Regarding the first unit of Japan's new main rocket "H3" whose launch was canceled last month, JAXA = Japan Aerospace Exploration Agency said that the investigation of the cause has progressed and the prospect of countermeasures has been established, and it will be launched again on the morning of the 7th. I am planning to do
The first "H3" was scheduled to be launched from the Tanegashima Space Center in Kagoshima Prefecture on the 17th of last month, but the launch was canceled because the equipment in the first stage of the rocket detected an abnormality just before launch.
JAXA plans to launch again on the 7th, saying that the investigation of the cause has progressed and the prospect of countermeasures is in place. On the evening of the 6th, the rocket was placed on a mobile launch pad and launched from the assembly building in about 30 minutes. moved to location.
During the launch last month, there was a disturbance in the electrical signal just before launch, causing a malfunction in the rocket's first stage equipment. The we.
As a result, no abnormalities were found, and we are preparing for launch.
"H3" is the first new development of a large Japanese rocket in about 30 years. increase.
The first unit is scheduled to be launched from the Tanegashima Space Center at 10:37 am.
What is the new rocket "H3"?
[Adopts original technology and simple design]
The new rocket "H3" has been developed by JAXA = Japan Aerospace Exploration Agency and Mitsubishi Heavy Industries for nine years.
This is Japan's first new development in 30 years since the H2, and is being promoted as a national project with a total development cost of over 200 billion yen as the successor to Japan's current flagship rocket, the H2A.
The "H3" has a maximum length of 63 meters and a diameter of 5.2 meters. ” and “Liquid Oxygen”.
All engines are new, and
the main engine of the ▽ first stage is "LE-9".
▽ The second stage engine is "LE-5B-3".
In addition,
it can carry an auxiliary rocket that uses solid fuel called ▽ "SRB-3".
Compared to the H2A, the "H3" employs unique technology to simplify the design, such as reducing the number of parts in the first stage of the engine and reducing the connection points with the main body in the auxiliary rocket. .
[Launch pad]
The launch pad is the Tanegashima Space Center in Kagoshima Prefecture, but the launch pad was also newly developed, and we have devised ways to improve the efficiency of the launch work, such as eliminating the upper piping.
[Changeable according to load weight]
The H3 can be equipped with up to 4 auxiliary rockets, as well as increasing the number of main engines from 2 to 3.
The cover "fairing" that covers the satellite has two sizes, long and short, and it is also characterized by being able to change the specifications according to the satellite to be loaded.
[The first machine is]
The first vehicle to be launched this time has ▽ two main engines, ▽ two auxiliary rockets, and ▽ uses a short type fairing, so the total length is 57 meters, and the weight without the satellite is about 422 tons.
It will carry the Earth Observation Satellite "DAICHI-3".
Increase power and reduce costs
The two biggest features of the new rocket "H3" are power enhancement and cost reduction.
[H2A is disadvantageous in price competition] The
current main rocket "H2A" has been launched 55 times so far, including "H2B" with enhanced launch capability, and failure was only once in 2003, "H2A" No. 6 The success rate is 98%.
On the other hand, "H2A" costs about 10 billion yen per launch.
As demand for launching commercial satellites increases and new rockets are being developed around the world, it is pointed out that H2A will be at a disadvantage in terms of price competition in the future.
[Targets of "H3"]
"H3" is 63 meters long, 10 meters longer than "H2A."
With a diameter of 5.2 meters, which is 1.2 meters longer, it is the largest in the history of domestic rockets.
The launch weight has been increased to about 1.3 times that of "H2A".
In terms of cost, the development aims to keep the cost of launching at approximately 5 billion yen, about half that of "H2A."
In addition to reducing the number of engine parts to about one-third by adopting our own technology, we have also developed a new launch pad for the rocket, eliminating the piping at the top and improving the efficiency of the launch operation. We are making efforts to do so.
Furthermore, the company aims to shorten the period from receiving an order to launching from two years to one year and to launch six satellites per year.
"H3" maintains the high reliability of Japanese rockets that has been built up until now, while simultaneously increasing power and reducing costs necessary for the new era of space development. The aim is to counter the
Extremely difficult engine development
[Launch postponed twice]
Initially, the launch of the first H3 was planned for fiscal 2020, but due to difficulties in development, we were forced to postpone the launch twice.
The reason for the postponement was the development of the main engine, which is said to be the most difficult part of rocket development, and is said to be ``a monster lurking''.
[What is "LE-9"]
"H3" aims to increase power and reduce costs while maintaining high launch reliability that has been built up to date.
The key to this is the new LE-9 main engine.
The big difference from the conventional main engine is the drive method of the device "turbo pump" that feeds the fuel.
Until now, there was a "sub-combustion chamber" that produced powerful gas to drive the "turbo pump", but in order to simplify the structure of the "LE-9", the "sub-combustion chamber" was eliminated.
The aim was to cut costs by reducing the number of parts to about one-third.
[The "vibration problem" that became a wall]
However, because the inside of the "turbo pump" was made larger in order to move it strongly, some of the equipment was overloaded, and in the engine combustion test conducted in May 2020, The problem of cracks in parts surfaced due to the effects of special vibrations.
JAXA = Japan Aerospace Exploration Agency announced in September 2020 that it will postpone the launch of the first unit to the next fiscal year.
After that, the influence of the special vibration was improved by improving the turbo pump, etc. However, in the engine combustion test in October 2010, the special vibration was confirmed again in a part of the device.
For this reason, in January last year, JAXA announced the second launch postponement.
[In the spirit of “everyday is burning”]
Considering that it takes several months to manufacture a "turbo pump," the development team manufactured five types of "turbo pumps" with different measures, and since March last year, they have conducted combustion tests one after another and verified them.
We cleared the final stage of the test conducted in November last year and were able to launch.
Overseas rocket development
[New Rocket Development Rush]
Against the backdrop of increasing demand for launching commercial satellites, the development of new large rockets is underway around the world in recent years.
Japan's new rocket "H3" has a total length of 63 meters, but rockets of the same size are being developed and operated in various countries.
The 70-meter-long "Falcon Heavy" in the United States
has already been put into operation .
▽ In Russia, "Angara A5" with a total length of 69.5 meters.
▽ In China, such as "Long March 5B" with a total length of about 54 meters.
Also,
in Europe, the 63-meter-long "Ariane 6" is under development.
▽ Development of the American rocket "Vulcan" with a total length of 69.5 meters is also underway.
Launch procedure
The first model of the new rocket "H3" will be launched from the Tanegashima Space Center in Kagoshima Prefecture around 10:37 am on the 7th.
[Airplane movement]
The rocket in the airframe assembly building will move to the launch site from 4:00 pm on the 6th (about 18 and a half hours before launch).
(16 hours before launch)
At around 6:30 pm on the 6th, we will connect the aircraft that has moved to the launch site to the ground equipment, and check if there are any problems with the disconnection of electricity and communications that caused the launch to be canceled last month. .
(From 12.5 hours before launch) After
10:00 pm on the 6th, the injection of liquid hydrogen and liquid oxygen necessary for combustion will begin.
(1 hour and 10 minutes before launch)
At around 9:40 am and around 10:30 am on the 7th, we will decide whether to launch based on the aircraft's condition and weather.
When the launch is decided, the work from 4 minutes before the launch is automatically switched, and the power supply is switched from the ground equipment to the inside of the rocket 2 minutes and 50 seconds before the launch.
About 6 seconds before launch, the main engine began to burn, and at around 10:37 am, the H3 left the launch pad at the same time as the auxiliary rocket burned.
[After launch]
The rocket rises with the main engine and auxiliary rocket.
▽ Auxiliary rocket separated at an altitude of 43 km 1 minute 56 seconds after launch.
▽The main engine continues to burn, and after 3 minutes and 31 seconds, the cover covering the artificial satellite called the "fairing" at the top of the rocket is removed.
▽ After 4 minutes and 56 seconds, the main engine stopped burning at an altitude of 258 km.
The first stage of the rocket is separated.
After that, it continued to rise,
and ▽The second stage engine started burning 5 minutes and 15 seconds after launch.
▽ We plan to separate the "DAICHI-3" installed at an altitude of 675 km after 16 minutes and 42 seconds.
"DAICHI-3" to be installed
"DAICHI-3" is an earth observation satellite developed by JAXA (Japan Aerospace Exploration Agency) and Mitsubishi Electric at a cost of approximately 28 billion yen.
It is used to monitor disasters, understand the situation, and create maps. It is planned to be operated together.
With a height of 5 meters and a weight of about 3 tons, it orbits the earth about 15 times a day and observes it using sensors attached to its top.
Compared to the first DAICHI, the image resolution has improved more than three times.
It means that an 80 cm object on the ground can be identified from an altitude of 670 km in space.
In addition, the communication speed is more than double that of conventional systems, making it useful for emergency observations and map information in the event of a disaster. Expected.
In addition, "DAICHI-3" will be equipped with a "dual-wavelength infrared sensor" developed by the Ministry of Defense and will be tested in outer space.
This sensor can detect two different infrared wavelengths at the same time, and is capable of demonstrating a higher identification capability. is expected to be utilized.
Future launches At least 24 planned by FY2029
The new rocket "H3" is planned to be operated for the next 20 years as a successor to the current mainstay "H2A".
According to the Cabinet Office's Basic Space Plan, at least 24 launches of "H3" are planned by 2029, including ▽ 3 times in the next fiscal year and ▽ ▽ 6 times in the year after next.
``H2A'' launched Unit 46 in January this year, and will finish manufacturing by Unit 50 in the year after next, and will be switched to ``H3'' after 2025.
[Orders for overseas commercial satellites]
We have already received one order for the launch of an overseas commercial satellite using the "H3" from a major British satellite communications company.
We would like to increase the number of orders received for H2A, which has remained at 5.
[For the "Artemis Project"]
In addition, it is also used for exploration of the moon and Mars, which are far away from the earth.
In the year after next, we plan to launch a probe that will return samples from the Martian satellite to Earth, as well as a probe that will land on the South Pole of the Moon and investigate the amount of ice.
In 2030, we plan to deliver supplies to the new space station "Gateway" that orbits the moon, and it is expected to play an important role in Japan's participation in the international lunar exploration project "Artemis Project" being promoted by the United States. .
Circumstances and countermeasures for cancellation
[Circumstances of cancellation]
The first H3 was scheduled to be launched from the Tanegashima Space Center in Kagoshima Prefecture on the 17th of last month.
However, 6.3 seconds before launch, after the main engine combustion started normally, the device in the first stage of the rocket detected an abnormality, and the launch was aborted just before the launch without sending an ignition signal for the auxiliary rocket.
JAXA and Mitsubishi Heavy Industries returned the aircraft of the first unit to the assembly building on the 18th of last month, the next day, and proceeded to investigate the cause while combining the rocket and ground equipment.
[Cause]
As a result, it was announced that the abnormality occurred in the first stage device of the rocket called "V-CON1".
The device malfunctioned due to the disturbance of the electrical signal sent from the ground equipment, and the current and voltage values became zero.
The rocket is powered through cables on the launch pad after it has been installed at the launch site.
It is said that when the electrical and communication lines were disconnected at the same time, the electrical signal was disturbed, causing a malfunction in the first stage device of the rocket.
[Countermeasure]
Therefore, it was confirmed that the disturbance of the electrical signal was suppressed by taking measures such as changing the disconnection of electricity and communication in stages.
JAXA and Mitsubishi Heavy Industries plan to move the rocket body from the assembly building to the launch site the day before the launch and reconfirm that there are no problems with the separation of the equipment, electricity, and communications before launching.
Rocket development expert "Thinking until the very last minute to make sure there is no omission"
Mr. Shoichiro Asada, who has served as general manager of Mitsubishi Heavy Industries' space business and is familiar with rocket development, commented on the cancellation of the launch of "H3" due to a malfunction in the rocket's first stage equipment, saying, "I am not ready for the actual launch. I think it was a phenomenon that would not have happened without it, and I think it was very difficult to verify in advance.Especially now that it is digitized, it is very difficult to handle voltage fluctuations and noise that caused it.Momentary fluctuations are fatal We have to think carefully about whether there are any problems when considering the entire rocket system.As for the inside of the fuselage, we have to conduct various tests to confirm that there are no problems. Although it has been done, I think that the final sequence (procedure) like this time could not be confirmed at the interface that connects the aircraft, the launch pad, and the launch pad."
On top of that, he said, ``Because a rocket is made up of many parts, it is not so easy to say whether all operations have been verified. If I overlooked the event, there is a possibility that some serious defect may have occurred, so in that sense, I think I have to thank you for giving me such a suggestion."
Then, in preparation for the next launch, he said, "In a sense, I think I've been given a chance this time, so I'd like you to think through it until just before the launch to see if there are any omissions. I want you to have a successful launch in the form of 'H3'. I want you to secure the trust of the world and compete with the global market."
Expert "This first machine is a 'test machine'"
Last month, there was a lot of discussion on the Internet about whether to describe the fact that H3 was not launched as a "failure" or to describe it as "cancelled."
Regarding this, Professor Hiroshi Ogasawara of the Department of Mechanical Engineering, Tokyo University of Science, said, ``The ultimate goal is to achieve the mission, and the mission should be to launch artificial satellites and spacecraft to the required distance under the required conditions. If that is not possible, there are various cases such as "failure", such as an explosion on the way and not climbing, or the inability to insert a satellite within the specified altitude range. "Success" or "failure" is the previous condition.
Then, after saying that the first aircraft this time is a ``test flight,'' he said, ``I say ``test flight,'' but since it is a time when various problems arise during the test flight, in a sense, I think it's playing a role as a role.It's an important role this time to get rid of everything so that it won't be brought into practical missions after the test period."