Quote from: jcm on 11/14/2022 02:09 pmStill only 2 objects cataloged from the launch (although there is currently a gap, 54245, which could be the third object).It seems unlikely that the second stage was deorbited given the performance concerns, so I assume the third object will eventually show up.Also, the two that are there have quite different inclinations (24.2 and 22.3), if I'm reading the elements right. This seems odd - I can't see any reason to change the inclination without changing the perigee. It's quite a bit less efficient than combining the maneuvers. So something is odd....
Still only 2 objects cataloged from the launch (although there is currently a gap, 54245, which could be the third object).It seems unlikely that the second stage was deorbited given the performance concerns, so I assume the third object will eventually show up.
When there's a deorbit, there's usually a marine hazard map for that. GPS missions include deorbit burns and they issue these notices as well.
Also just cataloged, the expected third object from the last F9 launch, as 54248 /2022-153C in a 150 x 58270 kmx 24.4 deg orbit; probably the F9 second stage.This leaves 54245 as an unexpected gap in the @18thSDS catalog
Quote from: LouScheffer on 11/14/2022 11:36 amQuote from: litton4 on 11/14/2022 11:11 amPlease can someone remind me (or point at an explanation) of what the GTO-xxxx numbers mean?Sure, the XXXX is the number of m/s left to get into geosynchronous orbit, so smaller numbers are better. It's a combination of two tasks - to circularize the orbit at geosynchronous height, and to remove any remaining inclination from the transfer orbit. As an example, a GTO with a GEO apogee from the Cape is about GTO-1800, whereas a GTO with GEO apogee from French Guiana is typically about GTO-1500, since the spacecraft has less inclination to remove.If your rocket has more dV than needed to simply reach GTO apogee, you can spend it by increasing the apogee above geosynchronous (which makes the plane change cheaper, by reducing the inclination cost), or reducing the inclination of the transfer orbit.Also, you can use the spare delta-v to raise the perigee significantly and reduce the inclination a bit more at apogee.
Quote from: litton4 on 11/14/2022 11:11 amPlease can someone remind me (or point at an explanation) of what the GTO-xxxx numbers mean?Sure, the XXXX is the number of m/s left to get into geosynchronous orbit, so smaller numbers are better. It's a combination of two tasks - to circularize the orbit at geosynchronous height, and to remove any remaining inclination from the transfer orbit. As an example, a GTO with a GEO apogee from the Cape is about GTO-1800, whereas a GTO with GEO apogee from French Guiana is typically about GTO-1500, since the spacecraft has less inclination to remove.If your rocket has more dV than needed to simply reach GTO apogee, you can spend it by increasing the apogee above geosynchronous (which makes the plane change cheaper, by reducing the inclination cost), or reducing the inclination of the transfer orbit.
Please can someone remind me (or point at an explanation) of what the GTO-xxxx numbers mean?
Quote from: LouScheffer on 11/14/2022 11:36 amQuote from: litton4 on 11/14/2022 11:11 amPlease can someone remind me (or point at an explanation) of what the GTO-xxxx numbers mean?Sure, the XXXX is the number of m/s left to get into geosynchronous orbit, so smaller numbers are better. It's a combination of two tasks - to circularize the orbit at geosynchronous height, and to remove any remaining inclination from the transfer orbit. As an example, a GTO with a GEO apogee from the Cape is about GTO-1800, whereas a GTO with GEO apogee from French Guiana is typically about GTO-1500, since the spacecraft has less inclination to remove.It's more commonly, and more appropriately in my opinion, written as GEO-1500, as in "GEO(stationary orbit) minus 1500 (m/s)". "GTO-1500" sounds like it would be 1500 m/s shy of the elliptical transfer orbit (with perigee at a couple hundred kilometers and apogee at ~36000 km), instead of 1500 m/s shy of the actual circular geostationary orbit. Nitpicking, I know, but that allows you to generalize it and say things like "TLI-100" (trans-lunar injection minus 100).On another note, it can be worth mentioning that one way of lowering the amount of Δv needed by the satellite to enter GEO, is to insert it into an orbit with apogee higher than 36000 km; this is called a super-synchronous transfer orbit. Since the velocity at the apogee is then lower, you need less energy to change the inclination. And this is what was done in this particular launch, putting the apogee at 38000 km. (Another way is of course to raise the perigee of the transfer orbit instead, so the satellite will need less energy to circularize. That however means that the upper stage of the launch rocket will need to reserve some propellant to lower its perigee again afterwards, so it can deorbit in a reasonable time.)
Quote from: litton4 on 11/14/2022 11:11 amPlease can someone remind me (or point at an explanation) of what the GTO-xxxx numbers mean?Sure, the XXXX is the number of m/s left to get into geosynchronous orbit, so smaller numbers are better. It's a combination of two tasks - to circularize the orbit at geosynchronous height, and to remove any remaining inclination from the transfer orbit. As an example, a GTO with a GEO apogee from the Cape is about GTO-1800, whereas a GTO with GEO apogee from French Guiana is typically about GTO-1500, since the spacecraft has less inclination to remove.
The booster has now been cataloged, 54248 in a 150 x 58270 km x 24.4 deg orbit.
Quote from: jcm on 11/15/2022 03:43 amThe booster has now been cataloged, 54248 in a 150 x 58270 km x 24.4 deg orbit.Interesting. The apogee is higher, and the perigee lower, then the initial transfer orbit (though not by much in m/s). Intuitively, this could be explained by a fuel dump or small maneuver at right angles to the flight path. This would not change the earth-relative velocity much (same orbital energy) but would change the eccentricity, potentially resulting in both a higher apogee and lower perigee.
Quote from: LouScheffer on 11/15/2022 01:06 pmQuote from: jcm on 11/15/2022 03:43 amThe booster has now been cataloged, 54248 in a 150 x 58270 km x 24.4 deg orbit.Interesting. The apogee is higher, and the perigee lower, then the initial transfer orbit (though not by much in m/s). Intuitively, this could be explained by a fuel dump or small maneuver at right angles to the flight path. This would not change the earth-relative velocity much (same orbital energy) but would change the eccentricity, potentially resulting in both a higher apogee and lower perigee.The apogee raise here is still a puzzle. It's not like it's a huge maneuver (50 m/s at an altitude of 20,000 km could do both the perigee drop and the apogee raise), but you can always do the perigee drop more efficiently by omitting any prograde component of the burn (and so not raising the apogee). For the same delta V (in this hypothetical case, and many others I've tried) they could have de-orbited the second stage completely.
Quote from: LouScheffer on 11/16/2022 12:52 pmQuote from: LouScheffer on 11/15/2022 01:06 pmQuote from: jcm on 11/15/2022 03:43 amThe booster has now been cataloged, 54248 in a 150 x 58270 km x 24.4 deg orbit.Interesting. The apogee is higher, and the perigee lower, then the initial transfer orbit (though not by much in m/s). Intuitively, this could be explained by a fuel dump or small maneuver at right angles to the flight path. This would not change the earth-relative velocity much (same orbital energy) but would change the eccentricity, potentially resulting in both a higher apogee and lower perigee.The apogee raise here is still a puzzle. It's not like it's a huge maneuver (50 m/s at an altitude of 20,000 km could do both the perigee drop and the apogee raise), but you can always do the perigee drop more efficiently by omitting any prograde component of the burn (and so not raising the apogee). For the same delta V (in this hypothetical case, and many others I've tried) they could have de-orbited the second stage completely.Could they have done it in the same phase of flight? The upper stage only has a few hours of endurance until the propellants are boiled off, and that is with the extension kit. They might well have done the most efficient disposal burn they could an hour after launch.
I'm back on a ship operating out of Port Canaveral. This time CT5 directly opposite the @SpaceX fleet. Got some great pics of MV Bob and Megan alongside. And a fairing half that's been fished out. @SpaceOffshore
Intelsat License LLC (“Intelsat”) herein requests an additional 30 days of Special Temporary Authority (“STA”)1 previously granted to Intelsat to drift Galaxy 32 (S3078) from its in-orbit testing (“IOT”) location of 149.05° W.L. to its permanent location of 91.0° W.L.2 Galaxy 32 was launched on November 12, 2022. The satellite completed its IOT at 149.05° W.L. on January 7, 2023.3 Galaxy 32 began its drift to 91.0° W.L. on January 11, 2023, and is expected to arrive on-station by the end of February 2023.
