United States Department of State
Washington, D.C. 20520
SENSITIVE BUT UNCLASSIFIED
December 18, 1998
SUBJECT: Review of APSTAR II/Long March 2E Failure Investigation Data
We have completed our review of the documents associated with the APSTAR II/Long March 2E launch failure, and offer the following analysis for your review.
The launch failure investigation began in January 1995 immediately following the failed launch of the Chinese LM-2E space launch vehicle (SLV) with the Hughes Space and Communications (HSC) designed APSTAR II communications satellite payload onboard. The investigation involved the formation of several groups of technical experts by both the Chinese and Hughes. Additionally, both parties contracted an independent investigation team of private consultants and space industry experts. Throughout the course of the investigation, Chinese and Hughes personnel engaged in an extensive exchange of technical data and analyses. There were no US Government monitors overseeing these activities.
After a thorough review of the data provided to the Office of Defense Trade Controls (DTC), this office has concluded that:
The Chinese were deficient (to varying degrees) in the areas of anomaly analysis, accident investigation techniques, telemetry (TLM) analysis, coupled loads analysis (CLA), hardware design and manufacture, testing, modeling and simulation, and weather analysis.
HSC [Hughes] assisted the Chinese in identifying their shortcomings in these areas, through provision of detailed technical analyses and critiques of Chinese failure analysis.
The interaction between HSC [Hughes] and the Chinese on the APSTAR II failure investigation resulted in significant improvement to the Chinese spacelift program and contributed to Chinaís goal of assured access to space.
The lessons learned by the Chinese are inherently applicable to their missile programs as well, since SLVs and ICBMs share many common technologies.
Our review of the APSTAR II failure investigation centered upon documentation provided by Hughes Space and Communications to DTC. The data included memoranda, faxes, technical reports, etc. Thus, our final assessment is based on solely upon the exchange of written information between Hughes personnel and their Chinese counterparts. Accordingly, we have categorized our analysis by the kinds of work Hughes performed for the Chinese.
ANOMALY ANALYSIS/ACCIDENT INVESTIGATION
The differences between Hughes Space and Communications and Chinese approaches to conducting the accident investigation were substantial. The Hughes teams followed an in-depth and exacting process for conducting and documenting an accident investigation. They provided descriptive accounts of failure analysis, highlighted with explanations to include empirical evidence, fault elimination, deductive reasoning, etc.
Throughout the course of the investigation, Hughes identified faults with Chinese practices and techniques.
HSC [Hughes] identified that the LV [launch vehicle] clamp band was not seated correctly during flight, owing to slippage possibly caused by vibrations and the use of a lubricant on the band. It recommended the Chinese review this area prior to future launches. (Hughes Failure Investigation Report, para 4.3.3, July l995).
HSC [Hughes] identified a possible design flaw in the venting system of the payload fairing (PLF), compared the system to western standards, and recommended the Chinese review this area prior to future launches. (Hughes Failure Investigation Report, para 4.3.3, July 1995).
HSC [Hughes] identified a possible design flaw in the nose dome of the fairing. Analysis of the PLF debris from both the APSTAR II and OPTUS B2 uncovered similarities in the probable failure of the nose dome. (Hughes Failure Investigation Report, para 4.3.3, July 1995).
HSC [Hughes] identified the effect of wind shear on both the APSTAR II and OPTUS B2 launches. Moreover, they identified western standards for command and control to remedy the negative effects of wind velocity on a vehicle in flight. (Hughes Failure Investigation Report, para 4.3. 1, July 1995).
HSC [Hughes] conduct of debris investigation was superior to Chinese analysis. Numerous rebuttals to Chinese analysis of launch debris identified inaccuracies, misrepresentations, and incomplete analyses of debris which were critical to fault identification. HSC [Hughes] results were supported by technical drawings, photographs, modeling, etc. (HSC Response to CALT Video, 8 May 95: Hughes Independent Spacecraft Review Team Final Report, July 1995; Hughes Failure Investigation Report, July 1995).
Telemetry (TLM) analysis helps re-create the events leading to an anomaly ó one of the most critical elements of any accident investigation. Through-out the course of this investigation, Hughes Space and Communications provided detailed explanations of its TLM analyses and identified probable errors in Chinese analyses.
HSC [Hughes] identified the TLM data as "the most important source of information regarding the failure." HSC [Hughes] analysis of TLM data directly pointed to failure of the PLF in-flight for APSTAR II, as well as to the previous in-flight failure of the OPTUS B2. HSC [Hughes] laid out the history of the flight via TLM analysis, identifying "77 points" (i.e. significant events) which were critical to its analysis. (HSC APSTAR II Failure Presentation to CGWIC, 13 Feb 95; Hughes Failure Investigation Report, para 4.1.1, 4.3.3, Section 5, July 1995).
HSC [Hughes] identified Chinese TLM analysis as deficient in several areas: the Chinese did not identify LV [launch vehicle] trajectory corrections due to wind shear effects; incorrectly interpreted accelerometer data; failed to identify a probable anomaly with the clamp band; and missed a probable fault with the PLF venting process. (HSC APSTAR II Failure Presentation to CGWIC, 13 Feb 95; HSC APSTAR Failure Review: Status Report, Pt II, 12-13 Apr 95; CALT APT Failure Investigation Report, 25 Jun 95; Hughes Independent Spacecraft Review Team Final Report, para 3.3.1, 3.3.3, 3.4.2, 3.4.3, 3.4.6, July 1995).
COUPLED LOADS ANALYSIS
The Hughes Space and Communications coupled loads analysis (CLA) team "spent extended time in Beijing with the CALT CLA team to understand and validate CLA methodology." In the course of these exchanges, Hughes shared modeling and calculation data, made comparisons to Western standards, and identified areas of concern in the Chinese CLA modeling processes. Both Hughes and the Independent Oversight Team (IOT), hired by Hughes and the Chinese, found discrepancies in Chinese CLA. Indeed, the Independent Spacecraft Review Team provided a telling insight into Chinese CLA efforts by stating, "Öthere was definite confusion in understanding the static and dynamic envelopes for the complete stack assembly."
HSC [Hughes] conducted joint re-analysis of CLA after reviewing the flightís TLM data. In several cases, it either re-affirmed or did not concur with pre-flight modeling conducted by the Chinese. This included sharing of modeling, calculations, methodologies, etc. (HSC APSTAR II Failure Investigation to CGWIC, 13 Feb 95; LM-2E Failure Module, 8 May 95; Hughes Failure Investigation Report, para 4.1.2, July 1995).
HSC [Hughes] specifically identified concerns with Chinese CLA early in the investigation: "Low fidelity of CLA mode definition Ö Uncertainty in loads." (APSTAR II Failure Review, Other Concerns, 12 Apr 95).
HSC [Hughes] compared and contrasted Chinese CLA with Western aerospace analyses of Ariane and Atlas. (HSC APSTAR II Failure Briefing, May 1995).
An IOT member, when referring to possible failure of the PLF, stated, "Ö (failure) could be the combination of incorrect design loads Ö (the Chinese) need further understanding of the impact both of static and dynamic loads upon the payload fairingÖ" (Memorandum from Mr. Ernest L. LaPorte to HSC and CGWIC, 14 Jun 95).
Hughes uncovered design and/or manufacturing flaws in the payload fairing, and determined that they directly contributed to the failure of two Chinese space launch vehicles. Additionally, Hughes identified possible problems with the Chinese manufactured launch vehicle clamp band and interface adapter.
The Structures Team conducted technical analyses on the PLF and identified flaws in the rivets used to secure the zipper area of the PLF (Hughes Failure Investigation Report, para 3.2.2, 3.4, 3.5.3, 4.2.1, 4.3.3, July 1995).
The Aerodynamics Team reviewed Chinese wind tunnel modeling and testing. It provided comparison with and reaffirmed open-source information from NASA, which identified design flaws in the PLF (Hughes Failure Investigation Report, para 3.2.2, 3.5.4, 4.3, 4.3.2, July 1995).
The Structures Team identified possible design flaws and possible improper installation of the launch vehicle clamp band (Hughes Failure Investigation Report, para 3.2.2, 3.5.3, 4.3.3, July 1995).
HSC [Hughes] recommended, that the Chinese conduct a thorough review of quality control procedures prior to any anomaly analysis investigation (Hughes Independent Spacecraft. Review Team Final Report, para 3.3. 1, July 1995).
HSC [Hughes] identified possible material and design faults with the Chinese manufactured interface adapter, the Environment and Interfaces Team (EIT), analysis of TLM supported this conclusion. Additionally, EIT identified a possible anomaly in Chinese ground operations procedures for the installation of the clamp band (Hughes Independent Spacecraft Review Team Final Report, para 3.3.1, 3.4.3, 3.4.6, July 1995).
HSC [Hughes] provided a critical assessment of the Chinese designed interface adapter an inadequate design by HSC standards (Hughes Independent Spacecraft Review Team Final Report, Lessons Learned, July 1995).
(Also: see ANOMALY ANALYSIS/ACCIDENT INVESTIGATION above, for other design/manufacturing issues).
Hughes made recommendations for improvements to Chinese testing methodologies and verified results of Chinese tests of hardware.
HSC [Hughes] recommended vibration testing of the spacecraft - launch vehicle adapter stack for future launches to preclude clamp band anomalies; the EIT supported this as well (Hughes Independent Spacecraft Review Team Final Report, para 3.3.1, 3.4.6, July 1995).
Hughes personnel suggested: "that for future applications, with this or new launch vehicles, a vibration or modal test be performed combining the adapters, perigee stage and spacecraft to resolve loads, modes, deflections and accelerometer testing." (Hughes Independent Spacecraft Review Team Final Report, July 1995).
In October 1995, following the conclusion of their joint investigation with Hughes, Chinese technical experts publicly made a series of commitments to their insurers to improve their spacelift program. In each case, the Chinese had previously (through June 1995) concluded that no problems existed. Hughes, on the other hand, insisted from the outset of the investigation that there were problems, and provided the technical analyses to support their claims.
PAYLOAD FAIRING: To strengthen their design, the Chinese made the following changes to the PLF: added bolts to the nose cap; included a support beam for the dome; added a frame and seal cap between the dome pieces; switched to a manual locking mechanism for a hatch door. Additionally, the Chinese increased their complement of ground tests and changed their ground operating procedures for the PLF.
WIND SHEAR ALOFT: The Chinese planned to increase monitoring and measuring times; prepared to modify SLV trajectory based upon modified wind prediction models.
COUPLED LOADS ANALYSIS: Stated plans to strengthen payload and launch vehicle compatibility analyses.
Hughes assistance directly supported the Chinese space program in the areas of anomaly analysis/accident investigation, telemetry analysis, coupled loads analysis, hardware design and manufacturing, testing, and weather analysis. Moreover, the assistance provided by Hughes is likely to improve the standing of the Chinese in the commercial launch market, as they make improvements in spacelift reliability and performance.
Hughes personnel knew the Chinese had problems in their space program. The Failure Investigation Team concluded that the Chinese launch failure hypothesis (provided independently from and prior to the Hughes failure report) failed to identify several key anomalies with the launch vehicle. Thus, we conclude Chinese anomaly analysis was not up to Western standards.
Comparing the APSTAR II failure to the January 1995 [actually February 1996] failure of a Long March-3B (INTELSAT payload) reveals similarities between the two cases. In both instances, the investigation teams identified common themes with regard to Chinese deficiencies in launch operations, anomaly analysis, modeling and simulation, manufacturing, and quality control, etc. However, we conclude the APSTAR II investigation provided more detailed assistance to the Chinese than the more general support provided during the Long March 3B investigation. The two investigation reports, centering on different variants of the Long March vehicle family, offer strong evidence that the Chinese spacelift program suffers from poor reliability. The reports reveal that U.S. contractors knew where the Chinese program suffered from inadequacies. Moreover, the contractors often corrected errors in incomplete or incorrect analysis or filled in gaps where the Chinese simply lacked the technical knowledge.
Essentially, the APSTAR II failure investigation (and to some extent, the investigation of the Long March 3B) served as a tutorial for the Chinese, allowing them to improve on areas in which their spacelift program was weak. The Lessons Learned section of the Independent Spacecraft Review Team final report also offers commentary on the serious concerns HSC [Hughes] had with Chinaís spacelift program: "HSC should never compromise on doing a coupled loads analysis. If politics, government constraints or vendor issues do not permit the analysis then it is our recommendation that this is not a suitable launch."
The impact and extent of any damage to U.S. national security as a result of the Hughes accident investigation into the APSTAR II launch failure is difficult to quantify. However, we believe the assistance provided by Hughes to China will prove to be significant to the degree it contributes to the increased reliability of their launch vehicles. The recent record of Chinese space launches in fact shows an improvement in reliability. The longer term effect of increased launch reliability will be to improve the rate of successful deployment of Chinese satellites and, in turn, to facilitate Chinaís access to space for commercial and military programs.184