SuperDraco's Also Key to Falcon 9 Reuse?

Jeff Findley writes:

Powering through the atmosphere with nearly empty fuel tanks and no full
second stage and payload on top (and the center of gravity resulting
from that) *is* more difficult. A F9 first stage on its own with nearly
empty fuel tanks will try very hard to fly with the bottom forward.

If you're braking for landing, don't you want the bottom forward?

Sure, but before landing you have to fly the thing back to the launch
site. I don't think landing will be a really hard problem.


Jochem

--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery

In sci.space.station message ev-dnQxeppPJx9PSnZ2dnUVZ_gmdnZ2d@giganews.
com, Wed, 29 Feb 2012 12:03:13, David Spain posted:

Jeff Findley wrote:
As far as current state of the art is concerned, I'd think that
Armadillo Aerospace has as much experience with liquid fueled rocket
powered VTVL control algorithms as anyone else in the business.

No doubt! The guys at SpaceX that think they can bring F9 stage one
down in one piece ought to talk the Armadillo folks about active
control of something with a long lever arm. Forget about cross-winds,
just pretend you're bringing the whole thing down in a vacuum. That
seems plenty hard right there. Oh and don't forget the weight in that
arm tends to shift a bit to and fro...


The long lever arm of the tankage above the main engines provides an
excellent place to mount half a dozen smallish sideways thrusters to
help keep it all upright.

Since SpaceX design in California, they'll have every reason to
disregard what the Florida brochures say about the Florida weather.

Does Stage 2 need to be fly-back? ISTM that it should be a fly-once-
round system (or 17 times round for less cross-range need).

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