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13 votes
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How does one dogleg from Florida to a sun-synchronous orbit?

A dogleg maneuver is done to change the inclination of a certain payload, and the reason it limits the payload capacity is most likely due to the cosine losses. In order to perform such a maneuver a ...
Jake Blocker's user avatar
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11 votes
Accepted

Is there a low Earth orbit with a 24-hour day night cycle?

There are not! To obtain a 24 hr day/night period, you have to pass through the Earth's shadow every 24 hours. This means you're orbiting once every 24 hours (as no orbits precess rapidly enough to ...
Anton Hengst's user avatar
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10 votes

Sun synchronous orbit and LTAN

From the way the question is phrased, it would be referring to the eclipse of the spacecraft by the Earth (i.e. the sun is blocked by the Earth), not of the spacecraft by the Moon. Eclipse can refer ...
aerocooper's user avatar
7 votes

Are sun-synchronous orbits always North to South?

You are correct in your understanding, Once it reaches the vicinity of the South Pole, specifically the most southern point in its orbit it will start going north. The reason they said north to ...
Hans's user avatar
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7 votes

How are "terminator-riding" sun-synchronous satellites never passing over the pole?

Could someone explain it like I was 5? TL;DR: A true "terminator-riding" satellite doesn't exist. The fuel maintenance costs for such an orbit would be ridiculously high. Sun synchronous satellite ...
David Hammen's user avatar
  • 75.1k
7 votes

How are "terminator-riding" sun-synchronous satellites never passing over the pole?

The satellite does not run parallel to the terminator, it crosses the terminator twice on each orbit. So on each orbit, half the path underneath the orbit is in shadow, the other half is in daylight. ...
Hobbes's user avatar
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7 votes
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Why can Amazônia-1 observe the Amazon "every day or two" while Landsat takes 16 days between observations? Is "orbital magic" at play here?

Field of view. Landsat satellites by design have a rather narrow field of view (185 km across) so as to reduce issues with off-nadir resolution while Amazonia-1 by design has a much wider field of ...
David Hammen's user avatar
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6 votes
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How Local time of a sun synchronous orbit is related to Right ascension of ascending node?

The special property of sun-synchronous satellites is the precession, at pace equal to Earth's orbital period around the Sun (1 year). That means, the satellite's RAAN drifts by a full 360 degrees ...
SF.'s user avatar
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6 votes
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What would be different about satellite orbits if Earth were prolate? Would we have Sun-synchronous and Molniya orbits?

Physically, you can think of a sun-synchronous orbit as having its orbital plane precessing once a year. Like a toy gyroscope’s plane of rotation precesses under the torque due to gravity, so does the ...
Bob Jacobsen's user avatar
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5 votes

Sun synchronous orbit and LTAN

The 800 km orbit is much more important than the LTAN. At 800 km orbit, the satellite is going to have a orbital period of roughly 100 minutes. For a few of those successive 100 minute orbits, it's ...
kacy wilson's user avatar
5 votes

What is the official universal time system of Mars?

It's not needed, so no "global treaty organizations" would be interested in spending even a minute thinking about it. In the meantime (so to speak), each landed mission on Mars plans its operations ...
Mark Adler's user avatar
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5 votes
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Could a cubesat in a 500km SSO orbit effectively monitor earth?

The Planet Labs Flock 3p constellation is in LEO at 500 km and doing an effective job of imaging all the land area of the Earth daily, albeit at around 5 meter resolution. The best angular resolution ...
pericynthion's user avatar
  • 10.1k
5 votes

Reason for satellite passes at the same local time each day?

These are called "Sun-synchronous orbits" and extensively used for remote sensing, where satellites are looking down at the Earth's surface. One of the main reasons for these orbits is that the ...
ChrisR's user avatar
  • 6,190
5 votes

formula linking RAAN and LTAN

Some tools do allow you to plug in local time of node crossing and then calculate the RAAN ($\Omega$) for you, but they may be out of your budget range. Rather than implement it yourself, I recommend ...
Ryan C's user avatar
  • 7,972
5 votes

Why can Amazônia-1 observe the Amazon "every day or two" while Landsat takes 16 days between observations? Is "orbital magic" at play here?

Sun-synchronous orbits are useful for global coverage since they are near polar orbits. Attached is the plot of the groundtracks of Amazonia-1 and Landsat-7 for a 24 hour period. So in one day, each ...
Alfonso Gonzalez's user avatar
5 votes

Why can Amazônia-1 observe the Amazon "every day or two" while Landsat takes 16 days between observations? Is "orbital magic" at play here?

Landsat orbits repeat their ground tracks almost exactly every sixteen days. Each Landsat sees some part of the Amazon three to six times per day, as the ground tracks @Alfonso Gonzalez posted show, ...
Ryan C's user avatar
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4 votes
Accepted

Is there a significant difference between launching a polar orbit mission south from New Zealand versus launching it north?

There shouldn't be a difference in whether the mission is technically feasible. The flight plan would be altered as deflection would be mirrored, but I can't see any reason engineering aspects would ...
user19742's user avatar
  • 987
4 votes

What is the official universal time system of Mars?

There is no official universal time system for Mars. However, NASA has proposed an analog for Universal Time on Earth, that they refer to as Coordinated Mars Time, or MTC: The prime meridian of ...
called2voyage's user avatar
  • 23.7k
4 votes

Are sun-synchronous orbits always North to South?

The north-south motion (or south-north) itself doesn't produce a sun-synchronous orbit. It's actually the deviation from straight north-south, coupled with the primary's (the planet or other body the ...
Tom Spilker's user avatar
  • 18.3k
4 votes
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how to better understand how dawn dusk orbits work?

If the Earth had a spherically distributed gravitational field, a satellite's right ascension of ascending node would be constant. Right ascension of ascending node (RAAN) is expressed in Earth-...
David Hammen's user avatar
  • 75.1k
3 votes

Are sun-synchronous orbits always North to South?

In addition to Hans' answer, these are the terms used in the spaceflight community to describe the orbits you're referring to. Satellites that orbit "north to south" are called polar orbits. These ...
Hobbes's user avatar
  • 128k
3 votes
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Satellites that take advantage of, or require constant availability of sunlight on the spacecraft itself, available in Sun-synchronous orbits?

Two classical examples of spacecraft which "take advantage" of being (almost) constantly insolated: 1- Sun Observation Missions: Spacecraft in Lagrange's points such as SOHO or in dawn-dusk orbit ...
Mefitico's user avatar
  • 1,987
3 votes
Accepted

What is the darkest orbit around Earth?

As @OrganicMarble suggests a nice Sun-synchronous orbit is probably the answer to both "least" and "most". Sun-synchronous orbits around the Earth are often used to keep satellites over areas of the ...
uhoh's user avatar
  • 149k
3 votes

Is it possible to have a "figure-8" orbit around the Moon and the Earth, and perhaps always face the sun?

Yes, it would be possible to have a figure-8 shaped orbit around the Earth/Moon system. In a two body system like the Earth/Moon or Sun/Earth system, there are five known points where the gravity of ...
Kit Matthews's user avatar
3 votes

Perturbation effects on sun-synchronous orbit

A sun synchronous orbit uses a combination of size, shape, and orientation, to exploit the gravitational perturbation of the earth's oblateness such that the orbit plane remains synchronous with the ...
Marco Concha's user avatar
3 votes

Are sun synchronous orbits possible for any place on Earth?

For: Do sun-synchronous orbit pass any spot around Earth... (emphasis added) Sun-synchronous orbits use the strong $J_2$ component of the Earth's gravity to precess their ascending node all the ...
uhoh's user avatar
  • 149k
3 votes

Time of satellite passing overhead

I think the step that has caused you problems is "Since the sun angle varies from day-to-day, this also means that the clock time that the satellites pass overhead will shift from day-to-day.&...
Puffin's user avatar
  • 9,724
3 votes
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Does the dawn-dusk orbit maintain the inclination with respect to the ecliptic plane?

First, a word of caution: Take diagrams published in conference papers that have little or no explanatory text with a huge grain of salt. Admittedly, this diagram was from an invited paper presented ...
David Hammen's user avatar
  • 75.1k
2 votes

How risky is launching a rocket during a geomagnetic and solar radiation storm?

Somewhat risky: SpaceX announced on 2022-02-08 that they lost 40 Starlink satellites because a geomagnetic storm increased drag at the orbit altitude (just 210 km just after launch) so much that the ...
Ludo's user avatar
  • 14.4k
2 votes

How does one dogleg from Florida to a sun-synchronous orbit?

Supplementary information. After asking this question I saw the photo below. The item on top is called GRAB 1 for Galactic Radiation and Background. However that's a cover: Galactic Radiation and ...
uhoh's user avatar
  • 149k

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