DTN 2 way to space dual carriage way on one road

[Amali De Silva - Mitchell]

I listened foe several hours to the CNN broad cast of the mission around the moon.

I heard the DTN as they chatted into space. 

What I want to know is can't we have 2 parallel DTN lines. Each line is exclusive to a one way. Similar to a dual carriage way road. 

Each line could seamlessly talk it wa only when they changes ove there was a delay..Hence if each has their own we listen to one channel and speak from the other 2 streams rather than switching 

Houda is this possible   ? 

Amali

[Amali De Silva - Mitchell]

Oscar

I appreciate the detailed response. 

What I witnesses is that the streaming of a communication from space was seamless over several minutes. The delay was in the switch over to Houston and back. 

Given that I was wondering if the I copy can be eliminated. 

Spaceship to Houston would have one line. Never closed of for a response. 

Same for Houston a line to space never closed off. 

So at either end they would have 2 open channels at the same time . Listen through one ans speak through the other. 

This way no breaks 

I do get the relay issue but there seemed to be none while the space craft was chatting continuously....

Let's see what zoom does tomorrow

Great to head laser tech is being used... let us know the implications for QT? 

Amali

On Sun, Apr 12, 2026, 17:00 Oscar Garcia <oscargarc...@gmail.com> wrote:

Hi,

Houda, nice to get in touch.

Amali, something to be aware of is that, connections in Space have a
natural delay because of distance delay and also technical delays
regarding the several hops that communications can have in this environment.
Distance in space can be measured in kilometers and also in light speed
time, roughly 300,000 km/second.
Communications cannot go faster than light speed.

In Earth communications, due of the wide deployment of fiber optics
using terrestrial and submarine cables, we are used to very fast
communications, that are close to speed of light, because fiber optics
use light to establish communications.

We all can remember that few years ago, when the network was mostly
copper wire based, in many cases, communications had much frequent
delays and interruptions.

In space, light speed is a limit that it's important to be aware of when
considering connectivity.
As an example, light takes an average of 8 minutes to reach Mars from
Earth, from 3 to 22 minutes, depending on the orbit on the ecliptic.
This mean that any call, between message and response, voice or data,
can take between 6 to 44 minutes.

That being said, all communications from space, jump between many hops
before they reach destination. That is what I mention above as a
technical delay.
For example, from the Moon or a spacecraft, the signal might jump to a
satellite, and from that satellite to another satellite, or to the
ground antennas of the Deep Space Network, and from there to some
government network and from there to a control center (many times there
are more than one control center) and from there, in  the case of a
public appearance like the one you mention from CNN, it might be
recorded and played back, or, if running in real time, then you will
notice the delay showing up on TV.
All these hops involve microseconds and sometimes seconds that, when
added, are noticeable as delay and sometimes also seen as interruptions.

As you mention, communications can be half or full duplex on the same
wiring/connection or on multiple wires and also depending on the
protocol used (DTN is a possibility but also other protocols can be used).

Something to highlight is, that during Artemis II mission, a technology
that has been in experimentation using laser for communications in
Space, was tested- We are waiting for the outcomes of that experience.

Hope it helps,

PS: my emails don't reach the mailing list so please forward my responses.

Kind Regards,
Oscar