OrbitalHub

Credits: NASA

The Orbiting Carbon Observatory 2 mission is scheduled to launch in February 2013.

The previous spacecraft failed to reach orbit on February 24, 2009, after being launched on top of a Taurus XL launch vehicle from Vandenberg Air Force Base in California.

The OCO spacecraft will make global CO₂ measurements from space, quite useful as scientists are trying to understand the global carbon cycle in order to be able to make predictions of future atmospheric CO₂ increases.

NASA awarded the launch services contract to Orbital Sciences Corp. of Dulles, Virginia. OCO-2 will be launched by a Taurus XL 3110 launch vehicle from Vandenberg Air Force Base.

We quote from the NASA press release:

“OCO-2 is a NASA’s first mission dedicated to studying atmospheric carbon dioxide. Carbon dioxide is the leading human-produced greenhouse gas driving changes in the Earth’s climate. OCO-2 will provide the first complete picture of human and natural carbon dioxide sources and sinks, the places where the gas is pulled out of the atmosphere and stored.”

You can find more information about the Orbiting Carbon Observatory on NASA’s website.

Credits: Orbital

The Orbiting Carbon Observatory (OCO) failed to reach orbit on February 24, 2009. OCO launched aboard a Taurus XL vehicle from Vandenberg Air Force Base in California.

OCO was to provide global CO2 measurements from space. The data collected during the mission would have helped scientists understand the global carbon cycle. This understanding is essential to improve the predictions of future atmospheric CO2 increases and its impact on the climate.

NASA appointed an investigation board on March 3, 2009. The members of the Mishap Board for the OCO Investigation are: Rick Obenschain, deputy director at NASA’s Goddard Space Flight Center in Greenbelt, Md., head of the investigation board, Jose Caraballo, safety manager at NASA’s Langley Research Center in Hampton, Va., Patricia Jones, acting chief of the Human Systems Integration Division in the Exploration Technology Directorate at NASA’s Ames Research Center at Moffett Field, Calif., Richard Lynch, Aerospace Systems Engineering, Goddard Space Flight Center, Dave Sollberger, deputy chief engineer of the NASA Launch Services Program at NASA’s Kennedy Space Center in Florida.

The official report of the board contains restricted information, so there is a summary of the report available to the public. The summary contains findings and recommendations regarding the OCO mission failure.

Quote from NASA press release:
“The board identified four potential causes that could have resulted in the fairing not separating:
* A failure of the frangible joint subsystem. A frangible joint is an explosive device that provides instantaneous separation of flight vehicle structures while maintaining confinement of explosive debris.
* A failure in the electrical subsystem that prevented sufficient electrical current to initiate the required ordnance devices.
* A failure in the pneumatic system, which supplies pressure to thrusters which separate the fairing.
* A cord snagged on a frangible joint side rail nut plate”.

The scientific community is also making a strong case for reproducing the OCO mission as soon as possible:
“I think a strong case can be made that the [Orbiting Carbon Observatory] should be reproduced as soon as possible. Here we are, on the verge of new international agreements, without thinking about how to monitor them. We are neglecting climate as an element of national security. We’re not getting the information we need. Where are [climate] changes happening, and where are they going to happen?”
-Ralph Cicerone, President of the National Academy of Sciences
Speaking to Congress, 4 March 2009

Credits: NASA

Understanding the Earth’s energy balance is important in order to anticipate changes to the climate. The Glory mission will make a significant contribution towards explaining the Earth’s energy budget.

There are two scientific objectives set for the Glory mission: mapping the global distribution, properties, and chemical composition of natural and anthropogenic aerosols, and the continued measurement of solar irradiance. Both will lead to a reliable quantification of the aerosol and Sun’s direct and indirect effects on Earth’s climate.

The Glory spacecraft uses Orbital’s LEOStar bus design. The structure of the bus consists of an octagonal aluminum space frame with two 750 W deployable solar panels and a 100 W body-mounted solar panel. Glory will have a launch mass of 545 kg.

Forty-five kilograms of hydrazine powers a propulsion module, which will provide orbital maneuvering and attitude control capabilities for the projected 36-month lifespan of the spacecraft. The spacecraft bus also provides 3-axis stabilization, X-band/S-band RF communication capabilities, payload power, command, telemetry, science data interfaces, and an attitude control subsystem to support science instrument requirements.

Credits: NASA

Three instruments will be mounted on Glory: the Aerosol Polarimetry Sensor (APS), the Total Irradiance Monitor (TIM), and the Cloud Camera Sensor Package (CCSP).

The APS will map the global aerosol distribution by measuring the light reflected within the solar reflective spectrum region of Earth’s atmosphere (which is visible, near- infrared, and short-wave infrared light scattered from aerosols).

TIM will collect measurements of the total solar irradiance (TSI), which is the amount of solar radiation in the Earth’s atmosphere over a period of time. TIM consists of four electrical substitution radiometers (ESRs) that are pointed towards the Sun, independently of the position of the spacecraft. TIM was developed by the University of Colorado’s Laboratory for Atmospheric and Space Physics (LASP). TIM inherited the design of an instrument flown on SORCE satellite, which was launched in 2003. A presentation of the TIM design and on-orbit functionality was published by Greg Kopp, George Lawrence, and Gary Rottman of LASP.

The CCSP will be used to distinguish between measurements done on clear or cloud- filled areas, as clouds can have a significant impact on the quality of the measurements. CCSP is a dual-band (blue and near-infrared) imager that uses non-scanning detector arrays similar to those used in star trackers.

Credits: NASA

Glory will be launched from Vandenberg Air Force Base, California, on top of a Taurus XL launch vehicle. The operational orbit is a 705 km, sun-synchronous, circular, 98.2 degree inclination, low Earth orbit (LEO). The launch date is set for Fall 2009.

Read more about Glory at the Glory Mission page on NASA Goddard Space Flight Center’s website. A Glory Fact Sheet is also available on Orbital Sciences Corporation’s website.

Credits: Orbital

Taurus is a four-stage, inertially guided, all solid fuel, ground launched vehicle, designed and built by Orbital Sciences Corporation. In a typical mission, Taurus can inject a 1,350 kg payload in low Earth orbit (LEO).

Taurus lifted off for the first time on March 13, 1994. Since then, Taurus has conducted six of eight successful missions.

Taurus is well suited for LEO missions to a wide range of altitudes. Different orbital profiles can be attained through launches from more than one launch site. An additional fifth stage can boost the performance of the launch vehicle, making possible high energy and geosynchronous transfer orbit (GTO) missions.

Depending on configuration, Taurus can have up to 5 stages.

Stage 0 is an ATK Thiokol Castor 120 Solid Rocket Motor (SRM). Castor 120 is a commercial version of the Peacekeeper first stage. The stage is 9.06 m long and 2.38 m in diameter, with a mass of approximately 49 tons. The first Taurus used the Peacekeeper first stage as Stage 0.

Peacekeeper was an Inter-Continental Ballistic Missile (ICMB) deployed by the United States beginning in 1986. The Peacekeeper ICMB could carry up to ten re-entry vehicles, each armed with a 300-kiloton warhead (just to have an idea about the order of magnitude, that is twenty times the power of the bomb dropped on Hiroshima). The last Peacekeeper was decommissioned in 2005.

Stage 1 is an ATK Orion 50S SRM, 7.53 m long and 1.28 m in diameter, with a mass of approximately 12 tons. In the XL configuration, the stage is 8.94 m long and has a mass of approximately 15 tons. Stage 2 is an ATK Orion 50 SRM, 2.64 m long and 1.28 m in diameter, with a mass around 3 tons. In the XL configuration, the stage is 3.11 m long and almost 4 tons. Stage 3 is an ATK Orion 38 SRM. Stage 3 has a mass of around 800 kg, a length of 1.34 m, and a diameter of 97 cm.

The payload fairing comes in two versions: the 63” diameter fairing, manufactured by Vermont Composites, and the 92” diameter fairing, manufactured by Texas Composites. The fairing encapsulates and protects the payload during ground handling, integration operations, and flight. The payload mating is done late in the launch operations flow, so the designs of both fairings provide for off-line encapsulation of the payload and transportation to the launch site.

Taurus can be assembled in different configurations, depending on the specific requirements of the mission. The configurations are designated using a four-digit code. The first digit indicates the vehicle configuration (1 – SSLV Taurus with Peacekeeper first stage used as Stage 0; 2 – Commercial Taurus Standard with Castor 120 Stage 0 and standard-length Stage 1 and Stage 2; 3 – Commercial Taurus XL with Castor 120 Stage 0 and XL-length Stage 1 and Stage 2), the second digit designates the fairing size (1 for 63” fairing and 2 for 92” fairing), and the third and fourth indicate the Stage 3 motor (0 if there is no Stage 3 in configuration, 1 for Orion 38, and 3 for STAR 37), and the Stage 4 motor (0 if there is no Stage 4 in configuration, and 3 for STAR 37) respectively.

Credits: Orbital

The primary launch site used for Taurus is Site 576E on North Vandenberg Air Force Base (VAFB). Launches from North VAFB provide flight azimuths from 158 to 235 degrees, allowing payload injection on high inclination orbits (60 to 140 degrees).

For other mission profiles, there are a number of alternate sites that Taurus can launch from: South Vandenberg Air Force Base (VAFB), Cape Canaveral Air Force Station (CCAFS) Launch Complex 46, Wallops Flight Facility (WFF), and Reagan Test Site on the Kwajalein atoll in the western Pacific.

Taurus was designed to be launched from minimalist launch sites. The main requirement for the launch site is a 40×40 inch concrete pad that is able to support the weight of the launch vehicle.

For more information about the Taurus launch vehicle, you can visit the dedicated web page on Orbital’s website. There is also a Taurus User Guide available from Orbital. The guide is an exhaustive document, presenting the vehicle performance, the payload interfaces, an overview of the payload integration, among other things.

Credits: NASA

Last week we presented GOSAT a.k.a. Ibuki, a mission that has as its objective the mapping of carbon dioxide and methane in the Earth’s atmosphere. A similar mission is getting ready to launch on the other side of the Pacific: the Orbiting Carbon Observatory (OCO). OCO is a NASA Earth System Science Pathfinder (ESSP) Program mission.

The mission team includes the Orbital Sciences Corporation, the Jet Propulsion Laboratory, and Hamilton Sundstrand Sensor Systems.

The atmospheric carbon dioxide (CO₂) is an important greenhouse gas. CO₂ absorbs and traps infrared radiation emitted by the Earth’s surface, preventing it from escaping to space. OCO will provide global CO₂ measurements from space. The data collected during the mission will help scientists understand the global carbon cycle. This understanding is essential to improve the predictions of future atmospheric CO₂ increases and its impact on the climate.

The OCO has a mass of 407 kg. The two GaAs solar arrays will provide 324 W orbit average for the scientific payload onboard. The satellite will use hydrazine thrusters for stabilization while on orbit. The estimated life span for the mission is 24 months.

The scientific payload includes three spectrometers. The spectrometers can detect what gases are in the Earth’s atmosphere and determine their amounts. The measurements will translate into monthly estimates of atmospheric CO₂ over 621-square-mile regions of the Earth’s surface. From its sun-synchronous orbit, OCO will map the globe once every sixteen days. These maps will help locate CO₂ sources and sinks.

Credits: NASA / Orbital

OCO will be placed on orbit by a Taurus XL launch vehicle. Taurus XL is a solid fuel launch vehicle built by the Orbital Sciences Corporation. According to the Taurus fact sheet, it provides launch capability for satellites weighing up to 1,590 kg. The range of launch missions supported by Taurus include low inclination low Earth orbit (LEO), polar LEO, sun-synchronous LEO, geo-transfer orbit, and interplanetary trajectory.

Depending on the configuration, Taurus can have a mass from 69,000 to 77,000 kg and can have a length from 27 to 32 m.

The mission launch is scheduled for early 2009. The Taurus XL launch vehicle will lift off from Vandenberg Air Force Base, California.