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0 pointsjustsee11y ago0 comments

Do you think changing the mission target of a 12 year mission on the day of landing has a scientific or bureaucratic / political motive? I'm inclined to believe it is the latter.

Until 12 November the FAQ [1] stated:

During the first week – the minimum mission target – a first run of the most important scientific measurements will be completed. During this phase the lander can operate on primary battery power, should this be necessary. In a second phase that is meant to last up to three months, a secondary set of observations will be conducted, using backup batteries that will be recharged by the energy from the solar cells on the lander. However, no one knows precisely how long the lander will survive on the comet.

Editing to omit the minimum mission target on 12 November [2] indicates something was already wrong at that stage, which would presumably relate to the two batteries that were to power the lander over more than a week, but no public announcement of any issue like that was made. So we should instead assume the batteries were fully operational.

Instead we have ESA announcements and news articles asserting that the reason for the very short period of operation was a lack of solar power, but solar was never planned to be required for over a week at least.

It seems obvious that they had a battery failure. That would not be surprising, but why not openly announce it?

[1] https://web.archive.org/web/20140805030451/http://www.esa.in...

[2] https://web.archive.org/web/20141112043243/http://www.esa.in...

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5 comments · 1 top-level

sherjilozair11y ago· 4 in thread

Because it's not important. What is more important is that the First Science Sequence was finished. In a detailed report, you may find that the battery didn't last as much as they thought it did (perhaps because of the double landings Philae had to make, etc.), but a public-facing article is not the place for it.

Also, there are probably N things that didn't happen as they thought it did. It is better to mention the K important things (K << N), than the N unimportant things that they got wrong.

If Philae, for example, didn't land on the comet at all, then they would have announced something like this: "Philae took a drive-by of the comet 67 p, and has done in-air experiments that would be valuable for us".

twic11y ago

It may not be important, but it's still interesting. We have two pieces of information about an interesting subject which appear to be inconsistent; attempting to resolve that inconsistency is the natural act of the curious mind.

acqq11y ago

Should we really give any weight to the two versions of the FAQ page, which contains also answers to the questions like "What is the difference between asteroids and comets?" What is the relation between FAQ page and the details of how many experiments, in which order, which schedule and using how much power at once are going to be done? Do you really believe something written for an uniformed person can ever be exact enough? If your cell phone battery lasts 5 days in stand by and you speak 5 hours and it's empty, everything is still according to the plan: you just used it more in shorter time frame. It's the experiments, not the lengths of time given as "during the first week" that matter.

uxp11y ago

Every once in a while I'll wake up, unplug my iPhone from it's charger and go to work, doing my normal planned routine, and have it die before I'm able to get back home to recharge it. Does that mean that my iPhone is a failure and I should sue Apple for failing to deliver on their promise of X hours of battery life? No. That's stupid. In agreement with you, sometimes things just don't work as desired, but the usefulness of the device isn't diminished, it's just altered.

hueving11y ago

If it's not important, why lie about it?

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