AUTHORS'
PERSPECTIVES in NASA's advanced space transportation the authors related development field (see that the
As active participants "Acknowledgments" relevance
systems.
from this "SERJ Story" are offered for consideration transportation communities. and combined-cycle propulsion
by today's advanced
researchers
and forward-planning
section of the paper),
express some concern here, to such ongoing
of the engine development
history
spaceflight
activities, focus further
will not always
be clear
non-success, propulsion
therefore, knowledge
presumably base.
not contributing
But we believe airbreathing/rocket candidate business," Spaceliner space
otherwise.
6JulO0 SAICwjde
To be presented at the 36 th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 16-19 July 2000, Huntsville, Alabama
Technical
Paper AIAA 2000-3109 Mach 4.5 Supercharged Engine Project: Ejector Ramjet (SERJ) HighCa.1970
aircraft,
not reusable never
since the SERJ status
engine
exploratory-development this project may be viewed significantly
-- no full-scale
engines
as an "also-ran" to the advanced
exploratory
aircraft engine.
transition
to the aviation
arena, this case history propulsion requirements Lessons systems of to be learned space
the expectation
Eric H. Hyde NASA Marshall Space Flight Center Huntsville,ercharged pursued described. Ejector Ramjet (SERJ) engine developments of the 1960s, as are
advanced
space-transportation
and propulsion
planning
and development
INTRODUCTION On Airbreathing Taking classes: propulsion propulsion, mainstay and Rocket Propulsion, and a Synthesis propulsion propulsion. of the Two systems To date, aviation types, have fall into two major airbreathing Rocket
Marquardt's Performance
Aircraft
Unfulfilled
Aspirations
William J.D. Escher and Jordan E. Roddy Science Applications International Corporation Advanced Technology Group, Huntsville, Alabama
demonstration history paper
the technical to us highly
and programmatic relevant. We submit
here should
be of considerable
interest
to those
participating
in today's activities.
for a future flight-safety, urge
"aircraft-like" operationaland
transportation
its highly-challenging goals, strongly
dependability informed
and ticket-price
and direction of the positive
of military nature
developments, engine's technology comments
perception
technical effort
is supported today
by the ongoing
combined-cycle as well
in 1970
expressed technical
not reflect those
on its basic programmatic materiel for a Mach needs
propulsion factors which
per se. related
Rather,
to this termination, available capability, budgets,
work on this combined-cycle reusable
type evolved, study status, as a candidate productive supports
space transportation development Bridging
into a U.S. Air Force/Navy-supported Mach 4.5 high-performance from the spaceflight military
the fact that this particular development -- does stage
engine
project
was for
at its exploratory in the paper approach,
-- it was terminated despairingly negative
that fully-integrated
airbreathing/rocket propulsion
hold high promise tomorrow's
toward meeting Spaceliner
the demanding
aircraft-like
class transportation
propulsion as those further
pursued
by NASA
and industry,
to follow.
Turning
all this around
to a positive
orientation,
it will be noted vehicle
that the SERJ studies
personnel
"in the aviation announced
is viewed
as a major
plus for the cause initiative firmly
of spaceflight. asks
NASA's
100 technology-roadmap system. Clearly,
engine of the
had its origins
in advanced
highly-reusable
launch
application
2
mid-1960s. Example SERJ-powered two-stage-to-orbit (TSTO) reusable vehicle systems were shown to as much as triple the "payload throw" of equivalent-technology all-rocket counterpart systems. Assessments of SSTQ systems powered by scramjetcapable variants of SERJ, in the late-1980s, confirmed orbital payload fractions of 4- to 8-percent, approaching that of the Concorde. These promising findings suggest that combined-cycle propulsion can lead to marked reductions of vehicle takeoff weights, engine thrust levels, and a general sequence of vehicle subsystem downsizing gains. This should all lead to favorable mission-application operational flexibility and accompanying life-cycle economics. With "aircraft like" being today's advanced spaceflight