30 times fainter than at Earth". But don't take my word for it, try reading the article.
Re:Xena (Score:4, Informative)
Xena was just a temporary suggestion for the name; since 13th September 2006 it's actually been called Eris [wikipedia.org].
Re:Upwards? (Score:4, Informative)
No, you're not, you're totally right - if you're pointing away from the sun then it doesn't contaminate anything. It depends where they're pointing it and what they're observing for whether it's an issue. You can mask out the sun but it will still be blocking a part of the sky - and more of it the nearer you are (obviously), and if you're any distance from it at all it will be many years before it gets out of the way.
The dust is probably more a problem though, I agree.
Re:Upwards? (Score:5, Informative)
Not necessarily. [wikipedia.org]
Re:Upwards? (Score:5, Informative)
Not to be picky, but I don't believe gravitational slingshots work that way. They are basically elastic collisions (mediated by gravity) with a planet, and therefore only give you an increase in velocity if you "recoil" in the direction of motion of the planet. In a nutshell, you borrow a tiny bit of a planet's or moon's forward momentum to come out travelling at twice its speed relative to the Sun.
Yes, they can do that. It is essentially an elastic collision as you say, but it doesn't have to result in the gained momentum being in the same direction as the planet's motion. Extrapolating your analogy, if you had an elastic collision between the probe and a high-latitude region of the planet (rather than at the equator) then your resulting trajectory would have a 'vertical' (meaning perpendicular to the ecliptic) component. This can be done by having your encounter with the planet you are using to gain the gravitational assist happen at a high inclination. Take a look at Voyager 2. From a quick wiki search, it's currently travelling on a trajectory 30 below the ecliptic after it's encounter with Neptune and Triton.
Re:Bandwidth make it improbable? (Score:4, Informative)
Distance is the main factor. By the time you're far enough away, you need really big antennas (the Deep Space Network) of which there aren't many; you don't want to keep one of the few DSN antennas pointed at this probe 24/7.
On the transmitter side, the power and size/weight budgets limit the signal strength.