Official "Science News" Thread

[cheesehead]

Ten gorgeous photos from the ten-year-old Spitzer Space Telescope:

http://www.businessinsider.com/10-ye...lescope-2013-8

Ten years ago, a Delta II rocket launched NASA's Spitzer Space Telescope from Cape Canaveral, Fla.

As the fourth Great Observatory to enter into space, Spitzer has studied comets and asteroids, counted stars, and most notably, discovered "buckyballs" — soccer-ball-shaped carbon spheres crucial to star birth. The telescope's infrared vision allows it to see the coldest, farthest, and dustiest parts of space with incredible detail and clarity.

Entering its second-decade of space scrutiny, Spitzer must now undertake the task of helping NASA observe and potentially capture and redirect an asteroid nearing Earth.
Check out what Spitzer has seen in the last decade »

- - -

NASA's Great Observatories, in order of launch:

Each was designed to observe a particular region of the electromagnetic spectrum, and to push the state of technology in its intended wavelength region.

Each was named in honor of a famous deceased astronomer. (Except for the Hubble, each was initially launched with a different technical designation, then renamed for the astronomer only after successful demonstration of its operation in orbit.)

1990(on my birthday!)-present - Hubble Space Telescope (visible light, near-ultraviolet and, after an update, near-infrared), named in honor of Edwin Hubble

1991-2000 (deorbited after equipment failure) Compton Gamma Ray Observatory (gamma rays and hard [high-frequency] X-rays), named in honor of Arthur Compton

1999-present - Chandra X-ray Observatory (soft [low-frequency] X-rays) - abbreviatedly named in honor of Subrahmanyan Chandrasekhar

2003-present - Spitzer Space Telescope (infrared) - named in honor of Lyman Spitzer

[kladner]

Great images! Thanks!

[xilman]

Radar has revealed a canyon larger than the Grand Canyon in Arizona, though still not a patch on Valles Marineris. This one is under a kilometer or more of ice in Greenland.

[ewmayer]

The big-Ag lobby is not gonna like this at all:

Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets

Very-low-carbohydrate diets or ketogenic diets have been in use since the 1920s as a therapy for epilepsy and can, in some cases, completely remove the need for medication. From the 1960s onwards they have become widely known as one of the most common methods for obesity treatment. Recent work over the last decade or so has provided evidence of the therapeutic potential of ketogenic diets in many pathological conditions, such as diabetes, polycystic ovary syndrome, acne, neurological diseases, cancer and the amelioration of respiratory and cardiovascular disease risk factors.The possibility that modifying food intake can be useful for reducing or eliminating pharmaceutical methods of treatment, which are often lifelong with significant side effects, calls for serious investigation. This review revisits the meaning of physiological ketosis in the light of this evidence and considers possible mechanisms for the therapeutic actions of the ketogenic diet on different diseases. The present review also questions whether there are still some preconceived ideas about ketogenic diets, which may be presenting unnecessary barriers to their use as therapeutic tools in the physician’s hand.

The Wikipedia article focuses mainly on the epilepsy connection, but there would appear to also be a strong human-evolutionary basis for such diets, grain cultivation being a relatively recent innovation in human history.

[ewmayer]

In Search of the Toxic Five: Only five chemicals pose "unreasonable risk" according to EPA. Not really.

[cheesehead]

NASA has invited suggestions for re-purposing the slightly lame (i.e., no longer positionally stable enough for its original mission) Kepler spacecraft. Here is one:

The Kepler spacecraft, though having two disabled reaction wheels, could be used to discover new Near-Earth Objects (including Potentially Hazardous Objects !) far more efficiently than any ground-based telescope can. There's nothing wrong with Kepler's optics. Its remaining positional accuracy, while not sufficient for its primary mission of discovering exoplanets, is still good enough to discover asteroids passing near Earth. That would require just reprogramming Kepler's computers and those at ground stations that receive Kepler data.

Alternatively (conflicts with NEO detection), Kepler could help find targets for NASA’s Asteroid Redirect Mission.

"NEOKepler: Discovering Near-Earth Objects Using the Kepler Spacecraft"
http://arxiv.org/pdf/1309.1096.pdf

(I've reformatted this abstract.)

Abstract

The Kepler Mission has been an irrefutable success. In the last 4.5 years, it has monitored 150 confirmed exoplanets in over 75 stellar systems and detected an additional 3,300 planet candidates. Using these data, we have learned the size distribution of planets in our galaxy, the likelihood that a star hosts an Earth-sized planet, and the percentage of stars that contain multi-planet systems.

The recent failure of a second reaction wheel has ended Kepler’s primary mission; however, its plight is a unique opportunity to make significant advances in another important field, without the time and costs associated with designing, building, and launching another spacecraft.

We propose a new Kepler mission, called NEOKepler, that would survey near Earth’s orbit to identify potentially hazardous objects (PHOs).

To understand its surveying power, Kepler’s large field of view produces an etendue

(aperture times field of view)

that is 4.5 times larger than the best survey telescope currently in operation.

In this paper, we investigate the feasibility of NEOKepler using a double “fence post” survey pattern that efficiently detects PHOs.

In a simulated 12-month survey, we estimate that NEOKepler would detect 150 new NEOs with absolute magnitudes of less than 21.5, 50 of which would be new PHOs. This would increase the annual PHO discovery rate by at least 50% and improve upon our goal of discovering 90% of PHOs by the end of 2020.

Due to its heliocentric orbit, Kepler would also be sensitive to objects inside Earth’s orbit, discovering more objects in its first year than are currently known to exist. Understanding this undersampled sub-population of NEOs will reveal new insights into the actual PHO distribution by further constraining current NEO models.

As an alternative science goal, NEOKepler could employ a different observing strategy to discover suitable targets for NASA’s Asteroid Redirect Mission.

[kladner]

The NEO task sure sounds like a silver lining to the disappointment of equipment failure. It is a area that needs a lot more attention.

[cheesehead]

Originally Posted by kladner

The NEO task sure sounds like a silver lining to the disappointment of equipment failure. It is a area that needs a lot more attention.

1) Without checking, my impression is that reaction-wheel failures and gyroscope failures have been the most (or one of the most) common mission-ending hardware problem areas for a long time. As I understand it, lubrication for spinning parts tends to evaporate/deteriorate in space vacuum/radiation/temperature extremes, and that hasn't been solved yet.

Including a couple more spare reaction wheels than customary in spacecraft that won't be serviceable seems to me to be a sensible low-cost way to improve expected operational lifetimes ... but maybe I'm not recalling how many failures are in other areas or how much extra expense there'd be ... or how much spares can be expected to deteriorate before use.

2) I wonder how much NASA solicits ideas for secondary missions (after primary-mission-ending failures) during project planning. Probably not much, because of budget squeezes. It could be sufficient to wait until failures occur or are imminent, before conducting idea contests.

[firejuggler]

Kepler had 4 reaction wheel, all functionning until July 2012. This was the second faillure.
AFAIK, kepler need 3 wheel at least to be precise enough.
more ibfo here http://en.wikipedia.org/wiki/Kepler_...Mission_status

[rogue]

Terramechanics research aims to keep Mars rovers rolling

[cheesehead]

Originally Posted by firejuggler

Kepler had 4 reaction wheel, all functionning until July 2012. This was the second faillure.
AFAIK, kepler need 3 wheel at least to be precise enough.

I'm shocked that NASA decided four were enough for Kepler.

For most missions I've known about, two reaction wheels were sufficient for mission operation, so the standard complement was four, requiring three failures to put it out of business. (Four reaction wheels were deemed enough for the Hubble S.T. and any two can suffice. But it has been a serviceable satellite, and those service missions have replaced failed reaction wheels.)

For a non-serviceable mission (Kepler's way away from Earth) requiring three reaction wheels for proper operation, I'd have thought that planners would have insisted on having at least five, if not six, reaction wheels onboard at launch.