Freefall achieved on LISA Pathfinder

ESA - LISA Pathfinder Mission patch.

24 February 2016

On Monday, the two cubes housed in the core of ESA’s LISA Pathfinder were left to move under the effect of gravity alone – another milestone towards demonstrating technologies to observe gravitational waves from space.

It has been an intense couple of months for LISA Pathfinder. After launch on 3 December and six burns to raise the orbit, it finally reached its work site – 1.5 million km from Earth towards the Sun – in January, and the team of engineers and scientists started to switch on and test its systems.

LISA Pathfinder operating in space

One of the most delicate operations entailed releasing the two test masses from the mechanisms that kept them in place during ground handling, launch and cruise.

First, the eight locking ‘fingers’ pressing on the corners of the identical gold–platinum cubes were retracted on 3 February. The cubes were then being held in position only by two rods, softly pushing on opposite faces.

These rods were retracted from the first test mass on 15 February, and from the second on the following day, leaving the cubes floating freely several millimetres from the walls of their housings.

The successful release of the two cubes, floating in space 1.5 million km away, left the team members thrilled and delighted.

LISA Pathfinder exploded view

Over the following days, minute electrostatic forces were applied to manoeuvre the cubes and make them track the spacecraft’s motion through space as it is slightly disturbed by external forces such as the pressure from sunlight.

This enabled the team to run further tests on the instruments, including the system used to measure the electrical charge of each cube and the procedures used to monitor their position and orientation.

Then the team aligned the two cubes with the laser beams that link them, and checked that the laser measurements agreed with those from the electrostatic sensors.

After verifying that everything was working as planned, the intensity of the electrostatic forces was gradually reduced until none was being applied along the sensitive axes of the masses. This resulted in a brief test of drag-free motion, on 19 February.

Finally, on 22 February, the team tackled the greatest challenge: setting the two cubes completely free, letting them move under the effect of gravity alone and actively manoeuvring the spacecraft around them.

To do this, LISA Pathfinder measures the position and orientation of each cube, and corrects its movement by firing microthrusters to keep it centred on one cube.

“This is a historic achievement: we are demonstrating the most precise freefall that has ever been obtained in space,” says Paul McNamara, LISA Pathfinder project scientist.

On 23 February, the spacecraft’s main operating mode was switched on for the first time. With the test masses in freefall, all of the key elements are now in place to start LISA Pathfinder’s scientific mission on 1 March, following some final tests on the fully operational payload in the coming days.

Inside LISA Pathfinder, with narration

Reproducing a motion as close as possible to actual freefall is the challenging condition needed to build and operate future space missions to observe gravitational waves.

Albert Einstein predicted the existence of gravitational waves, fluctuations in the fabric of spacetime, a century ago and they were recently directly detected with the ground-based Laser Interferometer Gravitational-Wave Observatory (LIGO), as announced on 11 February.

Space and ground experiments are sensitive to different sources of gravitational waves, so future space missions will be key partners to ground facilities such as LIGO, the European Gravitational Observatory and the Virgo Collaboration, which are already active in this quest.

A spaceborne gravitational wave observatory was identified as the goal for the L3 mission in ESA’s Cosmic Vision programme, and LISA Pathfinder will lay the foundations for these future investigations of the gravitational Universe.

“It is an immense reward to see this pioneering spacecraft ready to start its crucial mission,” concludes César García Marirrodriga, ESA’s project manager.

Related links:

About LISA Pathfinder mission: http://sci.esa.int/lisa-pathfinder/

More about...

LISA Pathfinder factsheet: http://www.esa.int/Our_Activities/Space_Science/LISA_Pathfinder_factsheet

Related articles:

What is gravity?: http://www.esa.int/Our_Activities/Space_Science/What_is_gravity

Gravitational waves: ‘dents’ in spacetime: http://www.esa.int/Our_Activities/Space_Science/Gravitational_waves_dents_in_spacetime

Images, Video, Text, Credits: ESA/ATG medialab/Markus Bauer/Paul McNamara/César García Marirrodriga/Stefano Vitale.

Best regards, Orbiter.ch

Repair Tasks Dominate Tuesday for Expedition 46 & Cygnus departure

ISS - Expedition 46 Mission patch.

February 23, 2016

International Space Station (ISS)

The crew of Expedition 46 was engaged in a variety of repair tasks today across the orbiting laboratory. ESA astronaut Tim Peake replaced cables in the station’s Advanced Resistive Exercise Device, the primary tool for astronaut resistive exercise vital for maintaining bone and muscle mass while in microgravity. NASA astronauts Scott Kelly and Tim Kopra worked to replace key components in the station’s Water Processing Assembly.

Peake also set up units for the NASA Space Automated Bioproduct Laboratory (SABL), which is capable of supporting life science research on microorganisms, small organisms, animal cells, tissue cultures and small plants.

Image above: Image shared by Expedition 46 Commander Scott Kelly with the caption “#Countdown Let’s take this 16 sunsets at a time. 8 days to go tomorrow! #GoodNight from @space_station! #YearInSpace.”

Meanwhile, Scott Kelly and Mikhail Kornienko are just one week away from the conclusion of their one-year mission. The pair are set to land in Kazakhstan at 11:27 p.m. EST March 1.

Spaceship Takes Out Trash Before One-Year Crew Goes Home

The Expedition 46 crew took out the trash today when it released the Orbital ATK Cygnus spacecraft from the grips of the International Space Station’s Canadarm2 robotic arm. In less than two weeks, another spacecraft will leave returning three crew members back to Earth.

Successful Commercial Space Station Supply Mission Concludes

The Cygnus was filled with trash and discarded gear over the last few days before the hatches were closed Thursday. Ground controllers then remotely guided the Canadarm2 to grapple Cygnus and detach it from the Unity module.

Image above: There are now four spacecraft docked to the International Space Station after the Cygnus left Friday morning. The next spacecraft to leave will be the Soyuz TMA-18M docked to the Poisk module on March 1.

NASA astronauts Scott Kelly and Tim Kopra commanded the Canadarm2 to release Cygnus February 19 (Friday) at 7:26 a.m. EST when it began gracefully departing the vicinity of the station. Orbital ATK controllers in Virginia will guide Cygnus into the Earth’s atmosphere Saturday morning where it will safely burn up high over the Pacific Ocean.

Image above: The Cygnus spacecraft is released from the International Space Station’s Canadarm2.

Kelly and a pair of cosmonauts Mikhail Kornienko and Sergey Volkov now turn their attention to their March 1 homecoming. They will be packing the Soyuz TMA-18M with science experiments and personal items for the ride home. Kelly and Kornienko will be completing 340 consecutive days in space, while Volkov will be wrapping up 182 days in orbit.

Related links:

- Advanced Resistive Exercise Device:
http://www.nasa.gov/mission_pages/station/research/experiments/1001.html

- Space Automated Bioproduct Laboratory (SABL):
http://www.nasa.gov/mission_pages/station/research/experiments/1283.html

- International Space Station (ISS): http://www.nasa.gov/mission_pages/station/main/index.html

- Space Station Research and Technology:
http://www.nasa.gov/mission_pages/station/research/index.html

Images, Video, Text, Credits: NASA/NASA TV/Mark Garcia.

Greetings, Orbiter.ch

A strange music heard behind the moon by Apollo 10 in 1969

NASA - Apollo 10 Mission patch.

Feb. 23, 2016

Image above: Earth view from the Moon. It is passing behind the moon the astronauts have heard a strange music.

A recording of the Nasa of "weird music" heard by the crew of Apollo 10 in May 1969 during their flight over the far side of the Moon caused a stir after a television report.

The three astronauts Thomas P. Stafford, commander John Young, pilot of the control module and Eugene Cernan, lunar module pilot, were conducting the general repetition of flight before the first moon landing July 21, 1969 during the Apollo 11 mission, which was Neil Armstrong.

For these whistles was presented Sunday night on the cable channel Discovery as part of its series "Unexplained records of NASA." These sounds have almost lasted an hour. They were recorded and transmitted to the control center in Houston (Texas, Southern United States) where they were transcribed and archived.

Extract from Discovery documentary:
 

Outer Space Music Pt 2 of 2 - NASA's Unexplained Files

The soundtrack, available in the archives of NASA since 1973, has been digitized in 2012 has recently surfaced.

"You hear that? That whistle," said Eugen Cernan on the recording. "It's really a strange music," he continues while their ship flies over the far side of the Moon at 1500 meters, cut off from radio contact with Earth.

Taken for fools?

Apollo 10 Crew, left to right: Cernan, Stafford, Young

The three astronauts felt the strange phenomenon so that they debated as to whether or not they had to report to the control center to their superiors for fear of not being taken seriously and jeopardize their chances of make future flights, according to the Discovery documentary.

As bizarre as these sounds may have been, they do not have an extraterrestrial origin, NASA insists. An engineer from the space agency interviewed in the program explained that "the radios in the two vessels, the lunar module and command module (when attached), created interference between them."

For more information about Apollo 10 Mission, visit:

Apollo: http://www.nasa.gov/mission_pages/apollo/index.html

NASA History: http://www.nasa.gov/topics/history/index.html

Apollo 10 Mission: https://en.wikipedia.org/wiki/Apollo_10

Images, Video, Text, Credits: ATS/NASA/Wikimedia/Discovery/Youtube/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

Satellites Sees Category 5 Southern Pacific Tropical Cyclone Hit Fiji

NASA logo / NOAA logo.

Feb. 22, 2016

Winston (was 11P- Southwestern Pacific Ocean)

NASA satellites provided data on Tropical Cyclone Winston before and after it made an historic landfall in eastern Fiji. The GPM, Suomi NPP and Aqua satellites provided forecasters with data that showed rainfall, strength and extent of the storm.

Tropical Cyclone Winston made landfall on Feb. 20 in Vitu Levi, eastern Fiji as a Category 5 hurricane on the Saffir-Simpson Hurricane Wind Scale. Winston was the first cyclone of that strength to make landfall in Fiji in recorded history.

The Fiji Meteorological Service estimated wind gusts near Winston’s center over 200 mph.  On Feb. 20 at 0900 UTC (4 a.m. EST) after landfall, the Joint Typhoon Warning Center noted that Winston's maximum sustained winds were near 155 knots (178.4 mph/287.1 kph) gusting to 190 knots (218.6 mph/351.9 kph).

Image above: On Feb. 20 at 0941 UTC (4:41 a.m. EST), the GPM core satellite saw that Winston was dropping rain at a rate of over 169 mm (6.7 inches) per hour in the western side of the eye. Image Credits: NASA/JAXA/Hal Pierce.

The Global Precipitation Measurement (GPM) core observatory satellite flew directly above tropical cyclone Winston on February 20, 2016 at 0941 UTC (4:41 a.m. EST). Tropical cyclone Winston had sustained winds estimated at 155 knots (178.4 mph/287.1 kph) at that time. A rainfall analysis derived from data collected by GPM's Microwave Imager (GMI) and Dual-frequency Precipitation Radar (DPR) instruments found that in addition to powerful winds Winston was dropping rain at a rate of over 169 mm (6.7 inches) per hour in the western side of the eye. Tropical cyclone Winston is the most powerful storm to hit Fiji.

On Saturday, February 20, 2016 the Fiji government declared a State of Natural Disaster for Fiji for the next 30 days. That means that the government will send support to ensure the safety of members of the public, businesses, economy and national assets. The declaration means that police can now arrest people without warrant who fail to abide by the law.

On Feb. 21 at 02:15 UTC (Feb. 20 at 9:15 p.m. EST) the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard NASA's Aqua satellite captured a visible image of Tropical Cyclone Winston in the South Pacific Ocean, west of Fiji. Even after passing over Fiji, Winston maintained an eye.

Image above: On Feb. 21 at 02:15 UTC (Feb. 20 at 9:15 p.m. EST) NASA's Aqua satellite captured this visible image of Tropical Cyclone Winston in the South Pacific Ocean, west of Fiji. Credit: Image Credits: NASA Goddard MODIS Rapid Response Team/Jeff Schmaltz.

By 0900 UTC (4 a.m. EST) that day, seven hours after NASA's Aqua satellite captured an image of Tropical cyclone Winston, the storm still maintained maximum sustained winds near 125 knots (143.8 mph/231.5 kph) down from 130 knots (149.6 mph/240.8 kph) just 12 hours before. It was located about 253 nautical miles (291.3 miles/468.9 km) west of Suva, Fiji near 17.6 degrees south latitude and 174.0 degrees east longitude and was moving west-southwest.

On Feb. 22 at 0200 UTC (Feb. 21 at 9 p.m. EST) the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA's Suomi NPP satellite captured this visible image of Tropical Cyclone Winston between Vanuatu to the west and Fiji to the east. Although still a hurricane, Winston's 20 nautical-mile-wide (23 miles/37 km) eye had become cloud-filled.

Joint Typhoon Warning Center said that the University of Wisconsin-Madison Cooperative Institute for Meteorological Satellite Studies microwave total precipitable water loop "indicates a band of dry air currently being entrained into the cyclone hindering further Intensification."

Image above: On Feb. 22 at 0200 UTC the VIIRS instrument aboard NASA-NOAA's Suomi NPP satellite captured this visible image of Tropical Cyclone Winston between Vanuatu (left) and Fiji (right). Image Credits: NASA/NOAA.

By 1500 GMT (10 a.m. EST) Winston's maximum sustained winds dropped to 90 knots (103.6 mph/166.7 kph) making it a Category 2 hurricane. Scatterometry satellite data showed that the hurricane-force winds extend 30 nautical miles (34 miles/55 km) from the center.  It was located about 348 nautical miles (400.5 miles/644.5 km) west of Suva, Fiji near 18.2 degrees south latitude and 172.3 degrees east longitude. Winston was moving to the south slowly at 3 knots (3.4 mph/5.5 kph).

GPM 3D Flyby of Winston

Video above: On Feb. 20 at 0941 UTC (4:41 a.m. EST), the GPM core satellite saw that Winston was dropping rain at a rate of over 169 mm (6.7 inches) per hour in the western side of the eye. Video Credits: NASA/JAXA/Hal Pierce.

The JTWC noted that Winston will maintain current intensity for about a day because it is still over warm sea surface temperatures. Thereafter, Winston will begin weakening and eventually become sub-tropical south of New Caledonia.

The GPM satellite is co-managed by NASA and the Japan Aerospace Exploration Agency, and the Suomi NPP satellite is co-managed by NASA and NOAA.

Related links:

NASA's Goddard Space Flight Center: http://www.nasa.gov/goddard

NOAA: http://www.noaa.gov/

GPM satellite: http://www.nasa.gov/mission_pages/GPM/main/index.html

GPM satellite: http://global.jaxa.jp/projects/sat/gpm/

Aqua satellite: http://aqua.nasa.gov/

Suomi NPP satellite: http://www.nasa.gov/mission_pages/NPP/main/index.html

Images (mentioned), Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center/Rob Gutro/Hal Pierce.

Greetings, Orbiter.ch

SOFIA Begins Fourth Year of Observations Targeting Planets, Asteroids, Stars, Galaxies, and More

NASA & DLR - SOFIA Mission patch.

Feb. 22, 2016

NASA’s “flying” telescope, the Stratospheric Observatory for Infrared Astronomy (SOFIA) aboard a highly modified Boeing 747SP jetliner, began its fourth series of science flights on Feb. 3, 2016.

This operational period, known as “Cycle 4,” is a one-year-long observing period in which SOFIA is scheduled for 106 flights between now and the end of January 2017.

Image above: This high-dynamic range (HDR) photo of the Stratospheric Observatory for Infrared Astronomy (SOFIA) was captured just before sunset at the Christchurch International Airport in Christchurch, New Zealand while aircraft crews were preparing for a nighttime observation flight. Image Credits: NASA Photo/Carla Thomas.

“The Cycle 4 program will make more than 550 hours of observations,” said Pamela Marcum, NASA's SOFIA Project Scientist. “We’ll be studying objects spanning the full gamut of astronomical topics including planets, moons, asteroids and comets in our solar system; star and planet formation; extrasolar planets and the evolution of planetary systems; the interstellar medium and interstellar chemistry; the nucleus of the Milky Way galaxy, and nearby normal and active galaxies.”

SOFIA’s instruments observe infrared energy – one part of the electromagnetic spectrum, which includes visible light, x-rays, radio waves and others. Many objects in space, for example newborn stars, emit almost all their energy at infrared wavelengths and are undetectable when observed in ordinary visible light. In other cases, clouds of gas and dust in space block visible light objects but allow infrared energy to reach Earth. In both situations, the celestial objects of interest can only be studied using infrared facilities like SOFIA.

“During the February third flight, the target objects ranged from a young planetary system around the naked-eye star Vega, only 25 light years from us, to an infant star 1,500 light years away in the Orion star forming region,” said Erick Young, SOFIA’s Science Mission Operations Director, describing the science conducted on Cycle 4’s inaugural flight. “We also observed a supermassive black hole hidden behind dense dust clouds in the center of a galaxy 170 million light years away.”

Scientists from the University of Georgia, University of Arizona, University of Texas at San Antonio, and the Space Telescope Science Institute in Baltimore, plus their collaborators from institutions in the United States and Europe, obtained data using the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) mounted on SOFIA’s telescope for imaging and spectroscopic observations during the flight.

Image above: NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) takes off from Palmdale, California at sunset. SOFIA is a partnership of NASA and the German Aerospace Center (DLR). Image Credits: NASA/Greg Perryman.

Later in Cycle 4, the SOFIA observatory is scheduled to deploy to the Southern Hemisphere for seven weeks in June and July 2016, with 24 science flights planned from a base at Christchurch, New Zealand. There, scientists will have the opportunity to observe areas of interest such as the Galactic Center and other parts of the Milky Way that are not visible or difficult to observe from the Northern Hemisphere.

The far-infrared High-resolution Airborne Wideband Camera-plus (HAWC+) will be added to SOFIA’s suite of seven cameras, spectrometers, and high-speed photometers during the latter part of Cycle 4. HAWC+’s optics, state-of-the art detector arrays, and upgradability will permit a broad range of important astrophysical investigations, including the unique and powerful capability of mapping magnetic fields in molecular clouds.

SOFIA in flight, telescope door open. Image Credit: NASA

SOFIA is a joint project of NASA and the German Aerospace Center (DLR). NASA’s Ames Research Center in Moffett Field, California, manages the SOFIA program. The aircraft is based at NASA’s Armstrong Flight Research Center's facility in Palmdale, California. NASA Ames manages the SOFIA science and mission operations in cooperation with the Universities Space Research Association (USRA) headquartered in Columbia, Maryland, and the German SOFIA Institute (DSI) at the University of Stuttgart.

For a list of science programs selected for Cycle 4, visit:

https://www.sofia.usra.edu/Science/proposals/cycle4/results.html

For more information about SOFIA, visit:

http://www.nasa.gov/sofia • http://www.dlr.de/en/sofia

For information about SOFIA's science mission, visit:

http://www.sofia.usra.edu • http://www.dsi.uni-stuttgart.de/index.en.html

Images (mentioned), Text, Credits: NASA/SOFIA Science Center/Ames Research Center/Nicholas A. Veronico/Yvonne Gibbs.

Greetings, Orbiter.ch

Titan Temperature Lag Maps & Animation

NASA & ESA - Cassini-Huygens Mission to Saturn & Titan patch.

Feb. 22, 2016

Images above: This sequence of maps shows varying surface temperatures on Saturn's moon Titan at two-year intervals, from 2004 to 2016. The measurements were made by the Composite Infrared Spectrometer (CIRS) instrument on NASA's Cassini spacecraft.

The maps show thermal infrared radiation (heat) coming from Titan's surface at a wavelength of 19 microns, a spectral window at which the moon's otherwise opaque atmosphere is mostly transparent. Temperatures have been averaged around the globe from east to west (longitudinally) to emphasize the seasonal variation across latitudes (from north to south). Black regions in the maps are areas for which there was no data.

Titan's surface temperature changes slowly over the course of the Saturn system's long seasons, which each last seven and a half years. As on Earth, the amount of sunlight received at each latitude varies as the sun's illumination moves northward or southward over the course of the 30-year-long Saturnian year.

When Cassini arrived at Saturn in 2004, Titan's southern hemisphere was in late summer and was therefore the warmest region. Shortly after the 2009 equinox, in 2010, temperatures were symmetrical across the northern and southern hemispheres, mimicking the distribution observed by Voyager 1 in 1980 (one Titan year earlier). Temperatures subsequently cooled in the south and rose in the north, as southern winter approached.

While the overall trend in the temperature shift is clearly evident in these maps, there is narrow banding in several places that is an artifact of making the observations through Titan's atmosphere. The moon's dense, hazy envelope adds noise to the difficult measurement.

The animation above shows a simplified model of the varying temperature data at yearly intervals. The latitude banding has been smoothed to more clearly show the how Titan's peak temperature moves from 19 degrees south to 16 degrees north latitude between 2004 and 2016. The small globe in the upper right corner shows the view of Titan as seen from the direction of the sun. The latitude on Titan where the sun is directly overhead (the subsolar latitude) is indicated by a yellow star.

Although it moves in latitude, the maximum measured temperature on Titan remains around -292 degrees Fahrenheit (-179.6 degrees Celsius, 93.6 Kelvin), with a minimum temperature at the winter pole only 6 degrees Fahrenheit (3.5 degrees Celsius or Kelvin) colder. This is a much smaller contrast than exists between Earth's warmest and coldest temperatures, which can vary by more than 200 degrees Fahrenheit, or more than 100 degrees Celsius.

These Titan surface temperature maps are a visualization of measurements that appeared in publication as: D. E. Jennings et al., Astrophysical Journal Letters, 816, L17, 2016, http://dx.doi.org/10.3847/2041-8205/816/1/L17.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md., where the instrument was built.

For more information about the Cassini-Huygens mission visit http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov and ESA's website: http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Images, Animation, Text,  Credits: NASA/JPL-Caltech/GSFC/Tony Greicius.

Best regards, Orbiter.ch

Three Times the Fun

NASA - Cassini International logo.

Feb. 22, 2016

Three of Saturn's moons -- Tethys, Enceladus and Mimas -- are captured in this group photo from NASA's Cassini spacecraft.

Tethys (660 miles or 1,062 kilometers across) appears above the rings, while Enceladus (313 miles or 504 kilometers across) sits just below center. Mimas (246 miles or 396 kilometers across) hangs below and to the left of Enceladus.

This view looks toward the sunlit side of the rings from about 0.4 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 3, 2015.

The view was acquired at a distance of approximately 837,000 miles (1.35 million kilometers) from Enceladus, with an image scale of 5 miles (8 kilometers) per pixel. Tethys was approximately 1.2 million miles (1.9 million kilometers) away with an image scale of 7 miles (11 kilometers) per pixel.  Mimas was approximately 1.1 million miles (1.7 million kilometers) away with an image scale of 6 miles (10 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini . The Cassini imaging team homepage is at http://ciclops.org and ESA's website: http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Image, Text, Credits: NASA/JPL-Caltech/Space Science Institute/Tony Greicius.

Greetings, Orbiter.ch