Questions tagged [time]

How passage of time impacts space exploration activities.

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1answer
499 views

Do the Voyager probes experience time moving faster due to relativity?

Time goes faster the weaker the gravitational field you are in as long as your velocity is constant. The Voyager probes have moved a long way from the sun and its planets so I presume time must be ...
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1answer
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How would people measure time on Venus?

On earth we can divide our day into 24 hours, and 365 days in the year. I am trying to imagine how people living on airships above the cloud-tops would think about time on Venus given that a single ...
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Juno to Jupiter Budget

Would the Juno program be more cost effective if the spacecraft took a direct flight to Jupiter rather than using gravitational pull from planets, which took nearly 5 years instead of say, 2 years? ...
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1answer
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How is gravitational time dilation experienced by spacecraft near Jupiter such as Juno

I understand (I think) that a vehicle on or near a planet with greater mass - such as the Juno probe entering Jupiter's orbit soon- will experience time slightly slower relative to us on Earth. ...
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1answer
209 views

How did NASA refer to dates and times of a mission in the 1970s?

Back in the 1970s, how did NASA describe when an event happened during a mission? For example, when Mariner 10 did its fly-by of Venus, how did the Mariner team refer to that moment in time? Did ...
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1answer
386 views

Local Time Calculation

How To Calculate Local Time Of A Sun Synchronous Orbit With A Given Altitude ( Say 600 km ) , Inclination ( 98 degrees ) ?
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1answer
152 views

Can we displace earth? [closed]

From the gravitation equation it is clear the earth gets pulled but we fall due to negligible mass. But, if each and every person on the earth takes a jet-pack and jumps to a height equivalent to 20 ...
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1answer
361 views

How far from earth have atomic clocks (or ultra-stable oscillators) been placed and monitored?

The various flavors of GPS satellite constellations use atomic clocks on each satellite. As far as I know, all of the constellations are "shells" of circular MEO orbits in 3 to 6 planes, 20,000 to 25,...
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1answer
404 views

Why did the Zond 5 tortoises lose body mass so quickly?

It is well-known that when we are in space for a long time, our bodies lose some mass. My question is how much time would be needed for a person to lose 10% of their body mass? The tortoise inside ...
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How long does it take for a satellite to reach MEO? [closed]

I'm just wondering how long it takes satellites from launch to orbiting in MEO.
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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 ...
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1answer
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Scott Kelly age vs Twin's

Scott Kelly just returned from nearly a year of orbiting the Earth in the space station. How much younger is he than his twin, now that he has spent a significant amount of time, traveling at high ...
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1answer
187 views

Time dilation between Earth and a similar planet revolving around a supermassive Black hole [closed]

I was thrilled watching 'Interstellar'. It was only much later that I came to realize certain anomalies in the movie (like the scene in which McConaughey approaches the Gorgantua — his body ...
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4answers
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How to obtain UTC of the epoch time in a satellite TLE (two line element)?

I want to convert the epoch time of a TLE to UTC. At this moment I am less interested in explanations and history - I just want to know quantitatively, with certainty, how to convert. I'm confused ...
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2answers
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Time, UTC, Julian Date, TLE epoch - how are they related quantitatively?

I am trying to understand the relationship (quantitatively) between JulianDate, UTC, and the epoch of Two Line Elements. It's a deep subject, especially if you include relativity, and a long subject - ...
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3answers
273 views

Has any other term been used for a solar day on a solar system body besides “sol” on Mars?

My interest was piqued by this question and answer. For several reasons NASA needed to refer frequently and extensively to a Martian solar day, and "sol" became the nom du jour. There have been ...
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4answers
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Where can the term “Sol” used?

Alright, I know that "Sol" is used on Mars to count days. But is the sun called: "Sol"? And can you use that term on Earth as well? The reason for the question is that the term "sol" is used in two ...
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Is space mining and development as shown in the television show “The Expanse” realistic?

In the television show "The Expanse", we see the Solar System having been partially colonized and developed during the 23rd century. The spacecraft in the show appear to depend on conventional ...
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4answers
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What decides if a launch has to be done instantaneously or during a window?

What determines if a launch has to be done instantaneously or has a launch window of minutes or hours? To what parts is it about celestial and ground issues? Just one example of alleged switching ...
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2answers
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How to calculate Coordinated Mars Time (MTC)?

I'm trying to figure out how to calculate Coordinated Mars Time (MTC). Can it be calculated directly from Earths current time/date, or calculated from the current Mars Sol Date (MSD)? From this wiki ...
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1answer
140 views

What would happen to perceived time in this scenario?

This is difficult for me to explain, but hopefully I can get my question across... Let's say there is a planet called Planet X one million light years from Earth (there probably is). Let's also say ...
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3answers
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How much faster (or slower) would it be for a new probe to reach Pluto?

New Horizions just reached Pluto after almost a decade in space. That means it was launched with technology that is well over a decade old (when you factor in planning and construction time). If we ...
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3answers
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Determining orbital position at a future point in time

This might come of as a millionth-time award winner beginner question, but since I'm not familiar with either correct terms or designations, I'll put this question in my own language, since I'm not ...
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1answer
500 views

Considering the relativity of time, how is time experienced in deep space? [closed]

To be more specific, if the relativity of time is governed by the mass and gravity of objects (I.E the satellites orbiting earth experience minor time dilation compared to us on the ground), how is it ...
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If the Alcubierre Warp Drive was used to travel to Alpha Centauri, how much time would pass on Earth?

If the Alcubierre Warp Drive was used to travel to Alpha Centauri, how much time would pass on Earth? Per this article, it would take merely days to travel there. Say a ship travels there, spends a ...
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1answer
405k views

The true meaning of Sol regarding time on Mars

I'm writing a story about Mars and I'm really confused as to how one should use the word 'Sol when talking about the passage of time there. For example, Would one say to a colleague: "Today is Sol 345,...
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1answer
220 views

Theoretically, could gravitational time dilation ever be an issue when visiting an alien planet?

If humanity ever got to the point of being able to explore new planets (assuming we could land there), are there any known entities in the universe that are so massive that gravitational time dilation ...
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2answers
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Would a Moon resident age differently than someone living on Earth?

Say there were a base on the Moon with people living/studying there. Would they age differently than those on earth due to a change in speed through space? Does the Moon move faster through space (...
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1answer
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What time of events is given for probes a long way away from Earth?

Philae is to land on 67P/Churyumov-Gerasimenko today at 17:02 CET. The comet is currently 3.409AU away from Earth. That means signals from the lander take a little over 28 minutes to reach Earth. Does ...
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4answers
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Has an interplanetary date/time system been established yet?

Obviously, with no humans living permanently off-planet yet, Earth-style dates and times are the most common system is use, and reasonably so. And it helps that Mars's day is almost the same length ...
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5answers
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How does GPS receiver synchronize time with GPS satellites?

GPS satellites transmit time values regularly, but if we put in consideration the time delay between the satellite and the receiver, the time value received wouldn't be accurate insofar as I know GPS ...
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1answer
644 views

how much does time slow down with gravitational time dilation, on a black hole with these graph trajectories.? [closed]

How much does time slow down with gravitational time dilation, on a black hole with these graph trajectories.? If you watch a journey into a black hole on Youtube before reading this question, it ...
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3answers
507 views

How would time measurement be done over great distances?

Already on earth the time is a bit of a problem with the time-zones. It is not that big a problem though, since we all "travel" at (nearly) the same speed. Not so in space. With the time dilatation (...
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3answers
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How would we communicate over light years?

Anyone who has been in an email conversation where the chain split into different threads, or has been in chat where they receive two diverging comments requiring a response before a reply to the ...
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4answers
1k views

Day versus night launches

Most launches that I've seen have occurred during the day. But I've also seen a couple of missions that have been launched at night. Are there any specific advantages or disadvantages to a day launch ...
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2answers
2k views

Do the Voyager space probes perform time synchronization regularly?

According to JPL: http://voyager.jpl.nasa.gov/mission/weekly-reports/ Voyager 1 travels at a velocity relative to the Sun of 19.03 km/s (or 0.000063478 c, or a time difference of ~ 0.0005 seconds per ...
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4answers
17k views

What time zone is used on ISS to define a day?

What time zone is used on ISS to define when a day starts? Is it the same as mission control? Do Russian cosmonauts use a different time zone respect to European and American astronauts?

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