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NASA Selects Inexpensive Space Project Candidates
coondoggie brings us a Networkworld report detailing NASA's selection of six mission proposals for further study by the Small Explorer (SMEX) Program. The goal of the program is to develop cheap, tightly focused science missions (PDF). Among the selected proposals are a satellite telescope bank for use in detecting exoplanets, and a solar coronograph which will study solar wind and coronal ejections. Networkworld provided links with more detailed information on most of the projects.
Sounds a bit similar to the Mars Project Challenge that was deadlined last week.
If you are a logged in member of MS, you can view the 28 entries that were submitted and will be considered for funding at an upcoming conference in Boulder CO.
Personally, I think the most worthwhile projects related to Mars exploration are the ones dealing with In Situ Resource Utilization and the idea of "manufacturing products" from the stuff that is available there (which is mainly CO2 and rocks). ;)
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Meanwhile, discoveries of "Earth-sized" planets remain rare "
:). The smallest known exoplanet is Gliese 876 d, with a mass of a least 5.88 times Earth's.
Try "non-existent"
HSTs primary mission isn't planet-hunting, so it was neither designed for that nor does it spend most of its time doing it.
Meanwhile, discoveries of "Earth-sized" planets remain rare despite the technology that has been developed within the decade.
How much of that technology has reached space in the last decade ? Off the top of my head, I can name only one planet-hunting mission - COROT (and that's an ESA mission, not a NASA one).
Statistics. We now know that planetary systems are fairly common.
And how do they know what size?
Well, the lower size limit is given by the detection sensitivity ("If we're lucky, we can find an Earth-sized rock, but not a Mars- or Mercury-sized one."). The upper limit is given by the mass at which a lump of gas and rock starts initiating nuclear fusion and doesn't count as a planet anymore.
If they are already aware that there is these planets, then wouldnt it be more accurate to say "and finally see over 1,000 planets that we already assume exist mathematically"?
No, we don't know anything about these planets yet, but from our current knowledge about the likelihood of planetary systems we can guess how many planets we're likely to find if we examine X million stars.
The smallest known exoplanet is the fourth planet of the pulsar B1257+12, with a mass considerably smaller than Earth. Many of the pulsar planets are Earth sized and smaller.
http://www.geoffreylandis.com
70% larger is still in the same ball park as Jupiter, at least as far as astronomers are concerned. Heck, anything below a brown dwarf is in the same ball park as Jupiter. (Astronomers also have weird definitions of "metal" and "ice" that may not quite correspond to their meanings in other fields of science).
A planet 70% more massive than Earth would count as an Earth-sized planet, too. Sure, we may not find the gravity there too appealing, but that may not bother any life that has evolved there.
These spacecraft are also low mass, and can fly on smaller rockets like the Pegasus, so the total mission cost is a lot lower than a big James Webb Telescope 'flagship' mission.
They are also a lot less capable, but can solve one specific science problem while Hubble, Chandra etc. are general facilities that can solve many different science problems - but not all problems, which leaves some nice 'discovery space' for the small missions. Also, SMEX missions are done in a finite number of years, and are thought of as good training for young scientists. I work on a big mission, but I think the small missions are crucial for the field's health.
Of course, you're right that bringing the launch cost down would be even better.
Typically, these missions will go into orbit on a Pegasus rocket, which costs on order $25 million (http://www.space.com/news/smalllaunch_fl_040223.html). So, the $105 million to design and build the satellite, and then to operate it when it is orbit (about 10% of the total cost) is quite a bit more than the launch.