SpaceX does it again!

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SpaceX is beginning to make the landings of its Falcon 9 first stage routine. They just successfully landed another first stage on their drone ship, even though this was once again a difficult geosynchronous satellite launch with high speeds and limited available fuel.

It also appears that they will also successfully place the commercial satellite in orbit.


  • Wayne

    “Launch & Landing of 25th SpaceX Falcon 9 Rocket with Thaicom 8”

  • Edward

    Very interesting. They took it to a supersynchronous transfer orbit — a higher orbit than geosynchronous or geostationary orbit (GEO). The reason to do this is to reduce the fuel needed by the satellite to change the orbital plane inclination, probably from around 28-ish degrees, to 0 degrees, depending upon how much the rocket could correct the inclination during launch.

    Orbital mechanics is a funny thing, often counterintuitive. Although it takes more energy to go to the supersynchronous transfer orbit, the satellite’s speed at apogee will be slower there than at the apogee of a geostationary transfer orbit. However, it takes a lot of fuel to change orbital planes, and the amount is related to the speed at the time of the burn. If you are going slower, it takes less fuel to rotate the orbital plane that if you are going faster, so counterintuitively it can take less overall fuel to go to a higher apogee, change planes, then drop back down to a lower apogee and circularize the orbit at GEO.

    Thaicom 8 is 3,100 kg, but the earlier and trickier JCSat 14 was 4,696 kg. The lower weight is why SpaceX was not pessimistic, this time, and was also able to take Thaicom 8 to a transfer orbit with a higher apogee.

    Meanwhile, after only six months, SpaceX is starting to make this look routine. And easy.

    Now let’s see if these Falcons really *can* fly multiple times. That should be an exciting launch!

  • Wayne

    As always– appreciate the rocket-science & orbital-mechanics factoids!!

  • Wayne

    Technical Webcast (full) is at—

  • Edward

    “appreciate the rocket-science & orbital-mechanics factoids!!”

    Thanks. I’m an engineer, and we can’t get these things in during ordinary conversation. Here, however, if it bores someone, they can just skip the comment and I won’t feel bad that they yawned at me.

    Thanks for the full webcast link.

  • mkent

    The landings are fun to watch, but it’s all about putting payloads into orbit.

    A bit of trivia: With this launch Falcon 9 now has more successful launches (24) than Delta IV Medium (23). I don’t think anyone would have predicted that in 2002.

  • Wayne

    mkent: Cool trivia! –Yeah, it is all about getting the job done, and the landings are even better, when the video doesn’t drop out at key points! That being said–cool video from the 1st stage vantage point & the 2nd stage video really gives one a fantastic perspective.
    Absolutely amazing SpaceX can pull this off so consistently & even more so that we can watch it on our ‘devices.’ (Whole lot of stuff, has changed dramatically from 2002, eh!)
    Love the science/engineering info! It builds on & reinforces concept’s I’m trying to get a grip upon. Any time you can work in science facts (or Star Trek references,) I for one enjoy & appreciate them!

  • NormD

    Sped up landing from rocket’s on-board camera

  • Edward

    Hosted Webcast:

    This version has the “talking engineers” commentary. I usually learn something from these SpaceX commentaries.

  • Dick Eagleson


    Allow me to add one more thumbs-up to your total. Excellent stuff.

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