23
votes
What makes time on the DSN so expensive?
I realize that the equipment is awfully expensive and probably takes a small army of people to maintain, but that still boils down to a few thousand dollars per hour of radio time ...
The cost in ...
- 73.2k
23
votes
Accepted
What happened to Voyager 2's tracking loop capacitor? How did it get damaged? What is it for? What's a tracking loop anyway?
On April 6, 1978, a fault-protection algorithm onboard Voyager 2 automatically switched from the prime to backup receiver. However, the backup receiver's tracking-loop capacitor3 was found to have ...
- 178k
19
votes
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Why was Canberra able to listen to Voyager 2 but not talk to it?
As per the March 4 JPL News story, only DSS43 has the right S-band transmitter, enough power and is in the right hemisphere to talk to Voyager:
Moreover, a special S-band transmitter is required to ...
- 2,506
18
votes
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Deep Space Network time budgets per spacecraft - is such statistics available?
I submitted a FOIA request for every contact made by the DSN from 2010 onward (I received contacts from Jan 1, 2010, till Sep 1, 2018)
Here is a summary of the contact time for all 86 Missions ...
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18
votes
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How did NASA's Deep Space Network encode and broadcast music to Opportunity?
TLDR; They didn't.
I submitted NASA FOIA request 19-JPL-F-00295 asking about this, and they responded:
[...] JPL confirmed that the song was not radiated to the spacecraft. It was just played on ...
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16
votes
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What is the numbering system used for the DSN dishes?
I found a sort of explanation in "Uplink-Downlink" the NASA history of the DSN.
The first digit [range of digits, really, see the table] gives the geographical area.
The second digit gives the ...
- 178k
14
votes
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Is NASA's Deep Space Network possibly a backup link for China's Zhurong rover?
I am almost certain the answer is not just no but is on the level of the underworld freezing over level of no. Congress has forbidden NASA from providing any support for China's space program.
Shortly ...
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13
votes
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Would an orbital Deep Space Network be more efficient?
Let's think about what it would take to do what you're suggesting.
The DSN uses some pretty large antennas, so you're talking about putting a 70 meter dish like this (and a power supply to run it) in ...
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13
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How will the closure of the Arecibo dish impact deep space communications?
There is some indirect evidence that Arecibo's loss has already impacted communication with some of the deep space probes.
NASA's official statement on Arecibo says this:
NASA’s Goldstone Observatory ...
- 47.7k
12
votes
Why doesn't thermal radio emission from a DSN "hot dish" completely swamp the benefits of a cold LNA?
Because the dish isn't a black body. At RF it has a very low emissivity, hence the name "reflector".
- 10.1k
12
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Why doesn't thermal radio emission from a DSN "hot dish" completely swamp the benefits of a cold LNA?
When discussing radio antennae, radio astronomers usually describe things in terms of temperatures. We can convert between power and temperature simply by multiplying (or dividing) by Boltzmann's ...
- 5,626
12
votes
What is the numbering system used for the DSN dishes?
Looking at the history of DSN on Wikipedia, it appears that the tens-place digit originally was allocated to identify the region or site, and within a region/site the dishes were numbered sequentially ...
- 167k
11
votes
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Has DSS-43 ever been used in high power mode (>>20 kW) for an emergency situation?
Edit: I modified the answer in 2022, added new data on communications with Voyager.
The sort of emergency that would require this power level is rare. You're looking at events where a remote (deep-...
- 126k
11
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If the ESA has its own deep space network, why does it use NASA's?
The DSN is used alongside ESTRACK. For Rosetta, for example:
NASA’s DSN network has provided continuing, routine support to the Rosetta mission since the start of the mission (see “Tracking the ...
- 126k
10
votes
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Why does the word "Mars" shows up in google maps when viewing the Goldstone DSN complex?
The answer is in the Wikipedia article:
The DSS 14, "Mars" telescope
So it's the name for one of the antennas of the Goldstone complex.
Here are the antennas and their names:
- 126k
10
votes
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Understanding the information contained in the Deep Space Network XML data?
It took me several days observing data from DSN. Here is my analysis of the fields from the XML data files.
station
name: ...
- 47.7k
9
votes
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Is it possible for the Deep Space Network to use MSPA and antenna arraying simultaneously?
If you have three apertures pointed at Mars, then you would array all three for both orbiters. There would be no point in throwing away the signal of one of the orbiters on any of the antennas. You ...
- 58.5k
9
votes
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Is there any publicly available logging, or "Wayback Machine" for DSN Now activity?
I have been looking into this as well. As I have been told by one NASA employee, there is no easy way to get old data, but there is a way if you're willing to go through lots of data. NASA saves old <...
- 206
9
votes
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Why does NASA use higher frequencies even though they have worse Free Space Path Loss (FSPL)?
The wavelength dependence of the definition of free space path loss (FSPL) is an artifact of the way the receiver's antenna gain is defined in the same link budget calculation. It's referenced to an ...
- 148k
8
votes
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Why does DSN sometimes uses two dishes at the same time to receive Voyager-1?
If you look at the "more detail" section of the DSN status web page, you'll see that 25 and 26 are operating in "array mode". With two antennas receiving, twice as much incoming signal is being caught,...
- 167k
7
votes
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Is Deep Space Network (DSN) technology sufficient for a crewed Mars mission?
The current DSN could be enough, depending on what the crewed mission requirements are. If you just want to communicate with voice and moderate-rate engineering and science data, then sure. If your ...
- 58.5k
7
votes
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How do we track the exact location of the spacecraft which is millions or billions of miles away from us?
How do we track the exact location of the spacecraft which is millions or billions of miles away from us?
We don't track the exact location of spacecraft. There are always errors in measurements, ...
- 73.2k
7
votes
Why is the operating temperature for the Voyagers' receiver noise calculation about 1550K?
Voyager's antenna is pointed at the sun. The transmitter on earth must be powerful enough to stand out against the sun, at least within the (very limited) receiver bandwith. All other sources of noise ...
- 1,172
7
votes
Has Same Beam Interference (SBI) been used or at least tested at Mars? Are there plans to use it in the next few years?
This seems to be reported by NASA - NTRS in a document on Orbiter-Orbiter And Orbiter-Lander Tracking Using Same-Beam Interferometry [Published 1992 Acquired 2013]:
Two spacecraft orbiting Mars will ...
- 1,673
6
votes
What type of comms traffic for deep-space missions needs to be prioritized?
Deep space communications are intermittent: the communications link only exists when a dish antenna is aimed at the spacecraft. If a spacecraft has an emergency, nobody knows about it until the next ...
- 126k
6
votes
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Why doesn't thermal radio emission from a DSN "hot dish" completely swamp the benefits of a cold LNA?
Planck → Rayleigh-Jeans:
I'm not talking about the infrared radiation from the telescope. That is probably removed by managing line-of-sight within the cryogenic waveguide, or a low-temperature ...
- 148k
6
votes
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How can the data rate be increased in noisy outer space?
Yes we have solutions:
Higher-power transmitter
More directional emitting antenna (by increasing the frequency for instance)
Larger receiving antenna
Less noisy electronics
Electronics with less ...
- 1,298
6
votes
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How is long-distance optical communications coming along in space?
The European Data Relay System has recently begun testing. It's for getting data from Earth orbiting satellites down to the ground quickly, without waiting for the satellite to pass over a base ...
- 5,178
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