Conference 7.286::space

From: [email protected] (Ken Hollis)
Newsgroups: sci.space
Subject: SSME Specs
Date: 28 Oct 90 21:16:57 GMT

Greetings and Salutations:

Because of enquiries (like that that follows), as the man sez, you asked for
it, you got it Toyota...

>From: [email protected] (Russ Cage) 
>Subject: Re: Some interesting SSME specifications. 
> 
>Anybody else notice that said propaganda sheet didn't have 
>a single hard number in it?  It was all in battleship-powers 
>or 747-thrusts or.... 
>-- 
>Russ Cage    Ford Powertrain Engineering Development Department

Shuttle Propulsion System

The space shuttle propulsion system consists of two large booster motors,
three space shuttle main engines (SSMEs), two orbital maneuvering system (OMS)
engines, and 44 reaction control system (RCS) thrusters.

Each booster motor measures 12 feet by 150 feet, weighs 1.3 million pounds,
and generates approximately 2.9 million pounds of thrust.  The booster also
serve as launch pad mounts for the entire vehicle and are ignited at launch
after all three SSMEs are producing at least 90% thrust (note : all three
engines are started at approximately 6.6 seconds in the order E3, E2, and E1,
and must be running correctly for the SRBs to ignite).  The solid propellant
consists of a cast mixture of ammonium perchlorate (oxidizer, 69.93% by
weight), aluminum (fuel, 16%) and iron oxide (0.07%), polymer (binder,
12.04%), and epoxy (curing agent, 1.96%).  After burnout at approximately
150,000 feet, the spent cases separate from the vehicle, arcing up to
approximately 220,000 feet before parachuting to the ocean for recovery and
reuse.

The three SSMEs burn liquid hydrogen and liquid oxygen from the external tank,
and are sequentially started at launch.  Engine thrust is throttleable. 
Throttle down is necessary during initial ascent to prevent excessive
aerodynamic loading of vehicle structure and during final ascent to limit
vehicle to three g's.  Each engine is gimbaled through two planes for vehicle
pitch, yaw, and roll control.  The SSMEs steer and accelerate the vehicle to
the desired preorbit position, and shut down.  The external tank is then
jettisoned and falls into the ocean.  The OMS engines are then fired to
accelerate the orbiter to the velocity necessary to inject it into the desired
orbit.

The SSME is a liquid hydrogen / liquid oxygen engine that employs two-stage
combustion.  In the first stage, an extremely fuel-rich mixture is partially
burned in two preburners.  The resulting two gas streams are first used to
drive high-pressure turbopumps.  The fuel-rich streams are then injected into
a main combustion chamber along with coolant fuel and the required oxidizer. 
There final burning occurs at a carefully controlled mixture ratio.

The SSME is rated at 470,000 pounds of thrust in a vacuum (375,000 pounds at
sea level).  The corresponds to 100% thrust and a chamber pressure of about
3,000 PSIA (Pounds Per Square Inch).  The thrust can be increased to 512,300
pounds (109%) and decreased to 305,000 pounds (65%) in about 4,700 pound (1%)
increments.  These thrust levels are referred to as Rated Power Level (RPL)
Full Power Level (FPL), Minimum Power Level (MPL) respectively (Standard power
is 104%..  Throttling is accomplished by varying the operating levels of the
preburners.  This varies the speed of the turbopumps and, therefore, the
propellant flowrates into the main combustion chamber.  To maintain the
desired propellant mixture ratio, the fuel flowrate is varied around the
oxidizer flowrate.

Specific Impulse Approximately 453.5 Seconds. Expansion Ratio 77.5 To 1
(Nozzle Exit Area VS Throat Area)

High Pressure Oxygen Turbopump (HPOTP) (100%, RPL)
                                 Main    Boost 
Pump Inlet Flowrate (LB/Sec)   1072.1    109.1 
Pump Inlet Press (PSIA)         379.1   3992.2 
Pump Discharge Press (PSIA)    4118.4   7210.9 
Pump Efficiency                   0.686    0.808 
Turbine Flowrate (LB/Sec)            58.8 
Turbine Inlet Press (PSIA)         5020.0 
Turbine Inlet Temp (Degrees R)     1522.5 
Turbine Efficiency                    0.759 
Turbine Speed (RPM)               27263 
Turbine Horsepower                23068


High Pressure Fuel Turbopump (HPFTP) (100%, RPL)

Pump Inlet Flowrate (LB/Sec)    149.1 
Pump Inlet Press (PSIA)         222.4 
Pump Discharge Press (PSIA)    6110.4 
Pump Efficiency                   0.763 
Turbine Flowrate (LB/Sec)        158.6 
Turbine Pressure Ratio             1.411 
Turbine Inlet Temp (Degrees R) 1794.5 
Turbine Efficiency                0.839 
Turbine Speed (RPM)           34386 
Turbine Horsepower            61402

If that isn't enough numbers, I am sure that I can dig up more.  I also hope
that is technical enough, now for the "absolutely irrelevant but interesting
part"...  Both the HPOTP & the HPFTP are about the size of a keg of beer,
maybe a little larger.  


ProLine:  gandalf@pro-canaveral         
Internet: [email protected]
UUCP:     crash!pro-canaveral!gandalf

  If Liquid Hydrogen is the 2nd coldest liquit on Earth, what's number one?

  Also, the power needs of the Battleship Iowa (mentioned in .0) will be pretty
low in the future. It was decomissioned last week and will be placed in
reserve. 

  George

Liquid helium is the coldest liquid on earth (and probably anywhere else).
I don't recall the temperature, but a single digit Kelvin number (like 3)
comes to mind.

- dave

  That's strange. I would have thought that hydrogen would liquify at a
lower temp seeing as how it is lighter.

  Of course, the boiling point is not what's important when trying to calculate
the liquid that can have the lowest temprature. The important thing is the
freezing point. I'm sure that the Liquid Hydrogen that NASA uses is not kept
that cold.

  I did, however, see a proposal once for a "slush Hydrogen" fuel which was
suppose to be Hydrogen that was partly frozen.

  George

    George,
    
    Helium is a noble gas.  That means that the outer electron shell is
    filled.   These gasses are, hmm, lets say symetrical, there are only
    limited attractive forces operating on them.  It takes VERY low
    temperature to enable the small attractive forces to overcome the
    kinetic energy of the molecule.
    
    Some fo the other noble gases are krypton, neon and argon.
    
    Tony

     Since I have a periodic table in my desk drawer, I looked up some
     boiling and melting point temperatures:

                     melting       boiling
                     point (�K)    point (�K)
                     ----------    ----------
         Hydrogen     13.96         20.46
         Helium        3.46          4.26
         Oxygen       54.36         90.16

     (0 �K = -273.16 �C)

     Only I thought that Helium couldn't be frozen...?

  Ok, thanks. Now I understand.

RE          <<< Note 664.6 by 29067::J_MARSH "Svelte & Petite-nosed" >>>
>     Only I thought that Helium couldn't be frozen...?

  You are probably right. As I recall, there something called "The laws of
Thermal dynamics" or some such thing. I believe one of them says that you 
can never reach absolute zero. Maybe that's because you can't freeze
Helium so by definition, nothing can get that cold.

  George

    I thought that helium couldn't be frozen (ie. into a solid), too.
    
    There are two isotopes of helium: He-3 and He-4. The former obeys
    Fermi-Dirac statistics, because of having half-integer spin from the
    combined spins of the particles which comprise it. It therefore behaves
    oddly at low temperatures (eg. it is a superfluid, showing no
    viscosity, and is also a perfect conductor of heat; if stirred to form
    a vortex, the vortex will only change spin-rate by discreet steps).
    
    Not that this has anything to do with the Shuttle main engines, but I
    thought someone might be interested.
    
    
    Dave Hazel

    Re: Freezing Helium
    
    	It is true that Helium can NOT be frozen at ordinary pressure by
    lowering the temperature. Helium can be made into a solid by increasing
    the pressure, however. It will freeze solid, for example, at about 1 K
    with the application of 26 atmospheres of pressure. It will not
    solidify at any temperature if the pressure is less than 25
    atmospheres.
    
    				Drew
    
    	

So what is this melting point listed in the CRC book?

Also, what pressure is the boiling point listed for?  1 bar?

Burns

    Re:.10
    
    	The CRC typically lists all melting and boiling points for one
    atmosphere of pressure unless otherwise noted (as was the case with the
    melting point of solid Helium). The CRC lists the melting point of
    Helium at 26 atmospheres as -272.2 C (1 K) and the boiling point as
    -268.934 C (4.23 K).
    
    				Drew
    

  Just to get this straight in my own mind, the correct terminology is Kelvins
and Degrees Centigrade, correct?  Degrees Kelvin is an incorrect term.

John

    Re:.12
    
    	"Degrees Kelvin" is correct. "Degrees Centigrade" is obsolete. It
    is now "degrees Celsius". Even if you were to drop "degrees" (e.g.
    "four Kelvin" versus "four degrees Kelivin"), you wouldn't ruffle many
    feathers out there.
    
    				Drew
    

    re .13
    
    The System International (pardon my anglicized spelling) unit for
    temperature is 'Kelvins', not 'degrees Kelvin' and the abbreviation is
    K not �K.
    
    Degrees Celsius and degrees Farenheit are correct.
    
    gary

    Re:.14
    
    	Boy, am I red! :-)
    
    			Drew
    

But in common useage the "degrees" is retained as in photoflood lamps which are
refered to 3200 degrees Kelvin or 5400 degrees Kelvin even if that in not
technically correct.

    Well, this IS the USA, one of the few countries that has not adopted
    SI...
    
    At some point in the evolution of the metric system, degrees K was a
    correct unit (probably the CGS standard), but it was renamed to Kelvins
    common useage not withstanding. After all it was the variations in
    common usage that SI tries to address. :-)
    
    Specification of color temp is sufficiently arcane that I expect it is
    a dimensionless number to most photo/video users.
    
    gary

12/14/90: MARSHALL SPACE FLIGHT CENTER TO START NEW SERIES OF 
SHUTTLE MAIN ENGINE TESTS IN TECHNOLOGY TEST BED FACILITY 


RELEASE NO: 90-201


Testing designed to better understand the internal operating
environment of Space Shuttle Main Engines is scheduled to begin
Tuesday, December 18 at NASA's Marshall Space Flight Center in
Huntsville, Ala.

A 170-second firing is planned in the Center's Technology
Test Bed facility for 2 p.m. CST. 

The test is the first in a series of Phase II Environmental
Characterization tests.  The engine will be operated at 100, 104,
and 86 percent power during the test, said Dan Dumbacher,
technical assistant to the Marshall Center Propulsion Laboratory
Director.

"For this new test series, we will be using a different
engine in the test stand then previously used.  During the 
upcoming five tests, we will acquire an improved understanding of
both internal engine component and system environments by heavily
instrumenting the engine with more than 550 instruments," said
Dumbacher.

"The information from these tests will provide NASA with an
increased knowledge base on the engines we are using today and
also give us the necessary data base for future engine designs
that will have increased reliability," Dumbacher said.

This new test series follows completion of liquid hydrogen
umbilical flow testing which was conducted this summer in the
Marshall Technology Test Bed facility to support the leak
investigations of the Space Shuttle Columbia at the Kennedy Space
Center in Florida.  

The previous series of engine tests in the facility were
completed in April, 1990.  During those firings, engineers
evaluated an enlarged throat in the main combustion chamber of a
modified engine and what effects it might have on the engine
performance.  Increased safety margins were demonstrated with this
configuration.

To date, nineteen Space Shuttle engine test firings have
occurred on the renovated Saturn 1C test stand for a total time of
31 minutes and 55 seconds.  The first test was in September,
1988.  During the 1960s, Saturn V first stage engines were test
fired in clusters on the Marshall stand.  The last Saturn test was
conducted in February, l969.  

    Would you like to see an SSME close-up?
    
    Here's the next best thing to being there (O.K., so I'm stretching it
    a bit):
    
    pragma::public:[nasa.shuttle.ssme]*.gif
    
    Closeups of several SSMEs - primarily of the powerhead assembly and
    various interconnections.    These are BIG images (940x732), so
    don't just copy all of them -- you'll be disappointed.
    
    
    An added bonus: public:[nasa.shuttle.flight_deck]*.gif has close-up
    pictures of various flight deck switch panels from Discovery (OV-103).
    
    - dave

RELEASE: 91-118 (7/25/91)

     A developmental Space Shuttle main engine sustained
extensive internal damage while it was undergoing ground
testing on Wednesday at NASA's Stennis Space Center near Bay
St. Louis, Miss.

     The test failure occurred at approximately 4 seconds
after engine start when engine sensors detected abnormal
operating conditions.  Ground-control systems terminated the
test immediately and there was no apparent damage to the
test stand on which the engine was mounted.

     The exact nature and extent of damage to the engine, as
well as the cause of the incident, are being investigated.
However, from initial external observations, the damage
appears to be largely internal to the engine.  A team of
engineers with NASA and the prime contractor for the main
engine, Rocketdyne Division of Rockwell International, have
begun gathering all pertinent test data for analysis.

     The engine which was being tested is a development
engine, and its configuration is different from engines used
in the Shuttle flight program.

     "Failures such as this do occur from time to time in
the aggressive ground-test program that we've always
maintained, and especially when we're testing advanced-
design components.  However, it has been over two years
since we've had such an incident and during that time, we've
accumulated over 100,000 seconds of engine operation, with
257 engine starts," said Jerry Smelser, manager of the Space
Shuttle Main Engine Projects Office at the Marshall Space
Flight Center in Huntsville, Ala.  "The engine, unit number
0215, had been tested extensively in the past.  It had been
run 15 times prior to the aborted test, with an accumulated
run time of 5,255 seconds, or approximately 87.6 minutes."
 

From: [email protected] (WILLIAM HARWOOD, UPI Science Writer)
Newsgroups: clari.tw.space,clari.news.aviation,clari.news.military
Date: 25 Jul 91 19:16:12 GMT


	CAPE CANAVERAL, Fla. (UPI) -- Engineers studied test data Thursday to
find out what caused a major shuttle engine failure during a test firing
in Mississippi Wednesday and whether the mishap will have an impact on
the shuttle Atlantis's launch next week.
	The test firing, conducted Wednesday afternoon on test stand A-1 at
the Stennis Space Center, ended abruptly about four seconds into a
planned 513-second run. The shutdown occurred, sources said, after the
engine suffered a loss of hydrogen fuel.
	The engine then experienced an oxygen-rich shutdown, which gutted the
interior of the main combustion chamber where oxygen and hydrogen are
burned to produce thrust.
	``We don't know the cause of the loss of fuel flow,'' said one
engineer. ``The fuel pump stalled for some reason.''
	NASA officials could not immediately say whether the engine's high-
pressure hydrogen turbopump was a suspect or whether the ground system
that supplied hydrogen to the test engine may have been involved.
	Shuttle main engines, built by Rocketdyne of Canoga Park, Calif., are
routinely test fired at Stennis to qualify them for flight or, as in
this case, to test modifications and improvements before they are
incorporated into the flight program.
	The engine that shut down Wednesday was being fired to test a design
change in the manifold that routes oxygen and hydrogen to the combustion
chamber. The hugh-pressure hydrogen pump was similar to flight units
like those used by Atlantis's three main engines.
	Atlantis was grounded Wednesday by a faulty $4 million main engine
computer. Work to replace the computer is expected to be finished over
the weekend, clearing the way for another launch attempt next Thursday
or Friday.
	But first, engineers will have to prove that what happened to the
test engine will not happen aboard Atlantis.
	``The fuel pump we were running (Wednesday) is essentially a flight-
configuration fuel pump,'' an engineer said. ``It'll take us a couple of
days to try to isolate exactly what happened. The engine project has got
to review the cause of the failure and verify it doesn't affect the
flight engines and that's got to be done before flight.''
	Failure of a high pressure hydrogen pump in flight could be
catastrophic. The pumps, about the size of a large beer keg, develop
some 70,000 horsepower at full thrust, enough to power 11 locomotives.
	The powerful pumps had a history of development problems, but in the
wake of the 1986 Challenger disaster NASA and Rocketdyne implemented
design changes and an unprecedented test program at Stennis to improve
overall engine performance and reliability.
	In the 16 post-Challenger flights to date, the shuttle main engines
have performed flawlessly, including the high pressure hydrogen fuel
pumps. The engine that failed Wednesday had been fired 15 times
previously, accumulating 87.6 minutes of run time.
	Engines currently are test fired weekly at Stennis and the vast
majority take place without incident. The premature shutdown Wednesday
apparently resulted in the most severe engine damage in several years,
although it was not immediately obvious to nearby observers.
	``I was here and saw the test and still didn't know (there was a
problem),'' said a NASA spokeswoman. ``I didn't know there was anything
unusual or any damage.''
	Back at the Kennedy Space Center, meanwhile, engineers pressed ahead
with plans to replace the faulty ``controller'' that malfunctioned six
hours before the crew's planned liftoff, forcing NASA to delay the
flight to late next week.
	The controller monitors engine performance 50 times per second during
the 8 1/2-minute climb to orbit and it must be working perfectly before a
shuttle can be cleared for flight. The problem Wednesday could not be
corrected, prompting NASA managers to order engineers to install a
replacement unit.
	After draining Atlantis's giant external tank and removing explosive
hydrogen fuel from on-board tanks, engineers opened the shuttle's engine
room Thursday and began setting up work platforms around main engine No.
3.
	If all goes well, the faulty controller will be unbolted and removed
Saturday, clearing the way for engineers to install and test a
replacement on Sunday.
	The work platforms then will be removed, Atlantis's engine room will
be sealed back up and engineers will be ready to restart the shuttle's
interrupted countdown, possibly as early as Tuesday, clearing the way
for another launch attempt around Aug. 2.
	Atlantis's crew -- commander John Blaha, 48, co-pilot Michael Baker,
37, flight engineer G. David Low, 35, Shannon Lucid, 48, and James
Adamson, 45 -- flew back to the Johnson Space Center in Houston Wednesday
afternoon for additional training.

                        Test Status Report
                            (9/18/91)


                   TECHNOLOGY TEST BED FACILITY


     A test firing of a modified Space Shuttle Main Engine was
manually terminated today approximately 113 seconds into a planned
180-second run in NASA's Technology Test Bed Facility at the
Marshall Space Flight Center in Huntsville, Ala. just after 3:08
p.m. (CDT) today.
     The test is part of a technology development program, and is
not related to the current Shuttle flight program.
     The test was deliberately terminated by the test conductor
due to a small fire observed at the base of the heavily
instrumented high pressure fuel turbopump.  The fire posed no
immediate threat to the engine or facility and is suspected to be
due to leaking instrumentation.  Preliminary inspections indicate
minimal damage to instrumentation or other hardware.  The exact
cause of the fire is under investigation.
     This test was the 23rd firing of a Space Shuttle Main Engine
at the Technology Test Bed facility since testing began in
September 1988.
     Dr. Helen Mc Connaughey, technical assistant to the director
of Marshall's Propulsion Laboratory, said an exact test date for
the next engine firing will be set once engineers have had time to
evaluate the results of today's test.
     The Technology Test Bed facility is used to assess advances
in propulsion technology, enhance the process for implementing
technology into emerging and operational programs, and to provide
a test capability for prototype hardware.

                           STATEMENT
                   TECHNOLOGY TEST BED FACILITY
                          10/22/91 TEST


     A test firing of a modified Space Shuttle Main Engine was
manually terminiated approximately 20 seconds into a planned
190-second run in NASA's Technology Test Bed Facility at the
Marshall Space Flight Center in Huntsville, Ala., at 7:45 p.m.
(CDT) tonight.
     The test is part of a technology development program, and is
not related to the current Shuttle flight program.
     The test was deliberately terminated by the test conductor
due to a small fire observed at the base of the heavily
instrumented high pressure fuel turbopump.  The fire posed no
immediate threat to the engine or facility and is suspected to be
due to leaking instrumentation.  Preliminary inspections indicate
minimal damage to instrumentation or other hardware.  The exact
cause of the fire is under investigation.
     This test was the 24th firing of a modified Space Shuttle
Main Engine at the Technical Test Bed facility since testing began
in September 1988.
     Helen Mc Connaughey, technical assistant to the director of
Marshall's Propulsion Laboratory, said an exact test date for the
next engine firing will be set once engineers have had time to
study today's test.
     The Technology Test Bed facility is used to assess advances
in propulsion technology, enhance the process for implementing
technology into emerging and operational programs, and to provide
a test capability for prototype hardware.
 

                                                 EG-91-112
                                                  November 18, 1991
Myron Webb
Public Affairs Officer

           SPACE SHUTTLE MAIN ENGINE TESTING ACHIEVES
                         MAJOR MILESTONE
                     AT STENNIS SPACE CENTER

     HANCOCK COUNTY, MISS.---America's space shuttle program
reached a major milestone on Fri., Nov. 15, 1991.  A 420-second
test of engine #2011 at NASA's John C. Stennis Space Center (SSC)
in Hancock County, Miss., resulted in the accumulation of more than
half a million seconds of firing time for the Space Shuttle Main
Engine (SSME).  This historic test brings the total firing time to
500,132 seconds, which is equivalent to more than 320 Space Shuttle
flights.

     The trek toward this milestone began on June 7, 1975, with a
SSME ignition test that lasted for eight-tenths (0.8) of a second.
The program has now accumulated more than 1,900 hot firings.

     SSC Director Roy Estess said, "Achieving this milestone on an
engine as complex as the SSME is almost unprecedented in the
business of propulsion.  We are pleased it occurred at Stennis."

     The SSME program is managed by the Marshall Space Flight
Center in Huntsville, Ala., for NASA's Office of Space Flight.

     With the achievement of this milestone, the SSME joins the
ranks of the "most-fired" rocket engines in the history of
America's space program.  Some engines with comparable numbers
include a variety of expendable engines, such as the Atlas and
Delta engines as well as the F-1, J-2 and H-1 engines for the
Apollo lunar landing program.

     The SSME accumulated most of its firing time, about 430,000
seconds, at SSC.  The other seconds have been achieved in 43
successful Space Shuttle flights, each of which uses three SSMEs;
in tests conducted at the Marshall Space Flight Center in
Huntsville, Ala.; and in tests conducted at Rocketdyne's Santa
Susana Field Lab in Ventura County, Calif.

     The SSME, the only reusable rocket engine in the world, is
built for NASA by the Rocketdyne Division of Rockwell International
Corp.  It uses liquid hydrogen and liquid oxygen propellant and is
one of the most powerful engines ever built.  One engine operating
at full power provided more than half a million pounds of thrust.
Each SSME weighs about 7,000 pounds, is 14 feet long and about 7.5
feet in diameter.

     "This is a significant, gratifying accomplishment," said
Rocketdyne President Robert D. Paster, Canoga Park, Calif.  "It
says a great deal about the teamwork between Rocketdyne and NASA
over the years.  Half a million seconds truly underscores the
reliability and maturity of this engine."

     NASA engineers successfully tested an advanced Space Shuttle
main engine today for 205 seconds at the Marshall Space Flight
Center in Huntsville, Ala.
     "We had a full-duration test and an initial look at the
computer data indicates it was a successful test," said Dr. Helen
McConnaughey, technical assistant to the Marshall Center
Propulsion Laboratory Director.
     The test was the twenty-fifth engine firing in NASA's
Technology Test Bed facility in the Center's West Test Area since
Space Shuttle Main Engine testing began in September 1988.
     The testing is being conducted to provide unique data which
will enhance understanding of the internal operating environment
of Space Shuttle Main Engines, said Helen McConnaughey.  The
engine was operated at levels between 100 and 104 percent power
during the test.
     Data from the instruments on the engine and the test facility
will be examined in the next week.

STATEMENT
TECHNOLOGY TEST BED FACILITY
3/31/92 TEST


     Part of a future technology program, a test firing of a
modified Space Shuttle main engine was automatically terminated
approximately .36 of a second into a planned 85-second run in
NASA's Technology Test Bed Facility at the Marshall Space Flight
Center in Huntsville, Ala., at 1 p.m. (CST) today.
     The test is part of a technology development program, and is
not related to the current Shuttle flight program.
     Preliminary indications are that the shutdown was caused by a
problem with the oxidizer preburner oxidizer value in the engine.
     The facility and engine were safely shutdown after today's
firing.  Instrumentation and engine hardware from today's test
will be evaluated to determine what caused the early shutdown.
     This test was the 30th firing of a modified Space Shuttle
Main Engine at the Technical Test Bed facility since testing began
in September 1988.
     Helen Mc Connaughey, technical assistant to the director of
Marshall's Propulsion Laboratory, said an exact test date for the
next engine firing will be set once engineers have had time to
study today's test data.
     Today's test is part of a new series of tests called the
Hydrostatic Bearing Test Series.  The series will provide
engine-system validation of a number of new technologies.
Technology Test Bed is used to assess and validate new propulsion
technologies for large oxygen and liquid hydrogen rocket engines.
 

There are now 7 images, plus one composite image of the "plumber's nightmare":
the engine room of the Space Shuttle.

   pragma::public:[nasa.shuttle.ssme]aft*.*

    aft-xx.gif (images 01..07 and PN (the composite))
    aft.txt (a description of what you are seeing)

They are all color images.  Warning: the composite image is 2088x1392


These images are courtesy of Ken Hollis (who works at the KSC).


- dave

From: [email protected] (AP)
Copyright: 1994 by The Associated Press, R

	CAPE CANAVERAL, Fla. (AP) -- A California company used
super-strength glue for up to six years to make unauthorized
repairs on space shuttle engines, a NASA official said Friday.
	The dabs of glue, used to fix a pump in main engines, did not
pose a hazard, said Boyce Mix, deputy manager for the shuttle main
engine program at the Marshall Space Flight Center in Huntsville,
Ala.
	He said he was not sure whether the glue, the kind sold at most
model shops, was used on shuttle Discovery, which returned to Earth
on Friday from an eight-day science mission.
	Technicians at Paragon Precision Products of Valencia, Calif.,
used the glue without company supervisors or other officials
knowing about it, Mix said.
	``That's the bad part of it. It was an unauthorized repair and
the management of this company did not realize what was going on,''
he said.
	``That's been corrected.''
	Small amounts of the glue were used only to attach thin silver
plating that came loose on tabs in low-pressure oxidizer
turbopumps. The tabs are on a device that directs the flow of
liquid oxygen in the pump.
	The glue was discovered during an inspection last month because
in at least one case it did not hold, Mix said. Engineers
determined that the silver plating is unnecessary and will be
removed.
	Paragon President Larry Smith told The Houston Post that his
company, which is still certified to work on shuttle engine pumps,
would review its procedures.

I'm not sure how superficial...it sounds like it was in the LOX stream!

Not good...

Burns

[This was lifted from sci.space.shuttle and formatted to fit in 80 columns -dg]

Hey I may not be a Rocketdyne employee, but I do know a little about
the SSME turbopumps.  I worked a little  project in 1986 and 1987
called Shuttle Return to Flight where we worked as the eyes of MSFC at
Rocketdyne and evaluated the flight readiness of the SSME (the
turbopumps were my area).  Here are the top level specs from the SSME
Pocket Data Book RI/RD87-142 (all data is at 100% rated thrust even
though they are run at 104% each mission).  There are four pumps, the
High Pressure Fuel Turbopump (HPFT), the High Pressure Oxidizer
Turbopump (HPOT), and their low pressure twins LPFT and LPOT which
simply maintain the inlet NPSH to prevent cavitation in the main pumps.
 In addition, the HPOT has a boost pump that supplies very high
pressure Ox to the pre-burners.

                          HPFT      HPOT M      HPOTB       LPFT       LPOT
Pump Flowrate (lb/s)      149.1      1072.1      109.1     148.6      895.8
Inlet Press (psia)        222.4       379.9     3992.2      30.0      100.0
Outlet Press (psia)      6110.4      4118.4     7210.9     280.5      414.2
Pump Efficiency              .763        .686       .808      .774       .689
Number of Stages            3           1          1         1          1
Tubine Flowrate (lb/s)    158.6        58.8       26.1     176.3
Turb Inlet Temp (R)      1794.5      1522.5      493.4     190.2
Turb Press Ratio            1.411       1.513      1.32      -
Turb Efficiency              .839        .759       .519      .649
Shaft Speed (RPM)      34,386      27,263     15,765      5042
Turbine Horsepower     61,402      23,068       2950      1504.8
Number of Stages            2           2          1         1 (sort of)

Other items not on this list.  All pumps are centrifical type.  The
HPFGT and HPOT use the very fuel rich pre-burner combustion gases to
drive the turbines (the few seconds of ISP this produces probably was
not worth it since the STME follow-on engine does not do this), while
the LPFT uses gaseous H2 and the LPOT uses gaseous LO2.  I have no data
on weight, but I remember that one man could lift the low pressure
units (don't worry though, it is not a standard procedure).  For a data
point the entire SSME is only 7000 lbs.  The high pressure turbopumps
by far are the most powerfull by unit mass turbopumps ever built.  The
outlet pressure of the HPFT corresponds to a head of 75,000 feet!

On construction,  this is the haziest part but all pump housings I
think are Inconel 715 (Rocketdyne loves this stuff!)  The turbines in
the low pressure units are straight forward, but the high pressure ones
use directionally solidified nickel alloys, and they finally solved the
HPFT trubine cracking problem after 10 years of research and tons of
$$'s by simply increasing a corner radius (stress 101 rules again!).
Biggest issue with the HPOT (and still is) is the pump end bearing set
getting hot and actually burning in the LO2 (not a good idea)  Alot of
work has gone into this item but they still change out the units after
each flight.  The Pratt and Whitney design was supposed to rectify this
but I understand they have similar problems (and oh gosh!!!, so do the
Japanese with their new booster engine).  All in all (even with a few
dozen design issues) these units are a work of art and perform very
well.  Their biggest drawback is they cost alot to build and even more
to maintain.


Timothy A. Martin
Martin Marietta Astronautics
Flight Systems - Advanced Programs

From:	US1RMC::"[email protected]" "NASA HQ Public Affairs Office" 21-MAR-1995 23:52:22.05
To:	[email protected]
CC:	
Subj:	New Space Shuttle Main Engine Ready for Flight

Ray Castillo
Headquarters, Washington, DC         March 21, 1995
(Phone:  202/358-4555)

June Malone
Marshall Space Flight Center, Huntsville, AL
(Phone:  205/544-7061)
                                                        
RELEASE:  95-32

NEW SPACE SHUTTLE MAIN ENGINE READY FOR FLIGHT

     NASA has successfully completed testing a new high 
pressure liquid oxidizer turbopump and is ready to fly an 
upgraded main engine on its first Space Shuttle flight in 
June 1995.

     "Completing flight certification of the Alternate High 
Pressure Oxidizer Turbopump is a major milestone in the 
Space Shuttle Main Engine (SSME) program," said Otto Goetz, 
SSME deputy project manager for development, Marshall Space 
Flight Center, Huntsville, AL.

     "The Alternate Turbopump is now ready for its first 
flight and for nine flights thereafter.  Credit goes to 
Pratt and Whitney and Rocketdyne, to the experts in 
Marshall's Science and Engineering Directorate, and to the 
folks at Stennis Space Center who supported an aggressive 
test program," Goetz added.

     NASA completed final certification of the new liquid 
oxygen high pressure turbopump on March 15.  The new pumps 
underwent a test program that is equivalent to 40 Space 
Shuttle flights.  By achieving this milestone, NASA reached 
the final step in certifying the turbopumps for flight. 

     "The certification is unprecedented in that none of the 
certification units had to be removed from the engine during 
the test series," said Goetz.  NASA did not perform any 
detailed inspections other than verifying free pump rotation 
after each test.  

     The high pressure liquid oxygen pumps used in the 
current SSME must be removed after each flight for 
inspection.  The new pumps will not need any detailed 
inspection until they have flown ten times.  The new pumps 
also are expected to increase safety margins and reliability 
for the SSMEs.  These engines provide approximately 1.5 
million pounds of thrust during launch of the Shuttle into 
low-Earth orbit.  

     The new turbopump also incorporates state of the art 
technology in its design.  The pump housing is produced 
through a casting process, thereby eliminating all but six 
of the 300 welds that exist in the current pump.  
Eliminating welds is one of the keys to increasing safety 
margins on the main engine.

     The new pump uses a new ball bearing material -- 
silicon nitride (a type of ceramic).  Silicon nitride offers 
several advantages over the steel bearings currently in use.  
The material is 30 percent harder than steel and has an 
ultra-smooth finish which allows for less friction during 
pump operation.  Friction creates heat that leads to wear on 
the bearings.  These new ceramic bearings eliminate concerns 
over excessive wear to the pump-end ball bearing. 

     Along with the new turbopump, NASA will fly a new two-
duct powerhead.  This new powerhead will significantly 
improve fluid flows within the engine system by decreasing 
pressure, reducing maintenance and enhancing overall 
performance of the engine.  It will replace three smaller 
fuel ducts in the current design with two enlarged ducts to 
achieve improved engine performance.  This new engine 
configuration is being called the Block I engine.

     On STS-70, one SSME will be a new Block I engine.  The 
remaining two engines will have the current SSME design.  
The first flight planned to incorporate the new pumps into 
all three engines is STS-73, currently targeted for launch 
in September 1995. 

     The SSME project is managed by NASA's Marshall Space 
Flight Center.  Pratt and Whitney, West Palm Beach, FL, 
developed and manufactured the new pump; Rocketdyne, Canoga 
Park, CA,will integrate the pump into the main engine.