4 ms·

That comment is worth a read, I had no clue they were actually generating lift on the body to reduce fuel/etc. Incredible stuff.

JshWright 9y ago
The new and improved grid fins debuted on this flight allow them even greater capabilities in that regard (greater control authority means they can achieve a higher angle of attack).
- deleted 9y ago
  [deleted]
schiffern 9y ago
Thanks. I made a mistake in that comment, saying the lift/drag of the Shuttle was 1. The hypersonic L/D was 1, but during subsonic approach it was 4.5. In hindsight it kinda makes sense that wings do something. :) The maneuver is more noticeable with the new titanium grid fins (needed because the old aluminum ones caught fire from aerodynamic heating). Not only are they larger, but they use a "sawtooth" leading edge that increases control authority. New: https://twitter.com/elonmusk/status/879065552060260352 https://twitter.com/elonmusk/status/879065552060260352 Old: http://www.spaceflightinsider.com/wp-content/uploads/2015/12/4571-spacex_falcon_9_orbcomm_og2-michael_howard.jpg http://www.spaceflightinsider.com/wp-content/uploads/2015/12... They also happen to be the largest titanium forgings in the world. https://forum.nasaspaceflight.com/index.php?topic=42544.340#msg1661163 https://forum.nasaspaceflight.com/index.php?topic=42544.340#...
- skykooler 9y ago
  Well, the plan is to use forging to make them, but the ones on this rocket were cast as a blank and machined. One presumes that they are still working on the forging system. https://twitter.com/elonmusk/status/878821062326198272 https://twitter.com/elonmusk/status/878821062326198272
azernik 9y ago
Saying in aviation: If you put a big enough engine on it, even a brick will fly. In this case, it's "given enough initial velocity and control authority, even a brick will glide", but the spirit is the same.
- WalterBright 9y ago
  I believe the proper term is "brick sthouse". A few years back a group of engineers decided to prove this by attaching a number of solid fuel rocket engines to a port-a-potty and launched it to great applause.
  - ajuc 9y ago
    In RC planes community it's quite common as well :) With modern brushless engines and LiPo batteries aerodynamics becomes optional. https://www.youtube.com/watch?v=bns5x4pvl5Y https://www.youtube.com/watch?v=bns5x4pvl5Y

JshWright 9y ago

The new and improved grid fins debuted on this flight allow them even greater capabilities in that regard (greater control authority means they can achieve a higher angle of attack).

deleted 9y ago
[deleted]

schiffern 9y ago

Thanks. I made a mistake in that comment, saying the lift/drag of the Shuttle was 1. The hypersonic L/D was 1, but during subsonic approach it was 4.5. In hindsight it kinda makes sense that wings do something. :) The maneuver is more noticeable with the new titanium grid fins (needed because the old aluminum ones caught fire from aerodynamic heating). Not only are they larger, but they use a "sawtooth" leading edge that increases control authority. New: https://twitter.com/elonmusk/status/879065552060260352 https://twitter.com/elonmusk/status/879065552060260352 Old: http://www.spaceflightinsider.com/wp-content/uploads/2015/12/4571-spacex_falcon_9_orbcomm_og2-michael_howard.jpg http://www.spaceflightinsider.com/wp-content/uploads/2015/12... They also happen to be the largest titanium forgings in the world. https://forum.nasaspaceflight.com/index.php?topic=42544.340#msg1661163 https://forum.nasaspaceflight.com/index.php?topic=42544.340#...

skykooler 9y ago
Well, the plan is to use forging to make them, but the ones on this rocket were cast as a blank and machined. One presumes that they are still working on the forging system. https://twitter.com/elonmusk/status/878821062326198272 https://twitter.com/elonmusk/status/878821062326198272

azernik 9y ago

Saying in aviation: If you put a big enough engine on it, even a brick will fly. In this case, it's "given enough initial velocity and control authority, even a brick will glide", but the spirit is the same.

WalterBright 9y ago
I believe the proper term is "brick sthouse". A few years back a group of engineers decided to prove this by attaching a number of solid fuel rocket engines to a port-a-potty and launched it to great applause.
- ajuc 9y ago
  In RC planes community it's quite common as well :) With modern brushless engines and LiPo batteries aerodynamics becomes optional. https://www.youtube.com/watch?v=bns5x4pvl5Y https://www.youtube.com/watch?v=bns5x4pvl5Y