Questions tagged [communication]

Questions regarding information transfer between spacecraft, and between spacecraft and Earth.

Filter by
Sorted by
Tagged with
98
votes
3answers
90k views

How did NASA achieve their live TV broadcast in 1969?

In 1969, NASA not only went to the moon, but broadcast the whole thing live on TV. How did they achieve the TV broadcast? What technology did they need to use to send a video and audio signal from ...
55
votes
3answers
15k views

How did NASA prevent third parties from spoofing Apollo communications?

The Apollo crews transmitted footage to Earth using SSTV, a ham radio technique that amateurs and pirates can use to send similar messages around the world. Did NASA have any technical ...
37
votes
1answer
75k views

How does Voyager 1 send signals to Earth?

I recently studied that Voyager 1 has traveled a distance of 125.01 AU as of August 3rd, 2013. I wonder, how would it be able to communicate with the Earth? How much time does it take for the signal ...
34
votes
3answers
6k views

Is there any way to communicate with Pioneer 11 through Voyager 1 or 2?

The position of Pioneer 11 is between Voyager 1 and 2, that means Pioneer 11 is closer to Voyager 1 and 2 than to Earth. According to the Wikipedia article on Pioneer 11 we lost communication with it ...
33
votes
2answers
6k views

What would it take to get a message to another star?

Let's assume that we've somehow detected the existence of an extraterrestrial civilization through "passive" means, such as detecting a suspicious exoplanetary atmospheric signature. We're now hoping ...
28
votes
1answer
5k views

What was the last message to Opportunity today (13 Feb '19)?

Several articles have mentioned that the last ever commands were sent to the unresponsive Opportunity rover today by NASA. Now, I know that it wasn't a verbal message, but was there anything digital ...
27
votes
6answers
7k views

Why no recent information about or photos of Ultima Thule?

It's been two weeks since New Horizons flew past Ultima Thule but the most recent news on the Johns Hopkins site is dated the fourth of January The image gallery has had no new pictures since the ...
23
votes
4answers
5k views

Can Voyager 1 receive signals from Earth?

There are answers about Voyager 1 sending messages to Earth, but can Earth still send signals to Voyager 1? I am just wondering if the signal of the Sun will eventually overcome the signal from Earth ...
22
votes
4answers
7k views

Is Quantum Entanglement technology possible for interplanetary communication in future to achieve low real-time latency?

There is a small debate over the comment session in NASA Lands InSight on Mars video uploaded by JPL. The 1 minute and a half video is about the essential part of InSight's EDL event cropped out from ...
22
votes
2answers
5k views

First call to the moon 1969

During the Apollo 11 mission to the moon, there was a phone call where the POTUS at that time, Richard Nixon, was able to speak to astronauts Neil Armstrong and "Buzz" Aldrin. How was this possible?
21
votes
1answer
4k views

If a Voyager crashes into something, would we know?

A recent question asked about the feasibility of using Voyager 2 to detect objects in the Oort cloud. The answers indicate, among other issues, the instruments on-board the Voyagers would likely be ...
21
votes
2answers
2k views

How precise must be the antenna orientation to communicate with a deep space probe?

I guess that everyone is familiar with the problem of aligning a TV satellite dish: some degrees off and the signal you desire is gone. How sensitive is communication with deep space probes to this ...
21
votes
1answer
4k views

Do astronauts go on a random banter with mission control like in the film 'Gravity'?

In the film 'Gravity', astronauts can be seen having casual chat with mission control. Do astronauts do that in real life? Do they have any specific policy that states what can be communicated over ...
21
votes
2answers
2k views

What is the procedure if communication with the ISS is lost for an extended period?

Between ground control and the ISS there is the occasional short communications loss which they are obviously able to deal with, but is there a procedure to follow if the communication is lost for ...
19
votes
5answers
27k views

How long does it take for a signal to travel between Earth, and Juno at Jupiter?

How long would it take for Juno's communication to reach the Earth? In other words: what is the time delay between perception by Juno and perception by NASA researchers?
19
votes
3answers
18k views

Apollo communication between the Earth and Moon

How was it possible for astronauts to send back tv/radio signals to earth from the moon? I have just been teaching my son about waves behavior and understand that radio waves are reflected back to ...
18
votes
3answers
5k views

Can we detect the cell phone, satellite phone, or walkie talkie of someone walking on Mars from Earth?

We certainly cannot see a person walking on Mars from Earth. But what if the person is trying to use a cell phone, walkie talkie, or satellite phone? Although he won't have much luck using any of ...
18
votes
2answers
3k views

Did NASA's Borg Collective-designed antennas work? Have similar designs ever been used in spacecraft beyond testing?

This interesting answer to the question Do antenna farms on spacecraft make any sense or are they purely aesthetic? in Worldbuilding SE links to the NASA Ames page 'Borg' Computer Collective Designs ...
18
votes
3answers
545 views

VLB interferometry in deep space - does it make sense for communication?

This is something I was thinking about right now when this beta was opened ... perfect! In radio astronomy, there is an technique which is called very long baseline interferometry. The idea is to ...
17
votes
2answers
2k views

What data compression algorithms have been successfully used in spacecraft?

Scientific spacecraft can generate very large amounts of data. However, both the storage available onboard the spacecraft and the bandwidth available to transmit the data to ground stations are ...
17
votes
4answers
614 views

How are the tiny spacecraft proposed by Project Starshot supposed to communicate with Earth?

Between power limitations and aperture-limited diffraction I just can't see how it's possible.
16
votes
5answers
3k views

Can I text on my cell phone from the ISS to Earth?

We know from Can we detect the cell phone, satellite phone, or walkie talkie of someone walking on Mars from Earth? that cell phone signals on Mars are potentially observable on Earth. I am not an ...
16
votes
2answers
3k views

Were there any CAPCOMs who were not astronauts?

The capsule communicator (CAPCOM) is the person in mission control who speaks to the astronauts. The position was invented by NASA's first flight director, Chris Kraft, who believed it would be best ...
16
votes
3answers
4k views

Could “live” video be transmitted from Mars?

With the approach of InSight to Mars today, and the two cubesats watching it, much is being made about seeing "Live Video" from the cubesats. I'm pretty sure that simply can't happen, but I'm ...
16
votes
1answer
2k views

What is carrier lock and bit lock?

I'm not sure if this question belongs here or in Amateur Radio, but during the acquisition of signal from New Horizons on New Year's Day, I heard the controllers call out "carrier lock", "symbol lock",...
16
votes
2answers
3k views

What bitrates are currently achievable for communication with interplanetary space probes?

In communication with interplanetary space probes, it is clear that one has to take the delay caused by speed of light into account. Besides that, what are current limits for the data upload and ...
16
votes
3answers
1k views

How well can Voyager 1 separate Earth signals from Solar noise these days?

This is a follow-up question to this question and this and this answer. UPDATED: see additional information and discussion below. As it continues to move farther from the Sun, the angular separation ...
15
votes
3answers
6k views

Why do ISS astronauts use lower quality microphones for official radio communication than for PR events?

In the first seconds of this video you can see/hear ISS astronaut Samantha Cristoforetti prepare for a PR event: During the preparation she uses two different ...
15
votes
2answers
4k views

How are GPS satellite clocks synchronized with each other in the earth's frame of reference?

I have been looking at different threads. It seems like the receiver clock on Earth doesn't have to be synchronized with the satellite clocks. But I believe the satellite clocks need to be ...
15
votes
1answer
763 views

Resilience to data transmission errors of the Juno spacecraft

What techniques have been employed for the Juno spacecraft to successfully transmit data packets back to Earth once she's in a polar orbit around Jupiter? Jupiter is a strong source of radio ...
15
votes
2answers
3k views

Space Shuttle “go at throttle up”

On all of the launch videos and recordings for the Space Shuttle, the mention is made from Houston (after getting through Max-Q) of "go at throttle up", indicating that the launch is ok for going back ...
15
votes
1answer
720 views

What, if any, mechanisms prevent unauthorized commands?

Since deep space probes and satellites receive commands from Earth via radio, what prevents unauthorized commands from being accepted by such devices? For deep space probes, the required power of ...
14
votes
5answers
4k views

Could we use a narrow paradigm, say laser, to get info faster from New Horizons? (With a moon base.)

There was just a question (actually, on Astronomy) about why the data rate from New Horizons is low. Of course, even with the most directional radio antennas, the spread is enormous. I guess ...
14
votes
3answers
2k views

Why not send Voyager 3 and 4 following up the paths taken by Voyager 1 and 2 to re-transmit signals of later as they fly away from Earth?

Voyager 1 and Voyager 2 spacecrafts are on their journey out of solar system. They collected so much of important data that helped us understand our solar system. As these spacecrafts moving out of ...
14
votes
1answer
2k views

Did USSR discontinue radio transmissions, relocate ships, to aid the US in response to Apollo 13?

In this article there is following statement by Dr. Ernst Stuhlinger: Let me only remind you of the recent near-tragedy of Apollo 13. When the time of the crucial reentry of the astronauts ...
14
votes
3answers
2k views

Cubesats in lunar orbit and beyond - how does communication work?

Somewhere I read that there are serious plans to send a cubesat into lunar orbit. A few years ago, the ISS was also offering a launch opportunity for such a mission. I guess that it was actually ...
13
votes
7answers
4k views

Where are the pictures during the time the pictures are sent from space to home?

Obviously the pics aren't floating around, but how can I explain this to a 10 year old?
13
votes
2answers
4k views

Apollo 17; what is a barber pole, and what did “it is gray” mean?

Following the links in this comment by @Uwe I've found some interesting sources of information on Ham (amateur) radio operators trying to listen in on Apollo transmissions. At the bottom of Sven ...
13
votes
1answer
1k views

Decoding Russian ISS telemetry

While the American segment of the ISS has data published on-line (http://spacestationlive.nasa.gov), the same cannot be said about the Russian segment. It is known that telemetry is transmitted to ...
12
votes
4answers
2k views

Does communications with spacecraft red shift the further away they are?

As Voyager 1 and 2 proceed further away do the radio waves red shift (change frequency)? If so, then don't we have to compensate for that red shift by modulating the frequency so that it arrives at ...
12
votes
2answers
2k views

What happens differently when ISS is inside this red boundary (Russia & Europe & …)?

The question Why are there advertisements in the Russian ISS flight control room? shows the image below. There is a large red boundary that looks like the boundary of the overlap of several circles ...
12
votes
1answer
2k views

From which Apollo mission is this audio sample?

I found this page where Evgeny Molotov, former head of the Research institute of Space instruments, plays supposed intercepted communication of unknown Apollo mission. Can anyone identify from which ...
12
votes
1answer
3k views

When does the ISS have a loss-of-signal?

The ISS has a camera mounted streaming live video from space (HDEV). From time to time, there is a blue screen visible, which is noted to be during times of "loss of signal". What exactly defines a "...
12
votes
1answer
1k views

How is data transferred from interplanetary missions?

I'm trying to find out information about the mechanics of data transmission from planetary probes: techniques, devices, methods, software. In short, How reliable data transmission is undertaken in ...
12
votes
1answer
489 views

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 ...
11
votes
4answers
4k views

Why aren't space telescopes put in GEO?

I don't know of any space telescope that has been placed in geosynchronous orbit among the communication satellites. I wonder why not? In GEO, a space telescope could use a single stationary radio ...
11
votes
3answers
4k views

Will the Tesla Roadster return any telemetry?

Is there any equipment fitted to the Tesla Roadster to send signals back to Earth, even for a short time after launch?
11
votes
1answer
2k views

Will Curiosity and the Mars 2020 rover be able to communicate with each other via a Mars orbiter?

Curiosity's UHF antenna on sol 2439 Could Curiosity and the Mars 2020 rover communicate with each other via the MRO orbiter ? And would it have advantages ? (Like: " I just saw a meteorite, and it'...
11
votes
2answers
2k views

What (actually) makes Iridium “the world's only truly global mobile satellite communications company”?

In this article about how the SpaceX anomaly will affect Iridium it says: In its official website, Iridium describes itself as "the world's only truly global mobile satellite communications company....
11
votes
2answers
25k views

How does NASA get information from space probes?

So I have briefly gone over answers to how things are stored as from this answer: https://space.stackexchange.com/a/2273/1247 but how is the information sent back? I'm thinking of probes like the ...