Questions tagged [deep-space-network]

Deep Space Network is a series of communication antennas around the world used for communication with deep space spacecraft.

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217 views

"Received power" on NASA's DSN web page

Out of curiosity, the "received power" shown for a spacecraft on NASA's "DSN now" web page 1 - is that at the receiver, or at the antenna? I'm looking at one of the antennas now ...
5 votes
0 answers
457 views

Did any of Voyagers' receivers' front ends take advantage of the "cold of space" to lower noise? (communications or radio/plasma science receivers)

Most of the Voyagers' electronics are kept warm by electrical heaters powered by their RTG's, and presumably protected by some amount of insulation from the "cold of space" which means loss ...
9 votes
1 answer
447 views

Tradeoffs between using two 34 m and one 70 m Deep Space Network dish?

Discussion at this answer to Why does DSN sometimes uses two dishes at the same time to receive Voyager-1? include the possibility that in some cases it would be preferable to use two 34 meter DSN ...
7 votes
1 answer
240 views

Has Same Beam Interference (SBI) been used or at least tested at Mars? Are there plans to use it in the next few years?

Question: Has Same Beam Interference (SBI) been used or at least tested at Mars? Are there plans to use it in the next few years? Considering that there's already some orbiters and landers and rovers ...
3 votes
0 answers
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Understanding shape of DSN's 'kinky uplink protocol' keeping frequency in coherent transponder's optimum bandpass?

This tweet by deep space SDR enthusiast and amateur radio operator Edgar Kaiser @df2mz shows a squiggly tone from MRO. Mars Reconnaiscance Orbiter (MRO) X-band downlink. The signal shows this ...
7 votes
1 answer
232 views

Why are modern satellite ground station and deep space communications dishes with secondary mirrors almost always Cassegrain?

The simplest dish antennas have a concave reflector and their feed horns at the primary focus which is "up in the air". That has several inconveniences, it's hard to go up there to do any ...
0 votes
1 answer
107 views

How does a spacecraft know what communication network to use?

Spacecrafts use different networks like TDRSS, DSN, ... to accomplish uplink/downlink. But how does it know which one to use during the mission? At what point does it find TDRSS more suitable than DSN ...
4 votes
1 answer
225 views

How do landers communicate with Earth when facing away?

For example, how do the Mars landers communicate when Mars is between them and the Earth? The MRO is in a low orbit; does it store and forward data?
9 votes
1 answer
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How does one test Ground Segment communications with, and "downlink" data from a spacecraft that's still on the ground?

NASA News item Ground Segment Testing a Success for NASA’s James Webb Space Telescope says: Testing teams have successfully completed a critical milestone focused on demonstrating that NASA’s James ...
6 votes
3 answers
819 views

Why is the operating temperature for the Voyagers' receiver noise calculation about 1550K?

In line 10 of Table 5.2 of DESCANSO IV - Voyager Telecommunications it shows a value of the uplink receiver noise spectral density of -166.7 dBm/Hz, which is 196.7 dBW/Hz which is 2.1E-20 Watts/Hz = $...
4 votes
1 answer
225 views

How many solar system bodies have had coherent radio transponders?

A transponder amplifies, (often) frequency-shifts, and rebroadcasts a received signal. Old-style telephone and TV distribution satellites in GEO used simple transponders to rebroadcast the uplinked ...
19 votes
1 answer
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Has DSS-43 ever been used in high power mode (>>20 kW) for an emergency situation?

This answer notes that while most Deep Space Network transmitters are 20 kW of power or less, one dish (DSS-43 in Canberra) is equipped with a transmitter capable of 400 kW. As described in 101, 70-m ...
3 votes
1 answer
296 views

What is a Beam Waveguide dish and why do deep space communications stations use them?

NASA Spaceflight.com's Deep Space Network upgrades and new antennas increase vital communication capabilities says: NASA’s Deep Space Network, commonly referred to as the DSN, has welcomed a new dish,...
4 votes
1 answer
177 views

How does a third DSN station serves as a “relay” to tie-together observations by two other stations doing VLBI?

Section 2.1 of the DESCANSO document 211 Wideband Very-Long Baseline Interferometry (from here, found here) says: The precision of a VLBI measurement improves with the length of the baseline. The ...
4 votes
0 answers
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Currently, how many communications channels can a single DSN dish maintain at the same time? Are there plans to increase this in the future?

DSN NOW screenshot 2021-07-10 at 07:14 UTC DSN NOW screenshot 2021-07-10 at 09:48 UTC The screen shots show Canberra's Dish 35 simultaneously transmitting and receiving, and above it is written MRO, ...
12 votes
2 answers
630 views

Can ESA control the two Voyager spacecraft?

This is such a dumb question. There are many space organizations. Let's take ESA for this case. Given the two Voyager spacecraft are transmitting a weak radio signal to the Earth, can ESA command and ...
2 votes
1 answer
210 views

How high is the first Deep Space Atomic Clock orbiting? Does it receive radiation equivalent to that in deep space?

The Livescience article NASA's Tiny New Atomic Clock Could Let Spacecraft Drive Themselves in Deep Space says: But the radiation still changes the way the electronics operate. And those changes ...
18 votes
1 answer
3k views

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 23-Aug-2021 Voyager 2 tweeted: DSN antenna DSS-43 at @CanberraDSN is starting a 300 min listen to hear the echo of a command tone sent up to me 35 hours ago. This will define the "Best Lock ...
2 votes
1 answer
202 views

Just how raw is the rawest signal data that the Deep Space Network routinely records for safety reasons?

When we watch videos of some Spacecraft landing there's a big screen with real-time plots of the data coming from the Deep Space Network's antennas. Presumably the information is recorded in fairly ...
4 votes
1 answer
503 views

Is delay-doppler radar imaging of NEO asteroids possible only if it spins fast enough?

Emily Lakdawalla's blog on the Planetary Society's page explains some of the basic principles in the delay-doppler radar imaging of asteroids, and other astronomical bodies by extension. Radar from a ...
6 votes
1 answer
334 views

What happened to the plan to build a DSN antenna array?

More than ten years ago there were plans to build large antenna arrays for DSN, about 400 antennas of 12m diameter. See these NASA papers 1, 2, 3, 4. What happened to these plans?
3 votes
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Was Dart antenna tested using a DSN antenna located in Australia?

So recently a tweet by a bot which tracks communications by the Deep Space Network stated that: DSS 43 receiving data from Double Asteroid Redirection Test at 312.5kb/s. IN LOCK IN LOCK 1 TURBO 11:11 ...
6 votes
1 answer
458 views

Does NASA's Deep Space Network sometimes listen to other space agencies' spacecraft "just for the heck of it" or other non-mission related reasons?

This answer mentions: It's well known that other countries routinely spy on each other (i.e. the NSA tapping of Angela Merkel's phone). NASA's Deep Space Network's space-related activities (like ...
4 votes
1 answer
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If the Voyagers' lowest playback speed is 7200 bits per second, how can it transmit to Earth at only 160 bps?

How to calculate data rate of Voyager 1? mention's Voyager's data rate is currently 160 bits per second, and clicking on a recent entry in the Voyager DSN Tracking Schedule on the Voyager Mission ...
7 votes
1 answer
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Will there be a command moratorium for Mars spacecraft again in 2021?

About every two years, Earth and Mars are on opposite sides of the Sun (a Mars-solar conjunction). Plasma expelled from the Sun can interfere with radio transmissions between Mars spacecraft and the ...
4 votes
2 answers
250 views

How does Deep Space Network's DSS-14 transmit radar and receive it at (almost) the same time? (monostatic radar)

@Hobbes' concise yet thorough answer to the question What are monostatic radar observations, and how will Deep Space Network's DSS-13 be used to observe asteroid 1999 WK4's flyby of Earth? tells us ...
12 votes
1 answer
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Is NASA's Deep Space Network possibly a backup link for China's Zhurong rover?

While the Tianwen-1 orbiter will dispense commands to the Zhurong rover, the Mars Express orbiter of the European Space Agency will serve as a backup. Wikipedia Since Mars Express normally ...
4 votes
0 answers
112 views

Why is the Deep Space Network now testing an asteroid redirection mission that hasn't launched yet?

The Double Asteroid Redirection Test is a planned demonstration of the ability of a spacecraft to impact into and redirect the path of an asteroid. The test is part of plans to develop a system to ...
6 votes
2 answers
989 views

Why does DSN sometimes uses two dishes at the same time to receive Voyager-1?

I just looked at the Deep Space Network site DSN Now at https://eyes.nasa.gov/dsn/dsn.html and I saw that both dish numbers 25 and 26 are receiving a 8.42 GHz downlink signal from Voyager 1. Both ...
3 votes
1 answer
279 views

Effective bandwidth for Mars rovers to Earth

I'm interested in what the effective bandwidth is for, in particular, the Curiosity and Perseverance rovers back to Earth. By 'effective' I mean 'averaged over a sufficiently long period', so at least ...
22 votes
1 answer
3k views

How hard is it to receive direct signals from vehicles on the surface of Mars, and has anyone other than the DSN done so?

Almost all communication from vehicles on the surface of Mars is relayed by spacecraft in orbit around Mars. However vehicles on the surface do communicate directly with Earth. This communication, ...
2 votes
1 answer
295 views

Will future deep space optical communications "ground stations" actually be in space, or on the ground?

Deep space communications ground stations are on the ground because their transmit and receive electronics alone is bulky and heavy, not to mention their 34 and 70 meter dish antennas! But those ...
0 votes
1 answer
211 views

How can the data rate be increased in noisy outer space?

What can we do to improve the data rate in outer space? I see that there are some noise sources that affect the signal quality between ground stations & deep space. As I've read so far in various ...
0 votes
1 answer
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What are monostatic radar observations, and how will Deep Space Network's DSS-13 be used to observe asteroid 1999 WK4's flyby of Earth?

NASA JPL page https://echo.jpl.nasa.gov/asteroids/1999KW4/1999KW4_planning.2019.html says of the radar observations during the close approach of asteroid 1994 KW4 (in part): Update on 2019 May 22: A ...
2 votes
2 answers
245 views

Why will radioastronomy telescopes be used to listen to InSight's entry into Mars' atmosphere instead of DSN?

The JPL News article How NASA Will Know When InSight Touches Down is interesting and worth a read. It says that during the atmospheric entry, descent and landing, the Mars InSight probe will be ...
27 votes
2 answers
1k views

How will the closure of the Arecibo dish impact deep space communications?

Earlier today, the U.S. National Science Foundation announced that it is decommissioning the Arecibo radio telescope. The 305 meter dish is famous for the 1974 message for extra-terrestrial ...
23 votes
1 answer
4k views

Why was Canberra able to listen to Voyager 2 but not talk to it?

The New York Times's When Voyager 2 Calls Home, Earth Soon Won’t Be Able to Answer explains that because Voyager 2's trajectory has taken it way below the ecliptic, of the three 70 meter dishes in the ...
8 votes
1 answer
821 views

If the ESA has its own deep space network, why does it use NASA's?

The European Space Agency has its own network for communicating for spacecraft in deep space, ESTRACK. It has stations distributed around the globe: Nonetheless, several ESA missions use NASA's Deep ...
2 votes
0 answers
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Is it common for the Deep Space Network to contact a TDRS satellite?

As I write this, one of the Madrid dishes of the Deep Space Network is in contact with TDRS satellite #13. I've never seen DSN contact a TDRS satellite before. I thought that system has its own ...
8 votes
1 answer
625 views

Autonomous Navigation for deep space missions

Autonomous navigation started in early phases of deep space exploration as a provision to achieve accuracy for planet/natural satellite targeting and approach, where radio tracking accuracies were low,...
2 votes
1 answer
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How are the velocity and range of a spacecraft measured from ground based stations?

How are the velocity and range of a spacecraft measured from ground based stations? For example we can go on NASA's website and look at the real time data for the mission status of their past ...
1 vote
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In terms of satellite networks What exactly are RTSWnet/AFSCN and CDAS (NEN, DSN as needed)? Are they like TDRS but for strictly military data?

Question: In terms of satellite networks What exactly are RTSWnet/AFSCN and CDAS (NEN, DSN as needed)? Are they like TDRS but for strictly military data? BACKGROUND: In this answer to Why Are EPIC/...
3 votes
1 answer
245 views

Exchange diameter for power in parabolic antenna

If I want to reduce the diameter of a satellite dish, how much power should I add to the transmitter? how is this formula? As I have already been informed a little in this other question I asked: X-...
6 votes
2 answers
408 views

How is long-distance optical communications coming along in space?

I remember there was a test of optical communication and some data transfer from lunar orbit to earth, and I think the ISS uploaded (or downloaded-up? which is correct here?) a movie from earth. In ...
1 vote
1 answer
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How can the download speed increase from space probes?

It always seems to be a genuine question that is How can we download data from far away probes in instant. When New Horizons reached Ultima Thule, it took us quite a few months to have a great picture ...
0 votes
1 answer
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What are the main sources of radio noise & interference limiting deep space data rates and availability?

Let's call "radio" anything electromagnetic below 300 GHz (1 millimeter), unless there is a compelling reason to do otherwise. The question How well can Voyager 1 separate Earth signals from Solar ...
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1 answer
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Will CHEOPS use DSN or ESA ground stations, or both?

The new ESA video Cheops: Europe's exoplanet mission shows an animation of the space telescope communicating with a ground station somewhere in central Spain. The Deep Space Network indeed has a ...
2 votes
3 answers
488 views

Did New Horizons use its smaller medium-gain antenna for most/all downlinking of Pluto and Arrokoth flyby data?

Brian May's New Horizons video (below) was released at about the same time that the New Horizons spacecraft passed 2014 MU69 Arrokoth and includes a lot of technically meaningful graphics. One item ...
10 votes
1 answer
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What exactly is the interaction that blocked Juno's data downlink near solar conjunction?

According to Space.com's article Juno Phones Home: Jupiter Probe Reconnects with Earth After 8th Flyby, Juno's recent close flyby of Jupiter and data collection happened while Jupiter was too close to ...
1 vote
1 answer
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How is the data from the three DSN sites transmitted to JPL, NASA and vice-versa?

We know that there are three major Deep Space Network (DSN) sites on Earth, roughly $120^{\circ}$ apart, to communicate with space probes in deep space continuously. All the data from the three DSN ...