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#120
by
mn
on 20 Feb, 2023 20:44
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#121
by
ZachS09
on 20 Feb, 2023 21:13
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IMO, "supersynchronous transfer orbit" may refer to a GTO with an apogee of 40,000+ kilometers. Anything between the 35,786-40,000 range is standard GTO.
Again, it's my opinion.
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#122
by
mn
on 20 Feb, 2023 21:44
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IMO, "supersynchronous transfer orbit" may refer to a GTO with an apogee of 40,000+ kilometers. Anything between the 35,786-40,000 range is standard GTO.
Again, it's my opinion.
Am I correct in understanding that apogee is measured from the center of earth?
If so GEO apogee is 42,164 km. Steven Pietrobon estimated an apogee of 42,529 so just barely supersync?
Edit: Steven Pietrobon wrote apogee, but he could have meant to write altitude. He does refer to altitude later in the same post.
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#123
by
ZachS09
on 21 Feb, 2023 00:58
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IMO, "supersynchronous transfer orbit" may refer to a GTO with an apogee of 40,000+ kilometers. Anything between the 35,786-40,000 range is standard GTO.
Again, it's my opinion.
Am I correct in understanding that apogee is measured from the center of earth?
If so GEO apogee is 42,164 km. Steven Pietrobon estimated an apogee of 42,529 so just barely supersync?
Edit: Steven Pietrobon wrote apogee, but he could have meant to write altitude. He does refer to altitude later in the same post.
The 35,786 number refers to the altitude above sea level.
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#124
by
Steven Pietrobon
on 21 Feb, 2023 05:12
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I never use distance from the centre of the Earth for the apogee and perigee! That would be too confusing. I calculate my altitudes by subtracting 6378.165 km (Earth's equatorial radius) from the distance to the centre of the Earth.
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#125
by
ZachS09
on 21 Feb, 2023 12:01
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I never use distance from the centre of the Earth for the apogee and perigee! That would be too confusing. I calculate my altitudes by subtracting 6378.165 km (Earth's equatorial radius) from the distance to the centre of the Earth.
Me neither.
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#126
by
FutureSpaceTourist
on 21 Feb, 2023 13:41
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#127
by
Comga
on 21 Feb, 2023 18:09
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I never use distance from the centre of the Earth for the apogee and perigee! That would be too confusing. I calculate my altitudes by subtracting 6378.165 km (Earth's equatorial radius) from the distance to the centre of the Earth.
Me neither.
There are times to use the altitude, and other times to use the radius.
There is a value of each for perigee and apogee around Earth, or periapsis and apoapsis in general.
In my calculations, they are commonly labled alt-a and alt_p vs r_a and r_p.
It's pretty clear which one to use for any given calculation.
It's not so obvious which is being used in conversation for orbits around GEO, so one has to be explicit when it matters.
That said, was the launch of I6-F2 to a few hundred kilometers above GEO or 7,000 km above GEO?
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#128
by
gongora
on 21 Feb, 2023 18:32
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For Earth orbits I usually see it called semi-major axis for the (apogee) distance from the center of the Earth.
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#129
by
Comga
on 21 Feb, 2023 19:11
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For Earth orbits I usually see it called semi-major axis for the (apogee) distance from the center of the Earth.
That may be incorrect.
The semi-major axis is half the distance from the apogee (apoapsis in general) to the perigee (periapsis), but the Earth (central body) is not at the center of the ellipse of the orbit.
Look at the orbits of Chandra and TESS.
Their week or two long orbits have semi-major axes and apogees a good fraction of the distance to the Moon, but perigees in the few thousand kilometers of altitude. These approach the limit where the apogee is almost twice the semi-major axis.
Ditto for the NRHO lunar orbits
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#130
by
alugobi
on 21 Feb, 2023 19:41
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What does this mean, "no TLE data"?
Isn't the sat calling home so they know: it's working; where it is?
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#131
by
mn
on 21 Feb, 2023 21:56
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I never use distance from the centre of the Earth for the apogee and perigee! That would be too confusing. I calculate my altitudes by subtracting 6378.165 km (Earth's equatorial radius) from the distance to the centre of the Earth.
Me neither.
There are times to use the altitude, and other times to use the radius.
There is a value of each for perigee and apogee around Earth, or periapsis and apoapsis in general.
In my calculations, they are commonly labled alt-a and alt_p vs r_a and r_p.
It's pretty clear which one to use for any given calculation.
It's not so obvious which is being used in conversation for orbits around GEO, so one has to be explicit when it matters.
That said, was the launch of I6-F2 to a few hundred kilometers above GEO or 7,000 km above GEO?
Steven Pietrobon clarified that he uses altitude from earth surface, that put's his estimate of 42,528 at roughly 7000 km above GEO, slightly supersync.
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#132
by
Conexion Espacial
on 22 Feb, 2023 03:23
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#133
by
FutureSpaceTourist
on 22 Feb, 2023 14:50
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https://twitter.com/astrogeo/status/1628221645453139968 Today before sunrise the Falcon 9 booster B1077 returned to Port Canaveral on the autonomous drone ship “Just Read the Instructions”. After sunset the SpaceX support ship “Shannon” left the Port presumably supporting the upcoming Crew 6 launch on February 27. @SpaceOffshore
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#134
by
Lewis007
on 22 Feb, 2023 19:22
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#135
by
Lewis007
on 23 Feb, 2023 18:54
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#136
by
GewoonLukas_
on 07 Mar, 2023 11:03
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#137
by
Targeteer
on 08 Mar, 2023 17:39
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#138
by
Targeteer
on 16 Mar, 2023 21:04
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#139
by
Chinakpradhan
on 01 Apr, 2023 17:31
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Inmarsat6 F2 mission patch won at a twitter quizzal with its congratulatory message