11 thoughts on “Blue Origin Team Does it Again!”

  1. Nice to see this.  Was it a soft landing of the crew capsule?  She was saying that it would land at about 1 mph but it seemed to me that it was still around 16 mph.

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  2. The final seconds before impact thrusters “feather” the velocity to 0 to 2 mph — similar to the final seconds when an airplane lands. Dust is from air flow of thrusters — not from impact.

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  3. It is amazing that the rockets can land vertically. Does anyone know how much wind there was on this landing?

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  4. Ace Fungo:
    As an Amazon Prime customer do I get free shipping if I let them strap me in this sucker?

    That is one way to handle a problem customer. “Step in here and wait. Customer service will be with you in a moment.”

     

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  5. 10 Cents:
    It is amazing that the rockets can land vertically.

    Many people don’t appreciate that the difficult part of the maneuver isn’t remaining vertical (that’s no harder than remaining on course during the ascent), but timing the landing burn so that you achieve zero velocity and zero altitude at the same moment.  In order save fuel, the most efficient way to land is what has come to be called a “suicide burn” (I believe the term originated with players of Kerbal Space Program, but it has come into general use in the rocket community).  The longer you spend slowing for landing, the more fuel you burn just fighting against gravity, so optimal fuel economy comes from waiting until the last moment, then burning at full thrust so that your vertical velocity reaches precisely zero at touchdown.  Obviously, there is zero room for error in this: if the engine starts a bit late, or doesn’t develop 100% thrust, it’s RUD time.  In practice, high thrust is used, but not 100% throttle, trading fuel for safety margin.

    Further complicating things is that rocket engines cannot be throttled to arbitrarily low thrust levels: they will only work over a limited range of thrust (and some engines cannot be throttled at all).  For example, the SpaceX Merlin 1D engine can only be throttled down to 70% of full thrust.  Even with only one of the nine engines on the first stage burning for the landing, 70% thrust is greater than the weight of the near-empty first stage, so there is no alternative to a suicide burn (SpaceX uses the less dire sounding term “hover-slam”, which is misleading because at no time is the stage actually hovering).  The BE-3 engine used on Blue Origin’s New Shepard is capable of much deeper throttling, down to 18% of full thrust, and if you look at the video of the landing, it is actually hovering in the final moments before touchdown.  This wastes fuel, but that isn’t so critical for a suborbital launcher where the mass fraction doesn’t have to be as extreme.

    Here is a video by Scott Manley that explains suicide burns and why they make sense.

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  6. To answer Richard Easton‘s comment , my birthday is the same day as the lunar landing: JULY 20th, so since a child, space flight has been a keen interest of mine — and I became a mechanical engineer because of  this interest, plus my strengths in math, science, and drawing (dare I say CAD … computer-aided design)!

    Because of great scientists like the ones on this blog, all inhabitants of this world have benefited immensely — THANK YOU! (though to0 many of the world inhabitants don’t understand why, perhaps more scientist need to blog and go to Toastmasters, and learn to sell).

    Further, I believe in peace through overwhelming strength, and leading science is an import component of this.  The West’s success at rockets makes peace worldwide far more likely. Weakness tends to encourages aggression. It is my hope Trump is of the Casper Weinberger foreign policy mold, and not the disastrous 1988 to 2016 USA foreign policy mold — but time will tell.

    Today, April 30th 2018, there is much to be thankful for!

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  7. Joe Conservative:
    To answer Richard Easton‘s comment , my birthday is the same day as the lunar landing: JULY 20th, so since a child, space flight has been a keen interest of mine — and I became a mechanical engineer because of  this interest, plus my strengths in math, science, and drawing (dare I say CAD … computer-aided design)!

    Because of great scientists like the ones on this blog, all inhabitants of this world have benefited immensely — THANK YOU! (though to0 many of the world inhabitants don’t understand why, perhaps more scientist need to blog and go to Toastmasters, and learn to sell).

    Further, I believe in peace through overwhelming strength, and leading science is an import component of this.  The West’s success at rockets makes peace worldwide far more likely. Weakness tends to encourages aggression. It is my hope Trump is of the Casper Weinberg foreign policy mold, and not the disastrous 1988 to present USA foreign policy regime — but time will tell.

    But today April 30th 2018, there is much to be thankful for!

    It’s nice to have so many space enthusiasts on this MB.

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