- Press Release
- Feb 3, 2023
Proton Return-to-Flight Update
Russian Government Inter-agency Launch Failure Review Board Report Released, ILS/LKE Independent Failure Oversight Board to Convene January 12th
SAN DIEGO, CA, January 7, 2000 – Attached is an English translation of the report, “Causes of Failure of Proton LV + 11C861 Upper Stage Stack During Express A # 1 Spacecraft Launch Mission on October 27, 1999,” prepared by the Inter-agency Launch Failure Review Board of the Russian Government. This report has been released by Khrunichev into the public domain and is being provided by ILS/LKE for your information.
ILS/LKE has also formed a cross-sectional independent Failure Review Oversight Board (FROB) to review the results of the Russian Government investigation, as well as the specific corrective action plan. The board members consist of independent experts with experience in failure analysis, drawn from Lockheed Martin and the industry. The Technical Assistance Agreement (TAA), necessary for the FROB to begin its work, has been approved by the U.S. State Department and the board is scheduled to meet with members of the Russian Inter-agency Commission and Khrunichev in Moscow on January 12, 2000. Following conclusion of these meetings, the FROB will prepare and issue its assessment and report of the Russian failure investigation and corrective actions. ILS/LKE and Khrunichev are committed to achieving a successful return to flight, with minimum disruption of our customers’ launch schedules. Following the successful completion of the FROB and briefings to the customer and insurance community under U.S. State Department license, the Proton return-to-flight is projected to be in February, with the launch of the ACeS/Garuda 1 commercial mission. Until additional licenses are approved by the U.S. State Department, ILS/LKE is not authorized to release additional information beyond that which is contained in the attached public domain report, nor may it offer any analysis or conclusions based on the report.
ILS/LKE has also formed a cross-sectional independent Failure Review Oversight Board (FROB) to review the results of the Russian Government investigation, as well as the specific corrective action plan. The board members consist of independent experts with experience in failure analysis, drawn from Lockheed Martin and the industry. The Technical Assistance Agreement (TAA), necessary for the FROB to begin its work, has been approved by the U.S. State Department and the board is scheduled to meet with members of the Russian Inter-agency Commission and Khrunichev in Moscow on January 12, 2000. Following conclusion of these meetings, the FROB will prepare and issue its assessment and report of the Russian failure investigation and corrective actions.
ILS/LKE and Khrunichev are committed to achieving a successful return to flight, with minimum disruption of our customers’ launch schedules. Following the successful completion of the FROB and briefings to the customer and insurance community under U.S. State Department license, the Proton return-to-flight is projected to be in February, with the launch of the ACeS/Garuda 1 commercial mission.
Until additional licenses are approved by the U.S. State Department, ILS/LKE is not authorized to release additional information beyond that which is contained in the attached public domain report, nor may it offer any analysis or conclusions based on the report.
Board for Investigating Causes of Failure
of Proton LV + 11C861Upper Stage Stack
During Express A # 1 Spacecraft Launch Mission
on October 27, 1999
by LKE on 6 January 2000
The Proton LV
Ser. No. 38602 + 11C861 upper stage + Express A #1 spacecraft stack was launched
on October 27, 1999 and this mission has ended in a failure. In this connection
the Inter-agency Board has been set up jointly by the Russian Aviation and Space
Agency (RASA) and the Russian Strategic Missile Force (RSMF).
Board has analyzed: (i) the telemetry data downlinked during the mission, (ii)
the main engine design and the main engine fabrication process used by the Voronezh
Mechanical Plant, and (iii) the status of the Stage II 8D411K/8D412K engines
and that of some sub-assemblies of the Stage III 8D48 engine installed on the
8K82K launch vehicle (known as Proton) Ser. No. 38602.
Board has reviewed the process used by the Space Rocket Plant, Khrunichev Space
Center to fabricate the above launch vehicle and analyzed the operations used
to process this launch vehicle during the launch campaign.
Based on the
above investigations, the Inter-agency Board concludes that
1. The 8K82K
launch vehicle Ser. No. 38602 was processed in compliance with the manuals in
force. All launch vehicle systems and units functioned nominally during processing
at either the Processing Facility or on the pad. The Launch Facility supported
the execution of all launch vehicle processing or fueling operations as well
as launch vehicle launch in compliance with the manuals and at the pre-scheduled
time. The results of analyses of all propellants or compressed gases are positive
for any processing or post-liftoff phase which fact is substantiated by the
respective service life documents.
Board has also reviewed the degree of compliance with the applicable operation
and maintenance manuals (OMM) in the course of the campaigns related to the
July 5, 1999 and October 27, 1999 Proton launches, with a special emphasis on
the shutdowns of the Launch Facility each lasting one year or more.
As a result it
has been demonstrated that
- The Launch
Facility is provided with OMM concurred with all organizations concerned,
and describing procedures to be followed in order to perform a launch after
a prolonged Launch Facility shutdown and
- No non-compliance
with the applicable OMM during the October 27, 1999 launch campaign has been
Board takes note of the fact that all action items have been implemented on
the LV Ser. No. 38602 as provided for in Sections I, II or III of the Comprehensive
Plan to Implement the Recommendations by the Inter-agency Board Set up to Investigate
the Failed Launch of LV Ser. No. 38901 on July 5, 1999.
2. The LV 8K82K
Ser. No. 38602 + 11C861 upper stage + Express A #1 spacecraft stack was launched
at 1600 Moscow Decree Time, October 27, 1999 from Pad 39, Area 200.
Until L + 221.96
seconds, Stage II flight proceeded nominally, each LV system and unit functioned
nominally and no fault has been found with their operation on the basis of the
telemetry data available.
At L + 221.96
seconds, off-the-nominal behavior was recorded of the 8D411K engine Ser. No.
5358161741 installed in Stabilization Plane I of Stage II. This manifested itself
in the unsealing of the engine’s exhaust duct followed by spontaneous shutdown
of the remaining engines.
of the debris of the 8D411K engine Ser. No. 535816741 identified the ignition
of the turbine exhaust duct. The examination further showed that the nature
of the burnout of turbine parts was similar to the burnouts that occurred (i)
during the earlier Proton mission, which ended in a failure on July 5, 1999,
and (ii) in the unsuccessful lot-by-lot test on November 5, 1992.
of the parts of the failed LV Ser. No. 38602 revealed metallic or non-metallic
debris in internal chambers of Stage II such as a piece of asbestos fabric under
the 8D411K-13 valve head, traces of aluminum and copper, and sand.
3. A review of
the hardware status shows that some of this foreign debris penetrated the engines
as a result of either the unsealing of the engines in the course of the failure
or the impact of the engines with the ground. However, additional experiments
on the exhaust duct containing an 8D411K-13 valve showed that the initial location
of the piece of fabric in this accident was most likely the fuel line downstream
of the 8D48-41 starter valve which means that this piece of fabric got into
the fuel line during engine fabrication. Moreover, silica sand particles egressed
into the 8D46-09-01 regulator Ser. No. 3429 and the content of chemical elements
in these particles is similar to that of the debris found in the 8D412K engine
Ser. No. 425, Proton LV Ser. No. 38902 following transportation and vibration
4. This Inter-agency
Board points out that the engines installed on Stages II and III of the Proton
LVs that failed during the July 5 or October 27 missions and the engines that
failed in the November 5, 1992 lot-by-lot tests were all manufactured in the
The latter period
is characterized by a slump in the production of liquid rocket engines at the
Voronezh Mechanical Plant (down to 19% of the 1986 level in 1992) combined with
the launch of civil-oriented production by the Engine Department in 1992. From
that point in time on, the per-produced-item number of non-compliances has jumped
up. These non-compliances are largely caused by fabrication-related sources
(primarily poor workmanship) and include deviations from the required geometrical
dimensions of parts belonging to turbopump sub-assemblies. Several gross non-compliances
were identified in its report by the Failure Investigation Board set up to review
the results of the unsuccessful November 5, 1992 lot-by-lot tests.
Thus a gross
neglect of requirements was committed in the course of fabrication of the turbopump
for the 8D48 engine designed for installation on Stage III of the 8K82K LV Ser.
No. 38602 (which eventually failed). More specifically, one of the 12 screws
bolting the ring seal cover was not counter-locked and the tightening moment
of each of the 12 screws failed to meet the requirements though the respective
operation which had been signed off by the worker, the quality inspection and
the manager. Moreover, uncertified tools were used for this operation.
5. An additional
numerical analysis as well as a review of the existing flight or ground test
statistics combined with the results of a metallographic examination lead to
the conclusion that:
- Any fatigue
destruction of the nozzle cutoff edge due to gas vibrations in the turbine
wheel/nozzle gap is ruled out since no frequencies and/or amplitudes required
by this mechanism are present;
- A review of
the ignition characteristics of the Stage II engines during the October 27
launch shows that these characteristics fall within their test-average limits
and do not exhibit any anomaly. Both the level and the time history of the
oxidizer pressure either upstream of the engine (the ___21
parameter) or downstream of the pump (the ___21 parameter)
demonstrate that the ignition proceeded nominally;
- An analysis
made by the Khimavtomatika Design Bureau, the Keldysh Research Center and
the TsNIIMash assuming the worst-case tolerances, deformations and mutual
vibration-induced displacements demonstrates that turbopump cover/nozzle interface
gap margins exist that guarantee that no wear hardening can occur. This conclusion
has further been corroborated by metallographic survey;
- An examination
of the cover and the screws that attach the oxidizer pump’s matching
ring seal to the failed engine’s turbine stator casing revealed discoloration
due to local fretting. Similar defects have also been observed on several
other engines which fact necessitates appropriate corrective actions.
On the other
hand, subsequent analysis showed that the respective displacements are too small
(of the order of ten microns) and the vibration frequencies are limited so that
neither cover burnout nor burnout spreading onto other turbopump components
can ever take place. To this one should add the somewhat more favorable temperatures
(in fact cooling conditions) in the vicinity of the cover and the specific overall
nature of the burnout in the failed engine.
6. Several structural
features of the turbopump resulting in stagnant vortex zones and the ability
of the turbine cover and the nozzle body to move relative to each other are
fraught with a risk of a failure in case foreign particulate matter (of either
metallic or non-metallic origin) accidentally enters the exit duct. In fact,
the post-failure examination has identified foreign particulate matter inside
some of the engine sub-assemblies.
that the failure of the October 27, 1999 Proton mission was caused by the ignition
of some of the turbopump sub-assemblies is largely corroborated by the time
histories of the major turbopump parameters (namely, pressure, temperature and
the speed) as recorded at the time of the accident during the unsuccessful July
5, 1999 mission, as well as by similarity between the post-accidental status
of the hardware in these failed missions and the phenomena observed in the 1978
ground tests involving the injection of metal debris into the oxygen duct.
7. A Comprehensive
Plan has been developed to identify the sources of contamination impairing engine
performance. Within the framework of this Plan use has been made of various
parts of the LV Ser. No. 38902 fabricated in the same period in which the failed
launch vehicles were fabricated.
This Plan includes
transportation tests of Stage II, dynamic tests of the 4-engine cluster, flow
tests of the Stage II oxygen tank using a fine-mesh filter, post-test examination
and fire tests including (in Test Phase 2) the simulation of the sources of
failure, as well as a post-test examination of the 8D48 engine installed on
Stage III of the failed LV Ser. No. 38602. As of December 25 the Stage II transportation
tests, the dynamic-load tests of the engine cluster, and the flow test of the
Stage II oxygen tank have been carried out and Engine 4 (rather than Engine
3) is currently being disassembled and examined. Apart from the Comprehensive
Plan, the Khrunichev Space Center have inspected the internal chambers of the
Stage II engines using an endoscope and a contamination extraction technique.
of the Comprehensive Plan has resulted in the following findings:
- The weight
of the particulate matter in the oxygen tank as measured through a flow test
falls within the constraints specified by the tank’s documents;
- The amount
of particulate matter identified differs from engine to engine. Thus a greater
number of foreign particles (in terms of weight and size) was found in Engines
3 and 4 (namely, in the pre-burner and downstream of the turbine) than in
Engines 1 and 2;
- The composition
of the mineralogenic particulate matter found in Engine 2 from a failed LV
is identical to that in Engine 3 taken off a launch vehicle subjected to transportation
The most likely
cause of the failure of the Proton LV Ser. No. 38602 on October 27, 1999 is
the presence of metallic or mineral particulate matter inside the engine resulting
in the ignition of the turbopump’s engine assembly in Stage II Engine #1
(P/N 8D411K, Ser. No. 5358161741). The most likely cause for the particulate
matter to find its way into the engine is poor workmanship at the Voronezh Mechanical
Plant in 1992/93.
The failure under
study is categorized as a fabrication-related one.
# # #
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