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January 29, 2009

Kepler – The Exo-Planet Hunter

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Credits: NASA

 

Kepler is the first NASA mission capable of finding terrestrial exo-planets. Of particular interest are the planets orbiting in the so-called habitable zone, where conditions are met so that liquid water can exist on the surface of the planet.

 

The observations made so far have brought clear evidence that planets orbiting around other stars are a common thing, rather than the exception to the rule. Due to the limitations of present technology, only gas giants, hot-super Earths in short period orbits, and ice giants have been discovered.

 

The Kepler mission, part of NASA’s Discovery Program, is designed to survey a portion of our region of the Milky Way. Kepler will survey a large number of stars, and explore the structure and diversity of many planetary systems.

 

 

The scientific objectives of the mission are very ambitious: determine the fraction of terrestrial planets in or near the habitable zone, determine the distribution of sizes and the orbits of exo-planets in the surveyed planetary systems, determine reflectivity, size, and density of short-period giant planets, estimate how many planets are in multiple-star systems, and determine the characteristics of the stars that have planets orbiting around them. Scientists hope to discover additional members of the planetary systems surveyed using other indirect techniques.

 

Credits: NASA/Ball Aerospace

 

The duration of the mission must be selected to allow the detection and confirm the periodic nature of the planet transits in or near the habitable zone. Due to the characteristics of orbits of such planets, a lifetime of three and a half years (as currently envisioned) would allow a four-transit detection of most orbits up to one year in length and a three-transit detection of orbits of length up to 1.75 years.

 

 

The mission lifetime will be extendible to at least six years. The extension will permit the detection of planets smaller than Earth with two-year orbits.

 

Kepler will be inserted in an Earth-trailing heliocentric orbit, then the spacecraft will slowly drift away from Earth. The selected orbit offers a very stable pointing attitude, and it avoids the high radiation dosage associated with an Earth orbit. However, Kepler will be exposed occasionally to solar flares.

 

The communication protocol with the spacecraft includes establishing contact twice a week for commanding, health, and status, and science data downlink contact once a month.

 

Credits: Jon Lomberg

 

There are two requirements that dictated the selection of the target field. The first requirement is the ability to monitor continuously the stars surveyed because transits last only a fraction of a day. This can be achieved by having the field of view out of the ecliptic plane, so the Sun will not interfere with the observations at any time during the year. The second requirement is to have the largest possible number of stars in the field of view.

 

 

To meet both requirements, a region in the Cygnus and Lyra constellations of our galaxy has been selected as the field of view.

 

Kepler will use the transit method for detecting exo-planets. The sensitivity of the photometer will allow the discovery of terrestrial exo-planets (planets comparable in size and composition to Earth that are orbiting other stars).

 

The transit occurs when a planet passes in front of its star as viewed by an observer. Depending on the size of the planet, the change in the brightness of the star has different amplitudes. Transits of terrestrial planets cause a change in the star’s brightness of about 1/10,000, and they last from two to sixteen hours.

 

Credits: NASA

 

Changes in star brightness that are produced by a planet transit must be periodic, and all transits produced by the same planet must cause the same variation of brightness and last the same amount of time.

 

Of course, the case when two or more planets are in transit at the same time must be considered, and this can make the detection method a little bit more complicated.

 

 

The method allows for the calculation of the orbit, the mass, and the characteristic temperature of the exo-planet. Once we know the characteristic temperature of an exo-planet, the question of whether or not the planet is habitable (by our standards) can be answered.

 

The Kepler instrument is a special telescope called photometer or light meter. The telescope has a very large field of view for an astronomical telescope, 105 square degrees. The primary mirror of the telescope is 0.95 m in diameter. The telescope needs a large field of view because it has to continuously monitor the brightness of more than 100,000 stars for the duration of the mission.

 

Credits: Ball Aerospace

 

The photometer is composed of one instrument, which is an array of charge-coupled devices (CCD), 42 in total. Each CCD is 50mm x 25mm and has 2200 x 1024 pixels. Data from the individual pixels that make up each star are recorded continuously and simultaneously.

 

The primary mirror of the photometer was coated with enhanced silver, which allows more light to reach the telescope’s detectors.

 

The spacecraft provides power, attitude control, and telemetry for the photometer. The mission requirements contributed to the simple design of the spacecraft. The only moving parts are the reaction wheels used to control the attitude of the spacecraft.

 

 

The launcher selected for the mission is Delta II. Delta II is a versatile launcher, and can be configured in two or three-stage vehicles in order to accommodate a variety of requirements.

 

Ball Aerospace is the prime contractor for the Kepler mission, building the photometer and the spacecraft, as well as managing the system integration and testing of the spacecraft. The Jet Propulsion Laboratory is managing mission development, while NASA Ames Research Center is responsible for ground system development, mission operations, and science data analysis.

 

Once the first observation results are downloaded from Kepler and made available to scientists, we will be able to place our solar system within the context of planetary systems in our galaxy.

 

The launch of Kepler is planned for March 5, 2009. For more information about the Kepler mission, you can visit the Kepler mission web page.

 

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January 8, 2009

Taurus II and Cygnus

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Credits: NASA

 

Orbital will employ its Taurus II medium-lift launch vehicle and the Cygnus spacecraft in order to service the International Space Station (ISS) under the Commercial Resupply Services (CRS) contract.

 

Orbital is one of the two companies awarded CRS contracts under the Commercial Orbital Transportation Services Project (COTS).

 

 

NASA announced the COTS project on January 18, 2006. The purpose of the program is to stimulate the development of access to low Earth orbit (LEO) in the private sector. At the time, with the imminent retirement of the Space Shuttle fleet, NASA was faced with the option of buying orbital transportation services on foreign launch systems: the Russian Soyuz / Progress, the European Ariane 5 / ATV, or the Japanese H-II / HTV.

 

Another factor taken into consideration by NASA was that competition in the free market could lead to the development of more efficient and affordable launch systems compared to launch systems that a government agency could build and operate.

 

Credits: Orbital

 

Orbital relies on proven experience in launch vehicle technology. Taurus II is designed to provide low-cost and reliable access to space, and it uses systems from other members of Orbital’s family of successful launchers: Pegasus, Taurus, and Minotaur.

 

Taurus II is a two-stage launch vehicle that can use an additional third stage for achieving higher orbits. The payloads handled by Taurus II can have a mass of up to 5,400 kg.

 

Orbital is responsible for overall development and integration of the first stage. The two AJ26-62, designed and produced by Aerojet and Orbital, are powered by liquid oxygen and kerosene. The core design is driven by NPO Yuzhnoye, the designer of the Zenit launchers.

 

The AJ26-62 engines are basically the NK-33 engines designed by the Kuznetsov Design Bureau for the Russian N-1 launch vehicle, and remarketed by Aerojet under a new designation.

 

 

The second stage uses an ATK Castor-30 solid motor with thrust vectoring. This stage evolved from the Castor-120 solid stage.

 

The optional third stage is developed by Orbital. The stage was dubbed the Orbit Raising Kit (ORK) and it uses a helium pressure regulated bi-propellant propulsion system powered by nitrogen tetroxide and hydrazine. ORK evolved from the Orbital STAR Bus. Because it is a hypergolic stage, it allows several burns to be performed in orbit, and can be used for high-precision injections using various orbital profiles.

 

Credits: Orbital

 

Cygnus will only have cargo capability and will be able to deliver up to 2,300 kg of pressurized or un-pressurized cargo to the ISS. The spacecraft will also be able to return up to 1,200 kg of cargo from ISS to Earth.

 

The two components of the Cygnus spacecraft will be the service module and the cargo module.

 

The service module is based on the Orbital STAR bus (like the ORK stage), and will use two solar arrays for producing electrical power for the navigation systems onboard.

 

The pressurized cargo module is based on the Italian-built Multi-Purpose Logistics Module (MPLM). The un-pressurized cargo module is based on NASA’s ExPRESS Logistics Carrier.

 

 

Cygnus will not dock to the ISS in the same manner as the European ATV, but it will be able to maneuver close to the ISS where the Canadarm 2 robotic arm will be used to capture it and berth it to the Node 2 module, similar to the Japanese HTV or SpaceX’s Dragon spacecraft.

 

The Mid-Atlantic Regional Spaceport (MARS), located at NASA’s Wallops Island Flight Facility on Virginia’s Eastern shore, was chosen by Orbital to serve as the base of operations for the Taurus II launch vehicle.

 

MARS has two FAA licensed launch pads for LEO access. MARS also offers access to suborbital launchers, vehicle and payload storage, and processing and launch facilities.

 

Credits: NASA

 

Due to the location of the spaceport, latitude 37.8 degrees N, longitude 75.5 degrees W, optimal orbital inclinations for the launches performed at MARS are between 38 and 60 degrees. Polar and retrograde orbits can also be serviced with additional in-flight maneuvering.

 

The first flight of Orbital’s new Taurus II / Cygnus launch system under COTS is scheduled for late 2010.

 

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December 15, 2008

MRO Completed First Phase of Its Mission

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Credits: NASA/JPL

The Mars Reconnaissance Orbiter (MRO) has completed the first phase of its science mission. During this phase, the orbiter returned seventy-three terabits of science data to Earth, which is more than all earlier Mars missions combined. The next phase of the MRO mission will take two years.

 

The list of scientific discoveries and observations made by MRO is stunning. We know now that Mars has a long history of climate change and that water was present in liquid form on its surface for hundreds of millions of years.

 

 

Signatures of a variety of watery environments have been observed, so future missions will be aware of locations that might reveal evidence of past life on Mars, if it ever existed.

 

MRO has imaged nearly forty percent of the Martian surface at such a high resolution that house-sized objects can be seen in detail. MRO has also conducted a mineral survey of the planet, covering sixty percent of its surface. Global weather maps were assembled using the data returned by MRO, and profiles of the subsurface and the polar caps have been put together using the radar mounted on MRO.

 

Credits: NASA/KSC

“These observations are now at the level of detail necessary to test hypotheses about when and where water has changed Mars and where future missions will be most productive as they search for habitable regions on Mars,” said Richard Zurek, Mars Reconnaissance Orbiter project scientist.

 

The images returned by MRO have been used by the Phoenix team to change the spacecraft’s landing site, and will help the NASA scientists select landing sites for future missions, like the Mars Science Laboratory (MSL).

 

 

Another role played by MRO was to relay commands to and to return data from the Phoenix lander during the five months the lander was operational on the Martian surface. MRO shared this task with the Mars Odyssey Orbiter.

 

MRO lifted off on August 12, 2005, from launch Complex 41 at Cape Canaveral Air Force Station. The cruise phase of the mission lasted seven months, the spacecraft reaching Mars orbit on March 10, 2006, after traveling on an outbound arc intercept trajectory.

 

MRO entered the final low orbit suited for science-data collection on November 2006, after slowing down in the Martian atmosphere by using aerobraking for five months. The first phase of the mission consisted in gathering information about Mars, and the remaining time left of its operational life will be dedicated mainly to using the spacecraft as a communication relay.

 

Credits: NASA/KSC

The declared goals of the MRO mission are: to determine whether life ever arose on Mars, to characterize the climate of Mars, to characterize the geology of Mars, and to prepare for human exploration.

 

The launcher of choice for the MRO mission was the Atlas V-401 launch vehicle, the smallest of the Atlas V family. This was the first launch of an Atlas V on an interplanetary mission.

 

 

The Atlas V-401 is a two-stage launch vehicle that does not use solid rocket boosters. The Atlas V-401 is fifty-seven meters tall and has a total mass at liftoff of 333,000 kg. Out of this, about 305,000 kg is fuel. In order to reach Mars orbit, MRO was accelerated to 11 km per second.

 

The first stage of the Atlas V, the Common Core Booster, is powered by liquid oxygen and RP-1. For the MRO mission, the first stage used a RD-180 engine. The RD-180 engine has an interesting story. It is a Russian-developed rocket engine, derived from the RD-170 used for the Zenit rockets.

 

Credits: NASA/JPL/KSC/Lockheed Martin Space Systems

Rights to use the RD-180 engine were acquired by General Dynamics Space Systems Division (later purchased by Lockheed Martin) in the early 1990s. The engine is co-produced by Pratt & Whitney and all production to date has been in Russia. According to Pratt & Whitney, RD-180 delivers a ten percent performance increase over current operational U.S. booster engines.

 

The stage weighs approximately 305,000 kg at launch and it provides about four million Newton of thrust for four minutes.

 

The upper stage of the Atlas V is the Centaur Upper Stage Booster. The Centaur is powered by liquid oxygen and liquid hydrogen. In the case of the MRO mission, it provided the remaining energy necessary to send the spacecraft to Mars.

 

The payload fairing used for the MRO mission was four meters in diameter. The role of the payload fairing was to protect the spacecraft from the weather on the ground as well as from the dynamic pressure during the atmospheric phase of the launch.

 

 

Lockheed Martin Commercial Launch Services developed the Atlas V as part of the US Air Force Evolved Expendable Launch Vehicle (EELV) program.

 

There are six science instruments, three engineering instruments, and two science-facility experiments carried by the MRO. The low orbit on which MRO is operating allowed the observation of the surface, atmosphere, and subsurface of Mars in unprecedented detail.

 

The science instruments are the HiRISE camera (High Resolution Imaging Science Experiment), the CTX camera (Context Camera), the MARCI camera (Mars Color Imager), the CRISM spectrometer (Compact Reconnaissance Imaging Spectrometer for Mars), the MCS radiometer (Mars Climate Sounder), and the SHARAD radar (SHAllow RADar).

 

Credits: HiRISE/MRO/LPL/NASA

 

The HiRISE camera provided the highest-resolution images from orbit to date, while the SHARAD can probe the subsurface using radar waves in the 15-25 MHz frequency band (these waves can penetrate the Martian crust up to one kilometer).

 

The engineering instruments assist the spacecraft navigation and communication. The Electra UHF Communications and Navigation Package is used as a communication relay between the Earth and landed crafts on Mars. The Optical Navigation Camera serves as a high-precision camera to guide incoming spacecrafts as they approach Mars. The Ka-band Telecommunications Experiment Package demonstrated the use of the Ka-band for power effective communications.

 

 

The science facility experiments are the Gravity Field Investigation Package, used for mapping the gravity field of Mars, and the Atmospheric Structure Investigation Accelerometers, which helped scientists understand the structure of the Martian atmosphere.

 

For more details on the MRO scientific payload, you can check out the dedicated page on the MRO mission web site.

 

The MRO was built by Lockheed Martin for NASA’s Jet Propulsion Laboratory in California. Fully loaded, the spacecraft had a mass of almost two tons. The spacecraft carried 1,149 kg of propellant for trajectory correction maneuvers and for the burns needed for the Mars capture.

 

Credits: NASA/JPL

 

The main bus of the spacecraft presents two massive solar arrays that can generate 2,000 W of power. On top, the high-gain antenna is the main means of communication with both Earth and other spacecrafts. The SHARAD antenna is the long pole behind the bus.

 

Other visible features are the HiRISE camera, the Electra telecommunications package, and the Context Imager (CTX).

 

You can visit the home page of the MRO mission on the NASA web site.

 

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December 12, 2008

Columbus

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Credits: ESA/NASA

 

Columbus is an integral part of the International Space Station (ISS), and it is the first European laboratory dedicated to long-term experimentation in zero-g conditions. The projected lifetime of the laboratory is ten years.

 

The laboratory is named after the famous Italian navigator and explorer Christoforo Columbus, who discovered the Americas in 1492.

 

 

The Columbus Laboratory is a large, pressurized aluminum cylinder measuring 4.5 meters in diameter and 6.9 meters in length. Its side walls contain eight research racks, with another two in the ceiling. Each one of these racks contains its own power and cooling systems. Video and data links systems feed information back to researchers and control centers on the Earth.

 

Columbus is the smallest ISS laboratory, but it has the same scientific, power, and data handling capacity as the other laboratories owned by Russia, USA, and Japan.

 

Credits: ESA/NASA

 

Scientific experiments started immediately on the Columbus because the laboratory arrived at the station with four scientific facilities pre-installed.

 

Columbus is used to carry out experiments in many different disciplines, including biology, biotechnology, fluid and material science, medicine, and human physiology.

 

 

The key element in these experiments is the micro gravity. In micro gravity, with gravitational forces much weaker than on the ground, processes that are obscured by gravity become noticeable. The research racks onboard Columbus are designed to investigate how micro gravity affects materials, biological specimens, and people.

 

Columbus contains the European Physiology Module Facility, the Fluid Science Laboratory, the BioLab, the Material Science Laboratory, and the European Drawer Rack, which can house a variety of small experiments.

 

Credits: ESA/NASA

 

Problems that are investigated on Columbus include the loss of bone cells by astronauts, plant growth in micro gravity, fluids behavior, and combustion of materials.

 

Experiments are also conducted outside of Columbus. These experiments are used to study the Earth or to expose materials to the harsh radiation, temperature, and the vacuum of space.

 

 

The mission that delivered the Columbus Laboratory to the ISS was STS-122. On February 7, 2008, the Space Shuttle Atlantis lifted off from Cape Canaveral, with Columbus docked into its cargo bay.

 

A vital part of the ISS and a prerequisite for the STS-122 mission, the Italian-built Node2 module (a.k.a. Harmony) was delivered to the ISS by the STS-120 mission in October 2007. The node is used as a connecting component for the Columbus Laboratory and the Kibo Laboratory. Node2 is also a docking port for the Space Shuttle.

 

Credits: ESA/NASA

 

Prior to the STS-122 mission , there were two spacewalks performed by the ISS Expedition 16 crew to prepare Node2 in order to receive the Columbus Laboratory.

 

ESA astronauts Léopold Eyharts from France and Hans Schlegel from Germany were members of the STS-122 mission. With five other NASA astronauts, they were part of the Columbus assembly and commissioning mission.

 

 

Schlegel spent twelve days in space and undertook two spacewalks to install the laboratory. Eyharts oversaw the installation and the start-up of the laboratory during a longer mission spent onboard the ISS.

 

Columbus was attached to the Harmony module on February 11, 2008, during the first spacewalk of the STS-122 mission. During this spacewalk, NASA astronauts Stanley Love and Rex Walheim spent nearly eight hours outside the ISS. The ISS robotic arm, Canadarm2, was used to move the laboratory from the cargo bay of the Space Shuttle to the starboard side of the Harmony module.

 

Credits: ESA/NASA

 

The second spacewalk of the mission lasted six hours and forty-five minutes. Schlegel and Walheim performed a regular station maintenance operation: they replaced the nitrogen tank that is used to pressurize the ammonia cooling system that runs on the ISS.

 

 

ESA was quite inspired to name the laboratory Columbus because it will open the world of micro gravity to a multitude of discoveries, in the same way that Christoforo Columbus opened up the New World to European explorers.

 

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December 5, 2008

The James Webb Space Telescope

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Credits: NASA

 

 

The James Webb Space Telescope (JWST) is the successor of the Hubble Space Telescope (HST). While Hubble looks at the sky in the visible and ultraviolet light, JWST will operate in the infrared.

 

JWST is a joint mission of NASA, ESA, and the Canadian Space Agency.

 

 

The project started in 1996 and was initially known as the Next Generation Space Telescope (NGST). In 2002, the project was renamed the James Webb Space Telescope in honor of NASA administrator James E. Webb, who led the agency from February 1961 to October 1968.

 

The JWST will use a large deployable sunshade to keep the temperature of the telescope to about 35K. Operating at this temperature gives the telescope exceptional performance in near-infrared and mid-infrared wavebands. The JWST observatory will have a five to ten year lifetime and it will not be serviceable by astronauts.

 

JWST will be able to see the first galaxies that formed in the early Universe, and how the young stars formed planetary systems.

 

Credits: NASA

 

The JWST observatory includes the Integrated Science Instrument Module (ISIM), the Optical Telescope Element (OTE), and the Spacecraft Element containing a spacecraft bus (which offers the support functions for the observatory) and the sunshield.

 

I will say a few words about each one of them.

 

 

The Optical Telescope Element (OTE) collects the light coming from space. Thanks to a 6.5 meter primary mirror, JWST will be able to see the galaxies from the beginning of the Universe. The OTE is also composed of the Fine Steering Mirror (FSM), the secondary mirror support structure (SMSS), and the primary mirror backplane assembly (PMBA). Other subsystems of the OTE are the tertiary mirror and the fine steering mirror. The PMBA contains the Integrated Instrument Module (IIM).

 

Because the primary mirror is too large to fit inside any available payload fairing, it had to be made out of eighteen hexagonal segments. Some of the elements will be folded before the launch and unfolded during the commissioning phase at the L2 point. NASA made available some neat animations showing how the observatory will be folded in order to fit into the launcher payload, and how the sun shields and the primary mirror will unfold before the observatory becomes operational.

 

Credits: NASA

 

The sunshield will keep the scientific payload of the observatory away from any light from the Sun, the Earth, or the Moon. Because JWST will observe primarily the infrared light from very distant objects, the temperature of the scientific payload must be maintained at very low values (under 50K). This requirement is so important that even a part of the observatory (the spacecraft bus) had to be placed on the warm side of the sunshield.

 

 

The sunshield not only protects the scientific instruments from the heat of the Sun, the Earth, the Moon, and the warm spacecraft bus electronics, but it also provides a stable thermal environment. This is necessary in order to maintain the alignment of the eighteen hexagonal components of the mirror while the observatory changes its orientation relative to the Sun.

 

The primary mirror is the essential component of a telescope. The design of the primary mirror was driven by a number of important requirements: the size, the mass, and the temperature at which the mirror will operate.

 

Credits: NASA

 

In order to be able to see galaxies from thirteen billion light-years away, scientists determined that the mirror must have a diameter of at least 6.5 meters.

 

The weight of the primary mirror has only one tenth of the mass of Hubble’s mirror per unit area. Considering the size of the mirror, this made the task of launching the telescope into space achievable.

 

 

Due to the fact that the telescope will observe the light in the infrared spectrum, the temperature of the mirror has to be as low as –220 degrees Celsius. If operating at the same temperature as the ground telescopes do, the infrared glow of the mirror would interfere with the light received from distant galaxies. Basically, these distant galaxies would disappear in the noise generated by the telescope.

 

The engineering challenge that scientists faced was to build a lightweight mirror that would preserve its optical and geometric properties when cooled to –220 degrees Celsius. Using beryllium was the solution. Beryllium is lightweight (it is widely used in the aerospace industry) and it is very good at holding its shape across a range of temperatures.

 

As we mentioned above, the PMBA contains the Integrated Instrument Module (IIM), which is the scientific payload onboard the observatory. The scientific payload includes the following scientific instruments: the Mid-Infrared Instrument (MIRI), the Near-Infrared Spectrograph (NIRSpec), the Near-Infrared Camera (NIRCam), and the Fine Guidance Sensor (FGS).

 

The MIRI is an imager/spectrograph that covers the wavelength range from 5 to 27 micrometers. The nominal operating temperature for the MIRI is 7K. The NIRSpec covers two wavelength ranges: from 1 to 5 micrometers (medium-resolution spectroscopy) and from 0.6 to 5 micrometers (lower-resolution spectroscopy). The NIRCam was provided by the University of Arizona. NIRCam covers the spectrum from 0.6 to 5 micrometers. The FGS is a broadband guide camera that is used for guide star acquisition and fine pointing.

 

Credits: ESA

 

The spacecraft bus is composed of every subsystem of the observatory minus the sunshield and the scientific payload, and it provides the necessary support functions for the operations of the observatory. The spacecraft bus contains the Electrical Power Subsystem (EPS), the Attitude Control Subsystem (ACS), the Communication Subsystem (CS), the Command and Data Handling Subsystem (C&DHS), the Propulsion Subsystem (PS), and the Thermal Control Subsystem (TCS).

 

One interesting thing I would like to mention here is that the C&DH subsystem is using a solid-state recorder as memory/data storage for the observatory. I cannot envision a hard disk drive taking all of the vibrations during the launch and running for ten years without any flaws, so the choice of using radiation hardened solid-state memory units on long-term space mission spacecrafts seems to be the optimal choice.

 

The launch vehicle chosen for this mission is the European Ariane 5. The Ariane 5, carrying the James Webb Space Telescope, will liftoff from Guiana sometime in 2013. The space telescope will operate from the L2 point of the Sun-Earth system.

 

 

All three agencies that are part of the project, ESA, NASA, and CSA, have web pages dedicated to the JWST observatory.

 

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November 27, 2008

GOSAT a.k.a. IBUKI Scheduled For Launch

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Credits: JAXA

 

If measures are not taken to address the effects of the greenhouse gases produced by our civilization, extreme climate changes will occur: droughts, heat waves, and floods.

 

Understanding the behavior of greenhouse gases is critical for developing effective measures to fight climate change.

 

 

The Greenhouse Gases Observing Satellite (GOSAT) is the first satellite to observe greenhouse gases from space. The main contributors behind GOSAT are the Japan Aerospace Exploration Agency (JAXA), the National Institute for Environmental Studies (NIES), and the Ministry of Environment (MOE). The chosen nickname for GOSAT is IBUKI, which means breath or puff.

 

The data collected by the GOSAT satellite will help us make better estimates as to how different areas on Earth contribute to global warming through the emission of greenhouse gases. The data will also help us understand the behavior of the greenhouse gases by combining global observation data collected on orbit with data collected on the ground, and it will also help us improve simulation models.

 

Credits: JAXA

 

The observation instrument onboard GOSAT is called the Thermal And Near-infrared Sensor for carbon Observation (TANSO).

 

There are two sensors that collect data for the instrument: a Fourier Transform Spectrometer (FTS) and a Cloud Aerosol Imager (CAI).

 

 

The sensors will observe the infrared light from the Earth’s surface and will return measurements that can be used to calculate the abundance of carbon dioxide (CO2) and methane (CH4).

 

The operational orbit will allow GOSAT to circle the Earth in roughly 100 minutes and to return above the same Earth coordinates every three days. One thing to mention here is that the observations can be done only on cloud-free areas, meaning that on average only ten percent of the total number of measurements can be used for calculating the abundance of CO2 and CH4. However, the number of measurement points surpasses the current number of ground measuring points (under 200) and areas that have never been monitored will be covered by GOSAT observations.

 

Credits: JAXA / MHI

 

A Mitsubishi H-IIA launch vehicle will inject GOSAT into its predetermined orbit: a sun-synchronous sub-recurrent orbit at a perigee altitude of 667 km, apogee altitude of 683 km, and an inclination of 98 degrees. It will be the fifteenth flight of an H-IIA. The model used for this launch, H2A202, has two solid rocket boosters.

 

Besides GOSAT, which is the main payload, the payload includes several piggyback payloads. In the case of an excessive launch capability, it is common practice to include in the payload small satellites that are made by private companies or universities.

 

Seven micro-satellites, six selected through public tender and one JAXA satellite, will be launched by the H-IIA launch vehicle with Ibuki: KAGAYAKI / SORUN CORPORATION (debris detection and Aurora electric current observation mission), STARS / Kagawa University (tether space robot demonstration), KKS-1 / Tokyo Metropolitan College of Industrial Technology (demonstration of the micro cluster and three axis attitude control functions), PRISM / The University of Tokyo (earth image acquisition by using an expandable refracting telescope), SOHLA-1 / ASTRO TECHNOLOGY SOHLA (measurements of thunder and lightning), SPRITE-SAT / Tohoku University (observations of the sprite phenomenon and gamma radiation of the Earth’s origin), and Small Demonstration Satellite-1 (SDS-1) / JAXA (on-orbit verification of the space wire demonstration).

 

For more details on the additional payload for the GOSAT/Ibuki mission, you can check out the piggyback payload web page on the JAXA web site. Some of the links on the page require knowledge of Japanese or hands-on experience with the Google translation tool.

 

 

The launch date for GOSAT/Ibuki has been set. The H-IIA Launch Vehicle No.15 will liftoff sometime between 12:54 and 1:16 PM on January 21, 2009.

 

Check out the GOSAT / IBUKI program page on the JAXA web site for more information.

 

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