Hubble unveils monster stars

ESA - Hubble Space Telescope logo.

17 March 2016

Astronomers using the unique ultraviolet capabilities of the NASA/ESA Hubble Space Telescope have identified nine monster stars with masses over 100 times the mass of the Sun in the star cluster R136. This makes it the largest sample of very massive stars identified to date. The results, which will be published in the Monthly Notices of the Royal Astronomical Society, raise many new questions about the formation of massive stars.

R136 observed with WFC3

An international team of scientists using the NASA/ESA Hubble Space Telescope has combined images taken with the Wide Field Camera 3 (WFC3) with the unprecedented ultraviolet spatial resolution of the Space Telescope Imaging Spectrograph (STIS) to successfully dissect the young star cluster R136 in the ultraviolet for the first time [1].

R136 is only a few light-years across and is located in the Tarantula Nebula within the Large Magellanic Cloud, about 170 000 light-years away. The young cluster hosts many extremely massive, hot and luminous stars whose energy is mostly radiated in the ultraviolet [2]. This is why the scientists probed the ultraviolet emission of the cluster.

As well as finding dozens of stars exceeding 50 solar masses, this new study was able to reveal a total number of nine very massive stars in the cluster, all more than 100 times more massive as the Sun. However, the current record holder R136a1 does keep its place as the most massive star known in the Universe, at over 250 solar masses. The detected stars are not only extremely massive, but also extremely bright. Together these nine stars outshine the Sun by a factor of 30 million.

The scientists were also able to investigate outflows from these behemoths, which are most readily studied in the ultraviolet. They eject up to an Earth mass of material per month at a speed approaching one percent of the speed of light, resulting in extreme weight loss throughout their brief lives.

“The ability to distinguish ultraviolet light from such an exceptionally crowded region into its component parts, resolving the signatures of individual stars, was only made possible with the instruments aboard Hubble,” explains Paul Crowther from the University of Sheffield, UK, and lead author of the study. “Together with my colleagues, I would like to acknowledge the invaluable work done by astronauts during Hubble’s last servicing mission: they restored STIS and put their own lives at risk for the sake of future science!” [3]

Pseudo image of R136

In 2010 Crowther and his collaborators showed the existence of four stars within R136, each with over 150 times the mass of the Sun. At that time the extreme properties of these stars came as a surprise as they exceeded the upper-mass limit for stars that was generally accepted at that time. Now, this new census has shown that there are five more stars with more than 100 solar masses in R136. The results gathered from R136 and from other clusters also raise many new questions about the formation of massive stars as the origin of these behemoths remains unclear [4].

Saida Caballero-Nieves, a co-author of the study, explains: “There have been suggestions that these monsters result from the merger of less extreme stars in close binary systems. From what we know about the frequency of massive mergers, this scenario can’t account for all the really massive stars that we see in R136, so it would appear that such stars can originate from the star formation process.”

In order to find answers about the origin of these stars the team will continue to analyse the gathered datasets. An analysis of new optical STIS observations will also allow them to search for close binary systems in R136, which could produce massive black hole binaries which would ultimately merge, producing gravitational waves.

Hubble and the sunrise over Earth

“Once again, our work demonstrates that, despite being in orbit for over 25 years, there are some areas of science for which Hubble is still uniquely capable,” concludes Crowther.

Notes:

1] R136 was originally listed in a catalogue of the brightest stars in the Magellanic Clouds compiled at the Radcliffe Observatory in South Africa. It was separated into three components a, b, c at the European Southern Observatory, with R136a subsequently resolved into a group of eight stars (a1-a8) at ESO, and confirmed as a dense star cluster with the NASA/ESA Hubble Space Telescope after the first servicing mission in 1993.

[2] Very massive stars are exclusive to the youngest star clusters because their lifetimes are only 2-3 million years. Only a handful of such stars are known in the entire Milky Way galaxy.

[3] STIS’s capabilities were restored in 2009 by astronauts who successfully completed Serving Mission 4 (SM4), one of the Hubble’s most challenging and intense servicing missions, involving five spacewalks.

[4] The ultraviolet signatures of even more very massive stars have also been revealed in other clusters — examples include star clusters in the dwarf galaxies NGC 3125 and NGC 5253. However, these clusters are too distant for individual stars to be distinguished even with Hubble.

More information:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

The results were published in the paper “The R136 star cluster dissected with Hubble Space Telescope/STIS. I. Far-ultraviolet spectroscopic census and the origin of Heii λ1640 in young star clusters” in the Monthly Notices of the Royal Astronomical Society.

The international team of astronomers in this study consists of Paul A. Crowther (Department of Physics and Astronomy, University of Sheffield, Sheffield, UK), S.M. Caballero-Nieves(Department of Physics and Astronomy, University of Sheffield, Sheffield, UK), K.A. Bostroem (Space Telescope Science Institute, Baltimore MD, USA; Department of Physics, University of California, Davis CA, USA), J. Maíz Apellániz (Centro de Astrobiología, CSIC/INTA, Madrid, Spain), F.R.N. Schneider (Department of Physics, University of Oxford, Oxford, UK; Argelanger-Institut fur Astronomie der Universität Bonn, Bonn, Germany), N.R. Walborn(Space Telescope Science Institute, Baltimore MD, USA), C.R. Angus (Department of Physics and Astronomy, University of Sheffield, Sheffield, UK; Department of Physics, University of Warwick, Coventry, UK), I. Brott (Institute for Astrophysics, Vienna, Austria), A. Bonanos (Institute of Astronomy & Astrophysics, National Observatory of Athens, P. Penteli, Greece), A. de Koter (Astronomical Institute Anton Pannekoek, University of Amsterdam, Amsterdam, Netherlands; Institute of Astronomy, Leuven, Belgium), S.E. de Mink (Astronomical Institute Anton Pannekoek, University of Amsterdam, Amsterdam, Netherlands), C.J. Evans (UK Astronomy Technology Centre, Royal Observatory Edinburgh, Edinburgh, UK), G. Gräfener (Armagh Observatory, Armagh, UK), A. Herrero (Instituto de Astrofísica de Canarias, La Laguna, Tenerife, Spain; Departamento de Astrofísica, Universidad de La Laguna, La Laguna, Tenerife, Spain), I.D. Howarth (Department of Physics & Astronomy, University College London, London, UK), N. Langer (Argelanger-Institut fur Astronomie der Universität Bonn, Bonn, Germany), D.J. Lennon (European Space Astronomy Centre, ESA, Villanueva de la Cañada, Madrid, Spain), J. Puls (Universitäts-Sternwarte, Munchen, Germany), H. Sana (Space Telescope Science Institute, Baltimore MD, USA; Institute of Astronomy, Leuven, Belgium), J.S. Vink (Armagh Observatory, Armagh, UK).

Related links:

Wide Field Camera 3 (WFC3): http://www.spacetelescope.org/about/general/instruments/wfc3/

Space Telescope Imaging Spectrograph (STIS): http://www.spacetelescope.org/about/general/instruments/stis/

European Southern Observatory (ESO): http://www.eso.org/

Links:

Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

Link to science paper: http://www.spacetelescope.org/static/archives/releases/science_papers/heic1605a.pdf

Image of R136 taken in 2009: http://www.spacetelescope.org/images/opo0932a/

ESO release on the discovery of R136a1 in 2010: http://www.eso.org/public/news/eso1030/

Images, Video, Text, Credits: ESO/NASA/ESA/P Crowther (University of Sheffield)/Hubble/K.A. Bostroem (STScI/UC Davis).

Greetings, Orbiter.ch

Jason-3 Begins Mapping Oceans, Sees Ongoing El Niño

NASA - Jason-3 Mission logo.

March 16, 2016

Image above: Sea level anomalies from February 12-22, 2016. The U.S./European Jason-3 satellite has produced its first map of sea surface height, which corresponds well to data from its predecessor, Jason-2. Higher-than-normal sea levels are red; lower-than-normal sea levels are blue. El Nino is visible as the red blob in the eastern equatorial Pacific.
Image Credits: NASA/JPL Ocean Surface Topography Team.

Jason-3, a new U.S.-European oceanography satellite mission with NASA participation, has produced its first complete science map of global sea surface height, capturing the current signal of the 2015-16 El Niño.

The map was generated from the first 10 days of data collected once Jason-3 reached its operational orbit of 830 miles (1,336 kilometers) last month. It shows the state of the ongoing El Niño event that began early last year. After peaking in January, the high sea levels in the eastern Pacific are now beginning to shrink.

Launched Jan. 17 from California’s Vandenberg Air Force Base, Jason-3 is operated by the National Oceanic and Atmospheric Administration (NOAA) in partnership with NASA, the French Space Agency Centre National d’Etudes Spatiales (CNES) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). Its nominal three-year mission will continue nearly a quarter-century record of monitoring changes in global sea level. These measurements of ocean surface topography are used by scientists to help calculate the speed and direction of ocean surface currents and to gauge the distribution of solar energy stored in the ocean.

Information from Jason-3 will be used to monitor climate change and track phenomena like El Niño. It will also enable more accurate weather, ocean and climate forecasts, including helping global weather and environmental agencies more accurately forecast the strength of tropical cyclones.

Jason-3 data will also be used for other scientific, commercial and operational applications, including monitoring of deep-ocean waves; forecasts of surface waves for offshore operators; forecasts of currents for commercial shipping and ship routing; coastal forecasts to respond to environmental challenges like oil spills and harmful algal blooms; and coastal modeling crucial for marine mammal and coral reef research.

“Jason-3 has big shoes to fill,” said Josh Willis, NASA project scientist for Jason-3 at NASA’s Jet Propulsion Laboratory in Pasadena, California. “By measuring the changing levels of the ocean, Jason-2 and its predecessors have built one of the clearest records we have of our changing climate.”

That record began with the 1992 launch of the NASA/CNES Topex/Poseidon mission (1992-2006) and was continued by Jason-1 (2001-2013); and Jason-2, launched in 2008 and still in operation. Data from Jason-3’s predecessor missions show that mean sea level has been rising by about 0.12 inches (3 millimeters) a year since 1993.

Over the past several weeks, mission controllers have activated and checked out Jason-3’s systems, instruments and ground segment, all of which are functioning properly. They also maneuvered Jason-3 into its operational orbit, where it now flies in formation with Jason-2 in the same orbit, approximately 80 seconds apart. The two satellites will make nearly simultaneous measurements over the mission’s six-month checkout phase to allow scientists to precisely calibrate Jason-3’s instruments.

John Lillibridge, NOAA Jason-3 project scientist in College Park, Maryland, said comparisons of data from the two satellites show very close agreement. “It’s really fantastic. The excellent agreement we already see with Jason-2 shows us that Jason-3 is working extremely well, right out of the box. This kind of success is only possible because of the collaboration that’s been developed between our four international agencies over the past quarter century.”

Jason-3 spacecraft. Image Credits: NASA/JPL

Once Jason-3 is fully calibrated and validated, it will begin full science operations, precisely measuring the height of 95 percent of the world’s ice-free ocean every 10 days and providing oceanographic products to users around the world. Jason-2 will then be moved into a new orbit, with ground tracks that lie halfway between those of Jason-3. This move will double coverage of the global ocean and improve data resolution for both missions. This interleaved mission will improve our understanding of ocean currents and eddies and provide better information for forecasting them throughout the global oceans.

NASA and CNES shared responsibilities for Jason-3’s satellite development and launch. CNES provided the Jason-3 spacecraft, while NASA was responsible for management of launch services and countdown operations for the SpaceX Falcon 9 rocket. NASA and CNES jointly provided the primary payload instruments. CNES and NOAA are responsible for satellite operations, with instrument operations support from JPL, which is managing the mission for NASA. Upon completion of Jason-3’s commissioning phase, CNES will hand over satellite mission operations and control to NOAA. Processing, archival and distribution of data products to users worldwide is being carried out by CNES, EUMETSAT and NOAA.

NASA uses the vantage point of space to increase our understanding of our home planet, improve lives and safeguard our future. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records. The agency freely shares this unique knowledge and works with institutions around the world to gain new insights into how our planet is changing.

For more information about Jason-3, visit: http://www.nesdis.noaa.gov/jason-3

For more information about NASA's Earth science activities, visit: http://www.nasa.gov/earth

Images (mentioned), Text, Credits: NASA/Steve Cole/JPL/Alan Buis/Tony Greicius.

Greetings, Orbiter.ch

Unexpected Changes of Bright Spots on Ceres Discovered

ESO - European Southern Observatory logo.

16 March 2016

Artist’s view of bright spots on Ceres imaged by the Dawn spacecraft

Observations made using the HARPS spectrograph at ESO’s La Silla Observatory in Chile have revealed unexpected changes in the bright spots on the dwarf planet Ceres. Although Ceres appears as little more than a point of light from the Earth, very careful study of its light shows not only the changes expected as Ceres rotates, but also that the spots brighten during the day and also show other variations. These observations suggest that the material of the spots is volatile and evaporates in the warm glow of sunlight.

Ceres is the largest body in the asteroid belt between Mars and Jupiter and the only such object classed as a dwarf planet. NASA’s Dawn spacecraft has been in orbit around Ceres for more than a year and has mapped its surface in great detail. One of the biggest surprises has been the discovery of very bright spots, which reflect far more light than their much darker surroundings [1]. The most prominent of these spots lie inside the crater Occator and suggest that Ceres may be a much more active world than most of its asteroid neighbours.

New and very precise observations using the HARPS spectrograph at the ESO 3.6-metre telescope at La Silla, Chile, have now not only detected the motion of the spots due to the rotation of Ceres about its axis, but also found unexpected additional variations suggesting that the material of the spots is volatile and evaporates in sunlight.

The bright spots on Ceres imaged by the Dawn spacecraft

The lead author of the new study, Paolo Molaro, at the INAF–Trieste Astronomical Observatory, takes up the story: "As soon as the Dawn spacecraft revealed the mysterious bright spots on the surface of Ceres, I immediately thought of the possible measurable effects from Earth. As Ceres rotates the spots approach the Earth and then recede again, which affects the spectrum of the reflected sunlight arriving at Earth.”

Ceres spins every nine hours and calculations showed that the effects due to the motion of the spots towards and away from the Earth caused by this rotation would be very small, of order 20 kilometres per hour. But this motion is big enough to be measurable via the Doppler effect with high-precision instruments such as HARPS.

The team observed Ceres with HARPS for a little over two nights in July and August 2015. "The result was a surprise," adds Antonino Lanza, at the INAF–Catania Astrophysical Observatory and co-author of the study. "We did find the expected changes to the spectrum from the rotation of Ceres, but with considerable other variations from night to night.”

Artist’s view of bright spots on Ceres imaged by the Dawn spacecraft

The team concluded that the observed changes could be due to the presence of volatile substances that evaporate under the action of solar radiation [2]. When the spots inside the Occator crater are on the side illuminated by the Sun they form plumes that reflect sunlight very effectively. These plumes then evaporate quickly, lose reflectivity and produce the observed changes. This effect, however, changes from night to night, giving rise to additional random patterns, on both short and longer timescales.

If this interpretation is confirmed Ceres would seem to be very different from Vesta and the other main belt asteroids. Despite being relatively isolated, it seems to be internally active [3]. Ceres is known to be rich in water, but it is unclear whether this is related to the bright spots. The energy source that drives this continual leakage of material from the surface is also unknown.

Dawn is continuing to study Ceres and the behaviour of its mysterious spots. Observations from the ground with HARPS and other facilities will be able to continue even after the end of the space mission.

The motions of the bright spots on Ceres

Notes:

[1] Bright spots were also seen, with much less clarity, in earlier images of Ceres from the NASA/ESA Hubble Space Telescope taken in 2003 and 2004.

[2] It has been suggested that the highly reflective material in the spots on Ceres might be freshly exposed water ice or hydrated magnesium sulphates.

[3] Many of the most internally active bodies in the Solar System, such as the large satellites of Jupiter and Saturn, are subjected to strong tidal effects due to their proximity to the massive planets.

More information:

This research was presented in a paper entitled “Daily variability of Ceres’ Albedo detected by means of radial velocities changes of the reflected sunlight”, by P. Molaro et al., which appeared in the journal Monthly Notices of the Royal Astronomical Society.

The team is composed of P. Molaro (INAF-Osservatorio Astronomico di Trieste, Trieste, Italy), A. F. Lanza (INAF-Osservatorio Astrofisico di Catania, Catania, Italy), L. Monaco (Universidad Andres Bello, Santiago, Chile), F. Tosi (INAF-IAPS Istituto di Astrofisica e Planetologia Spaziali, Rome, Italy), G. Lo Curto (ESO, Garching, Germany), M. Fulle (INAF-Osservatorio Astronomico di Trieste, Trieste, Italy) and L. Pasquini (ESO, Garching, Germany).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links:
Research paper: http://www.eso.org/public/archives/releases/sciencepapers/eso1609/eso1609a.pdf

Photos of the ESO 3.6-metre telescope and HARPS: http://www.eso.org/public/images/archive/search/?adv=&subject_name=3.6
and http://www.eso.org/public/images/archive/search/?ranking=0&release_id=&minimum_size=0&description=&published_until_year=0&published_until_month=0&title=&subject_name=HARPS&credit=&published_until_day=0&published_since_day=0&published_since_month=0&id=&published_since_year=0

NASA’s Dawn Mission: http://dawn.jpl.nasa.gov/

HARPS spectrograph: http://www.eso.org/public/teles-instr/lasilla/36/harps/

ESO 3.6-metre telescope at La Silla: http://www.eso.org/public/teles-instr/lasilla/36/

INAF–Trieste Astronomical Observatory: http://www.oats.inaf.it/

INAF–Catania Astrophysical Observatory: http://www.oact.inaf.it/weboac/index_en.html

NASA/ESA Hubble Space Telescope: http://www.spacetelescope.org/

Images, Text, Credits: ESO/L.Calçada/NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/Steve Albers/N. Risinger (skysurvey.org)/Videos: ESO/L.Calçada/NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/Steve Albers.

Best regards, Orbiter.ch

Burning like the Sun

ESA - European Space Agency patch.

16 March 2016

Engineers building parts of a new type of power plant for generating green energy with nuclear fusion are using their expertise from building rockets like Europe’s Ariane 5 to create the super-strong structures to cope with conditions similar to those inside the Sun.

Nuclear fusion to generate green energy

A technique for building launcher and satellite components has turned out to be the best way for constructing rings to support the powerful magnetic coils inside the machine.

Meaning “the way” in Latin, the International Thermonuclear Experimental Reactor, ITER, is the world’s largest nuclear fusion experiment on generating electricity and is now being built in France.

Spanish company CASA Espacio is making the rings using a method they have perfected over two decades of building elements for the Ariane 5, Vega and Soyuz rockets, as well as for satellites and the International Space Station.

“Forces inside ITER present similar challenges to space,” explains Jose Guillamon, Head of Commercial and Strategy.

Ariane 5 liftoff

“We can’t use traditional materials like metal, which expand and contract with temperature and conduct electricity. We have to make a special composite material which is durable and lightweight, non-conductive and never changes shape.”

At their centre of excellence in Spain with its track record in composites for space applications, CASA Espacio has been at the forefront of developing a technique for embedding carbon fibres in resin to create a strong, lightweight material.

The composite is ideal for rocket parts because it retains its shape and offers the robust longevity needed to survive extreme launches and the harsh environment of space for over 15 years.

Pre-compression rings

Now, the team is using a similar technique to build the largest composite structures ever attempted for a cryogenic environment. With a diameter of 5 m and a solid cross-section of 30x30 cm, ITER’s compression rings will hold the giant magnets in place.

Harnessing star energy

Nuclear fusion powers the Sun and stars, with hydrogen atoms colliding to form helium while releasing energy. It has long been a dream to harness this extreme process to generate an endless supply of sustainable electricity from seawater and Earth’s crust.

In a worldwide research collaboration between China, the EU, India, Japan, South Korea, Russia and the US, the first prototype of its kind is now being realised in ITER.

Construction is expected to be completed by 2019 for initial trials as early as 2020. A commercial successor for generating electricity is not predicted before 2050.

ITER fly-through

Designed to generate 500 MW while using only a tenth of that to run, ITER aims to demonstrate continuous controlled fusion and, for the first time in fusion research, produce more energy than it takes to operate.

Inherently safe with no atmospheric pollution or long-lived radioactive waste, one kilogram of fuel could produce the same amount of energy as 10 000 tonnes of fossil fuel.

At ITER’s core is a doughnut-shaped magnetic chamber, 23 m in diameter. It will work by heating the electrically charged gases to more than 150 000 000ºC.

Hotter than the Sun, the plasma would instantly evaporate any normal container. Instead, giant electromagnets will hold the plasma away from the walls by suspending it within a magnetic ‘cage’.

Construction site

Building something that can withstand this powerful magnetic field is an extreme engineering challenge.

CASA Espacio had the answer thanks to their expertise and method for making space components.

Now under construction, ITER’s rings will each withstand 7000 tonnes – the equivalent of the Eiffel Tower pressing against each one of the six rings.

Cut the cloth to fit spacecraft

Carbon fibres are woven like fabric and embedded in a resin matrix to create a lightweight, durable and stable composite.

“In the same way that you’d weave a different fabric for a raincoat than you would for a summer shirt, we can lay the fibres in different directions and alter the ingredients to adapt the resulting material to its role, making it extra strong, for example, or resistant to extreme temperatures in space,” explains Jose.

Tokamak

For ITER, glass fibres are laid to maximise their mechanical strength and can be built up in slices and stacked like doughnuts to create the cylindrical structure.

“Space expertise can provide a tremendous resource to so many companies in non-space sectors, helping them to improve their product and increase their revenues,” says Richard Seddon from Tecnalia, worked with ESA´s Technology Transfer Network, which helps companies employ technologies from space to improve their businesses.

ITER construction

“In this case, CASA Espacio had just the right proven expertise to provide the best solution for ITER.”

More information:

ITER: https://www.iter.org/

CASA Espacio: http://www.casaespacio.es/

ESA Technology Transfer Network: http://www.esa.int/Our_Activities/Space_Engineering_Technology/TTP2/Technology_Transfer_Network3

Technology Transfer Programme Office: http://www.esa.int/Our_Activities/Space_Engineering_Technology/TTP2

Images, Text, Video, Credits: ESA/F4E/ITER Organization.

Best regards, Orbiter.ch

NASA Celebrating 90 Years: Robert Goddard’s Rocket and the Launch of Spaceflight

NASA Goddard Space Flight Center logo.

March 15, 2016

Ninety years ago, on March 16, 1926, a rocket lifted off – not with a bang, but with a subtle, quiet flame – and forever changed the scope of scientific exploration. This event ties directly to the birth of NASA more than 30 years later.

Animation above: Employees at NASA's Goddard Space Flight Center in Greenbelt, Maryland, recreated the first liquid-fueled rocket launch in front of Building 8 in 1976. Image Credits: NASA/Goddard/Robert Garner.

Less than a century ago, astronomers relied entirely on ground-based observations to further scientific study. Today, descendants of that first liquid-fueled rocket provide eyes on cosmic phenomena, unravel mysteries of the early universe, and even take a closer look at what makes our own planet tick.

None of this would be possible without the experiments of Massachusetts physics professor Robert Goddard, best known for inventing the liquid-fueled rocket. The namesake of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, he dreamed as early as 1909 of creating an interplanetary vehicle. While he couldn’t achieve that in his lifetime, his inventions in the first half of the 20th century became the engineering foundation for the rockets that first took humans to the moon in the 1960s and for today’s rockets, which look further into space than ever before.

Prior to Goddard’s experimentation, rockets had not changed much in several centuries. Chinese engineers invented them as war machines in the 13th century, using solid gunpowder as fuel. But Goddard realized that liquid propellants offered a number of advantages over solid-fueled rockets. He began to test rockets fueled by liquid gasoline and liquid oxygen.

The new design posed a number of challenges. For instance, he had to find a way to mix the fuel with oxygen. Otherwise it wouldn’t burn fast enough to produce the necessary thrust to lift the weight of the rocket. He also had to find a mechanical solution to pressurize the fuel chamber so it would continually feed fuel to the engine. Each solution he found brought with it a new challenge to solve.

After nearly 17 years of work, Goddard successfully launched his creation on March 16, 1926.

Image above: Robert Goddard stands next to his first liquid-fueled rocket prior to its launch on March 16, 1926. Image Credits: Clark University Robert H. Goddard Archive.

"It looked almost magical as it rose, without any appreciably greater noise or flame, as if it said, 'I've been here long enough; I think I'll be going somewhere else, if you don't mind,'" Goddard wrote in his journal the next day.

Most rockets today use liquid fuels because they provide more thrust per unit of fuel and they allow engineers to time how long the rocket will remain lit more precisely. For example, the Atlas V, on which many NASA missions launch – such as the Magnetospheric Multiscale Mission, which launched in 2015 – and the Ariane V, on which NASA’s James Webb Space Telescope will launch in 2018, both use liquid fuels in one or more of their stages.

Over the course of his career, as well as posthumously, Goddard was awarded more than 200 patents for his inventions, many of which pertained to rocketry. These also included the invention of multistage rockets, which contain multiple fuel tanks and engine segments that can be jettisoned as they are emptied.

Goddard’s work didn’t stop there. He continued to improve upon his rocket concepts until his death in 1945. The U.S. failed to recognize the full potential of his work until after his death – in fact, some of his ideas about reaching outer space were ridiculed during his lifetime. But the first liquid-fueled rocket flight was as significant to space exploration as the Wright brothers’ first flight was to air travel, and 90 years later, his patents are still integral to spaceflight technology.

For more about Robert Goddard, visit:
http://www.nasa.gov/centers/goddard/about/history/dr_goddard.html

For more about NASA Goddard, visit: http://www.nasa.gov/goddard

Image (mentioned), Animation (mentioned), Text, Credits: NASA’s Goddard Space Flight Center/Ashley Morrow.

Greetings, Orbiter.ch

Picturing the Sun’s Magnetic Field

NASA - Solar Dynamics Observatory (SDO) patch.

March 15, 2016

This illustration lays a depiction of the sun's magnetic fields over an image captured by NASA’s Solar Dynamics Observatory on March 12, 2016. The complex overlay of lines can teach scientists about the ways the sun's magnetism changes in response to the constant movement on and inside the sun. Note how the magnetic fields are densest near the bright spots visible on the sun – which are magnetically strong active regions – and many of the field lines link one active region to another.

This magnetic map was created using the PFSS – Potential Field Source Surface – model, a model of the magnetic field in the sun’s atmosphere based on magnetic measurements of the solar surface. The underlying image was taken in extreme ultraviolet wavelengths of 171 angstroms. This type of light is invisible to our eyes, but is colorized here in gold.

For more information about Solar Dynamics Observatory (SDO):
http://www.nasa.gov/mission_pages/sdo/main/index.html

Image, Text, Credits: NASA/SDO/AIA/LMSAL/Goddard Space Flight Center/Steele Hill/Sarah Frazier/Rob Garner.

Greetings, Orbiter.ch

NASA's MMS Celebrates a Year in Space

NASA - MMS Mission patch.

March 14, 2016

NASA launched the Magnetospheric Multiscale, or MMS, mission on March 12, 2015. MMS consists of four identical spacecraft that orbit around Earth through the dynamic magnetic system surrounding our planet to study a little-understood phenomenon called magnetic reconnection. Magnetic reconnection is a fundamental process that happens in space, which powers a wide variety of events, from giant explosions on the sun to green-blue auroras shimmering in the night sky.

Image above: Artist concept of the Magnetospheric Multiscale, or MMS, mission to study how magnetic fields release energy in a process known as magnetic reconnection. Image Credit: NASA.

To celebrate the anniversary of the MMS launch, we're sharing a host of MMS facts from its flawless first year.

- 1 year: Length of time MMS has been in space

- 4: Number of observatories launched together on a single United Launch Alliance Atlas V rocket from Cape Canaveral Air Force Station, Florida, on March 12, 2015.

- 600: Number of people who helped build MMS.

- 8: Total pairs of booms successfully deployed.

- 100: Number of sensors flying on the four MMS observatories — all working perfectly.

- 33: Number of times per second that the Fast Plasma Investigation instrument on board MMS gathers pressure, velocity and temperature observations of the charged particles in space.

- 8 Terabytes: Amount of MMS data collected and shared with the public:
https://lasp.colorado.edu/mms/sdc/public

- 360: Number of times MMS has crossed the magnetopause.
- 6 miles: Closest approach of MMS observatories while flying in formation — a new space formation record set in October 2015.

- 43,500 miles: Greatest height at which GPS receivers have ever been used successfully — a record set by MMS in March 2015.

- 22,000 miles per hour: Fastest speed at which GPS receivers have ever been used successfully — a record set by MMS in March 2015.

Related article:

NASA Spacecraft in Earth’s Orbit, Preparing to Study Magnetic Reconnection:
http://orbiterchspacenews.blogspot.ch/2015/03/nasa-spacecraft-in-earths-orbit.html

Related Link:

NASA’s MMS website: http://www.nasa.gov/mms

Image (mentioned), Text, Credits: NASA’s Goddard Space Flight Center/Karen C. Fox/Rob Garner.

Greetings, Orbiter.ch