Comments on: Dawn postponed indefinitely…?

By: Ty Moore

Ty Moore — Sun, 05 Mar 2006 18:40:08 +0000

I think DAWN’s cancellation is quite a blow to the whole program. As has been said, almost complete hardware and a nearly flight ready vehicle should be funded to completion and launched. To do less after coming so far is a total waste…Going back to the Moon is fine, and certainly going to Mars is nice. But what about after that…? Shouldn’t we be thinking in terms of what humanity needs (material resources-wise) in the next thousand years? Should we not support a longer vision of resource and energy sustainability for the species?

Or are we so conditioned to the ‘here-now’ that we are completely incapable of thinking in such terms…?

By: The Bad Astronomer

The Bad Astronomer — Sat, 04 Mar 2006 17:40:48 +0000

Anonymous, I didn’t mean that Dawn had “a checkered past” as in nefarious dealings, incompetency, or anything like that. I guess I chose the wrong phrase to use. I simply meant that a series of things had gone wrong during the construction and testing. Mark Sykes has said (see March 3 2006 blog entries) the Xenon tanks were tested at twice the pressure they were likely to face, and were fine at the correct pressures.

It seems to me we have a mission almost entirely ready to fly, with tested hardware, an amazing flight plan, and a high chance at some incredibly exciting results. I just hope NASA will reverse this short-sighted decision.

By: Anonymous

Anonymous — Sat, 04 Mar 2006 08:22:15 +0000

Phil, I don’t think it is fair to say the Dawn mission had (note the past tense since NASA announced its cancellation) a checkered history. When NASA cancels a mission in the beginning of the building phase for two months and then, 1.5 years later in the spacecraft integration phase, orders a standdown for 3 months, the end result is alot more money spent and time lost.

When NASA first cancelled Dawn in December 2003, people were moved onto different projects, and instrument parts were ‘unordered’. When the mission was reinstated (minus two instruments: the laser altimeter and the magnetometer and minus extra support from the spacecraft company in order to save money) two months later, the remaining instruments needed to scramble to make up for lost time. Why? Specialized parts such as gratings and mirrors are manufactored by third party vendors who have their own manufactoring schedules, so if you take a specialized part out of their queue, you cannot insert yourself back into their queue in the same place where you were and so you lose time. The VIR mirror was in this situation for example.

Everyone was working under the tightest of time and money constraints given the fact that we lost time in the beginning and their partner space agencies lost trust of NASA, and I think they performed miracles, delivering all instruments exactly to specifications. For example, DLR Berlin couldn’t build the camera after Dawn’s first cancellation, and so a new camera was solicited, which was built on time (after being several months behind) by the MPI Lindau group. Another example, is that the Rome Dawn science team had no money from ASI for the three years of the construction phase, going to science meetings and traveling to interact with the mapping spectrometer builders on their personal credit cards.

Another facet I read in the press is problems with the xenon tanks, but what is not reported is that the tests performed on the tanks went far beyond the tanks’ specificied operating conditions.

The Dawn Independent Assesment Team who gave their report to NASA in February recommended to finish the project and launch. Dawn was >90% constructed at the time of its cancellation. Yes there were things that were critical to address, but they also stated that the Dawn mission was not different in their problem solving from any other space mission in their late stage of development. The Dawn Team was an exceptionally fine team, they worked well together, the science team was top-notch, and payload team who managed the construction had decades of experience. If you read in the literature about cost overruns, I think it is wise to investigate more to see the larger picture.

By: Troy

Troy — Wed, 01 Feb 2006 06:55:30 +0000

Regarding the mythology in an earlier post. According to Edith Hamilton’s mythology Ceres and Demeter are the same entity the former is Latin the latter Greek. Gaea (Mother Earth) was not a goddess but along with Ouranos (Father Heaven) were considered ‘vauge personalities’ the rest of the monsters, titans, and lastly the gods sprung from them.

I like the D.U.S.K. idea, with even a small number of interested people and congress will resume the project otherwise it can go by another acronym D.O.O.M.

Dead
On Arrival, it’s all
Over
Man

That was quite interesting about Spica. Most star names are arabic and many have interesting traslations, one I read about recently was Algol which has the same origin as our word for ghoul, named such because it tends to wink as it changes in brightness.

By: Blue

Blue — Wed, 25 Jan 2006 18:28:17 +0000

Oh, another thing. DAWN is a Discovery mission. These are specifically designed to be cost-capped proposals. In essence, DAWN’s overpromising and underperforming means that a mission that could have been successful wasn’t funded. If that is overlooked, the entire Discovery program will be threatened.

By: Blue

Blue — Wed, 25 Jan 2006 18:25:53 +0000

This cancellation has little to nothing to do with the VSE. The DAWN team has consistently overpromised, underperformed, and overspent. The mission has already been significantly descoped both in instrumentation and in mission length.

At this point, the issue is not the sunk costs. It is whether the remaining funds meant to go to DAWN could be better used on another Discovery mission.

By: Mungascr

Mungascr — Wed, 25 Jan 2006 15:41:26 +0000

On reflection, maybe they’re worried Dawn will find too much evidence that Ceres and perhaps even Vesta deserve to be classed as planets?

Ceres at least is apparently spherical (from HST image?) or close to being so and I recall reading somewhere has a differentiated geology -ie. has seperated into core-mantle-crust layers. May well be wrong but heard it apparently has more water (ice?) than all the oceans on Earth going on some models / calculations?

Vesta too -again may be wrong on this -fuzzy memory of reading something along these lines – has apparently (from spectral analysis?) got some volcanic-type geology or at least shows signs of having once been molten …

Don’t know if they’ve got quite the same claim for planetary status but more than average asteroids and studying them and comparing them with Gaspra, Ida, Itokawa, Eros, et al would be a marvellous and possibly very useful achievement indeed.

(Apologies if I’ve breached netiquette by two long-ish posts.)