Space time, clock, conversion, countdown, counters, date, distance, launch window, MET, velocity, launch, liftoff, T+, T-, T plus, T minus, PDT, CST, CDT, EDT, UTC, GMT, CET, CEST, LTC.
Earth time
Time zones
Local time Amsterdam
UTC Zone
UTC +1 = CET (Amsterdam)
UTC +2 = CEST (Amsterdam)
UTC +0 = GMT = Zulu
UTC -4 = EDT (New York, Cape Canaveral)
UTC -5 = CDT (Houston, Boca Chica)
UCT -6 = CST/MT/MDT (Denver)
UCT -7 = PDT (Los Angeles/Pasadena)
UTC is used on board the ISS.
Summer (CEST)
EDT +6 = CEST
CDT +7 = CEST
CST +8 = CEST
PDT +9 = CEST
Coordinated Universal Time (UTC)
The worldwide scientific standard of timekeeping. It is based upon carefully maintained atomic clocks and is highly stable. The addition or subtraction of leap seconds, as necessary, at two opportunities every year adjusts UTC for irregularities in Earth’s rotation.
UTC is used on board the ISS.
Spacecraft Event Time (SCET) or Orbiter UTC
The time something happens at the spacecraft, such as a science observation or engine burn.
One-Way Light Time (OWLT)
The time it takes for a signal – which moves at the speed of light through space – to travel from the spacecraft to Earth. From Saturn, one-way light time can range from about one hour and 14 minutes to one hour and 24 minutes.
Earth Received Time (ERT) or Ground UTC
The time the spacecraft signal is received at mission control on Earth (the Spacecraft Event Time plus One-Way Light Time).
Mission Elapsed Time (MET)
Used by NASA during their space missions. Because so much of the mission depends on the time of launch, all events after launch are scheduled on the Mission Elapsed Time. This avoids constant rescheduling of events in case the launchtime slips. The MET-clock is set to zero at the moment of liftoff and counts forward in normal days, hours, minutes, and seconds. For example, 2:03:45:18 MET means it has been 2 days, 3 hours, 45 minutes, and 18 seconds since liftoff.
Official U.S. Time
National Institute of Standards and Technology (NIST, U.S. Department of Commerce) and United States Naval Observatory (U.S. Department of Defense). United States Naval Observatory.
Moon time (Coordinated Lunar Time, LTC)
- 23-04-2024 A memo sent on Tuesday from the head of the US Office of Science and Technology Policy (OSTP) has asked the NASA space agency to work with other US agencies and international agencies to establish a moon-centric time reference system. Nasa has until the end of 2026 to set up what is being called Coordinated Lunar Time (LTC).
- 2026 Introduction.
Mars time (Coordinated Mars Time, CMT)
- Coordinated Mars Time (CMT).
- Mars is a planet with a very similar daily cycle to the Earth.
Its ‘sidereal’ day is 24 hours, 37 minutes and 22 seconds, and its solar day 24 hours, 39 minutes and 35 seconds. - A Martian day (referred to as “sol”) is therefore approximately 40 minutes longer than a day on Earth.
- A sidereal day on Earth is approximately 86164.0905 seconds (23 h 56 min 4.0905 s or 23.9344696 h).
- Sol (borrowed from the Latin word for sun) is a solar day on Mars; that is, a Mars-day. A sol is the apparent interval between two successive returns of the Sun to the same meridian (sundial time) as seen by an observer on Mars. It is one of several units for timekeeping on Mars.
Distances
- Miles x 1,60 = kilometer
- 250,000 miles = 400.000 kilometer (Distance to the Moon)
- 200,000 miles = 320.000 kilometer
- 50,000 miles = 80.000 kilometer
- 30,000 miles = 48.000 kilometer
- 25,000 miles = 40.000 kilometer
- 24,000 miles = 38.400 kilometer (Artemis I Entry Interface speed, Mach 32)
- 20,000 miles = 32.000 kilometer
- 15,000 miles = 24.000 kilometer
- 10,000 miles = 11,600 kilometer
- 5,000 miles = 8,000 kilometer
- 2,500 miles = 4,000 kilometer
- 1,000 miles = 1,600 kilometer
- 500 miles = 800 kilometer
- 100 miles = 160 kilometer
- 10 miles = 16 kilometer
- Feet x 0,30 = kilometer
- 400,000 feet = 120 kilometer (Artemis I Entry Interface altitude)
- 350,000 feet = 105 kilometer
- 300,000 feet = 90 kilometer (Artemis I Skip apogee)
- 250,000 feet = 75 kilometer
- 200,000 feet = 60 kilometer
- 150,000 feet = 45 kilometer
- 100,000 feet = 30 kilometer
- 50,000 feet = 15 kilometer
- 30,000 feet = 9,0 kilometer
- 28,000 feet = 8,4 kilometer
- 22,000 feet = 6,6 kilometer (Artemis I FBC jettison, Drogue parachutes)
- 6,800 feet = 2,kil0 ometer (Artemis I Pilot parachutes)
- 5,000 feet = 1,5 kilometer (Artemis I Main parachutes)
Atomic clock
An atomic clock measures by monitoring the resonant frequency of atoms. It is based on atoms having different energy levels. Electron states in an atom are associated with different energy levels, and in transitions between such states they interact with a very specific frequency of electromagnetic radiation. This phenomenon serves as the basis for the International System of Units’ (SI) definition of a second.
The accurate timekeeping capabilities are also used for navigation by satellite networks such as the European Union’s Galileo Program and the United States’ GPS. The timekeeping accuracy of the involved atomic clocks is important because the smaller the error in time measurement, the smaller the error in distance obtained by multiplying the time by the speed of light is (a timing error of a nanosecond or 1 billionth of a second (10−9 or 1⁄1,000,000,000 second) translates into an almost 30-centimetre (11.8 in) distance and hence positional error).
Thorium clock
The thorium clock represents a groundbreaking development in precision timekeeping, offering unprecedented accuracy based on the properties of thorium-229, an exotic isotope. Unlike traditional atomic clocks, which use microwave frequencies of cesium or rubidium atoms, the thorium clock operates using nuclear energy levels, specifically targeting a unique nuclear transition in thorium-229. This rare transition occurs at a much lower energy level than other nuclear states, making it accessible to laser excitation.
Thorium clocks are expected to be 100 times more precise than the best atomic clocks, maintaining accuracy within one second over the age of the universe. This is due to the stability of nuclear energy levels, which are far less susceptible to external electromagnetic fields than electron transitions used in atomic clocks.
The applications of this clock are vast, including testing fundamental physics theories, improving GPS satellite synchronization, and enhancing communication technologies. Moreover, the ability of thorium clocks to detect tiny shifts in time could allow scientists to explore the effects of gravity on time at unprecedented scales, offering insights into general relativity and dark matter.
In essence, the thorium clock not only promises to redefine precision timekeeping but also to push the boundaries of our understanding of the universe.
Footnote
- Sources: Aerospace dashboard, funkystuff.org
- Outgoing: NASA
- Keywords: Launch windows