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H-IIA Flight 24 Launch Updates
Ascent Data, ALOS-2 Overview, Secondary Payloads, Launch Vehicle Overview, Japanese Archive

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Japan's H-IIA Rocket successfully Launches ALOS-2 Radar Satellite
>>>Archived Launch Coverage

May 24, 2014

A Japanese H-IIA rocket blasted off from the Tanegashima Space Center on Saturday at 3:05 UTC on a mission to deliver the ALOS-2 radar satellite to orbit. Riding into a polar orbit aboard the H-IIA Rocket, ALOS-2 was accompanied by four small satellites. The mission was executed to perfection and H-IIA reached its planned 628-Kilometer orbit 15 minutes after lifting off to release the ALOS-2 satellite and its companions.

ALOS-2, the Advanced Land Observation Satellite 2 is a radar Earth Observation satellite operated by the Japanese Aerospace Exploration Agency to acquire high-resolution radar imagery of Earth for cartography, regional observation, resource management, disaster management and scientific purposes. The spacecraft weighs 2,120 Kilograms and is 9.9 by 16.5 by 3.7 meters in size when fully deployed on orbit.

ALOS-2 uses a modular approach consisting of a bus module, the large L-Band SAR antenna, a payload electronics unit and two small payload modules for the Compact Infrared Camera and the Space Based Automatic Identification System Experiment 2. ALOS-2 will enhance the capabilities of the previously flown SAR payload on ALOS and provide an increased resolution, faster revisit times, and observation at high incidence angles.

Launch Operations got underway as planned at the Tanegashima Space Center on the South-Eastern tip of Tanegashima Island - South of Kyushu, the southernmost of Japan's main islands takes about 30 minutes. The Rollout of the H-IIA rocket which is part of the Countdown Operation began around 13 hours and 5 minutes ahead of the planned liftoff time. Sitting atop the Mobile Launch Platform, the 53-meter H-IIA needed about 25 minutes for the 500-meter trip to Pad 1 to arrive at the launch pad at 14:26 UTC on Thursday (23:26 p.m. local time).

*File Image* - Photo: JAXA

After the rollout, H-IIA was ready for its overnight launch countdown that started with several hours of hands-on work by engineers at the launch pad. Teams at the launch pad connected the vehicle to ground data and power systems and also made umbilical connections for propellant loading. Later, the pad facilities and the launcher were closed out and teams departed the pad at 17:30 UTC as the 400-meter security zone came into effect. Teams also buttoned up the Vehicle Assembly Building for launch.

Photo: MHI

Photo: MHI

About 8.5 hours prior to launch, the various systems of the launch vehicle were powered up to begin extensive testing of all of its subsystems. The launch vehicle underwent communications checks via its S-Band and C-Band systems, the Flight Termination System was tested and the Flight Control System was initialized. The flight software was loaded into the computers of the vehicle and the control system was thoroughly checked. Engine slews on the first and second stage engines were performed and teams completed the final steps to start propellant loading.

Ahead of the start of propellant loading, the safety zone was extended to 3,000 meters. Fueling operations picked up around X-7 hours and 30 minutes. The first step of propellant loading was the pressurization and chilldown of the ground systems on the Liquid Hydrogen and Liquid Oxygen sides. Afterwards, the transfer lines were conditioned and the tanks of the first and second stage of the H-IIA were chilled down to prevent a shock to the metal when coming into contact with the -183-degree Celsius oxidizer and -252°C fuel.

Over the course of the three-hour fueling sequence, the two stages of the H-IIA were loaded with about 117,000 Kilograms of cryogenic propellants. When all tanks were full, propellant loading entered topping as LOX and LH2 were continuously replenished throughout the rest of the countdown. Replenish started at X-4 hours and 40 minutes. 

While propellants were being replenished, H-IIA was put though its paces one last time as part of a series of tests that included communication checks in S-Band and C-Band, checks of the Flight Control System, verifications of the Flight Termination System and ground support equipment tests.

The countdown entered its Terminal Countdown at X-60 minutes. Over the course of the final hour of the countdown, teams put the launcher through the final set of reconfigurations for the Automated Countdown Sequence. Another round of control system checks and communication verifications was performed and the refined flight software based on the latest measurements of conditions in the Upper Atmosphere was loaded into the flight computers.

Weather at Tanegashima Island was ideal for the launch. Although skies were cloudy, conditions were well within criteria with warm temperatures, low ground winds, a calm atmosphere and no precipitation.

As the countdown approached the Automated Sequence, the ALOS-2 satellite began the transfer to internal power and transitioned to flight mode, beginning its pre-programmed launch sequence. Teams verified that the range and launch corridor were clear before all Launch Control stations were polled for a GO/No GO for the Automated Countdown Sequence. All Stations reported GO for launch as all systems were in readiness for the automated countdown. 

With the opening of the launch window programmed into all sequencers on the ground and the launch vehicle, clocks started ticking at X-4 minutes and 30 seconds marking the start of the Automated Countdown Sequence. Throughout those final countdown minutes, computers choreographed the events of the countdown and monitored all vehicle parameters ready to trigger an abort in case of problems during the countdown.

The first step of the Auto Sequence was the termination of the propellant feed to the vehicle and the initiation of Propellant Tank Pressurization at X-4:20. All tanks reached flight pressure and clocks continued to tick down.

At X-3 minutes, the H-IIA launcher transferred from ground power supply to internal power.  The Flight Termination System was switched to internal battery as part of a separate procedure.

One minute before liftoff, thousands of Kilograms of water were being poured over the launch platform to suppress the acoustic loads at booster ignition and liftoff. Ordnances aboard the launcher were armed at X-30 and the Guidance System switched to Flight Mode at X-18 seconds. At X-11.5 seconds, the sparklers underneath the LE-7A Main Engine of the Core Stage ignited to burn off any residual Hydrogen that may be released during the Ignition Sequence.

Ignition sequence start was commanded at X-5.2 Seconds and the fuel and oxidizer valves of the main engine were opened and its turbopumps started spinning to flight speed. Engine ignition was carefully monitored by computers to ensure LE-7A reached its full liftoff thrust of 109,300 Kilograms.

When clocks hit zero, the twin SRB-A3 Solid Rocket Boosters were ignited and H-IIA jumped off its pad with a total thrust of 580,300 Kilograms as the boosters provided 80% of the kick at liftoff.

Lifting off right on time at 3:05:14 UTC, 12:05 p.m. local time, the H-IIA started its 14-minute ascent into orbit. Departing Tanegashima Island, the rocket made a short vertical ascent before starting the normal roll and pitch maneuver to begin flying south-east as part of a Dogleg Maneuver.

A Dogleg is a powered turn in the ascent trajectory of a rocket. In this case it became necessary as the ALOS-2 satellites was targeting a polar orbit at an inclination of 97.9 degrees. For a direct ascent into this orbit, H-IIA would need to fly south-west over the Philippines. To avoid populated islands located along the direct ascent path, the Dogleg has to be inserted in order to ensure no launch vehicle debris hit populated areas, both during a nominal flight and in a launch failure.

For the Dogleg, H-IIA flew downrange for about 100 Kilometers sticking to the south-easterly path before initiating the turn to the south-west late in the first stage burn ensuring that all debris fall short of populated areas. A Dogleg comes at the cost of launch vehicle performance in terms of payload capability as additional fuel is required for the turn.

Photo: JAXA Webcast

Photo: JAXA Webcast

Photo: JAXA Webcast

Image: JAXA/Spaceflight101

Image: JAXA/Spaceflight101

On its way uphill, H-IIA passed Mach 1 after about 75 seconds powered by its two Solid Rocket Boosters and liquid-fueled core stage. Maximum Dynamic Pressure was encountered a few seconds later as the launcher made its way through the dense atmosphere.

Each SRB-A3 – an improved version of the SRB-A – measures measures 15.2 meters in length and 2.5 meters in diameter, burning through 66,000 Kilograms of propellants to provide 235,000 Kilogram-force of thrust. The twin boosters burned out one minute and 50 seconds into the flight when the vehicle was 47 Kilometers in altitude traveling 1.6 Kilometers per second.

After sensing the pressure drop in the boosters that had consumed all their fuel, the H-IIA triggered booster separation at T+2:05 by severing the thrust struts of the two boosters that also ensured a clean jettison. The two boosters were headed for a splashdown in the Pacific, downrange from the launch site.

With the boosters gone, H-IIA was only powered by its LE-7A engine consuming 260 Kilograms of Liquid Oxygen and Liquid Hydrogen per second delivering 109 tons of thrust. Boosting the stack out of the atmosphere, the first stage continued to stick to the pre-planned trajectory and attitude profile.

Photo: JAXA Webcast

Four and a half minutes into the flight, the vehicle had reached an altitude of 150 Kilometers, allowing the protective payload fairing to be jettisoned. Cleanly separating from the vehicle, the fairing was headed for re-entry and splashdown and the exposed payloads continued their journey into orbit.

With the fairing gone, the first stage continued powered ascent for two more minutes reaching an altitude of of 299 Kilometers, moving at 2.1km/s. The LE-7A engine shut down at T+6 minutes and 37 seconds in preparation for stage separation that occurred at T+6 minutes and 45 seconds as the 37-meter long first stage was pushed away from the vehicle.

Six seconds after staging, the second stage ignited its LE-5B engine for a burn of eight minutes and 3 seconds to boost the stack into a circular orbit at 628 Kilometers. Over the course of its burn, the LE-5B engine provided 14,000 Kilograms of thrust consuming nearly 16,600kg of Liquid Oxygen and Liquid Hydrogen. Performance of the vehicle was nominal throughout the burn as H-IIA headed down in the center of the launch corridor – now flying south-west after the Dogleg was completed.

Main Engine Cutoff occurred at T+14 minutes and 56 seconds when the stack had reached its orbital velocity of 7.5 Kilometers per second. Orbital insertion occurred at an altitude of 633 Kilometers, 2,400 Kilometers downrange from the launch site. Immediately after shutdown, the second stage re-oriented for the separation of the ALOS-2 spacecraft, also known as Daichi.

Just before passing the 16-minute mark, the ALOS-2 satellite was released into orbit to begin a long mission to deliver high-resolution radar images for a variety of purposes. Following separation, ALOS-2 was set for a complex sequence taking several days to transition to its operational configuration in orbit. Immediately after separation, the satellite initiated its Rate Dampening mode – priming its propulsion system and using its thrusters to eliminate any rates on the vehicle, particularly rotation imparted during separation. Also, the satellite begins data transmission to ground stations to provide insight into its status as a number of automatic health polls are performed to verify all subsystems are in good condition following launch.

About 30 minutes after launch, ALOS-2 was set for the deployment of its two solar arrays. The two panels can be rotated to track the sun in order to deliver 5,200 Watts EOL power. Initially, the satellite will use its sun sensors to track the sun and generate power to re-charge its batteries. About nine hours into the flight, the satellite switches to Earth Acquisition Mode using its various navigation instruments including star trackers and Earth sensors to constantly point its radar to Earth.

Later in its first day in orbit, ALOS will unfold the SAR antenna that is 2.9 meters wide and 9.9 meters long weighing 548 Kilograms. To fully deploy the antenna that consists of five segments, ALOS-2 will complete a series of carefully planned steps. First, about 13 hours after launch, the SAR package is deployed to release the launch locks and free the individual panels. Next, the first wing is deployed about 24 hours after launch followed by the second wing ten hours later. As part of a final series of steps performed 37 and 47 hours after launch, ALOS-2 deploys its two X-Band Direct Transmission antennas to reach its fully operational mechanical configuration in orbit.

51 hours after launch, the satellite switches to Fine Mode – only using its reaction wheels to control its attitude that is determined via the various navigation sensors aboard the vehicle.

Image: JAXA

Image: JAXA

Following its initial flight phase, ALOS-2 enters commissioning – a process that takes several weeks to verify the performance of all systems and begins to operate the SAR payload to start instrument commissioning and data validation. After several weeks, ALOS-2 transitions to normal mission operations to deliver regular L-Band radar images.

After the release of ALOS-2, H-IIA continued its mission to release the four secondary payloads – Rising-2, UNIFORM-1, SOCRATES and SPROUT. The satellites were to be released as part of a sequential procedure starting at T+25 minutes and deploying one satellite every 4 minutes and 10 seconds. The four satellites are dedicated to scientific missions, technical demonstrations and outreach projects.

SPROUT, SOCRATES, UNIFORM-1 & Rising-1 Microsatellites

Image: Nihon University

Photo: AES

Image: Wakayama University/UNIFORM Project

Image: Tohoku University

Photo: JAXA

Secondary Payloads integrated on the adapter ring of the second stage

Rising-2 was first to be released at T+25 minutes. This 42-Kilogram satellite is equipped with a series of scientific instruments and imagers including a High Precision Telescope to conduct Earth observations and to study cumulonimbus clouds and upper atmospheric lightning (Transient Luminous Events).

Next up at T+29 minutes was UNIFORM-1 a technical demonstrator for the development of a wildfire monitoring system using a constellation of microsatellites to achieve a high-time resolution at a comparable low cost.

SOCRATES – the Space Optical Communications Research Advanced Technology Satellite was to be released at T+33 minutes to begin a technical demonstration mission to verify the concept of a Small Optical TrAnsponder SOTA - a laser communications terminal for use in space flight applications.

The final satellite to be deployed was the 6.7-Kilogram SPROUT carrying a deployable membrane to evaluate this technology for application in future space missions.

Payload Overview

ALOS-2

ALOS-2 - the Advanced Land Observation Satellite 2 is a radar Earth Observation satellite operated by the Japanese Aerospace Exploration Agency to acquire high-resolution radar imagery of Earth for cartography, regional observation, resource management, disaster management and scientific purposes. The satellite is the follow-on project to ALOS-1 that was launched in January 2006 and operated for five years until experiencing a complete power loss in 2011.

ALOS-2 will enhance the capabilities of the previously flown SAR payload on ALOS and provide an increased resolution, faster revisit times, and observation at high incidence angles. 

ALOS-2 was manufactured by Mitsubishi Electric Corporation under contract by JAXA to facilitate two primary instruments - the PALSAR-2 Phased Array L-Band Synthetic Aperture Radar, a Compact Infrared Camera - and a small AIS (Automatic Identification System) terminal.

The spacecraft weighs 2,120 Kilograms and is 9.9 by 16.5 by 3.7 meters in size when fully deployed on orbit. ALOS-2 uses a modular approach consisting of a bus module, the large L-Band SAR antenna, a payload electronics unit and two small payload modules for the Compact Infrared Camera and the Space Based Automatic Identification System Experiment 2.

The main instrument of the ALOS-2 spacecraft is PALSAR-2 - the Phased Array L-Band Synthetic Aperture Radar-2 that uses Active Phased Array Antenna technology. Radar satellites bounce radar signals off the ground and record the weak echo signal to deduce radar reflectiveness of sites on the ground which differs between the various types of vegetation, water bodies and man-made structures. Overall, the system consists of two main components: the antenna subsystem and the electric unit. The antenna is 2.9 meters wide and 9.9 meters long weighing 548 Kilograms.

The Compact Infrared Camera CIRC is a small payload developed by MELCO under contract from JAXA using COTS (Commercial off the Shelf) components to build a compact infrared imager for deployment on several spacecraft to create an operational wildfire detection capability.

>>>Detailed ALOS-2 Spacecraft Overview

Image: JAXA

Photo: JAXA

Rising-2

Image: Tohoku University

Photo: Tohoku University

Rising-2 is a microsatellite project of Tohoku University and Hokkaido University, Japan, to create an Earth observation satellite with a resolution of 5 meters for the study of cumulonimbus clouds and upper atmospheric lightning (Transient Luminous Events).

The primary instrument of Rising-2 is the High Precision Telescope featuring a Cassegrain Design to be used for Earth Observations and the observation of Transient Luminous Events. The telescope has a field of view of 0.27 by 0.2 degrees corresponding to 3.3 by 2.5 Kilometers on the ground.

The Bolometer Array Instrument is an uncooled infrared imager covering a spectral range of 8 to 14 micrometers (thermal infrared). It is used to acquire images of cumulonimbus cloud regions, ground surfaces and maritime areas for a variety of purposes. Imagery provided by the instrument can be used to determine the temperature of the top region of cumulonimbus from which the altitude of the clouds can be deduced.

Rising-2 is equipped with two Lightning and Sprite Imagers that feature identical detectors but are equipped with different passband filters. The two cameras will be used to detect Transient Luminous Events such as sprites and elves above thunderstorm clouds as well as lightning emissions at lower altitudes.
The Rising-2 Wide Field Camera will be used to detect the location of lightning flashes and Terrestrial Gamma-ray flash events. A Very Low Frequency Receiver VLFR is installed on the satellite to record the low-frequency signatures of lightning events.

>>>Detailed Secondary Payload Overview

SOCRATES

SOCRATES - the Space Optical Communications Research Advanced Technology Satellite is a microsatellite project of the National Institute of Information and Communications Technology in Japan. The primary objective of the mission is the demonstration of a Small Optical TrAnsponder SOTA - a laser communications terminal for use in space flight applications.
The main payload of SOCRATES is SOTA - the Small Optical Transponder that will be used to demonstrate a compact laser communications terminal for use on satellites, microsatellites and nanosatellites. The objectives of the mission are the verification of on orbit acquisition, tracking and communication performance of the small optical terminal as well as the collection of data associated with propagation through the atmosphere at various wavelenghts.

>>>Detailed Secondary Payload Overview

Image: AES

UNIFORM-1

Image: Wakayama University/UNIFORM Project

The overall goal of the Uniform program at Wakayama University is the development of a wildfire monitoring system using a constellation of microsatellites to achieve a high-time resolution at a comparable low cost.

The Uniform-1 satellite is based on a 50 by 50 by 50-centimeter satellite structure with a mass of under 50 Kilograms. The spacecraft carries two primary instruments - a microbolometer array for infrared imaging and a visible imaging payload.
The main payload of the satellite consists of a Microbolometer Array that is used for imaging in the thermal infrared spectral band between 10 and 12 micrometers. The Microbolometer Array achieves a ground resolution of 100 meters over a swath width of 100 Kilometers. UNIFORM-1 will acquire high resolution optical images of targets to provide imagery to better locate and asses wildfires and help in response efforts.

>>>Detailed Secondary Payload Overview

SPROUT

SPROUT is a project of Nihon University and stands for Space Research On Unique Technology.

The main payload of the SPROUT spacecraft is an external membrane that is triangular in shape and measures 1.5 meters. The membrane is expanded by Nitrogen gas fed from a cartridge that deploys two tubes to which the membrane is attached.

This membrane experiment serves as a pathfinder for future spacecraft utilizing solar sails for power generation. Additionally, the experiment will yield measurements of orbital drag by recording the orbital parameters of the spacecraft with its membrane deployed and experiment with the attitude of the satellite to provide data for orbital modeling for future missions.

>>>Detailed Secondary Payload Overview

Image: Nihon University

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H-IIA approved to Launch ALOS-2 Satellite on Saturday

May 23, 2014

The Japanese Aerospace Exploration Agency and Mitsubishi Heavy Industries are ready for the launch of an H-IIA rocket from Tanegashima on Saturday at 3:05:14 UTC carrying the ALOS-2 radar satellite and four secondary payloads to orbit. Approval to begin countdown operations with the rollout of the launch vehicle was given on Friday.

Over the past two weeks, final payload preparations took place as the large ALOS-2 satellite was integrated on is payload adapter that already had the four smaller secondary satellites installed. The next step was the encapsulation of the stack in the protective payload fairing. 4.07 meters in diameter and 12 meters long, the fairing offers just enough space to the large ALOS-2 satellite. The assembled fairing was lowered onto the spacecraft and payload adapter assembly and electrical and data connections were put in place before the fairing was bolted in position. Final checks took place to make sure good connectivity between the payload adapter and the spacecraft & fairing was given and that the fairing air conditioning system was working.

Later, the stack was handed over to launch vehicle operator Mitsubishi Heavy Industries for installation atop the H-IIA rocket. The installation was completed as planned and integrated testing commenced to verify that all data paths between the flight control system and the various subsystems and controllers were in place and that commands could be executed properly.

Leading up to launch, the combined JAXA and MHI teams performed several countdown and launch rehearsals over the course of the week also involving the assembled H-IIA launcher that was put through its paces to verify that all control systems of the rocket were functioning and issuing the correct commands at the appropriate times. No problems were found and teams are proceeding toward an on-time launch on Saturday during a 14-minute window opening at 3:05 UTC.

H-IIA has a liftoff weight of 285,000 Kilograms standing 53 meters tall with a core diameter of 4 meters using a two-stage stack with two Solid Rocket Boosters attached to the first stage. The rocket is capable of delivering payloads of up to 11,000 Kilograms to Low Earth Orbit. 

The first stage of the H-IIA is 37.2 meters long and capable of holding about 100,000 Kilograms of cryogenic propellants, Liquid Oxygen and Liquid Hydrogen for consumption by the single LE-7A main engine. LE-7A is a staged combustion cycle engine delivering 1,087 Kilonewtons of thrust. Attached to the first stage are two SRB-A Solid Rocket Boosters - each 15.1 meters long and 2.5 meters in diameter weighing 76.6 metric tons. 

Each of the boosters burns 66,000kg of propellants during a 115-second burn. SRB-A3 delivers 2,305kN of thrust. Booster separation is triggered by pyrotechnics and the SRBs use struts to ensure a clean separation.

The second stage of the H-IIA 202 is 9.2 meters long with a diameter of 4 meters. It also uses LOX and LH2 propellants, being filled with 16,600kg of cryogenics.

Photo: JAXA

Payload Integration & Fairing Installation

Photo: JAXA

One LE-5B engine powers the second stage providing a vacuum thrust of 137kN. The engine can make multiple ignitions to target a variety of orbits.

>>>H-IIA Launch Vehicle Overview
>>>Live Launch Coverage
>>>Countdown Timeline
>>>F24 Ascent Data

The Launch Countdown operation for H-IIA begins about 14 hours before launch with the rollout of the launcher from its final assembly building. The trip from its assembly building to the sea-side launch pad - located at the South-Eastern tip of Tanegashima Island - South of Kyushu, the southernmost of Japan's main islands takes about 30 minutes. 

*File Image* - Photo: NASA

After arriving at the Pad, technicians connect data and electrical lines and put propellant umbilicals in place before completing final fueling preparations and close-outs. About eight hours before launch, teams evacuate the launch pad to get ready for the long propellant loading sequence.

Beginning at about X-7 Hours and 45 Minutes, the complex propellant loading sequence gets underway with the pressurization and chilldown of ground support systems handling the -183-degree Celsius LOX and -253°C LH2. Fueling goes through a number of steps including ground support system chilldown, propellant tank chilldown and propellant loading, before tanking enters replenish mode. The propellant loading sequence takes approximately three hours until the 116,600 Kilograms of cryogenics needed for launch are loaded. Replenishing the propellants as they boil off, the tanks are kept at topping level until late in the countdown.

The majority of the countdown will be spent with extensive tests of the launch vehicle's flight control system, checks of all electronics and controllers and verifications of the radio link between the launcher and the ground.

Flight Termination System testing is also performed in the early stages of the countdown.

At X-60 Minutes, the Terminal Countdown Sequence will start. During the final hour of the countdown, last-minute items will be closed out and the vehicle will be reconfigured for the Automatic Countdown Sequence starting just 4.5 minutes prior to blastoff.

As computers are given control of the countdown, H-IIA's Propellant Tanks will be pressurized for flight.

At X-3 minutes, the launch vehicle is switched to internal power while ALOS-2 will have been switched to battery power ahead of the final countdown sequence. One minute before liftoff, thousands of Kilograms of water are being poured over the launch platform to suppress the acoustic loads at ignition & liftoff. Launch Vehicle Ordnances will be armed at X-30 Seconds and the Guidance System of the Vehicle is being switched to Flight Mode 12 Seconds later before the sparklers underneath the LE-7A main engine ignite to burn off residual Hydrogen.

Ignition Sequence Start is commanded at X-5.2 Seconds and the LE-7A Engine soars to life as the turbopumps spin up to flight speed being monitored by on-board computers to make sure the engine is healthy before the booster ignition command is issued at T-0 - committing the vehicle to launch.

As the boosters ignite, H-IIA will jump off its pad with a total thrust of 580,930 Kilograms. The twin boosters deliver 76 % of the total liftoff thrust of the launcher that will make a short vertical ascent before executing its roll and pitch program to achieve the planned ascent trajectory - flying south-east to depart Tanegashima Island as part of a Dogleg maneuver. On its way uphill, H-IIA quickly passes Mach 1 and Maximum Dynamic Pressure.

The two SRB-A3 boosters, each delivering 235,000 Kilogram-force of thrust, will help accelerate the H-IIA to 1.6 Kilometers per second before burning out at T+1 minute and 55 seconds.

The declining pressure in the combustion cambers will trigger their separation ten seconds after burnout 55 Kilometers in altitude and 55km downrange. Both SRBs separate simultaneously after completing their job.

Powered flight continues on the LE-7A engine of the first stage alone. The engine delivers 109,300 Kilograms of thrust, burning about 260 Kilograms of cryogenics per second.

Once reaching an altitude of 150 Kilometers, the launcher will jettison its protective payload fairing at T+4:30 to expose the payload stack on its way uphill. At that altitude, the vehicle has left the dense portion of the atmosphere and the satellite can no longer be harmed by aerodynamic friction and other forces.

*File Image* - Photo: JAXA

*File Image* - Photo: JAXA

The first stage will continue to burn until T+6 minutes and 36 seconds, boosting the vehicle to a velocity of 3.2 Kilometers per second. Stage separation occurs eight seconds after MECO at an altitude of 311 Kilometers and the second stage will prepare for its ignition.

The single LE-5B engine will ignite six seconds after staging, at T+6:50, reaching its full thrust of 13,970 Kilograms for a burn of more than eight minutes. The mission is targeting an orbit of 628 Kilometers at an inclination of 97.4 degrees.

Image: JAXA

Following shutdown of the LE-5B at T+15:14, the second stage will use its attitude control system to re-orient for spacecraft separation taking about 50 seconds between shutdown and ALOS-2 release. The second stage will then continue its mission to deploy the secondary payloads starting at T+25 minutes with a deployment every 4 minutes and 10 seconds until the release of the fourht satellite at T+37:30.

Following separation, ALOS 2 will execute a carefully planned sequence starting with the acquisition of a stable three-axis attitude and initiating communications with ground stations. Solar array deployment occurs shortly after insertion. A major milestone will be the deployment of the 10-meter radar antenna that unfolds is four deployable segments as part of a methodical process. Over the first hours and days, the spacecraft completes a series of health checks to make sure it made it into orbit in good shape.

Afterwards, operations will transition to commissioning to test the radar instrument and prepare for normal mission operations that get underway several weeks after launch.

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JAXA prepares to Launch large Radar Satellite aboard H-IIA

May 7, 2014

Photo: JAXA

The Japanese Aerospace Exploration Agency and Mitsubishi Heavy Industries are gearing up for the launch of an H-IIA rocket carrying the Advanced Land Observation Satellite-2. Launch is currently planned for May 24 during a 15-minute window opening at 3:05 UTC. In addition to ALOS-2, H-IIA will deliver four secondary payloads to orbit – the scientific Rise-2 satellite that will observe lightning in the upper atmosphere, the SOCRATES satellite that will demonstrate a laser communications terminal for small satellites, UNIFORM-1 a prototype wildfire monitoring satellite and SPROUT – a small technical demonstrator and outreach satellite.

Preparations for the launch are underway at the Tanegashima Space Center where MHI is preparing the H-IIA launch vehicle that was delivered to the launch site in early April and began integration a short time later.

H-IIA has a liftoff weight of 285,000 Kilograms standing 53 meters tall with a core diameter of 4 meters using a two-stage stack with two Solid Rocket Boosters attached to the first stage. The rocket is capable of delivering payloads of up to 11,000 Kilograms to Low Earth Orbit. 

The first stage of the H-IIA is 37.2 meters long and capable of holding about 100,000 Kilograms of cryogenic propellants, Liquid Oxygen and Liquid Hydrogen for consumption by the single LE-7A main engine. LE-7A is a staged combustion cycle engine delivering 1,087 Kilonewtons of thrust. Attached to the first stage are two SRB-A Solid Rocket Boosters - each 15.1 meters long and 2.5 meters in diameter weighing 77 metric tons. 

Each of the boosters burns 66,000kg of propellants during a 115-second burn. SRB-A3 delivers 2,305kN of thrust. Booster separation is triggered by pyrotechnics and the SRBs use struts to ensure a clean separation.

The second stage of the H-IIA 202 is 9.2 meters long with a diameter of 4 meters.

It also uses LOX and LH2 propellants, being filled with 16,600kg of cryogenics. One LE-5B engine powers the second stage providing a vacuum thrust of 137kN. The engine can make multiple ignitions to target a variety of orbits. A 4.07-meter fairing tops the stack and protects the payloads.

The ALOS-2 satellites and the four secondary payloads are also completing final inspections and processing at the launch site before being integrated on the payload dispenser and installed on the H-IIA launcher.