[X] My Assistant

[Guest_BruceMoomaw_*]

Which would have made eminent sense -- except that the only competitive programs either of those two divisions had was the Explorers, which had a lower cost cap. Once again, I wonder whether NASA ought to just throw ALL possible space-science subjects together for competitive missions within a specific cost cap, instead of having separate competitions for Solar System missions, solar missions, space astronomy missions, magnetospheric missions, etc. I've already mentioned the suggestion that Solar Probe could be included among the competitive proposals for New Frontiers, since it's in exactly the same cost zone.

So basically, your Discovery mission will get cancelled if it's over-running the budget, unless we really really like it, in which case we'll move it to another division.

Not strictly true -- Kepler would have been moved to the Universe Division whether it underwent a cost overrun or not. And it was that Division's management which then separately decided to keep it on despite its huge cost overrun.

[Guest_AlexBlackwell_*]

Not strictly true -- Kepler would have been moved to the Universe Division whether it underwent a cost overrun or not. And it was that Division's management which then separately decided to keep it on despite its huge cost overrun.

Quite honestly, I think Kepler would have been axed by now if other observatory missions (e.g., TPF, SIM, etc.) had not been in such dire straits.

[Guest_BruceMoomaw_*]

In that connection, there's a new, interesting little note from Ed Weiler attacking NASA for trying to oversell SIM as a regular "detector of Earthlike planets" ( http://www.nasawatch.com/archives/2006/03/...ament.html#more ):

"Former OSS colleagues...
"When we sold SIM, years ago, it was sold and designed as a machine that would primarily find gas giant planets, and -- if you were within a tiny, tiny fraction of the galaxy, namely within 30 light years of the Sun -- you had a shot of finding a few 3-Earth-mass rocky planets, maybe, if they exist.

"How did this suddenly get translated into 'SIM project will search for Earth-like planets orbiting nearby stars...' in the newly minted NASA Strategic Plan on page 12? Has physics changed? Is it different on the West Coast vs. the East Coast? Seems like a bit of a stretch of the truth considering most of the planets that a SIM will find are gas-giant sized. Again, since I started this program as Origins Director, got it funded and sold it year after year as AA/OSS, and I am an astronomer, I believe some forces are 'stretching' the truth here. Kepler finds Earth-like planets! I would hate to see that CRITICAL mission short-changed as the 'real' Earth finder and statistics builder.

"Just a plea for truth in advertising in these interesting times...Plus... if Kepler shows us that Earths are very rare, say 1 in a million stars... some might say we can forget SIM since it 'looks for Earth-like planets' in a tiny fraction of the galaxy!

"Just something to ponder as you consider how you market these things..."
________________________

Now, the presentations to the Earthlike Planets Strategic Mapping Workshop DID imply that Weiler is overstating his case -- they did present SIM as being "the true finder of nearby Earthlike planets", and TPF as just the "characterizer" of those located mostly by SIM.

http://www.hq.nasa.gov/office/apio/pdf/ear...ke_minutes1.pdf :
"SIM will survey 250 dwarf stars of types A, F, G, K, and M within 15 parsecs, looking for planets of up to several Earth masses by astrometry. Planets of up to 3 times the Earth’s mass will be identified with a confidence of 5 sigma. Planets of one Earth mass will be identified with a confidence of 1 sigma. [Michael Shao said in Feb. 2005 that extending SIM's mission from 5 years to 10 years would allow it to detect 1.5 Earth-mass planets out to 10 parsecs with 5-sigma confidence -- Moomaw.] These results will provide a short list of high-priority stellar targets for TPF (the stars most likely to have Earth-like planets). SIM will also provide orbital phase data to aid in timing and orienting the TPF observations. SIM therefore enhances the efficiency of TPF, and estimates of this enhancement range from threefold to tenfold...Dr. Martin asked if the principal argument for SIM is its enhancement of TPF efficiency. Dr. Marcy replied that the significant technology challenges of TPF mean that SIM is also needed to protect TPF-C from falling below its science floor. Dr. Beichman added that SIM gives the planet-finding program robustness and direct measurement of planetary masses, in addition to increasing the efficiency of the TPF missions. In summarizing his argument for the value of SIM, Dr. Marcy said one could call SIM the terrestrial planet FINDER, whereas TPF is the terrestrial planet CHARACTERIZER."

http://astron.berkeley.edu/~gmarcy/marcy_japan.pdf :
"The simulations of SIM observations of Earth-mass planets show that 3 Earth-mass planets are detectable and 1.5 Earth-mass planets are marginally found at 5 pc. Thus, the SIM survey of 200 nearby stars will identify a subset that has planets of 3-10 Earth masses (should they be common) and another subset that is likely to have even lower mass planets, 1.5-3 Earth masses, albeit with some false alarm interlopers. SIM can thus produce an input sample of nearby stars that is enriched by about a factor of 3 in 1.5-3 Earth-mass planets over an original sample. Assuming, for example, that nu [the fraction of stars with earths in the habitable zone] is 0.1, it is easy to show that SIM will produce an output list of stars that is enriched by a factor of 3 in habitable earths over the original input sample of stars. Thus, SIM will provide TPF and Darwin with target stars having either strong or plausible evidence of rocky planets. SIM will also identify those stars that TPF and Darwin should avoid, notably those with a large planet near the habitable zone that renders any earths dynamically unstable...

"If nu is indeed ~10%, TPF/Darwin will be hard pressed to detect these few Earths because of their rarity and their faintness.... Moreover, for modestly inclined orbital planes, TPF/Darwin will miss planets located angularly within the diffraction-limited Inner Working Angle... A planet orbiting 1 AU from a star located 5 pc away will spend roughly 1/3 of its orbit inside the IWA, leaving it undetected. Thus if the occurrence of earths in habitable zones is of order 10%, SIM will triple the efficiency of TPF and Darwin both by identifying the likely host stars and by predicting the orbital phase during which the 'earth' is farthest from the glare of the host star."

But while SIM will thus be extremely useful in targeting the observations of TPF and greatly improving that mission's efficiency, its launch delays will seriously interfere with its ability to MEASURE nu -- the frequency of earths around Sunlike stars -- which is a critical value to know in deciding whether to make the first TPF the TPF-Coronagraph or the TPF-Interferometer, aka Darwin (which is much more sensitive and thus capable of surveying a much larger number of longer-range stars than TPF-C, but is also much more expensive). Thus Kepler is important in measuring nu to make that crucial decision years before SIM is even launched -- and thus, if we don't fly Kepler, we will certainly have to delay the launch of TPF by 5 years or so. Is this worth Kepler's half-billion-dollar cost? Kind of a judgement call.

[Jyril]

Kepler finds Earth-like planets! I would hate to see that CRITICAL mission short-changed as the 'real' Earth finder and statistics builder.

"Just a plea for truth in advertising in these interesting times...Plus... if Kepler shows us that Earths are very rare, say 1 in a million stars... some might say we can forget SIM since it 'looks for Earth-like planets' in a tiny fraction of the galaxy!

Exactly. Kepler must fly. ESA has already cancelled its equivalent, the Eddington mission.

[Orlin Denkov]

Interresting details in an Associated Press article: NASA reviews canceled asteroid mission

The review, headed by NASA Associate Administrator Rex Geveden, will take into account JPL's new findings and the results from an independent team dispatched to evaluate the mission. A decision was expected as early as the end of the month. NASA headquarters declined to say what the new evidence was and refused to make Geveden available for an interview.

Is that "new evidence" the one which was mentionned in the Planetary Society blog?
I really hope that the cancelation will be revised and Dawn will fly at last...

[Guest_AlexBlackwell_*]

Interresting details in an Associated Press article: NASA reviews canceled asteroid mission

Is that "new evidence" the one which was mentionned in the Planetary Society blog?
I really hope that the cancelation will be revised and Dawn will fly at last...

Interesting, Orlin. Thanks for posting this.

[Guest_AlexBlackwell_*]

NASA's Dawn Mission Cancellation Under Review
By Leonard David
Senior Space Writer, Space.com
posted: 16 March 2006
12:30 p.m. ET

===============

"When pressed by scientists to clarify whether or not the Dawn mission has been restored, NASA Associate Administrator for Science, Mary Cleave, said NASA is responsive to Congressional language that dictates 'if we get to a certain percentage cost overrun we have to review a project. And if it gets to another percentage Congress will zero the money going in and we will be in this limbo with no money going in.'

"Another reply regarding the status of Dawn came from Andrew Dantzler, director of NASA’s solar system division in Washington, D.C.

"I really can’t get into the details on Dawn,' Dantzler told the LPSC gathering, but noted that the cancellation 'is under review by our management.' Because of that fact, he added, it would not be appropriate to get into specifics.

"The cost to stand down Dawn was slated not to be more than $5 million dollars and hasn’t been, Dantzler said. 'Continuing Dawn is significantly more,' he said.

"Dantzler said that termination of a mission or a budget cut 'is a very serious issue,' with NASA doing everything it can not do that.

"In terms of the technical problems of Dawn, Dantzler said that 'it would not be wise to go into technical detail.'"

[dvandorn]

All of the issues aside, I would just *love* it if I were to have reason to start a new thread here entitled "Nasa Dawn Asteroid Mission Told To 'Stand Back Up'...



-the other Doug

[helvick]

All of the issues aside, I would just *love* it if I were to have reason to start a new thread here entitled "Nasa Dawn Asteroid Mission Told To 'Stand Back Up'...

The applause would definitely be echoed over here on this side of the atlantic.

[ElkGroveDan]

The applause would definitely be echoed over here on this side of the atlantic.

OK let me make a few calls and see what I can do.

[Orlin Denkov]

If we really can do something (calls, or whatever else) - we really must do it
Dawn have many and many supporters and deserve to fly - for our pleasure, and for the science achievments

[Bob Shaw]

We might be better to push for a pair of SMART-1 follow-ups in the form of Vesta Express and Ceres Express, with some US instruments aboard (well, they're already built, so they could be sold to ESA as scrap). Of course, somebody would have to build a magnetometer - JAXA, perhaps?

Bob Shaw

[algorimancer]

We might be better to push for a pair of SMART-1 follow-ups in the form of Vesta Express and Ceres Express, with some US instruments aboard (well, they're already built, so they could be sold to ESA as scrap). Of course, somebody would have to build a magnetometer - JAXA, perhaps?

Bob Shaw

I would think that throwing together something like NEAR - ion propulsion, basic camera and spectrometer, ought to be relatively inexpensive. Although this may be a little far out for solar power, which introduces all sorts of problems.

[Mariner9]

I can't beleive what I'm reading.

I seem to be hearing: "it's easy to put together an asteroid mission with ion drive, anyone can do it for cheap"

Uh.... wasn't that the basic problem here in the first place? They thought they could just take hardware off of Deep Space 1, modify it slightly, and off to Vesta Dawn will go?

I could have sworn that things didn't quite work out that smoothly, and Dawn just get canceled for budgetary and technical problems.

[Guest_BruceMoomaw_*]

According to Keith (shudder) Cowing, the decision on whether to zap Dawn permanently is coming up in a few hours:
http://www.nasawatch.com/archives/2006/03/...mission_re.html

However, hope never dies -- not only is the Dawn team already planning their followup mission, they've NAMED it:
http://www.cosis.net/abstracts/COSPAR2006/...006-A-00375.pdf