Re: Bigelow Aerospace to offer $760 million for spaceship

On Oct 31, 1:11 am, fairwa...@xxxxxxxxx (Derek Lyons) wrote:
Len <l...@xxxxxxxxxxxxxx> wrote:
As for Rotary, rotors are fine for hovering or landing.
However, the laws of physics do not allow rotors
--especially large rotors--to perform well at significant
axial speeds. (thust x velocity ~ constant; low velocity
implies inefficient climb)

Umm... Len, you do know that Rotary only intended to use the rotors
for hovering and landing (and as a drag brake during descent)? They
weren't going to be used to climb at all.

Perhaps so. But I don't think that this was
the original intent. But let's give Rotary the
benefit of the doubt on that one.

I agree that rotors have potential for landing.
As part of consulting assessment task some
years before Rotary Rocket came into existence,
I designed a VTOVL vehicle that used stowed
(coiled) rotors for final deceleration and landing.
The task involved a positive effort to show
viability for VTOVL concepts. IMO, VTOVL concepts
are viable, but only at significantly higher gross
masses than most VTOVL advocates claim.
IMO, SSTOs --whether VTOVL or HTOHL require
gross liftoff masses of at least 800 to 1000 tonnes
with current technology and engines.

In the early 1960's at North American, after two
weeks active duty in an ASW squadron, I did a
conceptual design of a redeployable sonbuoy
that used rocket tip rotors for lifting out of the
water, translating to a new position and then
setting back into the water. So, I am not dead
set against powered or unpowered rotors for
appropriate applications.

Len


D.
--
Touch-twice life. Eat. Drink. Laugh.

http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL


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