Ephemerides¶

Calculate the position of the Sun in the GCRF inertial frame using low-precision analytical methods.

Parameters:

Returns:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r_sun = bh.sun_position(epc)

Calculate the position of the Moon in the GCRF inertial frame using low-precision analytical methods.

Parameters:

Returns:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r_moon = bh.moon_position(epc)

Calculate the position of the Sun in the GCRF inertial frame using NAIF DE ephemeris.

This function uses the high-precision NAIF DE ephemeris kernel (DE440s or DE440) for solar position computation. The kernel is loaded once and cached in a global thread-safe context, making subsequent calls very efficient.

If the ephemeris has not been initialized, it will be automatically loaded on the first call. For more control over initialization and error handling, use load_common_spice_kernels() explicitly.

Parameters:

Returns:

Raises:

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import brahe as bh

# Optional: Pre-initialize for better error handling
bh.load_common_spice_kernels()

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r_sun = bh.sun_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of the Sun in the GCRF inertial frame using NAIF DE ephemeris.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v_sun = bh.sun_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of the Sun in the GCRF inertial frame using NAIF DE ephemeris.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x_sun = bh.sun_state_spice(epc, bh.EphemerisSource.DE440s)

Calculate the position of the Moon in the GCRF inertial frame using NAIF DE ephemeris.

This function uses the high-precision NAIF DE ephemeris kernel (DE440s or DE440) for lunar position computation. The kernel is loaded once and cached in a global thread-safe context, making subsequent calls very efficient.

If the ephemeris has not been initialized, it will be automatically loaded on the first call. For more control over initialization and error handling, use load_common_spice_kernels() explicitly.

Parameters:

Returns:

Raises:

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import brahe as bh

# Optional: Pre-initialize for better error handling
bh.load_common_spice_kernels()

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r_moon = bh.moon_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of the Moon in the GCRF inertial frame using NAIF DE ephemeris.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v_moon = bh.moon_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of the Moon in the GCRF inertial frame using NAIF DE ephemeris.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x_moon = bh.moon_state_spice(epc, bh.EphemerisSource.DE440s)

Calculate the position of Mercury in the GCRF inertial frame using NAIF DE ephemeris.

This function uses the high-precision NAIF DE ephemeris kernel (DE440s or DE440) for Mercury position computation. The kernel is loaded once and cached in a global thread-safe context, making subsequent calls very efficient.

If the ephemeris has not been initialized, it will be automatically loaded on the first call. For more control over initialization and error handling, use load_common_spice_kernels() explicitly.

Parameters:

Returns:

Raises:

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import brahe as bh

# Optional: Pre-initialize for better error handling
bh.load_common_spice_kernels()

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r_mercury = bh.mercury_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of Mercury in the GCRF inertial frame using NAIF DE ephemeris.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v_mercury = bh.mercury_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of Mercury in the GCRF inertial frame using NAIF DE ephemeris.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x_mercury = bh.mercury_state_spice(epc, bh.EphemerisSource.DE440s)

Calculate the position of Venus in the GCRF inertial frame using NAIF DE ephemeris.

This function uses the high-precision NAIF DE ephemeris kernel (DE440s or DE440) for Venus position computation. The kernel is loaded once and cached in a global thread-safe context, making subsequent calls very efficient.

If the ephemeris has not been initialized, it will be automatically loaded on the first call. For more control over initialization and error handling, use load_common_spice_kernels() explicitly.

Parameters:

Returns:

Raises:

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import brahe as bh

# Optional: Pre-initialize for better error handling
bh.load_common_spice_kernels()

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r_venus = bh.venus_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of Venus in the GCRF inertial frame using NAIF DE ephemeris.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v_venus = bh.venus_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of Venus in the GCRF inertial frame using NAIF DE ephemeris.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x_venus = bh.venus_state_spice(epc, bh.EphemerisSource.DE440s)

Calculate the position of Mars (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Mars body center, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Mars satellite ephemeris kernel (mar099s, ~68 MB), which is auto-downloaded and loaded on first use. For third-body force applications prefer mars_barycenter_position_spice, which needs only the DE kernel. Loaded kernels are cached in a global thread-safe context, making subsequent calls very efficient.

If the ephemeris has not been initialized, it will be automatically loaded on the first call. For more control over initialization and error handling, use load_common_spice_kernels() explicitly.

Parameters:

Returns:

Raises:

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import brahe as bh

# Optional: Pre-initialize for better error handling
bh.load_common_spice_kernels()

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r_mars = bh.mars_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of Mars (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Mars body-center velocity, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Mars satellite ephemeris kernel (mar099s, ~68 MB), which is auto-downloaded and loaded on first use. For third-body force applications prefer mars_barycenter_velocity_spice, which needs only the DE kernel.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v_mars = bh.mars_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of Mars (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Mars body-center state, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Mars satellite ephemeris kernel (mar099s, ~68 MB), which is auto-downloaded and loaded on first use. For third-body force applications prefer mars_barycenter_state_spice, which needs only the DE kernel.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x_mars = bh.mars_state_spice(epc, bh.EphemerisSource.DE440s)

Calculate the position of Jupiter (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Jupiter body center, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Jupiter satellite ephemeris kernel (jup365, ~1.1 GB), which is auto-downloaded and loaded on first use. For third-body force applications prefer jupiter_barycenter_position_spice, which needs only the DE kernel. Loaded kernels are cached in a global thread-safe context, making subsequent calls very efficient.

If the ephemeris has not been initialized, it will be automatically loaded on the first call. For more control over initialization and error handling, use load_common_spice_kernels() explicitly.

Parameters:

Returns:

Raises:

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import brahe as bh

# Optional: Pre-initialize for better error handling
bh.load_common_spice_kernels()

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r_jupiter = bh.jupiter_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of Jupiter (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Jupiter body-center velocity, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Jupiter satellite ephemeris kernel (jup365, ~1.1 GB), which is auto-downloaded and loaded on first use. For third-body force applications prefer jupiter_barycenter_velocity_spice, which needs only the DE kernel.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v_jupiter = bh.jupiter_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of Jupiter (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Jupiter body-center state, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Jupiter satellite ephemeris kernel (jup365, ~1.1 GB), which is auto-downloaded and loaded on first use. For third-body force applications prefer jupiter_barycenter_state_spice, which needs only the DE kernel.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x_jupiter = bh.jupiter_state_spice(epc, bh.EphemerisSource.DE440s)

Calculate the position of Saturn (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Saturn body center, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Saturn satellite ephemeris kernel (sat441, ~662 MB), which is auto-downloaded and loaded on first use. For third-body force applications prefer saturn_barycenter_position_spice, which needs only the DE kernel. Loaded kernels are cached in a global thread-safe context, making subsequent calls very efficient.

If the ephemeris has not been initialized, it will be automatically loaded on the first call. For more control over initialization and error handling, use load_common_spice_kernels() explicitly.

Parameters:

Returns:

Raises:

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import brahe as bh

# Optional: Pre-initialize for better error handling
bh.load_common_spice_kernels()

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r_saturn = bh.saturn_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of Saturn (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Saturn body-center velocity, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Saturn satellite ephemeris kernel (sat441, ~662 MB), which is auto-downloaded and loaded on first use. For third-body force applications prefer saturn_barycenter_velocity_spice, which needs only the DE kernel.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v_saturn = bh.saturn_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of Saturn (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Saturn body-center state, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Saturn satellite ephemeris kernel (sat441, ~662 MB), which is auto-downloaded and loaded on first use. For third-body force applications prefer saturn_barycenter_state_spice, which needs only the DE kernel.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x_saturn = bh.saturn_state_spice(epc, bh.EphemerisSource.DE440s)

Calculate the position of Uranus (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Uranus body center, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Uranus satellite ephemeris kernel (ura184, ~387 MB), which is auto-downloaded and loaded on first use. For third-body force applications prefer uranus_barycenter_position_spice, which needs only the DE kernel. Loaded kernels are cached in a global thread-safe context, making subsequent calls very efficient.

If the ephemeris has not been initialized, it will be automatically loaded on the first call. For more control over initialization and error handling, use load_common_spice_kernels() explicitly.

Parameters:

Returns:

Raises:

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import brahe as bh

# Optional: Pre-initialize for better error handling
bh.load_common_spice_kernels()

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r_uranus = bh.uranus_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of Uranus (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Uranus body-center velocity, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Uranus satellite ephemeris kernel (ura184, ~387 MB), which is auto-downloaded and loaded on first use. For third-body force applications prefer uranus_barycenter_velocity_spice, which needs only the DE kernel.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v_uranus = bh.uranus_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of Uranus (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Uranus body-center state, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Uranus satellite ephemeris kernel (ura184, ~387 MB), which is auto-downloaded and loaded on first use. For third-body force applications prefer uranus_barycenter_state_spice, which needs only the DE kernel.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x_uranus = bh.uranus_state_spice(epc, bh.EphemerisSource.DE440s)

Calculate the position of Neptune (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Neptune body center, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Neptune satellite ephemeris kernel (nep097, ~105 MB), which is auto-downloaded and loaded on first use. For third-body force applications prefer neptune_barycenter_position_spice, which needs only the DE kernel. Loaded kernels are cached in a global thread-safe context, making subsequent calls very efficient.

If the ephemeris has not been initialized, it will be automatically loaded on the first call. For more control over initialization and error handling, use load_common_spice_kernels() explicitly.

Parameters:

Returns:

Raises:

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import brahe as bh

# Optional: Pre-initialize for better error handling
bh.load_common_spice_kernels()

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r_neptune = bh.neptune_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of Neptune (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Neptune body-center velocity, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Neptune satellite ephemeris kernel (nep097, ~105 MB), which is auto-downloaded and loaded on first use. For third-body force applications prefer neptune_barycenter_velocity_spice, which needs only the DE kernel.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v_neptune = bh.neptune_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of Neptune (body center) in the GCRF inertial frame using NAIF DE and satellite ephemeris kernels.

This function returns the Neptune body-center state, combining the planetary-system barycenter from the DE kernel (DE440s or DE440) with the body-center offset from the Neptune satellite ephemeris kernel (nep097, ~105 MB), which is auto-downloaded and loaded on first use. For third-body force applications prefer neptune_barycenter_state_spice, which needs only the DE kernel.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x_neptune = bh.neptune_state_spice(epc, bh.EphemerisSource.DE440s)

Calculate the position of the Mars system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required. This is the position used by third-body force models. For the true Mars body center use mars_position_spice.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r = bh.mars_barycenter_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of the Mars system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter velocity using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v = bh.mars_barycenter_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of the Mars system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter state using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x = bh.mars_barycenter_state_spice(epc, bh.EphemerisSource.DE440s)

Calculate the position of the Jupiter system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required. This is the position used by third-body force models. For the true Jupiter body center use jupiter_position_spice.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r = bh.jupiter_barycenter_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of the Jupiter system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter velocity using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v = bh.jupiter_barycenter_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of the Jupiter system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter state using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x = bh.jupiter_barycenter_state_spice(epc, bh.EphemerisSource.DE440s)

Calculate the position of the Saturn system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required. This is the position used by third-body force models. For the true Saturn body center use saturn_position_spice.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r = bh.saturn_barycenter_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of the Saturn system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter velocity using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v = bh.saturn_barycenter_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of the Saturn system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter state using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x = bh.saturn_barycenter_state_spice(epc, bh.EphemerisSource.DE440s)

Calculate the position of the Uranus system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required. This is the position used by third-body force models. For the true Uranus body center use uranus_position_spice.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r = bh.uranus_barycenter_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of the Uranus system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter velocity using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required.

Parameters:

Returns:

Raises:

1
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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v = bh.uranus_barycenter_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of the Uranus system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter state using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required.

Parameters:

Returns:

Raises:

1
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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x = bh.uranus_barycenter_state_spice(epc, bh.EphemerisSource.DE440s)

Calculate the position of the Neptune system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required. This is the position used by third-body force models. For the true Neptune body center use neptune_position_spice.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r = bh.neptune_barycenter_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of the Neptune system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter velocity using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v = bh.neptune_barycenter_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of the Neptune system barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Returns the planetary-system barycenter state using only the DE kernel (DE440s or DE440); no satellite ephemeris kernel is required.

Parameters:

Returns:

Raises:

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4

import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x = bh.neptune_barycenter_state_spice(epc, bh.EphemerisSource.DE440s)

Calculate the position of the Solar System Barycenter in the GCRF inertial frame using NAIF DE ephemeris.

This function uses the high-precision NAIF DE ephemeris kernel (DE440s or DE440) for Solar System Barycenter position computation. The kernel is loaded once and cached in a global thread-safe context, making subsequent calls very efficient.

If the ephemeris has not been initialized, it will be automatically loaded on the first call. For more control over initialization and error handling, use load_common_spice_kernels() explicitly.

Parameters:

Returns:

Raises:

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import brahe as bh

# Optional: Pre-initialize for better error handling
bh.load_common_spice_kernels()

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
r_ssb = bh.solar_system_barycenter_position_spice(epc, bh.EphemerisSource.DE440s)

Calculate the velocity of the Solar System Barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Parameters:

Returns:

Raises:

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import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
v_solar_system_barycenter = bh.solar_system_barycenter_velocity_spice(epc, bh.EphemerisSource.DE440s)

Calculate the state (position and velocity) of the Solar System Barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Parameters:

Returns:

Raises:

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2
3
4

import brahe as bh

epc = bh.Epoch.from_date(2024, 2, 25, bh.TimeSystem.UTC)
x_solar_system_barycenter = bh.solar_system_barycenter_state_spice(epc, bh.EphemerisSource.DE440s)

Convenience alias for solar_system_barycenter_position_spice.

Calculate the position of the Solar System Barycenter in the GCRF inertial frame using NAIF DE ephemeris.

Parameters: