Satellite Back From The Dead 176
Papa Legba writes "Just ran across this amazing story about an amateur satellite that has returned from the dead. AMSAT-OSCAR 7 was launched in 1974 for radio hobbyists to use. In 1981 the onboard batteries died and the satellite went silent. Then on June 21st 2002, 20 years later, a hobbyist testing some new equipment made an amazing discovery. AMSAT-OSCAR 7 is live once more, both broadcasting and accepting signals. The theory expounded is that the dead battery short that took the satellite offline has cleared and it is now only running on its solar cells. While this does restrict it to daytime use, it is amazing that it works at all. " This was in the science section before - but worth the front page.
did anybody check (Score:5, Funny)
Re:did anybody check (Score:4, Funny)
Re:did anybody check (Score:1)
Please, wait to signal it. (Score:5, Funny)
We don't want the first extraterrestrial slashdotting.
Google Cache (Score:1, Troll)
Is anyone else... (Score:2, Funny)
Just don't talk to this thing for too long. It might not be quite the same as it was before.
One Word... (Score:2)
Re:One Word... (Score:2)
Foolish humans. (Score:2, Funny)
Invasion date set to July 1st.
P.S. Make sure mothership is upgraded with latest security patch, we don't want some nerd with an apple laptop to hack our shield system again.
Re:Foolish humans. (Score:3, Funny)
wait a sec (Score:4, Funny)
And all this time I thought those herbal treatments they advertised were stupid scams!
Re:wait a sec (Score:5, Funny)
i don't know about you, but my amateur penis doesn't have onboard batteries.
Re:wait a sec (Score:1, Funny)
Re:wait a sec (Score:1)
Re:wait a sec (Score:1)
---
Re:wait a sec (Score:3, Funny)
Re:wait a sec (Score:4, Funny)
Oh, wait...
Pornolized (Score:1)
Makes me wonder.... (Score:2, Funny)
Re:Makes me wonder.... (Score:2)
Re:Makes me wonder.... (Score:1)
someone must hate the admins over there... (Score:5, Funny)
Re:someone must hate the admins over there... (Score:2)
Re:someone must hate the admins over there... (Score:2)
More info: (Score:5, Informative)
AMSAT Miracle
STOP PRESS - Announcement....
First heard by Pat Gowan G3IOR, Oscar 7 seems to have made a comeback! Pat copied and downloaded CW telemetry. This information was confirmed by several AMSAT members as coming from OSCAR-7. This satellite was launched on November 15 1974, giving it a life of 27 and one half years. The receive frequency was 145.9738.
Jan King W3GEY commented, "G3IOR's telemetry frame is interesting. Apparently he did hear the AO-7 mode B beacon tonight.
"I got out my December 1974 and looked up the telemetry equations for the Morse Code Telemetry Encoder and what I found is in the attached spreadsheet.
"I'm blown away. Most of this stuff makes pretty good sense. In particular, the temperatures make sense and I would have guessed that they would be the most solid IF the reference voltage held (which it did). Interpreting some of this for those who may not understand or don't remember, the telemetry says the spacecraft was in Mode B; all the other beacons and Mode A were off. It is possible that the thing had just turned on because the old 24 hour timer just reset it to Mode B. The damn thing may think it is still on an every other day cycle. The power output of the transponder is 1.16 watts which may mean it is transmitting white noise plus beacon power. That seems about right, but a little low as I recall. The instrumentation switching regulator is in the middle of its normal range and seems to be working fine. The internal temperatures are around 15 deg. C; the external temperatures are around 5 C and the transponder PA temp, which should be the warmest - IS - it's 35.1 deg. C. The array current value is bust. I think maybe it always was. Need to look for some old telemetry to confirm that. The array current calibrations looks off. The array currents are in the normal range but all four show current. This can't be. Only two at a time should show current. Without a battery on line, this is entirely possible. The big find is that the battery voltage telemetry shows a voltage of 13.9 volts. Normal is 13.6 to 15.1 volts. So that would suggest the battery was normal BUT, the 1/2 battery voltage is measuring only 5.8 volts. That can't be. This imbalance probably means that the 5.8 volts is the correct value for the lower half of the battery (which is a low value for that half, if the cells were normal - they are probably not) and there is a break somewhere in the upper 1/2 of the battery string. My guess is the indicated voltage is really what the BCR is putting out with only the spacecraft load as a real load and the battery string has an effective break (or a pretty high resistance) somewhere in the upper half.
"So, this old war horse of a spacecraft seems to have come back from the dead if only for a few moments. And it is telling us, that even in a 1460 km high orbit a cheap spacecraft built by a bunch of hams, without very many high rel parts and without designing for a radiation dose like this, can last for 27+ years in space as far as a majority of its electronics is concerned. Even the damn precision reference voltage regulator is still in calibration!"
Like many of us, stunned by the announcement of the return of an old friend, Past President and BOD Chairman Bill Tynan added "Wow! Shades of Harry Potter and Steven King. It makes one believe in ghosts."
[ANS thanks President Robin Haighton for this item]
Comes back alive... (Score:1, Redundant)
Maybe an Alien turned it back on for us! (Score:2, Funny)
Seems Slashdotted... (Score:5, Informative)
Nasa Catalog Number: 7530
Launched: November 15, 1974
Launch vehicle: Delta 2310
Launched piggyback with: ITOS-G (NOAA 4) and the Spanish INTASAT
Launch location: Vandenberg Air Force Base, Lompoc, California
Weight: 28.6 kg
Orbit: 1444 x 1459 km
Inclination: Inclination 101.7 degrees
Period:
Size: Octahedral shaped 360 mm high and 424 mm in diameter
Modes: A, B, and C
Beacons:
29.502 MHz (200 mw) Used in conjunction with Mode A
145.972 MHz (200 mw) Used in conjunction with Mode B and C [low power Mode B]
435.100 MHz (intermittent problem -- switches between 400 mw and 10 mw)
2304.1 MHz (40 mw) Must be commanded on. Auto off after 15 minutes. Requires STA to operate.
Transponder I: Mode A
Type: linear, non-inverting
Uplink: 145.850 - 145.950 MHz
Downlink: 29.400 - 29.500 MHz
Translation Equation:
Downlink (MHz) = Uplink (MHz) - 116.450 MHz +/- Doppler
Output Power: 1.3 watts PEP (start of life)
Transponder II: Mode B and Mode C (low power)
Type: linear, inverting
Uplink: 432.125 - 432.175 MHz *See Note
Downlink: 145.975 - 145.925 MHz
Translation Equation:
Downlink (MHz) = 578.100 - uplink (MHz) +/- Doppler
Output Power: 8 watts PEP Mode B (start of life), 2.5 watts PEP Mode C
Telemetry:
Similar to AO-6. Built by a multi-national (German, Canadian, United States, and Australian) team of radio amateurs under the direction of AMSAT-NA. It carried Mode A (145.850-950 MHz uplink and 29.400-500 MHz downlink) and Mode B (432.180-120 MHz uplink and 145.920-980 MHz downlink (inverted)) linear transponders and 29.500 and 145.700 MHz beacons. The 2304.1 MHz was never turned on because of international treaty constraints.
Four radio masts mounted at 90 degree intervals on the base and two experimental repeater systems provided store-and-forward for morse and teletype messages (Codestore) as it orbited around the world. The Mode-B transponder was designed and build by Karl Meinzer, DJ4ZC and Werner Haas, DJ5KQ. The Mode-B transponder was the first using "HELAPS" (High Efficient Linear Amplification by Parametric Synthesis) technology was developed by Dr. Karl Meinzer as part of his Ph.D.
Additional information about AO-7 was printed in the September 1974 AMSAT Newsletter [slashdot.org].
AO-7 was operational for 6.5 years until a battery failure ceased operation in mid 1981. Then on June 21, 2002, Pat Gowen, G3IOR, posted this email message on AMSAT-BB:
Jan King, W3GEY, the AMSAT-OSCAR-7 Project Manager commented:
The full text of W3GEY's comments are here [slashdot.org].
Initial reports on the health of AO-7 are:
References
[slashdot.org] Return to Satellite Summary [slashdot.org]
Credits: Thanks G3IOR, WD0E, W3GEY, DB2OS, W3IWI.
Last update June 23, 2002 - N7HPR [mailto]
Re:Seems Slashdotted... (Score:1)
Well nuts, my Intel P4 is fater than that!
Re:Seems Slashdotted... (Score:1)
How does this work? (Score:1, Offtopic)
You'll have to forgive me, but I don't understand how SlashDot works. Both articles are in the "Science" section, under the "Space" topic. Why is one on the front page, and one not on the front page?
If the "Front Page" bit has nothing to do with the "Section" bit, why not just click the "Front Page" bit on the original story, instead of running two stories and fragmenting the comments? Aren't the comments valuable at all around here? Or do only the stories matter?
And, are "topics" orthogonal to "sections", or do the sections partition the topics, or what? What the hell is a topic, and why does each story only seem to have one?
Re:How does this work? (Score:1)
daytime use? (Score:2)
Re:daytime use? (Score:2)
Re:daytime use? (Score:1)
Re:daytime use? (Score:2)
Re:daytime use? (Score:1)
Re:daytime use? (Score:2)
Re:daytime use? (Score:1)
daytime anywhere. check satscape (www.satscape.co.uk) or heavens abobe (www.heavens-above.com) (among others) for satellite pass predictions for your particular cordinates.
Only place that matters?
You got to be kidding, right? Last time I recall, Earth was the only place that matter. For all of us (not only US, got the joke ;)
Re:daytime use? (Score:1)
Um, NO! (Score:4, Informative)
NO amateur satellites are there - The cost of launch is simply too prohibitive, and it raises groundstation equipment requirements too much.
The highest-flying amateur satellites (AO-10 and AO-40) are in highly elliptical orbits. Almost all others are in various low-earth orbits, circling the Earth every 80-100 minutes.
Do a freshmeat search for "predict" - It's an excellent satellite position prediction package for Linux.
Oh, and BTW. (Score:3, Informative)
AO-10 and AO-40 require relatively high-gain antennas (Yagis or dishes) and tracking systems to use them.
Some of the LEO satallites, especially the FM repeater satellite UO-14 (AO-27 is the same type/orbit but runs lower downlink power and isn't on 24/7) are acessible using a $200-300 dual-band handheld with a good whip antenna. Spend $60-70 for an Arrow antenna and you can get EXCELLENT results.
2000+ mile range with 5 watts and an entirely handheld setup - Talk about cool.
From Ithaca, NY, I have heard a station in Mexico and one in Edmonton, AB on a regular basis via UO-14. I've even heard California.
Andy, N2YPH
I need to replace my antenna... The old one sucked and broke. Only $10 though.
Shortwave radio? (Score:1)
It may not be so reliable or clear, but I can receive stations from North Carolina in London.
Re:Shortwave radio? (Score:2)
Secondly, HF propagation is susceptible to the whims of the Sun.
Thirdly, you can achieve higher bandwidths at satellite frequencies.
Lastly, and now that I think about, most importantly, is one of the reasons I pointed out earlier - At VHF/UHF, antennas are much smaller - You can get incredible range out of a tiny package, whereas with HF you need comparatively huge antennas.
Re:Um, NO! (Score:1)
Do a freshmeat search for "predict" - It's an excellent satellite position prediction package for Linux.
"Predict" can be found at
ftp://ftp.amsat.org/amsat/software/Linux/predic
Re:Um, NO! (Score:1)
apt-get install predict
installs it.
As a ham interested in satellite work, I find this to be quite interesting. Ever since I 'upgraded' to Linux, I've had no satellite tracking software. (Although I never really used it under Windows, so I hadn't even noticed anything missing.)
planettrack is fun. (Score:2)
It has a really nice socket interface with some good Perl example code, which I was hoping to use to automatically do Doppler correction for a Kenwood TS-790 (I think that was the model... Either way, it was a dual-band all-mode VHF/UHF rig W2CXM bought for satellite work - But I graduated so no more TS-790...)
It has built-in support for a few automatic antenna tracking systems, and for the rest there's the socket interface.
Re:daytime use? (Score:1)
Re:daytime use? (Score:1)
Re:daytime use? (Score:2, Informative)
"We're Back From the Dead" (Score:1)
What about the SPOT satellites? (Score:2)
The SPOT 3 satellite died in orbit on November 1996, way before its SPOT 4 successor was launched (March 1998). Meanwhile, to be able to continue their business [spotimage.fr], the owners of the SPOT network more or less resurrected SPOT 1, which was launched on February 1986.
Sadly, I don't remember or even knew all the details, so I would be glad if someone could step up to provide some more.
Related, but slightly OT: last November, a 50 Mbps laser link between SPOT 4 orbiting at 832 km and another satellite (Artemis) orbiting at 31,000 km was successfully tested [spotimage.fr]. This allows ground stations to keep contact with SPOT 4 for a much longer time, and avoids having to rely too much on the onboard storage systems. Now, that's high-tech.
Back from the DEAD.... (Score:1, Funny)
It's Alive!!
It's Alive!!
_______________________________________________
Re:Back from the DEAD.... (Score:2)
Re:Back from the DEAD.... (Score:1)
Grrrrr.... argh..... solid transisitors.... must have... transistors.... argh....
Scary! (Score:1)
and for its next incredible feet (Score:1)
Illegal to contact dead satellites (Score:5, Interesting)
So, basically what they are telling us is that it is illegal to do something that was legal when it originally came out, (which is what the government usually does). We can't use the satellite for it's original purpose.
In other words, it's illegal to talk to previously dead satellites.
Re:Illegal to contact dead satellites (Score:1)
It is now illegal for a amateur to transmit on that frequency to that satellite as the frequency has been reassigned to other uses (not Amateur Radio).
Re:Illegal to contact dead satellites (Score:2)
Another thing 432.1 is a legal frequency for us hams to transmit on in the US - and its a well known fact that the so called band plan is a gentlemens agreement (in the same since lsb is used for bands below 20 meters) in other words its not a law. 432.1 is in the weak signal portion of the 70cm band - personally I've always considered some satellite work weak signal.
Re:Illegal to contact dead satellites (Score:5, Informative)
While I doubt enforcement efforts would be made against the curious, it is in AMSAT's best interest not to encourage use of this bird. AMSAT is generally highly respected by the various administrations around the globe and won't jeopardrise their reputation by encouraging something that may be considered illegal by some.
I suggest you put the interests of Amateur Radio ahead of your own. If it can be shown that amateurs won't even obey the rules within their service then our chances for many significant gains at WRC 2003 and beyond will diminish greatly.
Not quite. (Score:5, Informative)
Illegal or not, most amateurs will not transmit there as it's reserved for weak-signal work, and who knows, they might want to run moonbounce themselves sometime in the future.
If 432.1 were in repeater or FM simplex territory, no one would care.
Either way - The satellite has two uplinks and this only affects one of them.
If you want to track Oscar 7... (Score:5, Informative)
AO-07
1 07530U 74089B 02167.52996888 -.00000029 00000-0 10000-3 0 935
2 07530 101.7955 212.2077 0012102 193.4285 166.6467 12.53558681262239
Also, you may see it's orbit here [heavens-above.com]
Re:If you want to track Oscar 7... (Score:1)
Behold.... (Score:1)
Taken over? (Score:1)
One can only wonder what messages they intend to send, and if they are listening for us to respond.
Too bad it's not a Microsoft satellite (Score:4, Funny)
Re:Too bad it's not a Microsoft satellite (Score:2)
Oh come on -- if it *were* a Microsoft satellite then the hAkre d00dzE would have already taken it over and used it to knock all the government-owned satellites out of orbit
Microsoft would have responded by issuing a "Trustworthy Orbiting" initiative and advised everyone to upgrade to "Satellite XP" -- but only if they're prepare to sign the new licensing agreement that includes something about ownership of your firstborn child.
Oh no! (Score:2)
You came across a beacon transmitting S CLUB 7 ?!?!
NO! SHUT THEM ALL DOWN! HURRY! Listen to them, R2... they're dying in there... We're all doomed....
Slashdotting a satellite (Score:5, Funny)
I find it amazing that a hunk of metal orbiting our planet for longer than I have been alive still functions, yet a modern webserver with possibly more advanced components succombs to slashdotting in minutes.
Solution: Build webservers out of 1974 satellite components. (Although that large gap of 20 years downtime may pose a problem.)
Re:Slashdotting a satellite (Score:2)
Re:Slashdotting a satellite (Score:3, Funny)
equipment ? (Score:1)
Re:equipment ? (Score:2)
Re:equipment ? (Score:4, Informative)
See www.arrl.org/hamradio.html [arrl.org]
for a general overview of Ham radio.
Then you can set up your radios and antennas.
A page was referenced, but posted by an AC so its only at 0. Here's the link again: www.qsl.net/vk3jed/1st_sat.html [qsl.net]
As for books, look around the ARRL site, they have a vast collection of good books.
-----------
73 de K6LNX
Re:equipment ? (Score:1)
Re:equipment ? (Score:1)
Anyhoo, you do need at least a no-code (morse code) license to use a ham radio, and that basic license gets you privlidges above 50mhz. (6 meter).
Higher class licenses require a code test at 5wpm. You can upgrade a tech license to a tech plus code if you wish.
Definately check out www.arrl.org for a whole buncha information, or go pick up a book at any bookstore or Radio Shack.
V'Ger arrives at Earth and signals its Creator. (Score:1)
From Star Trek - The Movie
V'Ger arrives at Earth and signals its Creator.
When there is no response, V'Ger blasts energy bolts at the planet in an attempt to rid it of all its carbon infestations.
First contact... (Score:5, Funny)
Radio technician: Sir! We're getting a signal from a satellite that's...
Commander: That's what, soldier?
Radio technician: *gulp* Well, sir, there's those stories about ghost satellites... I mean, we always thought they were just, you know, made up...
Commander: What the hell are you talking about, son? Spit it out!
Radio technician: I better just play the transmission for you, sir.
Satellite: BRRAIIINNNSSSS....
Radio technician: It's... it's a zombie satellite, sir. Undead.
Commander: (quietly) God help us all. (to technician) Get me the Pentagon!
Radio technician: Uh... sir... the phone lines are dead! (suddenly the power goes out)
Commander: Oh. My. God. (satellite bursts out of a closet and eats the commander)
In A.D. 2101 (Score:5, Funny)
Mechanic: Somebody set up us the bomb.
Operator: We get signal.
Captain: What !
Operator: Main screen turn on.
Captain: It's You !!
Satellite: How are you gentlemen !!
Satellite: All your base are belong to us.
Satellite: You are on the way to destruction.
Captain: What you say !!
Satellite: You have no chance to survive make your time.
Satellite: HA HA HA HA
Captain: Take off every 'zig' !!
Captain: You know what you doing.
Captain: Move 'zig'.
Captain: For great justice.
August 4, 1977 (Score:1)
... And Oscar-7 fights back.
Re:First contact... (Score:2)
Messages from Outer Space (Score:2, Funny)
In 2002 A.D. (Score:1)
What !!
Even more mirrors (Score:2)
yes, clearly worth the front page (Score:2)
What I don't get (O/T) (Score:1)
..and still nobody has written up the spidergoat story [news.com.au]...
Why would NASA launch it?????????? (Score:1)
Did we have a budget surplus or something?
Re:Why would NASA launch it?????????? (Score:1)
Its very rare that just an amateur satellite gets launched on its own. They're usually small enough to be used for ballast, or they "tag along" with one that has extra room on the rocket.
Advanced math? Trig, calculus, orbital mechanics.. (Score:5, Funny)
Subtraction.
-
Believe (Score:1)
Hmmmm... (Score:2)
After 20 years... (Score:1)
Seriously though... don't they (= whoever puts the sat up there) have a cleanup-plan to get the things back down on earth when they are retired? I know it's very, very expensive, but (1) so is the satellite, and (2) I generally wonder about the likelyhood of problems if everyone leaves their electronic junk up there, collisions by deviation of orbit and interference and things like that...
After all, it can't be that hard to just crash it in the atmosphere and let it go up in smoke, if they want to get rid of it. Then at least we won't hear about some spaceship or newer satellite hitting one of those old piles of junk in 20 years, or some other fun thing happening (more likely every day) to these expensive toys.
Re:After 20 years... (Score:1)
As to why it wasn't deorbited, I don't think it had a kick motor as it was intended to be placed in a LEO and remain there. Also, launch opportunities at the time dictated great restraints on size and weight so the focus was on radio capability. Also, let's not forget that the battery failure AO-7 suffered would have precluded any possibility to command it to de-orbit and most folks would not have wanted the liability associated with the thing de-orbiting itself at random.
At some point a method of cleanup in space will probably be necessary. While not active for better than 20 years, AO-7 was still tracked and you can bet that anything lauched today still takes its orbit into account so a crash won't happen, unless something goes drastically wrong.
One day AO-7 will return to Earth due to the natural forces of orbital decay. In the mean time I think this is a fascinating story and is worth following.
So... (Score:2, Funny)
There's hope for my marriage, after all.
it's y2k (Score:1)
Did anyone check (Score:1)
Re:Oh, gee. (Score:1)
Re:worth the front page? (Score:1)
Ain't gonna happen. (Score:2)
802.11 is just not suited well for space-based communications anyway...