OrbitalHub

Credits: NASA/Tony Gray and Kevin O’Connell

… or to be more exact, the cheese re-entered the Earth’s atmosphere and performed a successful splashdown in the Pacific Ocean onboard SpaceX’s Dragon spacecraft on December 8, 2010. The same day, roughly three and a half hours earlier, the Dragon spacecraft was placed into low Earth orbit by a Falcon 9 launch vehicle, which lifted off from Cape Canaveral Air Force Station Space Launch Complex 40 on COTS Demo Flight 1.

On this flight, several key components of the Dragon spacecraft were tested: the Draco thrusters, which control the spacecraft throughout flight and reentry; the PICA-X heat shield, which is the SpaceX variant of NASA’s phenolic impregnated carbon ablator (PICA) heat shield; avionics; telemetry; and the drogue and main parachutes used for stabilization and landing.

The Dragon spacecraft is capable of fully autonomous rendezvous and docking, can carry over three metric tons in each of the pressurized and unpressurized sections, and it supports five to seven passengers in crew configuration. SpaceX’s primary goal for this demo flight was to collect as much data as possible.

Before the launch, Elon Musk, SpaceX CEO and CTO, made the following statement:

“When Dragon returns, whether on this mission or a future one, it will herald the dawn of an incredibly exciting new era in space travel. This will be the first new American human capable spacecraft to travel to orbit and back since the Space Shuttle took flight three decades ago. The success of the NASA COTS/CRS program shows that it is possible to return to the fast pace of progress that took place during the Apollo era, but using only a tiny fraction of the resources. If COTS/CRS continues to achieve the milestones that many considered impossible, thanks in large part to the skill of the program management team at NASA, it should be recognized as one of the most effective public-private partnerships in history.”

Credits: ESA – P. Carril

In 2007, projections of sea level rise made by the Fourth Assessment Report of the Intergovernmental Panel on Climate Change were in the range of 28–43 cm by 2100, but there are new projections of the sea level rise that are in the order of 1.4 m.

While the trend is quite obvious, it is very important to be able to make accurate predictions.

Cryosat has been designed to measure the ice thickness on land and also at sea, and will provide enough data so that a precise rate of change of the ice thickness can be determined. A better understanding of how the volume of ice on Earth is changing will also be possible.

The declared primary goals of the CryoSat mission are to determine the regional trends in Arctic perennial sea-ice thickness and mass, and to determine the contribution that the Antarctic and Greenland ice sheets are making to mean global rise in sea level. Cryosat will also measure the variations in the thickness of Earth’s polar caps and glaciers. The spacecraft will be operational for a minimum of three years.

Credits: ESA/P. Carril

The spacecraft has a launch mass of 720 kg, of which 23 kg is the fuel required for orbital maneuvers and attitude corrections. The overall size of the spacecraft is 4.6 m x 2.34 m. Two solar panels are attached to the spacecraft’s body and provide a maximum of 800 W of power. As the CryoSat-2 orbit is not Sun-synchronous, providing enough power to the scientific payload has been a considerable challenge.

The operational orbit will be a 717 km non Sun-synchronous orbit with a 92 degree inclination.

The primary payload of the CryoSat-2 spacecraft is the SAR/Interferometric Radar Altimeter (SIRAL). In order to have the position of the spacecraft accurately tracked, a radio receiver called Doppler Orbit and Radio Positioning Integration by Satellite (DORIS) and a laser retro-reflector are part of the payload as well. A global network of laser ranging stations (the International Laser Ranging Service or ILRS for short) will support the mission. Three star-trackers will ensure a proper orientation of the spacecraft.

Using the Synthetic Aperture technique, CryoSat-2 measurements taken by SIRAL will have a 250 m resolution in the along-track direction. The instrument is designed to operate in three measurement modes: Low Resolution Mode (LRM) mostly over the oceans, Synthetic Aperture Radar (SAR) mode over sea-ice areas, and SAR Interferometric (SARIn) mode over steeply sloping ice-sheet margins, small ice caps, and mountain glaciers.

Credits: ESA – AOES Medialab

CryoSat-2 will be placed in orbit by a Dnepr launch vehicle. With a lift-off mass of 211 tons, Dnepr is 34 m long and 3 m in diameter, and has three stages that use hypergolic liquid propellants (N₂O₄ nitrogen peroxide and UDMH unsymmetrical dimethylhydrazine). In addition, there are Dnepr configurations with a third and a fourth stage for missions that require more energy. The launch vehicle is based on an ICMB designated as SS-18 Satan by NATO. The development and commercial operation of the Dnepr Space Launch System is managed by the International Space Company (ISC) Kosmotras. Dnepr can lift 4,500 kg to low Earth orbit (LEO) or 2,300 kg to a 98 degree Sun-synchronous orbit. Among other satellites launched by Dnepr are Demeter, Genesis I, Genesis II, and THEOS. Dnepr, carrying Cryosat-2, will lift off from Baikonur Cosmodrome in Kazakhstan.

The Rockot launch vehicle that attempted the orbiting of the first CryoSat mission, on October 8, 2005, failed to reach orbit. Due to faults in the onboard software, the second stage engine of the launcher did not shut down. The mission was terminated when the launch vehicle exceeded the flight envelope limit. The Rockot second stage/Breeze-KM/CryoSat stack crashed somewhere in the Arctic Ocean.

You can find more information about Cryosat-2 on ESA’s dedicated website. The Cryosat-2 mission EADS team also has a blog on EADS Astrium website. Check out the latest updates from Baikonur brought to you by Klaus Jäger (Astrium Spacecraft Launch Manager) and Edmund Paul (Astrium Spacecraft Operations Manager). A presentation of the SIRAL-2 instrument is available on Thales Group’s website.

Credits: ESA – P.Carril

The European Union’s Global Monitoring for Environment and Security (GMES) initiative was born as the result of a growing need for accurate and accessible information about the environment, the effects of climate change, and civil security. GMES uses as its main information feed the data collected by satellites developed by ESA. Data is also collected by instruments carried by aircraft, floating in the ocean, or located on the ground.

GMES provides services that can be grouped into five main categories: land management, marine environment, atmosphere, aid emergency response, and security.

There are five Sentinel missions designed as components of the GMES initiative. These missions will complement the national initiatives of the EU members involved. The missions will collect data for land and ocean monitoring, and atmospheric composition monitoring, making use of all-weather radar and optical imaging. Each of the Sentinel missions is based on a constellation of two satellites.

Sentinel-1 is an all-weather radar-imaging mission. The satellites will have polar orbits and collect data for the GMES land and ocean services. The first satellite is scheduled for launch in 2012. Sentinel-1 will ensure the continuity of Synthetic Aperture Radar (SAR) applications, taking over from systems carried by ERS-1, ERS-2, Envisat, and Radarsat. Sentinel-1 satellites will be carried to orbit by Soyuz launch vehicles lifting off from Kourou.

Sentinel-2 will provide high-resolution multi-spectral imagery of vegetation, soil, and water, and will cover inland waterways and coastal areas. Sentinel-2 is designed for the data continuity of missions like Landsat or SPOT (Satellite Pour l’Observation de la Terre). Each satellite will carry a Multi-Spectral Imager (MSI) that can ‘see’ in thirteen spectral bands spanning from the visible and near infrared (VNIR) to the shortwave infrared (SWIR). The first Sentinel-2 is planned to launch in 2013. Vega will provide launch services for Sentinel-2 missions.

Credits: ESA – P.Carril

Sentinel-3 will determine parameters such as sea-surface topography and sea and land surface temperature. It will also determine ocean and land colour with high accuracy. The first Sentinel-3 satellite is expected to reach orbit in 2013. The spacecraft bus has a three-meter accuracy real-time orbit determination capability based on GPS and Kalman filtering.

Sentinel-4 is devoted to atmospheric monitoring and it will consist of payloads carried by Meteosat Third Generation (MTG) satellites that are planned to launch in 2017 and 2024. Sentinel-5 will be used for atmospheric monitoring as well. The payload will be carried by a post-EUMETSAT Polar System (EPS) spacecraft, planned to launch in 2020. A Sentinel-5 precursor will ensure that no data gap will exist between the Envisat missions and Sentinel-5.

You can find out more about the GMES initiative and the Sentinel missions on a dedicated page on ESA’s website.

Credits: ESA-AOES Medialab

The Soil Moisture and Ocean Salinity (SMOS) mission, which is the second Earth Explorer Opportunity mission to be developed as part of ESA’s Living Planet Program, will provide global maps of moisture over the Earth’s landmasses and salinity over the oceans. These observations will improve our understanding of hydrology and ocean circulation patterns.

The science objectives for the SMOS mission are global monitoring of surface soil moisture and surface salinity over oceans, and improving the characterization of ice and snow-covered surfaces.

The SMOS satellite is built around a standard spacecraft bus called Proteus, which was developed by the French space agency CNES (Centre National d’Etudes Spatiales) and Alcatel Alenia Space. Proteus measures one cubic meter and plays the role of a service module, hosting all the subsystems that are required for the satellite to function.

A GPS receiver collects satellite position information. A hydrazine monopropellant system consisting of four 1-Newton thrusters, which are mounted on the base of the spacecraft, provides the thrust for orbit control. Three 2-axis gyroscopes and four small reaction wheels control the attitude of the satellite. A star tracker also provides accurate attitude information for instrument measurements.

The solar panels can produce up to 900 W, covering the 525 W maximum payload consumption. During eclipse periods, the satellite uses a 78 AH Li-ion battery. SMOS has a launch mass of 658 kg: a 275 kg platform, 355 kg payload, and 28 kg of fuel.

The SMOS satellite will deploy a new type of scientific instrument in space: a microwave imaging radiometer that operates between 1,400 – 1,427 MHz (L-band). The instrument is called Microwave Imaging Radiometer using Aperture Synthesis, or MIRAS, for short. MIRAS consists of a central structure and three deployable arms, and uses 69 antenna-receivers (LICEFs) for measuring microwave radiation emitted from the surface of the Earth. The instrument is the result of almost ten years of research and development.

Credits: ESA-AOES Medialab

The data collected by MIRAS needs to go through a validation process. The radiation received by the instrument is a function that depends not only on soil moisture and ocean salinity, other effects need to be considered when instrument data is converted into units of salinity and moisture.

Factors that have to be considered are the distribution of vegetation, the litter layer, the soil type, the varying roughness of the surface, and the physical temperature of the surface of the land and sea.

In order to quantify the effects of factors mentioned above, dedicated campaign activities were conducted. Ground-based and airborne instruments similar to the one mounted on SMOS were used to collect data that was correlated with in-situ observations made by large ground teams. Long-term observations were carried out from an oilrig platform in the Mediterranean and at the Concordia Station in Antarctica.

The Committee on Earth Observation Satellites (CEOS) has defined a number of levels for the SMOS Mission Data Products. They range from Raw Data to Level-3 Data Products, which are Soil Moisture and Ocean Salinity global maps. Level-3 data will be available from the SMOS Level 3/4 Processing Center in Spain.

Eurockot will provide the launch services for the SMOS mission. A Rockot launcher, which is derived from a Russian Intercontinental Ballistic Missile (ICBM) SS-19, will lift off from the Plesetsk Cosmodrome, 800 km north of Moscow. The Rockot launcher will inject the satellite in a 758 km quasi-circular orbit.

The CNES Satellite Operations Ground Segment and ESA/CDTI (Centro para el Desarrollo Technologico Industrial) Data Processing Ground Segment will be responsible for the SMOS mission ground segment.

Initially scheduled for 2008, the launch of the Earth Explorer SMOS satellite will take place some time from July to October 2009.

You can find more details about SMOS on the dedicated page on ESA’s web site.

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: SpaceX

The Draco thruster and the Draco propulsion tank completed qualification tests at the SpaceX Test Facility in McGregor, Texas.

The certification test included 42 firings with over 4,600 pulses of varying lengths. The tests are performed in a vacuum test chamber in order to simulate the space environment. The total firing time on a single thruster was over 50 minutes.

“The Draco thrusters allow Dragon to maneuver in close proximity to the ISS in preparation for berthing or docking,” said Tom Mueller VP Propulsion, SpaceX. “Maximum control during these procedures is critical for the safety of the station and its inhabitants.”

The Dragon spacecraft utilizes 18 Draco thrusters for maneuvering, attitude control, and to initiate the return to Earth. One important characteristic of the thrusters is that they are powered by storable propellants with long on-orbit lifetimes. This will allow the Dragon spacecraft to remain berthed at the International Space Station for up to a year.

The inaugural flight of Falcon 9 is scheduled for late 2009 from SpaceX’s launch site in Cape Canaveral, Florida.