Falcon 9 launch rescheduled for Saturday

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SpaceX and NASA have now rescheduled the Falcon 9/Dragon launch to ISS for Saturday morning at 4:47 am Eastern.

I am wondering if lack of light is going to effect the effort to vertically land the first stage.



  • Blair Ivey

    “I  am wondering if lack of light is going to effect the effort to vertically land the first stage”

    ‘We choose to do these things; not because they are easy, but because they are hard.’

  • Matt in AZ

    If the landing barge to the east is a few time zones away, there should be plenty of light. How far downrange is the recovery?

  • mpthompson

    I saw a graphic earlier this week that placed the barge about 200 to 300 miles north-east of the launch site. Probably not enough to make much difference regarding daylight. However, I suspect the rocket doesn’t rely on visual localization to determine it’s position with respect to the barge. Or, if it does, the barge should have its own floodlights to light up the landing area.

  • D K Rögnvald Williams

    I wasn’t aware that the rocket has eyes.

  • Tom Billings

    One thing that *will* be made more difficult is aircraft making visual records of the first stage descent. Even though this descent has been done several times, this is the first time with those hypersonic “paddles”. If there is an at altitude “anomaly” that destroys the vehicle after those paddles deploy, then having visual records would be highly desirable.

    Perhaps those portions of the flight will be high enough that light will be available. At 30 kilometers you can see a *long* way to the horizon. Can that be calculated by anyone here? I would be surprised if no one at SpaceX had done that calculation.

  • mpthompson

    Having done motion control algorithms (nothing like this though), telemetry data from the gyroscopes, accelerometers and GPS receivers would very likely be far more useful to the engineers than any visual data from cameras. Cameras are most useful for PR and from an engineering standpoint to confirm that items such as the fins deployed as expected, but provide very limited data useful for guiding the rocket to a small patch on the surface of the ocean. High quality telemetry data will confirm and refine the physicals models used to design the control algorithms. The data can also be used to dissect the flight in great detail and understand what happened should something go wrong.

    Given this is the first attempt to use the fins in this fashion, I would be pleasantly surprised if the SpaceX engineers have good enough models and other information to successfully guide the stage down to a 10 meter patch of sea. Instead, I see them getting within a few kilometers on the first attempt, 100’s of meters on the next few attempts and then finally sticking it. That’s typically how the engineering process works. The first few flights of the Falcon 1 are a perfect example of this.

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