NASA Revamps Historic 4-Million-kg Mars Antenna 66
coondoggie writes NASA is working on some difficult renovations to reinvigorate its 70-meter-wide 'Mars antenna.' The antenna, a key cog in NASA's Deep Space Network, needs about $1.25M worth of what NASA calls major, delicate surgery. The revamp calls for lifting the antenna — about 4 million kilograms of finely tuned scientific instruments — to a height of about 5 millimeters so workers can replace the steel runner, walls and supporting grout."
In other news, Apple is happy. (Score:5, Funny)
Antenna problems are not specific to the iphone.
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The revamp calls for lifting the antenna [...] to a height of about 5 millimeters
They should really avoid holding it that way.
Okay! I hadn't made used the joke yet! It can die now.
Re:In other news, Apple is happy. (Score:5, Funny)
I hadn't made used the joke yet!.
In Soviet Russia, joke hadn't made used YOU!
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Man, that joke was so clever and insightful, did you RTFA to come up with it?
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That was a really stupid quote too:
X will get us better search rankings. But x has nothing to do with this story, which involves...
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Johnny had a tip that the science examination would have a question about penguins, so he memorized every little fact about them. Come the exam day, there was only one question: "write all you know about the Amazon region"
Johnny wrote: ... etc, etc "
"The Amazon is a region where there are no penguins, which are aquatic, flightless birds of the order Sphenisciformes, family Spheniscidae,
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"Man, that joke was so clever and insightful, did you RTFA to come up with it?"
No, it was plainly and clearly tattooed across your mother's wide-load ass.
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houston, we have a solution (Score:2)
iPhone (Score:3, Insightful)
What the hell does this have to do with the iPhone and its antenna?
Dear Journalists,
Referencing anything to do with the iPhone in an attempt to sound hip and relevant just makes you look stupid.
Signed,
Blhack
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The Gordon Freeman Method (Score:3, Insightful)
Might I suggest a crowbar. That's what I used for all my scientific research in Half Life. You could probably use one to lift the thing up a few millimeters.
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Just Goldstone is Being Worked On? (Score:4, Insightful)
So they're only revamping one out of three of the 70-m DSN antennae? I hope that they plan to do Canberra and Madrid, too. You need all three of them to get good 24-hr coverage. Actually, we need more of them. There are just too many missions needing 70-m time to downlink data right now. And nothing was sadder than watching good observations (which were otherwise totally possible) get killed because some other mission had priority on the big dishes.
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Maybe only this one is experiencing the problems with the bearing surface at this point.
I agree we need more antennae for this work, especially with the increase in probes that NASA is supposed to be making.
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Entirely possible, yep. It would have been nice if the story had commented, though.
Re:Just Goldstone is Being Worked On? (Score:4, Insightful)
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You're still paying the cost for the launch. To simply put something into orbit is around $10,000/kg. That's Earth orbit, getting it to Saturn is even more expensive. I'm pretty sure that you'd be lucky to do it for under a few tens of millions of dollars, probably more in the hundreds.
Even if you did it, you still have to downlink the data to Earth at some point. And now you're still contending for the dishes. Yes, you can be more flexible as to when you downlink and you could even use a 35-m dish (wh
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There is a reason the antenna needs to be that size, and there's a reason they are on earth...
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http://www.wired.com/wiredscience/2010/06/solar-sail-deployment/ [wired.com]
Hard? Yes. Impossible? No.
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A solar sail isn't an antenna. An antenna has to be much more rigid in order to accurately reflect the radio waves to the receiver. It's apples and oranges.
In any case, you're talking about an 8-m sail, a far cry from a 70-m dish.
And no one said it was impossible. But possible and smart are far from identical concepts.
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The problem is that the equipment required to receive and process the faint signals involved isn't trivial, neither is the antenna required. It would pretty much be beyond the current state-of-the-art.
No, ins
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http://en.wikipedia.org/wiki/Tracking_and_Data_Relay_Satellite [wikipedia.org]
I can't imagine the gear is *that* much different than NASA's other in-space relay satellites, or even Iridium satellites for that matter (considering that they're not just dumb pipes).
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"Working solo, TDRS-1 provided more communication coverage, in support of the September 1983 Shuttle mission, than the entire network of NASA tracking stations had provided in all previous Shuttle missions."
While not a rocket scientist, I do have an EE degree and have worked with quite a bit of radio equipment. I'm sure it would be possible for TDRS satellites to handle store and forward if it was thought about during the design phase.
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Yes, it's considerably different - DSN is much more sensitive (because of the lower incoming signal strength), with considerably higher pointing accuracy and much more signal processing capability (to pick up said faint signals from the background noise). DSN also has far more transmitting power in order to ensure sufficient signal strength at the receiving end.
Iridium and TDRS aren't dumb pipes, no. But they're not anywhere near the class or capability of the the DSN antennas either.
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start having craft in orbit
Craft in orbit where?
If you mean craft in orbit arround earth the trouble is it's hard to put huge antennas in space. In general antenna gain is related to physical size and antenna gain is important for long distance work because (unlike amplifier gain) it makes the antenna pick up more signal without making it pick up more noise (assuming noise is equal in all directions)
If you mean craft in orbit around the target planet then you still need to downlink the data to a big antenna
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We're winding down the big fun space program for a while, so I would imagine a lot of really neat stuff is going to rust away.
Hell, we are so pathetic that we will be riding bitch with the Ruskies into space for a while here.
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There are currently no plans that I know of to scale back the unmanned space program. (The opposite, if anything.) So your sort of grousing in the wrong place.
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Can't we simply call it 4 Gigagrams?
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Just don't break the other DSN dishes while Goldstone is being worked on...
"What's going on??? Tracking station forty three, Canberra, come in, Canberra! Tracking station sixty three, can you hear me, Madrid? Can anybody hear me? Come in, come in!"
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Robledo (Madrid) was done a few years back - they had to replace the bearings IIRC. In fact it was largely due to the work on DSS63 at Robledo that NASA started to look at the DSS14.
We had to do this with a 7 million kg antenna (Score:5, Interesting)
We had to go through this with a 7 million kilogram antenna at the Green Bank Telescope:
http://www.gb.nrao.edu/gbt/track.shtml [nrao.edu]
The original azimuth track wore down too quickly, apparently due to faulty materials, workmanship, etc. You can see photos of the scope rotating out of the way sections of the track could be replaced at a time.
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You use a track on the GBT, but the 70 meters use a large horizontal bearing. These are Apollo era antennae, old enough that they were originally pointed with a internal ha-dec antenna model as an analogue computer (as was the old 140 foot at Greenbank). They really need to be replaced.
Happened where I work (Score:5, Informative)
I work at a commercial communications satellite company and we have an old earth station with a 32 meter antenna that's rarely used today, but we still keep it as a backup. Actually, the cost of bringing it down is more than the scrap value, so it's mostly just standing there.
What nobody realized was that the antenna had been tracking a single geostationary satellite for decades, so it was moving very slightly around one position. Geostationary satellites aren't exactly stationary, but close, there's a slight movement around a central point.
The result was that, when they tried to point the antenna to a different satellite they found that the circular steel rail had been cold-rolled over the years so each wheel was sitting in a small valley in the rail. The azimuth motor didn't have enough torque to get off that valley and point the antenna to a different position, although there was no problem in tracking a satellite in the old position.
The solution was to jack up the whole antenna, cut off a section of rail and weld a new piece of rail beneath each wheel. The trickiest part was grinding the rail so that the new parts were perfectly aligned.
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Just to mention another interesting detail, this earth station [google.com] I mentioned has Wernher von Braun's signature in the visitor's book.
4 million kilograms (Score:5, Funny)
4 million kilograms; why can't we just use metric as it was intended?
4 Gigagrams.
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what is with this metric stuff? This is NASA, right? 'million kilograms' 'meter-wide'?
why didnt they just list the $1.25M cost in EUROS?
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Ahem [wikipedia.org]...
_AC
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4 million kilograms; why can't we just use metric as it was intended?
4 Gigagrams.
4 nano hellagrams
Re:4 million kilograms (Score:4, Funny)
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1.5 Your Moms?
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This is NASA we're talking about (Score:2)
Better stick to the FFF system [wikipedia.org] or they'll get confused.
That would make it about 100,000 firkins.
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4 million kilograms? (Score:1, Redundant)
Shouldn't that be 4 gigagrams?
Wind (Score:2)
have carefully lifted several million pounds of delicate scientific instruments about five millimeters (0.2 inches) and transferred the weight of the antenna to temporary supporting legs.
A crucial missing part of the summary. I was wondering how they prevented the thing from digging or otherwise tipping back due to the wind.
Not the first time (Score:4, Informative)
This is not the first time that they have replaced the bearing on the 70 meter antennae. I believe that for DSS 14 (AKA Goldstone Mars) this would be the 3rd bearing change.
These 70 meters are reaching their end of life, and almost certainly will be replaced with arrays of smaller (but still large) antenna within the decade.
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I believe that the last time they lifted it clear of the bearing surface by 2 to 3 METERS!
By the way, the others were built later with an improved az bearing.
bad reporting, where is the dish? (Score:1)
Why does Slashdot keep linking to this writer? I had to actually go to the NASA web site to determine that the dish was at Goldstone. How hard is it to write a complete story?
Can't they just put a giant bumper around it? (Score:1)
Ask Steve Jobs, they're pretending that's a real solution.
Slashdot pizza party! (Score:1)
Everyone lift, swap it all out, bada bing bada boom and fuhgedaboutit!
5mm? (Score:2)
This is where I show my complete lack of understanding on this subject. They are lifting the antenna 5 milimeters? Who are they hiring to work on this, Smurfs and Fraggles? I don't see how raising an antenna by 5mm is going to give a human any significantly larger area to work with.
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