Mitsubishi Heavy Industries Technical Review Vol. 51 No. 1 (March 2014)
52Contribution to Japan's Flagship Launch Vehicle-part 1Continuous Successful Launch ofH-IIA and H-IIB launch Service Privatization
KOKI NIMURA*1

KATSUHIKO AKIYAMA*2

MASAHIRO ATSUMI*3

TAKASHINOMA*4

ATSUTOSHI TAMURA*5

The Flight #4 H-IIB launch vehicle carrying the H-II Transfer Vehicle (HTV4) was launchedat 4:48:46 am on 4 August, 2013 from Tanegashima Space Center, and successfully injected theHTV4 into its designated orbit. H-IIA/B launch vehicles have now been successfully launched 20consecutive times. In addition, the Flight #4 H-IIB was the first launch vehicle to be privatized,
and the privatization was accomplished smoothly. This paper introduces one aspect of theactivities behind the reliability of the H-IIA/B launch vehicle.

|1. Introduction
The past launch record is shown in Table 1, and the H-IIA/B launch vehicle family, which isJapan’s flagship launch vehicle program, is shown in Figure 1.
Table 1

Record of H-IIA/B launch

Success Rate of H-IIA and H-IIB: 96.2%
TypeFlight No. Launch Date

H-IIA
H-IIA
H-IIA

TF1
TF2
F3

2001.8.29
2002.2.4
2002.9.10

H-IIA

F42002.12.14

H-IIA
H-IIA
H-IIA
H-IIA
H-IIA
H-IIA
H-IIA
H-IIA

F5F6
F7
F8
F9
F10
F11
F122003.3.28
2003.11.29
2005.2.26
2006.1.24
2006.2.18
2006.9.11
2006.12.18
2007.2.24

H-IIA

F132007.9.14

H-IIA
H-IIA
H-IIB
H-IIA

F14
F15
TF1
F16

2008.2.23
2009.1.23
2009.9.11
2009.11.28

H-IIA

F172010.5.21

H-IIA

F18

2010.9.11

H-IIB
H-IIA
H-IIA
H-IIA
H-IIB
H-IIA
H-IIB

F2F19
F20
F21
F3F22
F42011.1.22
2011.9.23
2011.12.12
2012.5.18
2012.7.21
2013.1.27
2013.8.4

MissionOrbit

LRE
MDS-1/DASH
DRTS/USERSADEOS-II/Small
Satellites
Classified
Classified
MTSAT-1R
ALOS
MTSAT-2
Classified
ETS-VIIIClassified

GTO
GTO
GTO/LEO

Success
Success
Success

Postponement
Postponement
On TimeSSO

Success

On Time

GTO
SSO
GTO
GTO
-Success
FailedSuccess
Success
Success
Success
Success
Success

On TimeOn Time
Postponement
Postponement
On TimeOn TimeOn TimeSuccess

On TimeSuccess
Success
Success
Success

On TimeOn TimeOn TimeOn TimeSuccess

On TimeSuccess

On TimeSuccess
Success
Success
SuccessSuccess
Success
Success

On Time
Postponement
On TimeOn TimeOn TimeOn timeOn TimeTransfer toMoon
WINDS
GTO
GOSAT/Small Satellites
SSO
HTV1
ISS
Classified
Transfer to
PLANET-C/IKAROS
Venus
Quasi-Zenith
QZSOrbit
HTV2ISSClassified
Classified
KOMPSAT-3/GCOM-W1
SSO
HTV3
ISS
Classified
HTV4
ISS
SELENE

Note*1

General Manager, Space Systems Division, Integrated Defense & Space Systems*2

Chief Staff Manager, Space Systems Division, Integrated Defense & Space Systems

GTO: Geostationary
Transfer Orbit
SSO: Sun-SynchronousOrbit
LEO: Low Earth Orbit
ISS: HTV Orbit heading
to International Space
Station・Privatization by MHI
H-IIA: from F13
H-IIB: from F4*3Director, Space Systems Engineering Department, Space Systems Division, Integrated Defense & Space Systems*4Chief Staff Manager, Space Systems Engineering Department, Space Systems Division, Integrated Defense & Space Systems*5Deputy Director, Space Systems Engineering Department, Space Systems Division, Integrated Defense & Space Systems

Mitsubishi Heavy Industries Technical Review Vol. 51 No. 1 (March 2014)
53Figure1 H-IIA/B Launch Vehicle Family

H-IIA launch vehicles have succeeded 25 times; the only failure was Flight #6. The resultscompared with the success rate of the flagship rockets of other nations are shown in Figure 2. The
success rate of the H-IIA launch vehicle reached 95.5%, the world’s top level. In addition, the trendof the on-time launchratio, representing the ratio launched on the date it was originally planned, isshown in Figure 3. It has a high ratio of 92% for the last 4 years and has continued to increase
from 2000.

Figure 2 Comparison of Launch Success Rate

Figure 3 On-Time Launch Ratio

Furthermore, the number of defects that occurred at the Tanegashima Launch Site is shownin Figure 4. It is understood that as the quality of the product improves, the number of defects
decreases. Here, we introduce the activities that support the high reliability of the H-IIA/B launchvehicle.

Mitsubishi Heavy Industries Technical Review Vol. 51 No. 1 (March 2014)
54

Figure 4

Number of defects at Tanegashima Launch Site

|2. Activities to Support the Reliability of the Product
When we consider the reliability of the product , there are two activities we regard asimportant: data trend evaluation activity (2σ evaluation) and quality evaluation activity.

2.1

Data Trend Evaluation Activity

The outline of the data trend evaluation activity is shown in Figure 5. The activity is toarrange the functional test data, etc. in time series from the equipment manufacturer, MHI Nagoya
Oye plant to Tanegashima Launch Site and to evaluate whether the data are within the range[dispersion of average value +-2σ of the past record value]. In general, the value of the [dispersionof average value +-2 σ] is less than the specified value (SPEC value). Through this activity, whenthe value deviates from [dispersion of average value +-2 σ] even if it meets the specified value, it isassumed that some changes are produced in the process and the cause and impact are investigatedthoroughly. And we evaluate the dispersion between the data of the same test of each vehicle, It is
assumed that continuing this activity steadily leads to the early detection of the sign of defect.

Figure 5

Outline of Data Trend Evaluation Activities (2σEvaluation)

In the H-IIA launch vehicle, about 5,000 data points are evaluated. As a result of having an
investigation into a cause beyond the dispersion of 2σ by the trend evaluation, there were 8 or morecases of defects detected regarding design or manufacture. Two of those examples are introduced
here.

Mitsubishi Heavy Industries Technical Review Vol. 51 No. 1 (March 2014)55

The first example is shown in Figure 6. During the propulsion functional test of the second
stage, the pressure drop rate in one enclosed space exceeded the value of the [average value +2σ
dispersion of the previous unit]even though the value was within the SPEC value.
As a result of the investigation, the cause of the large drop in pressure rate was discovered to
be a contamination lied between the sealed section of the check valve in the system, so the gas ofthe enclosed space was able to leak out. And the cause of contamination was design defect of themanual valve in the system.The design modification of the manual valve was started immediately,
and a countermeasure product was manufactured and replaced before the launch.
The second example is shown in Figure 7. We discovered that about 3% nitrogen gas got
mixed in the helium gas for driving engine valves supplied from the facility to the launch vehicle,
which was after the investigation into a 5% delay in the engine valve operation time.

Figure 6

Data Trend Evaluation Activities – Example of Performance (1)Figure 7

Data Trend Evaluation Activity – Example of Performance (2)Mitsubishi Heavy Industries Technical Review Vol. 51 No. 1 (March 2014)
56

2.2

Quality Evaluation Activity

The outline of the quality evaluation activity is shown in Figure 8. In general, the quality ofa product is based on a drawing/SPEC, which is decided by a engineering department, and it iscertified by manufacture/inspection of the manufacture/quality assurance department. This process
is similar for launch vehicles.

Figure 8

Outline of quality evaluation activities

In addition to this general process, for the H-IIA/B launch vehicle, after the failure of theH-IIA launch vehicle #6, the engineering department took a leading part in quality evaluation
activity. It has continued to be performed until now. And this activity is undertaken by the persons
in charge of each system. They reevaluate the quality of the launch vehicle regarding designcontents, manufacturing condition, inspection result and launch separately from the regular process
mentioned above. The main points of view for the evaluation are the following 3:(1) Confirmation of design/process change(2) Confirmation of trend changes in data(trend evaluation)(3) Confirmation of the horizontal deployment status about the defects occurred recently
We have often experienced the cause of defects was the some change. So we pay mostattention to evaluating various changes; the following is an introduction to the above point of viewof (1).
Twenty-two H-IIA launch vehicles and 4 H-IIB launch vehicles have been launched. It hasgiven the impressions that the H-IIA/B launch vehicle has already been refined regarding design,and manufacture with same design and launch indifferently. However, actually, there have been thefollowing changes, even with the most recently launched H-IIA launch vehicle #22 and H-IIBlaunch vehicle #4. (The total number includes minor changes.)・ Number of changes in design/process/procedure:
H-IIA launch vehicle #22 137
H-IIB launch vehicle #4207
・ Number of changes of manufacture jigs
H-IIA launch vehicle #2287
H-IIB launch vehicle #4118
These changes are evaluated not only about their validities but also are evaluated carefullyand quantitatively about their impact to the other system and are judged the impact for launch.

Mitsubishi Heavy Industries Technical Review Vol. 51 No. 1 (March 2014)
57|3. Activity that Develops/Maintains Human Capabilities
The activity that supported the reliability of the product was explained in section 2. On theother hand, it is important to educate/maintain human capabilities to preserve the reliability of theentire launch program. For example, human capabilities have a considerable effect on the on-timelaunch rate introduced in section 1. The various defects related to the vehicles and facilities occur
for every vehicle on the day of the launch. The collection of defect-related data, cause analysis andactions must be completed in a short time to launch on-time. If the cause of a problem does not
become completely clear, it is still necessary to decide upon the launch in a short time as the defectmay not have a harmful effect on the mission of the launch. We consider that to develop andmaintain engineers with these capabilities is important.
We perform "launch service operation rehearsal" in Tanegashima and "simulated problem
training" in Nagoya Aerospace Systems Oye plant as part of the activity stated above.
The launch service operation rehearsal is a practical rehearsal when the personnel responsible
for the launch gather at the Tanegashima launch site and execute training under the assumption theday is the day of launch. Personnel who evaluate the data at the time of launch enter the control
room and start the rehearsal. Carefully prepared "simulated problems" are shown to the personnel.
The training is a troubleshoot for these simulated problems and to propose answers and report oncauses and actions for the launch in a limited time. Through this training, the necessary capabilities
to make an appropriate decision in a short time are cultivated. Troubleshooting during an actual
rehearsal is shown in Figure 9. The rehearsal is performed once for each vehicle. Since it isinsufficient to develop and maintain capabilities only through this training, we also execute similar
training called "simulated problem training" in Nagoya Oye plant. This serves as part of theeducation for young engineers.

Figure 9 Troubleshooting in the control room during
exercise rehearsal

The development of the recent H-IIB launch vehicle was completed 4 years ago (2009). The
development of the H-IIA launch vehicle was completed in 2001. H-IIA/B launch vehicle is an
improved product of H-II launch vehicle that was completed in 1994. H-II is the last vehicle wehave developed from the beginning. The capability to make adequate judgments in the short timestated above has been taught to young engineers through this H-II launch vehicle development test
experience; however, there is no situation for young engineers to develop from the beginning andto experience tense situations that require quick decision making. On the other hand, due to theH-IIA/B launch vehicle being placed in an environment where launch failure is never acceptable,
experienced engineers are mostly expected to make on-the-spot decisions just before the launchwhile young engineers have less opportunity to make major decisions. Therefore, for the purpose of
having many decision experiences for young engineers, education and training programs arepracticed to judge "simulated problems" in conditions that are the same as the actual launch inTanegashima. Through the training, young engineers can recognize their current capabilities andwork with the incentive that they are going to learn by themselves; also skill levels of individual
personnel can be understood to help place them in the right position.

Mitsubishi Heavy Industries Technical Review Vol. 51 No. 1 (March 2014)
58

Steadily continuing such activity and educating/maintaining the judgment of personnel,including younger personnel, enables quick judgment and decision making for defect occurred on
the launch day and as a result, it is assumed, this will lead to on-time launch rate improvement.

|4. Conclusions
One aspect of the activity supporting reliability represented by the launch success rate andon-time launch rate was introduced as a product and a human point of view. These activities were
designed for continuous success by senior and veteran personnel directly concerned in launchvehicle development and launch. The H-IIA/B launch vehicle is a vehicle that can continue
operating for at least seven years, and we are proceeding with the construction of the structure tocontinue effective performance without lowering quality. The development of a new flagshiplaunch vehicle, which is to be the successor of the H-IIA/B launch vehicle, is discussed and thespace transportation vehicle demanded is one of low cost but high reliability. The next challenge
we have to try is to design launch vehicle to be able to simplify the evaluations we currently utilize.