Thunder Lost - The Delta 3 Story
Thirteenth in a Series Reviewing Thor Family History
by Ed Kyle, Updated 8/29/2010
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Delta 269, the Second Delta 3, at Pad 17B in 1999
While assembling its 1986 bid for the U.S. Air Force Medium
Launch Vehicle (MLV) program, McDonnell Douglas considered using Japan's then
in-development H-1 liquid hydrogen upper stage and/or its LE-5 engine. Discussions
were held with Japanese officials about the possibility of creating a "joint"
launch vehicle that would marry the U.S. Delta 3920 first stage to Mitsubishi's second
stage, presumably to fly from both countries. In the end the idea was bypassed in
favor of upgrading the existing Delta design to create the MLV winning "Delta
In 1988, the U.S. Air Force offered another launch vehicle
program for bids. The "MLV II" program's specifications (2.6 tonnes to
GTO) seemed to align with the capabilities of General Dynamics Atlas Centaur, but
McDonnell Douglas nonetheless offered a bid. Its design used a liquid
hydrogen/liquid oxygen upper stage, to be built by Martin Marietta, married to the
then-in-development Delta 2 first stage and strap-on motors. General Dynamics won
the competition in May 1988 with its improved Atlas Centaur, which it named "Atlas
After Delta 2 entered service in 1989-90, McDonnell Douglas again
considered a high energy upper stage. Delta 2 could lift more than 1.8 tonnes to
GTO, enough to handle the then-common Hughes HS-376 spin-stabilized satellites, but
spacecraft were growing heavier. In 1987, Hughes began offering its 3-axis
stabilized HS-601, which would weigh 2.5 to 3.1 tonnes. The satellite would require
a 4 meter diameter payload fairing, substantially wider than Delta 2's 2.9 meter
Designers initially contemplated a "Delta 7930" design
similar to the MLV II bid. It was a Delta 2 with a 3.2 meter diameter liquid
hydrogen second stage powered by a single RL10 engine. This rocket would have been
able to lift 2.6 tonnes to GTO. It also would have adhered to Delta's long-term
incremental growth tradition.
Delta 3 Materializes
Delta 3 (Delta 280) Cutaway Drawing (Boeing)
In the post-Challenger commercial launch era, incremental growth
wasn't enough. Hughes even-heavier HS-601HP grew to more than 3.5 tonnes.
McDonnell Douglas had to switch to a wide-body, 4 meter diameter second stage, and
more-powerful Alliant 46 inch diameter Graphite Epoxy Motors (GEM-46) strap-on solids to
lift the heavier stage and payload. The first stage was also modified with a
shorter but fatter kerosene fuel tank (4 meters rather than 2.4 meters diameter), to allow
the new rocket to fit within the Delta 2 service tower.
On May 10, 1995, McDonnell Douglas announced that it would
develop the new rocket, which it named "Delta 3", using more than $200 million
of its own funds, with a planned first launch in 1998. Payload capacity to GTO had
grown to 3.8 tonnes, with nearly 8.3 tonnes possible to LEO from Cape Canaveral.
On the same day, Hughes and McDonnell Douglas announced that they
had signed a contract for 10 Delta 3 launches. The companies increased the total to
13 launch contracts in subsequent months, creating the possibility of a $1.5 billion total
contract value. By 1998, Hughes had assigned three of the launches to the NASA/NOAA
GOES N, O, and P weather satellites and five to ICO Global Communications for its Medium
Earth Orbit constellation. In 1997, Space Systems/Loral reserved five Delta 3
launches, increasing the Delta 3 backlog to 18 launches through 2002.
International Competition, and Merger
A factor that came into play during the mid-1990s, with the end of the
Cold War, was Russia's push to increase its commercial space launch quota, specifically
for the Proton rocket. McDonnell Douglas opposed increasing the Russian quota in
1996, as it had opposed an earlier Ukrainian quota for the Zenit rocket. The company
specifically noted that higher foreign quotas would cause it to lose value in its Delta 3
Meanwhile, satellite manufacturers such as Hughes called for eliminating
the quotas to reduce their launch costs. At the time, U.S. satellite makers held a
much larger worldwide commercial market share than U.S. launch providers. In the
end, the satellite argument won.
Another post-Cold War reality was rationalization of the U.S.
aerospace industry. On December 15, 1996, McDonnell Douglas and Boeing announced
their intention to merge under the Boeing name. The merger was not consummated until
July 1, 1997. Although it was not immediately apparent, the merger would have
decisive consequences for the Delta 3 program.
Delta 3 Design
Delta 3 First Stage Manufacturing at Pueblo, Colorado
Delta 3 was an 8930 model under the four-digit numbering system.
The rocket used an 8000-series Thor first stage with nine GEM-46 strap on motors, a
Rocketdyne RS-27A main engine, and a 4 meter diameter kerosene tank mounted on top of the
standard 2.4 meter diameter liquid oxygen (LOX) tank. The third digit in the model
number, a "3", signified the presence of the new Delta Cryogenic Upper (second)
Alliant built the GEM-46 motors in Bacchus,
Utah. GEM-46 was a scaled up version of the GEM-40 used by Delta 2. The
graphite-epoxy case motors used HTPB solid propellant. Six ground-lit GEM-46 produced more
than 62 tonnes of thrust each at liftoff. Three air-lit solids produced 64 tonnes of
thrust each. At liftoff, the boosters and RS-27A main engine together created 462.7
tonnes - more than 1 million pounds - of thrust.
Like Delta 2, Delta 3 was assembled in Pueblo, Colorado.
Huntington Beach fabricated the first and second stage liquid oxygen tanks, the
interstage, and other parts. Rocketdyne built RS-27A propulsion systems in Canoga
Park, California for both rockets.. Japan's Mitsubishi Heavy Industries manufactured the 4
meter diameter second stage liquid hydrogen tank and first stage kerosene tank.
Mitsubishi used tank tooling from its H-2 stage. H-2, a 4 meter diameter liquid
hydrogen two-stage rocket, entered service in 1994.
Delta Cryogenic Upper Stage Assembly at
McDonnell Douglas selected a two-tank, non-common bulkhead design
for the DCUS. It was the first entirely new high energy upper stage developed in the
US since the 1960s. The company fabricated its own 3-ish meter diameter ellipsoidal
liquid oxygen tank that was attached to, and hung beneath, the cylindrical 4 meter liquid
hydrogen tank. Trusses arranged in a triangular configuration provided the intertank
attachment. Five helium pressurant bottles were mounted in the intertank space.
Pratt & Whitney's existing RL10 engine design was
insufficient for Delta 3. The company offered a new RL10B-2 that produced more
thrust (11.22 tonnes) and that used a big three-piece extendible carbon-carbon composite
nozzle to improve specific impulse. The nozzle was 2.5 meters long and 2.1 meters in
diameter. At 462 seconds specific impulse, the engine would be the world's most
The RL10B-2 engine fit to the base of the liquid oxygen
tank. Another set of triangular trusses supported a doughnut shaped
avionics shelf below the liquid oxygen tank, surrounding the top of the RL10B-2. The
shelf held Delta's RIFCA (Redundant Inertial Flight Control Assembly) which controlled the
vehicle during all stages of flight. Four hydrazine thruster modules, and the
hydrazine bottle that provided their propellant, were also mounted to the shelf.
These provided roll control during the main engine burns and three-axis control during
DCUS was 10.98 meters long and 4 meters in diameter. The
RL10B-2 engine, the avionics shelf, and the LOX tank fit inside the rocket's interstage
while the load-bearing LH2 tank sat above and atop the interstage, its orange spray-on
insulation visible to the outside world. The stage could restart up to two times,
with a total burn time of up to 700 seconds.
Delta 3's 4.0 meter diameter composite payload fairing separated
into two halves in flight. For the first time with Delta, the fairing would be used
to encapsulate payloads at their processing facility before transportation to the launch
pad for integration with the vehicle. The new "encapsulation" method
provided better protection for the payloads on the launch pad and reduced the launch
vehicle's time on the pad by about one week compared to Delta 2.
Huntington Beach manufactured the Delta 3 composite payload
fairing and interstage. In 1998, Boeing subcontracted similar work for Delta 4 to
ATK in Luka, Mississippi. The 1998 contract was awarded to allow components to be
barged up the Tennessee River from Luka to Boeing's new Delta 4 factory in Decatur,
Daniel Collins, who would subsequently be vice president of
Boeing's Launch Systems Division and Chief Operating Officer of United Launch Alliance,
served as Boeing's Delta 3 program manager.
Testing and Development
RL10B-2 with Nozzle Extensions Being
Tested in Arnold Test Cell (Note Cherry-Red Carbon-Carbon Sections)
In August 1995, Pratt & Whitney
awarded the RL10B-2 extendible nozzle subcontract to Europe's Snecma. Snecma
delivered its first development nozzle one year later, during August 1996.
The RL10B-2 qualification test program
included 188 tests on several engines for a total of 17,288 sec of accumulated test time. Pratt & Whitney delivered an early RL10B-2 test engine to the Arnold
Engineering Development Center during August 1996, where it was mated to the Snecma nozzle
extension. In 1997, the engine was tested in Test Cell J-4 under near vacuum
An entire Delta 3 test article second stage, called the
"X-Stage", was tested in the Spacecraft Propulsion Research Facility's B-2
vacuum test chamber at NASA's Lewis Research Center's Plum Brook Station beginning in
February 1998. The testing, which lasted until early April 1998, included tanking
and detanking and 13 engine firings that simulated one, two, and three-burn mission
profiles for a total of 860 seconds. The heavily instrumented X-Stage was not
equipped with the extendible nozzle, because the B-2 stand could not accommodate a nozzle
of that size, but was otherwise largely representative of a flight stage.
"X-Stage" Being Lowered into Plum Brook Test
A second Delta 3 upper stage was tested at Goddard Space
Center's Acoustic Facility in February and March of 1998. During this testing, the
stage was subjected to acoustic loading representative of launch conditions. It was
also exposed to shock loads that represented stage separation.
Only one launch site, Cape Canaveral Space Launch
Complex 17B, was modified to handle Delta III. During 1997, the launch deck at 17B was
strengthened and a new exhaust deflector and exhaust ducting system was added to handle
the higher thrust GEM-46 solid booster motors. New LH2 and LOX piping was added to
the Umbilical Mast to support the new cryogenic upper stage. A new LH2 storage area
was constructed on the complex, southeast of the pad.
In 1998, after a January Delta 2 launch
christened the rebuilt pad, a series of "pathfinder" propellant loading tests
were performed to test the modified launch pad equipment for Delta 3.
But even as the first launch campaign prepared for kick
off, Delta 3 was being outmoded. Up the coast a few miles, Boeing, now firmly in
charge of former McDonnell Douglas launch systems, began work on an entirely new launch
complex for the newly won Delta 4 Evolved Expendable Launch Vehicle program. The new
launch pad was expected to cost about $250 million, rivaling the entire development cost
of Delta 3.
The late 1990s were not kind to rockets flown from Cape
Canaveral. Delta 241, an ultra-reliable Delta 2, exploded seven seconds after
liftoff from Complex 17 on January 17, 1997. A Titan 4 pitched over and exploded 41
seconds after launch from Complex 41 on August 12, 1998. Two more Titan 4 upper
stage failures would occur during April 1999 following launches from the Cape.
Combined, these four military satellite launch failures cost U.S. taxpayers more than $3
In the midst of this failure string, Boeing employees,
in June 1998, stacked their company's first Delta 3 on Complex 17B for a planned July
launch, but the flight was delayed a few weeks as officials dealt with pyro component
testing issues. Finally given the "go", crews stacked the payload, a $225
million communications satellite named Galaxy 10. The mission was identified as
Delta 259 During Service Tower Rollback
Delta 259 lifted off at 01:17 UTC on August 27,
1998. The first stage RS-27A main and vernier engines, augmented by six ground-lit
solid rocket motors, drove the 301 tonne rocket skyward on a combined total of more than
462 tonnes of thrust. The rocket quickly shot upward into the night sky and turned
downrange over the Atlantic. It passed safely through "Max-Q", the region
of maximum dynamic pressure when the largest forces of the flight were imparted onto the
vehicle. It flew on, nearing 20 km in altitude and 1,100 meters/second velocity,
until its six ground lit motors were nearly finished with their 75 second-long
Then, suddenly, inexplicably, the ascending rocket
turned sideways and was instantly replaced by an expanding fireball. Streams of
tumbling, burning debris dropped toward the ocean. Observers watched one large
object, which turned out to be Galaxy 10, explode when it impacted the Atlantic
about 15-20 km offshore.
An investigation quickly determined that the rocket had
begun to suffer 4 Hertz roll oscillations about 50 seconds after liftoff, when the RIFCA
system loaded a new set of flight control system gain constants - something that it did
every 10 to 15 seconds as the rocket flew through differing phases of flight. The
roll oscillation was created when the RS27A and three of the ground-lit solid motors
vectored in a way that amplified a natural 4 Hertz resonance of the vehicle. As the
system fought the resonance, it rapidly used up its hydraulic fluid. At T+65
seconds, the fluid ran out, leaving the solid motor nozzles stuck in their final position.
The RS-27A system tried to correct, but was unable to counteract the forces created
by the powerful solids. Delta 259 began to pitch over at T+72 seconds, and break
apart, its final destruction ensured by a flight termination system.
The Delta 3 guidance system, it turned out, had not been
designed to handle the particular 4 Hertz roll mode that led to the failure. During
Delta 3 development, McDonnell Douglas/Boeing designers had identified 56 roll modes.
Extensive Delta 2 flight data had shown that the most significant roll mode at
liftoff remained dominant throughout the first stage flight. The team assumed,
incorrectly, that Delta 3 would behave in a similar fashion. Since the 4 Hertz roll
mode was not significant at Delta 3 liftoff, the designers had not added its effects into
the control system.
But Delta 3 used substantially heavier, more powerful
solid motors than Delta 2. While three of the Delta 3 solids used thrust vector
control, none of the Delta 2 solids provided steering. It turned out that Delta 3's
4 Hertz roll mode did become more significant as the solid motor propellant was
The relatively straightforward fix was to modify the
flight control software. Analysts noted, in hindsight of course, that full vehicle
dynamic testing or more extensive flight control analyses would have discovered the roll
oscillation before the launch. Some also wondered why the inaugural flight had
carried a costly live payload. Boeing blamed the design flaw, in part, on lack of
communication between design groups.
Delta 269 Liftoff. Modified SLC 17B Exhaust
Duct Created Distinctive Plumes Around Rockets when Solids Ignited.
The second Delta 3 mission, Delta 269, launched with the
$145 million Orion 3 communications satellite on May 5, 1999. This time the flight
proceeded flawlessly through the first stage burn, allowing the RL10B-2 second stage
engine to perform its first flight burn, pushing the stage and payload into a parking
The stage coasted until about 21 minutes 54 seconds
after liftoff, when the RL10B-2 engine restarted for a planned 162 second burn and, 3.4
seconds later, suddenly shut down. The stage began tumbling, but gradually restored
its attitude. Orion 3 separated into a 138 by 153 km orbit, well short of the
planned 185 by 25,956 km orbit. The satellite could not be recovered to a useful
orbit and so was declared a total loss.
Another failure investigation began. Five months
after the failure, the investigative board determined that the RL10B-2 engine's combustion
chamber had burst during the restart due to defective brazing of a welded reinforcing
strip. Pratt & Whitney had to modify its brazing process and its inspection methods.
In many ways, the second Delta 3 failure was a
bigger setback than the first. According to a November 18, 1999 report by the
Associated Press, the two Delta 3 failures cost Boeing more than $100 million. The
failures also delayed the program by more than 2 years compared to original plans.
During the investigation, all RL10 flights, including Atlas Centaur launches, had to be
stopped, which resulted in the loss of one payload to Ariane 4. About the same time,
Delta 3 lost its next payload when ICO delayed bankruptcy. Other potential payloads
vanished as economies around the world slid into recession.
A little-noted 1999 decision would also have
implications for Delta 3. On August 31, 1999, Boeing announced that it would develop
Delta 2 Heavy by adding Delta 3's GEM-46 strap on solids to the existing Delta 2 design.
The more powerful motors increased GTO payload by 10% over the standard Delta 2
design. NASA planned to use the first new Delta 2 Heavy to launch its Space Infrared
Telescope Facility (SIRTF).
Delta 280 First Stage Stacking
A collapsing commercial satellite market forced Boeing
to fly the third Delta 3 with a dummy payload named DM-F3 (for Delta Mission Flight 3) on
August 23, 2000. The main intent of the flight was to qualify the second stage, which was
similar to the yet-to-fly Delta 4 second stage.
This time Delta 3 flew as Delta 280. Devoid of the
usual mission decals, the rocket's large white interstage and payload fairing, separated
by the orange band of insulation on the second stage liquid hydrogen tank, provided an
unusually simplified appearance. Only the Boeing logo and a simplified Delta logo on
the first stage fuel tank cluttered the image. The rocket's starkness implied an
The DM-F3 payload was a spool-shaped dummy
that weighed 4,348 kg. The mission was designed to demonstrate a propellant
depletion shutdown of the second stage RL10B-2 engine during its second burn. The
press kit listed a targeted 185 x 25,408 km x 27.5 degree subsynchronous transfer orbit.
Delta 280 Second Stage/Interstage Stacking
For the first time, Delta 3 lifted off
during daylight - shortly after dawn at the Cape. The rocket repeated its previous
performances, shedding its first six GEM-46 solid motors about 80 seconds after liftoff
and its second set at about the 160 second mark. The payload fairing, also a Delta 4
item, jettisoned at about T+227 seconds. Thirty four seconds later, the first stage
RS-27A propulsion system cut off. Stage separation occurred 296 seconds after
liftoff, with the vehicle traveling 4,784 meters/second and climbing past an altitude of
The second stage performed two burns.
The first, 538 second long burn boosted Delta 280 into a 157 x 1,363 km x 29.5 degree
parking orbit. The second burn began 1,315.5 seconds after liftoff, following a 495
second coast to the equator. The burn was expected to be 163.3 seconds long, but
ended a few seconds earlier.
Delta 280 Payload Fairing with Encapsulated DM-F3 Payload
Simulator, Stacking at SLC 17B.
DM-F3 separated into a 180.76 x 20,694 km x
27.5 degree orbit, prompting speculation that Delta 3 had failed again. But the
propellant depletion mission worked differently than the more familiar command shutdown
mission. Atmospheric wind and ambient launch temperature conditions altered the
targeted orbit apogee, which was not determined until shortly before liftoff. Delta
280 ended up with a targeted apogee of 23,404 km. The achieved orbit was 0.9% below
the targeted orbital velocity, within the allowable margin of error (3,000 km for the
The variation was unsurprising given the
use of a propellant depletion profile on the first complete mission of a new rocket
stage. Propellant management, involving the precise prediction of burn rates for two
liquid propellants, is as much art as rocket science. It typically takes a few
flights to tightly "tune" the performance of a new stage fitted with a new
rocket engine. Most new launch vehicles use command cutoff profiles during initial
flights. Such missions have lighter than maximum payloads and are planned to carry a
bit of excess propellant. Delta 280 carried a maximum payload and was fired to push
that payload to the maximum possible velocity.
Delta 280 Liftoff
Five years after the program had begun, and two years
after its first flight attempt, Delta 3 had finally flown true.
There may have been celebrations at the Cape, but they
were likely muted. The commercial satellite market, along with the world-wide
economy, had collapsed. The next planned Delta 3 launch was more than a year away,
Delta 3's tough start had cost business, and the
collapsing commercial satellite market had caused more to vanish. But there was
another factor in play. Boeing had poured hundreds of millions of dollars into Sea
Launch, an international commercial launch venture, even before Boeing merged with
McDonnell Douglas. Sea Launch Zenit could out-lift Delta 3 by a sizable margin - and
its first two launches had succeeded.
In 2000, Boeing also purchased Hughes Space &
Communications, the satellite builder. Satellite profit margins were sizeable.
Launch services profit margins were slim to none, especially with emerging
competition from Russia. Unlike McDonnell Douglas, Boeing had little incentive to
continue to support Delta 3 in a shrinking commercial satellite launch market.
Meanwhile, Boeing's more powerful Delta 4 EELV
development program was underway, with first launch expected during 2002. Delta 4,
if it could be brought in at a competitive cost, could make Delta 3 obsolete.
During May 2001, Boeing reported that it held only five
"firm" Delta 3 launch contracts, with none due to fly until 2003. The
company announced that it planned to phase out Delta 3 after no more than about 20 had
By January 2002, Boeing was reported to be planning to
phase out Delta 3 after it had flown out a 9-vehicle inventory. Two were to fly in
2003 and five in 2004. The program was to end after 2005. But by the end of
March 2002, Boeing was reported to be considering ending the Delta 3 program
altogether. The company was said to have already cannibalized parts from four Delta
After Delta 4 successfully flew for the first
time in November 2002, Boeing decided to quietly end Delta 3. There were no press
releases, but in September 2003 Wilbur Trafton, president of Boeing Launch Services, noted
in an interview both that Delta 3 was being killed and that Delta 4 was not going to
handle commercial business for the foreseeable future.
Delta 3 RS-27A engines, first stage propulsion sections and LOX
tanks if completed, and GEM-46 solid motors were diverted to the Delta 2 and Delta 2 Heavy
programs. Parts from Delta 3 upper stages, including RL10B-2 engines, and payload
fairings could be reassigned to Delta 4. The 4 meter interstages, first stage fuel
tanks, and second stage tanks, however, could not find a home. It is not clear how
many such parts were actually manufactured.
Modified SLC 17B continued to host Delta 2 launches. It
also served as the exclusive home of Delta 2 Heavy because only it had been designed to
handle the GEM-46 motors. But by 2010 the end of even Delta 2 was in sight.
During the late 2000s, Boeing and Pratt & Whitney donated an
uncannibalized Delta 3 upper stage fitted with a test-fired RL10B-2 engine to the
Discovery Center in Santa Ana, California. The stage today stands in the corner of a
museum parking lot, visible as a sort of billboard, but likely little noted, by passerby
on Interstate 5.
"Dynamics Gets Pact to Build 11 Atlas
Rockets", San Diego County Business, 5-4-1988.
"Delta Upgrade Challenge to Atlas",
Flight International, 2-7-1990.
"McDonnell Douglas Announces Delta 3",
McDonnell Douglas, 5-10-1995.
"Hughes Buy 10 Launches as First Delta 3
Customer", Business Wire, 5-10-1995.
"Russia Pushes for Bigger Market Share,
Aviation Week Reports", Business Wire, 1-19-1996.
"Hughes Announces Selection of McDonnell
Douglas Delta 3 to Launch Five Satellites for ICO", Hughes, 10-25-1996.
Boeing/McDonnell Douglas Merger Agreement
"Space Systems Loral Selects McDonnell
Douglas Delta 3", Space Systems Loral, 2-13-1997.
"Hot Fire Ignition Test with Densified
Liquid Hydrogen Using a RL10B-2 Cryogenic H2/O2 Rocket Engine", Nancy McNelis, Lewis
Research Center, AIAA-97-2688, 1997.
"Performance of the Spacecraft Propulsion
Research Facility During Altitude Firing Tests of the Delta 3 Upper Stage", Michael
Meyer, Lewis Research Center, AIAA-98-4010, July 1998.
"Challenging Pneumatic Requirements for
Acoustic Testing of the Cryogenic Second Stage for the new Delta 3 Rocket", Andrew
Webb, Goddard Space Flight Center, 9-3-1998.
Delta 259 Failure Investigation Press Releases,
Boeing, 8-1998 through 10-1998.
"Boeing Delta 2 Heavy Lift Rocket Developed
for NASA Payload", Boeing, 8-31-1999.
"Delta 269 Investigation Report",
"Delta 280 Mission Book", Boeing,
"Delta 3 Rocket Falls Short, but Still a
Success, Boeing Says", Space Flight Now, 8-24-2000.
"Delta 3 Payload Planners Guide",
by NASA, McDonnell Douglas, Boeing, Pratt & Whitney Rocketdyne
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