A New Rocket Engine?

View 782 Tuesday, July 16, 2013

Riots in Los Angeles last night, but they weren’t much. The Attorney General advocates dual jeopardy for Zimmerman. He has to be guilty of something! Several radio talk show hosts are saying the same thing. There is one interpretation of a telephone conversation in which Martin intimated that he was being stalked by a creepy dude: that Martin thought he was being pursued by a male rapist, and that he confronted the stalker with violence out of fear. That approaches high tragedy: each of those in the fatal confrontation thought he was doing the right thing in protecting the neighborhood. I have no evidence of this other than Martin’s final call.

If Martin had called 911 as Zimmerman did the result would probably have been different.

Development of commercial space will be needed to increase productivity sufficiently to make a big enough pie to distribute and spread the wealth – you can’t socialize unless you produce. I am often informed of claims to progress in space technology.

Space access breakthrough by Poms

Hi Jerry,

just in case you do not have this yet – here is a link for you:

http://www.reactionengines.co.uk/sabre_howworks.html

Regards

This leads to a nice web site presentation of an engine concept first postulated in an Arthur Clarke story about 1950 or so: A supersonic ramjet that once flown to high altitude as a ramjet becomes a rocket (by closing the ram intakes and feeding oxidant into the system) to achieve orbital velocity.

There were a number of projects aiming at development of this sort of engine. The NASP National AeroSpace Plane project generated numerous  tests. Most rocket scientists abandoned the concept because the plumbing was expensive and the mass savings were low. In order to achieve an appreciable fraction of orbital velocity it is necessary to fly at very high Mach numbers in the atmosphere. This puts re-entry temperature stress on the leading edges of the wings and the intake surfaces of the air intake scoops, and as of 1990 at least there were simply no materials to build those of. NASP was reluctantly abandoned because many concluded that it would need unobtanium for the intake scoops.

The ramjet-then-rocket concept appealed to Clarke and to many who followed him, but the numbers don’t give all that much advantage to the concept. LOX is cheap and cryogenics have mass costs, with the mass added to the structure which must be put into orbit; while LOX is of course part of the reaction mass that does not go to orbit.

We designed the SSX at 600,000 pounds Gross Lift Off Weight (GLOW) and about 50,000 pounds structure weight as an x-project that as Max Hunter put it “Might not make orbit but it will scare it to death”; SSX http://www.jerrypournelle.com/slowchange/SSX.html was intended to supply the knowledge required to build a single stage to orbit system, refuelable and reusable. The Air Force didn’t have the money to build the 600,000 GLOW SSX so the scale model DC/X was built to test the Vertical Takeoff and Landing concepts; it did that. DC/X could be controlled at low speeds, and was steerable and landable.

I would be astonished if the SABRE ramjet/rocket engine described on this web site had actually been built and flight tested. I note that the web site claims Mach 5 cruising speeds. The X-51 achieved that but not as a sustained cruising speed. http://jalopnik.com/5549364/scramjet-destroys-nasa-record-hits-mach-5-for-three-minutes

The original ramjet to orbit concept required reaching speeds above Mach 20 before converting to onboard oxidant.

I’d appreciate enlightenment from anyone who knows more, but I have no confidence that we known how to fly to space and return with this concept. I still believe we can build reusable Single Stage to Orbit systems at above 600,000 pound GLOW vertical takeoff and landing. X-33 was intended to be vertical takeoff horizontal landing but after billions of dollars were spent no fling hardware was tested. The SSX cold have been tested with three flying X vehicles for less than X-33 cost.

 

Sabre engines seeking funding…

Jerry

It seems Reaction Engines Ltd. are looking for the next round of funding (approx £200M) having managed to extract the promise of £60M from the UK government.

See:- http://www.bbc.co.uk/news/science-environment-23332592

It seems the only functional part of Sabre is the pre-cooler for refrigerating the intake gases.

The history of British Government involvement in space technology is spotty (see the history of the Blue Streak missile

http://en.wikipedia.org/wiki/Blue_Streak_%28missile%29 ).

Best regards

Ian Crowe

Subj: Video: Hexacopter view of SpaceX Grasshopper 325m flight and precision landing

http://www.youtube.com/watch?v=eGimzB5QM1M&feature=c4-overview&list=UUtI0Hodo5o5dUb67FeUjDeA

Rod Montgomery==monty@starfief.com

Now imagine a thousand of them each with a kilo of C-4 as a payload.

Re: Russian security at US events

Jerry,

this has already been debunked. Infowars is spinning this tale based on a single snippet of a press release and ignoring the context. See http://ace.mu.nu/archives/341506.php which links to another site with a fuller explanation.

Here’s the relvant portion:

"The Russian Emergency Situations Ministry and the USA Federal Emergency Management Agency (FEMA) are going to exchange experts during joint rescue operations in major disasters. This is provided by a protocol of the fourth meeting of the U.S.-Russia Bilateral Presidential Commission Working Group on Emergency Situations and seventeenth meeting of Joint U.S.-Russia Cooperation Committee on Emergency Situations, which took place in Washington on 25 June.

The document provides for expert cooperation in disaster response operations and to study the latest practices.

In addition, the parties approved of U.S.-Russian cooperation in this field in 2013-2014, which envisages exchange of experience including in monitoring and forecasting emergency situations, training of rescuers, development of mine-rescuing and provision of security at mass events."

Note that what Infowars elided is that this was a conference or meeting to discuss sharing information about provision of security, not an agreement to actually provide security.

Rick C

Good. Actually I had expected to see the US and Russia in a much closer alliance by now.  Clinton dumped that with his anti=Slav activities in the Balkans. Everyone seems to forget that Russians have always been Pan-Slavic.  They never listen to "Serbo-Russian March during Serbo-Ottoman war” AKA Marche Slav by Tchaikovsky.

http://www.youtube.com/watch?v=92vq1cJex4o

They are still Russians, and they saw us aiding the Bosnian oppressors. The music contains some of Russia’s soul.

Dear Jerry Pournelle:

You write:

<<

We had good strategic reason to go into Afghanistan and throw out those who had harbored our enemies; and to make it plain that if they went back to harboring our enemies we would be back. Then we should have left. Instead we stayed. I do not know why.

>>

Whereas I do. The explanation is simple; the military of the USA is not in the business of winning wars. It is in the business of forever waging wars. To win a war, in the usual sense, is to enforce a peace on the victor’s terms; but to the American military-industrial complex, war is peace, and peace on its terms means a bigger and better war.

This is of course a special case of the Iron Law of Bureaucracy.

– paradoctor@aol.com

That is not the business of the military.  It is the result of their political masters.  Military professionals don’t seek war.