From ed2bedb011b15a2bfbec02a2f5f20ba70aa4e058 Mon Sep 17 00:00:00 2001 From: Nazfib Date: Sun, 2 Jun 2024 19:41:23 +0200 Subject: [PATCH] Increase Tundra orbit periapsis requirement With a 1000 km periapsis (eccentricity 0.82), the resulting orbit has barely any apogee dwell time; it moves west very quickly across the sky when it's at apogee. At an eccentricity of 0.423, the ground track moves from being a figure-of-eight to a teardrop shape. As far as I can tell, this is the highest eccentricity that gives a proper Tundra orbit. A 17000 km periapsis corresponds to an eccentricity of around 0.446, which makes the maximum eccentricity a little higher than that value. Also decreased the minimum eccentricity a little bit. According to Capderou's "Handbook of Satellite Orbits", a 0.2668 eccentricity Tundra orbit was considered for ESA's "Archimedes" telecommunications project. --- .../Contracts/Commercial Applications 2/FirstTundraSat.cfg | 6 +++--- GameData/RP-1/Contracts/Earth Satellites/FirstTundraSat.cfg | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/GameData/RP-1/Contracts/Commercial Applications 2/FirstTundraSat.cfg b/GameData/RP-1/Contracts/Commercial Applications 2/FirstTundraSat.cfg index 68c6279f5a9..55c228a461f 100644 --- a/GameData/RP-1/Contracts/Commercial Applications 2/FirstTundraSat.cfg +++ b/GameData/RP-1/Contracts/Commercial Applications 2/FirstTundraSat.cfg @@ -5,7 +5,7 @@ CONTRACT_TYPE group = CommApp2 agent = Federation Aeronautique Internationale - description = Program: Advanced Commercial Applications
Type: Optional

A Tundra orbit is a highly elliptical geosynchronous orbit (note: not geostationary orbit) with a high inclination (usually near 63.4) and an orbital period of one sidereal day. A satellite placed in this orbit spends most of its time over a chosen area of the Earth, a phenomenon known as apogee dwell. The ground track of a satellite in a tundra orbit is a closed figure eight. An extreme version of this orbit puts the perigee around 1000 km and the apogee around 70,000 km. The orbit in this contract is actually using data from the Sirius satellites, the only known satellites using a Tundra orbit. + description = Program: Advanced Commercial Applications
Type: Optional

A Tundra orbit is a highly elliptical geosynchronous orbit (note: not geostationary orbit) with a high inclination (usually near 63.4) and an orbital period of one sidereal day. A satellite placed in this orbit spends most of its time over a chosen area of the Earth, a phenomenon known as apogee dwell. The ground track of a satellite in a tundra orbit is a closed figure eight. The orbit in this contract is actually using data from the Sirius satellites, the only known satellites using a Tundra orbit. synopsis = Launch a test satellite into a Tundra Orbit completedMessage = Success! The Tundra orbit is highly eccentric and lets the satellite spend most of its time over a point in the high latitudes. @@ -117,10 +117,10 @@ CONTRACT_TYPE title = Reach the correct orbit within the parameters. Note: The argument of periapsis values mean that the apogee needs to be high in the northern latitudes. This is like a Molniya orbit, but with an orbital period the same as an Earth sidereal day. minInclination = 61.4 maxInclination = 65.4 - minEccentricity = 0.3 + minEccentricity = 0.25 minArgumentOfPeriapsis = 220 maxArgumentOfPeriapsis = 320 - minPeA = 1000000 + minPeA = 17000000 minPeriod = 23h 54m 4s maxPeriod = 23h 58m 4s diff --git a/GameData/RP-1/Contracts/Earth Satellites/FirstTundraSat.cfg b/GameData/RP-1/Contracts/Earth Satellites/FirstTundraSat.cfg index f836eb3ce40..125092fdb21 100644 --- a/GameData/RP-1/Contracts/Earth Satellites/FirstTundraSat.cfg +++ b/GameData/RP-1/Contracts/Earth Satellites/FirstTundraSat.cfg @@ -7,7 +7,7 @@ CONTRACT_TYPE tag = exclude_EarlySatellite - description = Program: Targeted Satellites
Type: CAPSTONE

A Tundra orbit is a highly elliptical geosynchronous orbit (note: not geostationary orbit) with a high inclination (usually near 63.4) and an orbital period of one sidereal day. A satellite placed in this orbit spends most of its time over a chosen area of the Earth, a phenomenon known as apogee dwell. The ground track of a satellite in a tundra orbit is a closed figure eight. An extreme version of this orbit puts the perigee around 1000 km and the apogee around 70,000 km. The orbit in this contract is actually using data from the Sirius satellites, the only known satellites using a Tundra orbit.&br;&br;Place a satellite into a Tundra orbit.&br;&br;There will be an orbit showing in the map view and tracking station. You do not have to place the satellite into this orbit, but it is instead meant to show you where your perigee and apogee should approximately be located, but more importantly, it shows the proper shape of the orbit. + description = Program: Targeted Satellites
Type: CAPSTONE

A Tundra orbit is a highly elliptical geosynchronous orbit (note: not geostationary orbit) with a high inclination (usually near 63.4) and an orbital period of one sidereal day. A satellite placed in this orbit spends most of its time over a chosen area of the Earth, a phenomenon known as apogee dwell. The ground track of a satellite in a tundra orbit is a closed figure eight. The orbit in this contract is actually using data from the Sirius satellites, the only known satellites using a Tundra orbit.&br;&br;Place a satellite into a Tundra orbit.&br;&br;There will be an orbit showing in the map view and tracking station. You do not have to place the satellite into this orbit, but it is instead meant to show you where your perigee and apogee should approximately be located, but more importantly, it shows the proper shape of the orbit. synopsis = Launch a satellite into a Tundra Orbit @@ -121,10 +121,10 @@ CONTRACT_TYPE title = Reach the correct orbit within the parameters. Note: The argument of periapsis values mean that the apogee needs to be high in the northern latitudes. This is like a Molniya orbit, but with an orbital period the same as an Earth sidereal day. minInclination = 61.4 maxInclination = 65.4 - minEccentricity = 0.3 + minEccentricity = 0.25 minArgumentOfPeriapsis = 220 maxArgumentOfPeriapsis = 320 - minPeA = 1000000 + minPeA = 17000000 minPeriod = 23h 54m 4s maxPeriod = 23h 58m 4s