Re: RS-68 Aerospike

"Mike Dennis" <mapson@xxxxxxxxxx> wrote in
news:BgUxe.33224$IL3.22569@xxxxxxxxxxxxxxxxxxxxxx:

> Does anyone know of any work toward an RS-68 derived axial
> aerospike engine? Wouldn't it likely reduce the weight and
> throttle range for an expendable launcher--and therefore
> cost?

The RS-68 is a lowered-cost medium performance engine; the
only proposed derivative I'm aware of is replacing the
ablatively cooled exhaust nozzle with a regeneratively cooled
nozzle. I assume that would permit slightly higher chamber
pressure and an improved specific impulse--compared to the
SSME, it's pretty mediocre at sea level and even in vacuum.
But it's much cheaper to build.

I don't see how a more complex aerospike nozzle would have
the benefits you envision. It would improve Isp, which would
be a plus. I'm not aware of >any< plans to work with aerospike
nozzles on any large engines, anywhere.

I'd rather go with COBRA:

http://www.pratt-whitney.com/prod_space_cobra.asp

Have you heard of any specific plans to upgrade the RS-68?

--Damon


.

Relevant Pages

  • SSME vs. J2 / RS-68
    ... NASA Eyes Alternative to Shuttle Main Engine for Heavylift ... NASA is considering dropping the Space Shuttle Main Engine (SSME) from ... and performance merits of the SSME and RS-68. ...
    (sci.space.history)
  • NASAs Exploration Systems Progress Report - May 18, 2006
    ... NASA has chosen the RS-68 engine to power the core stage of the ... agency's heavy lift cargo launch vehicle intended to carry large ... Recent studies examining life-cycle cost showed the RS-68 is best ... NASA's Exploration Systems Mission Directorate in Washington. ...
    (sci.space.news)
  • Re: RS-68 Aerospike
    ... > axial aerospike nozzle is that much more expensive, ... > "reusable" technologies don't speak to those in the ... which is pretty low for a cryogenic engine. ... better understanding of how complex an aerospike nozzle would ...
    (sci.space.shuttle)
  • Re: Stick - Saturn IB Reprise?
    ... Altitude compensation isn't really much of an issue for an upper-stage ... engine, which essentially always runs in vacuum. ... to flight-prove attractive-but-uncertain advanced technology is exactly ... A lesser problem is that the only aerospike engine which is close to being ...
    (sci.space.policy)
  • Re: Time to Think ?Horizontal? for Future Space Launches
    ... The ease or difficulty of scaling a rocket engine is a separate issue ... reason to believe a 2,200,000 lbf Aerospike engine cannot be built at ... got three pump sets on 7 stages for a total of 21 pump sets. ...
    (sci.space.policy)