SpaceX Has A Pipedream

Spaceflight Now has a recent article [Reprinted from CBS Space] on SpaceX's vision of making their boosters reusable. The simulation video is sharp. The stated intention is for direct descent and landing under rocket thrust. Sounds simple enough on the face of it but I immediately saw some flaws in the plans.

First Stage; Slant range puts the booster a long way from the launch site and variable target orbits increase possible descent points over a large arc, typically well out over the Atlantic. The sheer height of the Falcon 9 booster makes me want to install much larger landing legs [and more of them]. This is why all flyback booster designs thusfar have wings, wheeled landing gear and sometimes jet engines.

Second stage, This might actually be a bit easier than the first stage. Because the 2nd stage is itself orbital [or nearly so], one can pick the reentry point and bring it down where desired. A reentry heat shield adds a lot of weight though. At least 2 motor restarts are needed, but restarts are not that uncommon here. Need a lot of spare fuel for both the deorbit and the landing. Second stage motor nozzles are typically optimized for high altitude/vacuum operations and will be inefficient back at sea level.
I believe it was NRL that was ground testing a booster 20 or so years ago that was low-pressure [no turbo pumps] and had a variable expansion thrust bell, kinda like the "turkey feathers" on a fighter jet engine nozzle. This allowed inflight expansion ratio optimization for any altitude.

Capsule and boosters are shown returning on thrust alone. Even with thrust for landing, parachute systems would still be more economical and probably lighter for slowing and stabilizing the vehicles in an upright position instead of relying on attitude thrusters and the mains alone. Parachutes would also add some safety in case of motor failure, or at least reduce the splat.

>>>>>>
"We'll see if this works," Musk said. "But it's going to be certainly an exciting journey. And if it does work, it'll be pretty huge. If you look at the cost of a Falcon 9 ... it's about $50 (million) to $60 million. But the cost of the fuel and oxygen and so forth is only about $200,000. So obviously, if we can reuse the rocket, say, a thousand times, then that would make the capital cost of the rocket for launch only about $50,000. ... It would allow about a hundred-fold reduction in launch costs."
<<<<<<

Was Mr Musk reading that off a script???
Nobody's gonna get 1000 uses out of any booster, even if there is that large a backlog of flight contracts. Divide flight contracts by; payload production rates, vehicle refurbishment rate, available ground support, optimal launch windows... I'm sorry but I would've scoffed at 100 flights per booster. How about 10 flights each on a 5-10 booster fleet. By then; if the economics are sound, you'll be building a few replacements and/or an improved new fleet anyway.
Note that Elon says a 1000 fold reduction in booster cost relates to only a 100 fold reduction in overall launch costs. That sounds reasonable as other costs go up drastically. Additional flight systems complication, booster retransport, refurbishment, range comm/nav systems, additional facilities...manpower, manpower, manpower.

I have great respect for SpaceX and what they have accomplished. In fact I'd like to work for them, and I can't say that about most of the aerospace industry or NASA itself.

http://spaceflightnow.com/news/n1109/30spacexflyback/

Sidewinder on Steroids

Here's yet another gem I found at China Lake Alumni.
1970 gallery.  It's called the HAP Sidewinder. HAP
stands for High Altitude Project.  The limited research
I found indicates that it was created by combining a
Sparrow rocket motor with the front end of an AIM-9L.  
Some test flights were performed, but the project was
soon cancelled.

I've never been a big Sidewinder fan and the
proliferation of variants has always made the study of
them a bit bewildering.  Having admitted that, I must
say;  I LIKE THIS!

I can look up the 2 diameters and easily scale a drawing
from there.I have an Estes Python nosecone which will
serve for the Sidewinder seeker section,  or I can turn
one, as well as turning the transition section.  
Sigh... just add it to an already long list of unstarted
and semi-started projects

China Lake YouFoe Quiz

Here's another pic I found at China Lake Alumni.
The very first pic in the 1962 gallery.
I haven't seen one of these in at least 20 years.
I do know what it is.
Do you?

Mystery Mono at China Lake

Sometimes it pays to repeat a search from time to time.
Previously, when I Googled Monocopter I'd get some of the
usual scattering of model vidclips and discussion, and a whole
lot of that Euro turbofan jetpak, which may be mono, but
aint no copter.  This time around the photo below popped
out at me.  Quite a find.
It was at the China Lake Alumni website, in the photo gallery
page for 1963. China Lake is home to the US Navy weapons
test facilities.  The site search engine, unfortunately, yielded
no other photos or info. I kept the original file name on the pic;
Monocopter perch 16AUG63 CLK SL-027985



I am able to infer a few things from the pic. Foremost is that 
the protuberance on the far side of the hub is not the same as
the wing on this side, so I believe this really is a monocopter.  
The wing is mounted to the hub at the center of lift, therefore  
is probably capable of changing pitch in flight, likely in response
to control inputs to the elevon at the wingtip. If the hub isn't
made from actual truck hubcaps I'll be surprised as hell.   If it's
heavy enough the disk hub will stabilize a rotor despite the lack
of a proper flybar.  I had already designed a monocopter using
a ring shaped hub, although the ring on mine is proportionately
larger in relation to the wing since it'll have no extra internal mass.

Two things are puzzling.
Obviously; what is the powerplant?
The other is the source of the 1/2 round shadow directly below
the hub? You can see that the sun is to the left and the shadows
are stretching to the right, therefore the hub's actual shadow is
to the right as well.

If anyone knows ANYTHING further, PLEASE comment!