Slashdot Mirror
Intelsat Loses Another Satellite
Alarash writes "Intelsat reported a few days ago that its IS-804 Satellite is lost in space. According to the press release, the '[...] satellite experienced a sudden and unexpected electrical power system anomaly on January 14, 2005, at approximately 5:32 p.m. EST that caused the total loss of the spacecraft.' The satellite was in charge of the South Pacific's media delivery. As a reminder, Intelsat-7, another satellite from Intelsat, got lost a couple of months ago."
All links are from their site. Here is a image of the coverage area of the satellite:
t _foot.aspx?name=804&loc=174&spot=global t _foot_details.aspx?name=804&loc=174
:. aspx
http://www.intelsat.com/resources/coveragemaps/sa
Here is some technical data on the satellite:
http://www.intelsat.com/resources/coveragemaps/sa
Also here is some Satellite Basics
http://www.intelsat.com/resources/satellitebasics
_JS
Well I didn't know so for others here is a summary of Intelsat
----
There don't appear to have been any warnings on the 14th. It's unlikely it was fried by a solar flare.
This sig seemed like a good idea at the time....
You'd need an insanely powerful radio transmitter to fry a satellite. Read up on EMP.
Using a missile (like the old American ASAT program) would be more feasible.
It's reasonably likely that Metal Whiskers can caused this. Nasa also has more information about this pehnomenon. Both links I've provided have nice pics.
Follow me
The problem with sunspot activity and satellites is that there are a few 'thousand' functional satellites orbiting (or geostationary) at any given moment. If it's a numbers game, then the tin foil hat croud will need to re-think, since there is no consipracy. It just broke. A random failure in a sea of success. These things are shielded up pretty good. I've worked this trade for a long time (Military/Civil), I've not heard of many failures put down to the sun.
Sure there are numerous little problems - failed transponders and such - but these things fly with backups of most things.
You can download small programs that plot the locations of most known birds - real time 3d graphics, based on ephemeris.
Of course, SBRS and ADSCS will be mildly inconvenienced at having to 'work' for a few days - heh. It's their area of operations.
I used to survey satellite downlinks in my previous life - the majority of satellites had large chunks of unused bandwidth - in some cases a few newly launched sats had their entire C and K band 'empty' - mostly Japanese owned birds.
Intelsat has always been well loaded, they even palm off satellites in decayed orbits to various asian countries (deemed to be end of lifed) - probably just to eek out as much money as possible. I doubt intelsat will be happy about this. There is huge competition in the industry, it's no tax write off.
First of all, the two sats were not manufactured by the same companies and are different in design, so it's not like a recurrent problem in a series of satellites.
a ils.aspx?year=2004&art=20041203_01_EN.xml&lang=en& footer=82
Secondly, the first sat was recovered on dec. 3 as stated here: http://www.intelsat.com/aboutus/press/release_det
-- It's always darker before it goes pitch black.
Sorry, but if you divide a power by the square of a length, then you don't get a power, but power per area (also known as energy flux).
Your calculation would be right if
a) the laser had an opening angle of 45 degrees (so radius of covered area equals distance of light),
b) the satellite had a cross section of exactly 1 square meter and
c) there would be vacuum between you and the satellite.
Now b is not impossible, but a would imply a rather badly focused beam. OTOH c would imply reduced power.
According to this article, a laser gives a spot with a diameter of 7km on the moon (distance 3.6*10^8 m), so at the point of the satellite it would be 7000/3.6e8 * 3.5e7 m = ca. 680 m, which assuming a circular spot gives an area of 3.6e5 m^2.
If there were no atmosphere, for your 250 kW laser pulse, this would amount to an energy flux of about 0.69 W/m^2. Orders of magnitude above your value, but still too low to do any harm (for comparison, the total energy flux of an 80W light bulb [light and heat together, i.e. taking the complete 80W into account] is about 6.4 W/m^2. That is, a 2.5 megawatt laser would generate the same energy flux at the satellite as a 80W lightbulb would.
Now, what will the satellite have to cope with anyway? Well, obviously the sun. Now, the energy flux of the sun above atmosphere is 1370W/m^2. That is, even the 2.5 megawatt laser would just add 0.5% to the energy flux the sun throws at the satellite anyway.
That's of course without taking into account the atmosphere.
The Tao of math: The numbers you can count are not the real numbers.
Correct my physics!
Ok, I'll give it a go. Lasers are not point sources - the formula you used is for an isotropic radiator, not a beam source. You'd need to know the divergence of the laser to calculate the power/m2 at the satellite. Also, your peak pulse power is off by about a factor of 10-20 (or more...)
Say the beam half-angle divergence of your 250 kW laser is 1 milliradian (mrad) (pretty crappy). At 35,000 km, the beam will be at least 35*tan(0.001)*2 = 70 km wide. That's only 65 uW/m2. Not even bright, much less cripplin'.
Increase the intensity of the beam to 5 MW and reduce the divergence to .25 mrad, and you get a beam 8750*2 = 17.5 km across and a power density of only 20 mW/m2. That's less than a class II supermarket scanner laser.
Damaging a geostationary sat is hard with a laser!
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
Space bats, however, would have to have radar or lidar because sound cannot travel in space.
You have two hands and one brain, so always code twice as much as you think!
I am attaching an article from the Wall Street Journal describing how although this is the first major failure of an Intelsat satellite, the other two major satellite manufacturers in the US have "seen their reputations tarnished by a spate of commercial-spacecraft malfunctions." Given that these are multimillion dollar products and are incredibly critical to the world these days, it is surprising to me that there would be such significant quality control problems. /. I would have thought the slashdot crowd would have been all over this. Anyhow, here's the article:
Also, I'm surprised that I don't see more technical discussion of this issue on
Lockheed Faces Quality Concerns
After Failure of Intelsat Satellite
By ANDY PASZTOR
Staff Reporter of THE WALL STREET JOURNAL
January 18, 2005; Page A6
The sudden loss of a satellite operated by Intelsat Ltd. raises reliability concerns about spacecraft manufactured by Lockheed Martin Corp., which until now managed to avoid the negative publicity over failures that has bedeviled its leading U.S. rivals.
The abrupt shutdown last weekend of Intelsat 804, an eight-year-old Lockheed Martin-built satellite serving the South Pacific, also is likely to prompt greater industrywide efforts to enhance outside insurance coverage or set aside larger in-house reserves to cope with significant malfunctions in orbit.
With the commercial satellite-services industry transitioning to control by various private-equity groups, the financial implications of technical problems are coming under increased scrutiny. "Potential failures clearly are going to be highlighted in the minds" of the new breed of investors, according to Armand Musey, a former Wall Street analyst who helps run Near Earth LLC, a boutique investment bank specializing in space.
Buying additional insurance -- or revising self-insurance plans to minimize the impact of further catastrophic equipment malfunctions -- are bound to be "at the top of the list of fixes," Mr. Musey said.
During the 1990s, U.S. commercial and military space projects costing more than $11 billion either failed to reach appropriate orbits because of rocket failures or didn't operate properly once they got to the correct orbit. More recently, Boeing Co. and Loral Space & Communications Ltd., the other big U.S. satellite makers, have seen their reputations tarnished by a spate of commercial-spacecraft malfunctions.
The causes of those problems range from improperly assembled solar arrays to electrical-power glitches to substandard propulsion systems installed on commercial-communications satellites, some of which carry price tags as high as $150 million. Launch and insurance costs can boost the final price to $250 million or more.
For Intelsat, the No. 2 global commercial-satellite operator, it is the second time since mid-December that a major satellite problem has held up its pending $3 billion takeover by a group of private-equity firms. Instead of anticipating final approval of the transaction this month, Intelsat executives now are being forced back to the negotiating table to hammer out new terms, according to company and industry officials.
Intelsat, which is incorporated in Bermuda but has its headquarters in Washington, is expected to need months to negotiate a revised agreement and then submit the terms for shareholder approval. If the negotiations turn contentious, some industry officials say that could prompt rival bidders to place their own offers.
The satellite that went dead wasn't insured, and Intelsat said it is working with its own fleet and other operators to restore service to customers. Many small Pacific islands relied on the Intelsat satellite for phone and data services. Lockheed Martin, based in Bethesda, Md., has said only that it is working with Intelsat to determine the cause of the shutdown. Most satellites are manufactured to last for about 15 years.
For the broader satellite industry, the latest malfunctio
"Lack of technical competence coupled with the arrogance of power, as usual, leads to no good end."
The "total loss" of a US$73 million ($106.19 million) satellite on Saturday morning left several Pacific Islands and Scott Base in Antarctica without telephone communications to the outside world.
Story here.