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Monster European Environmental Satellite
andygood writes: "Spaceflight Now has this article about the 'Mother of All Earth Observation Satellites' which will be launched by Europe in early 2002. This thing is the size of a juggernaut and 'every hour will gather as much data as can be stored on a dozen PC hard disks'. 'ENVISAT' (ENVIronmental SATellite) has been in the works for almost fourteen years with a price tag of 2.3 billion (Euro)."
how much data the European Space Agency thinks can be stored on a "PC Hard Disk" nowadays... 1 GB, 10 GB, 100 GB? They're a little short on meaningful statistics. But it's a press release - the only time the press does math is when one of them gets stuck with the bar tab and figures out a tip.
It would also be interesting to hear what storage technology they're using. Surely they're not flying a Terabyte RAID5 array (what with launch vibration, etc.). More likely dense and hardened DRAM (and lots of it), I'd guess. It almost makes me want to go read the article to find this out.
(HST), the first large orbital optical observatory. Built from 1978 to 1990 at a cost of $1.5 billion
HST Programs & STS-82 Costs
Servicing Mission Costs - HST
NICMOS 105
STIS 125
GS 8
Other Flight Hardware 35
Simulators/Testing 46
Ops/Software Development 28
Total 347 Million
Servicing Mission Costs - Shuttle
Nominal Shuttle Flight Costs
448 Million
All the above are in USD
Source - http://www.gsfc.nasa.gov/gsfc/service/gallery/fac
Scientists: Analyze data
Special Interest Lobbyists: Point out that at least one scientist somewhere thinks that the changes may not be due to human activity
Politicians: Heeding lobbyists, maintain status quo
Net Results: Nothing
Are Euro at the same exchange rate as Canadian money? If so thats like three fiddy these days. What a bargain!
Strange women lying in ponds distributing swords is no basis for a system of government.
And yes, we are all watching you! Its all about you. You are so amazingly interesting that we, as taxpayers, are funding programs and supporting political leaders that focus in on your every move.
INSOC Forever!
Strange women lying in ponds distributing swords is no basis for a system of government.
Perhaps the Monster Satellite should keep watch over Japan, since that's where Godzilla attacks most. I haven't heard of European monsters; none visible from space anyway.
"Would it kill you to put down the toilet seat?" -- Maya Angelou
we want to retain an overview, for example, of ocean water quality, of greenhouse gases or temperature distribution in the atmosphere, and to be able to establish the extent to which tropical forests are being cut down
I see statistics about this every day in the newspaper. Clearly, we can measure all these things from the ground - what does a satellite give us? Is it just there for the global view?
Actually, most of these things are already gathered from satellites in one form or another. This satellite gives more extensive, detailed data that many of the others that are already in existence. Nothing extremely groundbreaking but serious improvements in a number of areas.
Whatever gases get released into the atmosphere, stay in the atmosphere. Big news.
Actually, no, this is just plain wrong. Gases and materials are continually being added and removed from our atmosphere. Oxygen is removed by animal life and combustion. Carbon Dioxide is removed by plant life and the oceans, as well as various geological processes. Various emissions created by industrial processes are removed by rain (I.E, acid rain). CFC's work their way up into the upper atmosphere over time and destroy Ozone. Our understanding of all of these processes is incomplete. So we need more detailed data. This satellite gathers that data.
Once their presence is identified from space, poisonous algae can be prevented from spreading
Help me understand why anyone cares enough about poisonous algae to send a satellite into space.
Hmmm. Gee, I can't imagine why anyone would care about huge masses of poisonous algae. It kills of fish, it kills off other aquatic life. It affects fishing, which for many people is an extremely important source of food. It effects the chemical composition the ocean, and in turn how the ocean interacts with the atmosphere.
So in order to get some answers, I went to the satellite's web page [esa.int] and found myself overwhelmed by the amount of incomprehensible information. The page is basically a sales portal for scientists who want to buy the data, but doesn't give any information comprehensible to a little layman like me.
Incomprehensible? To you maybe. If you really want to know go do a little research on google for some of the topics mentioned in the article. Yes, the site you linked to is in fact designed for scientists. Why should everything be spoon fed to your level of ignorance? If you want to know, go educate yourself.
So, does anyone have a good source that will explain to me why I should care one snippet about this satellite, and not think that ESA just blew E2.3 billion on the world's biggest piece of space debris?
Yes, now that you mention it Micheal kindly provided a link to it at the top of the page. This satellite is exceptional only in it's size. If you can't logically reason out why those sorts of data might be useful, well google is your friend.
Why?
- The data volume for our instrument was a mere 5 GB per 100 minutes orbit, hence approx. 3 GB/hour. This instrument is considered as low-volume for data size, the bigger instrument having approx. two orders of magnitude more data!
- The design of a satellite such as ENVISAT takes years. It is true that today, one would probably design things differently. Ah, how easy it would be to know 5 years in advance how a system should be designed...
- This satellite is purely for civilian usage, no spying or whatever. All results will be available to buy (or download for low-resolution images). If ENVISAT would have military aspects, I would certainly not be allowed to talk about it freely on
/.
- All data analysis software was developed in C++. It runs on IBM AIX clusters, but with the goal of being UNIX platform agnostic. No Linux (yet?), sorry, but many open source components were used. ESA is paranoid about vendor lock-up.
Must I add that it was fun to work on such a project?I assume this data rate is decoded, not the raw telemetry, which is quite useless. Lets see.
The 'housekeeping data' of a satellite contains thousands of satellite parameters, e.g. orbital position, currents, voltages, radiation level, temperatures, what is on/off, status of each instrument. On many scientific satellites, all this affects the performance of all instruments. Often the HK data is recorded once per a few seconds.
This is because when voltage across some critical part is raising, you have to shut the satellite down. Then, from the last set of HK data, you have to fig out what is wrong, and correct or shut down the dangerous part, and still have a 90% functional satellite.
Lets assume you have of the order 10000 parameters to monitor, and the values are recorded 15 times/minute. Assume each values takes five bytes when decoded (including a STRING for parameter name. The raw telemetry will of course be more compact). This gives 10000x15x60x24x5 bytes/day, or about 1 GB/day, just to know the satellite is OK.
Now, add the HK, calibration and science data for each instrument. I have analyzed some data from satellite X-ray instruments, so I use it as a crude estimate. (This is very crude, other instruments may be completely different) A modern X-ray instrument produces about 1GB/hour in decoded data (instrumental HK, calibration, science). Thus,we have about 20 GB/day/instrument. I haven't bothered to read the article, but I assume the satellite contains about half a dozen instruments.
This would produce about 100 GB/day. Problem solved.
I can not understand why so many people continue to be taken in by the global warming/cooling scam. My only supposition is that, faced with the realization that man has essentially no impact on the universe at large, it become vitally important for them to believe that at least they are having a major impact on the earth. The fact that we are still minor players in the biosphere (there are, for example, well over a metric ton of termites per human, and termites are minor players among the insects. The insects, in turn, are dwarfed by the plant kingdom,...) is evidently so scary to them that they simply can't accept it.
-- MarkusQ