NASA's Voyager 1 Explores Final Frontier of Our 'Solar Bubble'

PASADENA, Calif. -- Data from Voyager 1, now more than 11 billion miles (18 billion kilometers) from the sun, suggest the spacecraft is closer to becoming the first human-made object to reach interstellar space.

Research using Voyager 1 data and published in the journal Science today provides new detail on the last region the spacecraft will cross before it leaves the heliosphere, or the bubble around our sun, and enters interstellar space. Three papers describe how Voyager 1's entry into a region called the magnetic highway resulted in simultaneous observations of the highest rate so far of charged particles from outside heliosphere and the disappearance of charged particles from inside the heliosphere.

Scientists have seen two of the three signs of interstellar arrival they expected to see: charged particles disappearing as they zoom out along the solar magnetic field, and cosmic rays from far outside zooming in. Scientists have not yet seen the third sign, an abrupt change in the direction of the magnetic field, which would indicate the presence of the interstellar magnetic field.

"This strange, last region before interstellar space is coming into focus, thanks to Voyager 1, humankind's most distant scout," said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena. "If you looked at the cosmic ray and energetic particle data in isolation, you might think Voyager had reached interstellar space, but the team feels Voyager 1 has not yet gotten there because we are still within the domain of the sun's magnetic field."

Scientists do not know exactly how far Voyager 1 has to go to reach interstellar space. They estimate it could take several more months, or even years, to get there. The heliosphere extends at least 8 billion miles (13 billion kilometers) beyond all the planets in our solar system. It is dominated by the sun's magnetic field and an ionized wind expanding outward from the sun. Outside the heliosphere, interstellar space is filled with matter from other stars and the magnetic field present in the nearby region of the Milky Way.

Voyager 1 and its twin spacecraft, Voyager 2, were launched in 1977. They toured Jupiter, Saturn, Uranus and Neptune before embarking on their interstellar mission in 1990. They now aim to leave the heliosphere. Measuring the size of the heliosphere is part of the Voyagers' mission.
The Science papers focus on observations made from May to September 2012 by Voyager 1's cosmic ray, low-energy charged particle and magnetometer instruments, with some additional charged particle data obtained through April of this year.

Voyager 2 is about 9 billion miles (15 billion kilometers) from the sun and still inside the heliosphere. Voyager 1 was about 11 billion miles (18 billion kilometers) from the sun Aug. 25 when it reached the magnetic highway, also known as the depletion region, and a connection to interstellar space. This region allows charged particles to travel into and out of the heliosphere along a smooth magnetic field line, instead of bouncing around in all directions as if trapped on local roads. For the first time in this region, scientists could detect low-energy cosmic rays that originate from dying stars.

"We saw a dramatic and rapid disappearance of the solar-originating particles. They decreased in intensity by more than 1,000 times, as if there was a huge vacuum pump at the entrance ramp onto the magnetic highway," said Stamatios Krimigis, the low-energy charged particle instrument's principal investigator at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "We have never witnessed such a decrease before, except when Voyager 1 exited the giant magnetosphere of Jupiter, some 34 years ago."
Other charged particle behavior observed by Voyager 1 also indicates the spacecraft still is in a region of transition to the interstellar medium. While crossing into the new region, the charged particles originating from the heliosphere that decreased most quickly were those shooting straightest along solar magnetic field lines. Particles moving perpendicular to the magnetic field did not decrease as quickly. However, cosmic rays moving along the field lines in the magnetic highway region were somewhat more populous than those moving perpendicular to the field. In interstellar space, the direction of the moving charged particles is not expected to matter.

In the span of about 24 hours, the magnetic field originating from the sun also began piling up, like cars backed up on a freeway exit ramp. But scientists were able to quantify that the magnetic field barely changed direction -- by no more than 2 degrees.

"A day made such a difference in this region with the magnetic field suddenly doubling and becoming extraordinarily smooth," said Leonard Burlaga, the lead author of one of the papers, and based at NASA's Goddard Space Flight Center in Greenbelt, Md. "But since there was no significant change in the magnetic field direction, we're still observing the field lines originating at the sun."

NASA's Jet Propulsion Laboratory, in Pasadena, Calif., built and operates the Voyager spacecraft. California Institute of Technology in Pasadena manages JPL for NASA. The Voyager missions are a part of NASA's Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate at NASA Headquarters in Washington.

Winners of 2012 George M. Low Award

WASHINGTON -- Two companies that share a commitment to teamwork, technical and managerial excellence, safety, and customer service have been selected to receive NASA's premier honor for quality and performance, the George M. Low Award.

NASA recognizes URS Federal Technical Services Inc. of Germantown, Md., in the large business award category and ATA Engineering Inc. of San Diego in the small business award category. ATA Engineering Inc. was involved in the Mars Science Laboratory/Curiosity mission.

"NASA's industry partners are crucial in our work to reach new destinations and expand our nation's capabilities, and we're happy to recognize these two companies with the high honor of the George M. Low Award," said NASA Administrator Charles Bolden. "Their success both in space and on the ground has demonstrated excellence and innovation that will help us reach our challenging goals and keep America the leader in space exploration."

URS Federal Technical Services Inc. is the institutional services contractor at NASA's Kennedy Space Center in Florida. With 1,100 employees and subcontractors, the company maintains 1,250 facilities, roadways, railroad tracks and an airfield; provides utilities, indoor climate control, life support and propellant storage; conducts non-destructive evaluation; cleans, samples and calibrates components; and coordinates logistics.

Evaluators cited URS' automation initiative, which deployed tablet computers to employees to reduce their paperwork burden; its process for ensuring customer satisfaction; and the breadth of its safety program in an industrial environment with so many potential hazards.

ATA Engineering Inc. supported development of the Mars Science Laboratory and its robotic rover, Curiosity, at NASA's Jet Propulsion Laboratory in Pasadena, Calif. With 93 employees, the company played a key role in the mission by conducting detailed mechanical simulation work to support spacecraft's challenging entry, descent and landing at Mars in August last year.
Evaluators cited ATA's problem-solving ability, demonstrated with the design of Curiosity's sampling scoop; its emphasis on contracting with small business and hiring young talent with high potential; and its strong culture of teamwork.

"I congratulate these companies for winning our premier award. It's our recognition for their management's leadership and employee commitment to the highest standards in performance," said Terrence Wilcutt, the agency's chief of safety and mission assurance. "For NASA to do the kind of things the country asks us to do in exploration, science, research, and technology development, we depend on our contractors to operate at an exemplary level. URS Federal Technical Services Inc. and ATA Engineering Inc. have set the example for all of us."

The Low award demonstrates the agency's commitment to promoting excellence and continual improvement by challenging NASA's contractor community to be a global benchmark of quality management practices.
The award was established in 1985 as NASA's Excellence Award for Quality and Productivity. It was renamed in 1990 in memory of George M. Low, an outstanding leader with a strong commitment to quality products and workforce during his 27-year tenure at the agency. Low was NASA's deputy administrator from 1969 to 1976 and a leader in the early development of space programs.

Albert Einstein Delivers Gear to Expedition 36 Crew

Europe’s Automated Transfer Vehicle-4 (ATV-4) automatically docked Saturday at 10:07 a.m. EDT to the aft-end port of the Zvezda service module. The ATV-4, nicknamed the “Albert Einstein,” launched June 5 atop an Ariane 5 rocket delivering cargo, experiment hardware and supplies. Also aboard the ATV-4 are propellant, water and oxygen and air.

The ATV-4, which launched from a European Space Agency (ESA) launch pad in Kourou, French Guiana, is ESA’s heaviest spacecraft ever. The 13-ton spacecraft delivered 5,465 pounds of dry cargo, experiment hardware and supplies. It is also carrying 1,896 pounds of propellant for transfer to the Zvezda service module, 5,688 pounds of propellant for reboost and debris avoidance maneuver capability, 1,257 pounds of water and 220 pounds of oxygen and air.

Zvezda’s docking port was opened four days earlier when a trash-filled ISS Progress 51 resupply craft undocked. As it was backing away, external cameras on the Progress took photographs of the port for ground controllers to inspect for possible damage on sensors that could have prevented Saturday’s ATV-4 docking.

When the Progress 51 launched in April a Kurs antenna failed to deploy after it reached orbit. Controllers were concerned this could have potentially damaged sensors when it docked to the Zvezda port. The Russian cargo craft is now orbiting Earth for engineering tests before re-entering Earth’s atmosphere Tuesday for a fiery disposal over the Pacific Ocean.

The “Albert Einstein” is scheduled to end its mission at the International Space Station in late October. The trash-filled vehicle will re-enter the Earth’s atmosphere and burn up over the Pacific Ocean. While there, the ATV-4 will provide extra storage space and more habitable volume for the crew. 

NASA’s MMS Achieves Major Mission Milestone

The team completed their first comprehensive performance test a few hours early on observatory number one, an indication that no significant issues were encountered.

This summer, they expect to start environmental testing, which ensures the spacecraft can withstand the extreme conditions of space. Technicians are working to integrate components on the remaining three observatories. Due to launch in late 2014, MMS will investigate how the sun and Earth’s magnetic fields connect and disconnect, explosively transferring energy from one to the other – a fundamental physical process that occurs throughout the universe, known as magnetic reconnection.

Shining a Light on Cool Pools of Gas in the Galaxy

Newly formed stars shine brightly, practically crying out, "Hey, look at me!" But not everything in our Milky Way galaxy is easy to see. The bulk of material between the stars in the galaxy -- the cool hydrogen gas from which stars spring -- is nearly impossible to find.

A new study from the Hershel Space Observatory, a European Space Agency mission with important NASA participation, is shining a light on these hidden pools of gas, revealing their whereabouts and quantities. In the same way that dyes are used to visualize swirling motions of transparent fluids, the Herschel team has used a new tracer to map the invisible hydrogen gas.

The discovery reveals that the reservoir of raw material for making stars had been underestimated before -- almost by one third -- and extends farther out from our galaxy's center than known before.

"There is an enormous additional reservoir of material available to form new stars that we couldn't identify before," said Jorge Pineda of NASA's Jet Propulsion Laboratory, Pasadena, Calif., lead author of a new paper on the findings published in the journal Astronomy and Astrophysics.

"We had to go to space to solve this mystery because our atmosphere absorbs the specific radiation we wanted to detect," said William Langer of JPL, principal investigator of the Herschel project to map the gas. "We also needed to see far-infrared light to pinpoint the location of the gas. For both these reasons, Herschel was the only telescope for the job."

Stars are created from clouds of gas, made of hydrogen molecules. The first step in making a star is to squeeze gas together enough that atoms fuse into molecules. The gas starts out sparse but, through the pull of gravity and sometimes other constricting forces, it collects and becomes denser. When the hydrogen gets dense enough, nuclear fusion takes place and a star is born, shining with starlight.

Astronomers studying stars want to follow this journey, from a star's humble beginnings as a cloud of molecules to a full-blown blazing orb. To do so requires mapping the distribution of the stellar hydrogen fuel across the galaxy. Unfortunately, most hydrogen molecules in space are too cold to give off any visible light. They lurk unseen by most telescopes.

For decades, researchers have turned to a tracer molecule called carbon monoxide, which goes hand-in-hand with the hydrogen molecules, revealing their location. But this method has limitations. In regions where the gas is just beginning to pool -- the earliest stage of cloud formation -- there is no carbon monoxide.

"Ultraviolet light destroys the carbon monoxide," said Langer. "In the space between stars, where the gas is very thin, there is not enough dust to shield molecules from destruction by ultraviolet light."

A different tracer -- ionized carbon - does, however, linger in these large but relatively empty spaces, and can be used to pin down the hydrogen molecules. Researchers have observed ionized carbon from space before, but Herschel has, for the first time, provided a dramatically improved geographic map of its location and abundance in the galaxy.

"Thanks to Herschel's incredible sensitivity, we can separate material moving at different speeds," said Paul Goldsmith, a co-author and the NASA Herschel Project Scientist at JPL. "We finally can get the whole picture of what's available to make future generations of stars."

Resupply Craft Undocks

A trash-filled ISS Progress 51 resupply craft undocked from the aft-end port of the Zvezda service module Tuesday at 9:58 a.m. EDT. Commander Pavel Vinogradov closed the Russian cargo craft’s hatch Monday after a 6-1/2 week stay at the International Space Station.

The Progress 51 delivered 3.1 tons of food, fuel and equipment for the station crew on April 26. It had launched two days earlier from the Baikonur Cosmodrome in Kazakhstan. However, after reaching orbit one of its antennas for the KURS automated rendezvous system did not deploy.

As the Progress cargo craft departed, the ship's external cameras focused on navigational sensors on the Zvezda docking port. Imagery was gathered to confirm the sensors were not damaged when the Progress arrived at the station with one of its navigational antennas folded against its side. Those sensors are required for a new cargo ship to dock properly June 15. 

A Hubble View of NGC 1579: The Trifid of the North

Unlike the venomous fictional plants that share its name, the Trifid of the North, otherwise known as the Northern Trifid or NGC 1579, poses no threat to your vision. The nebula’s moniker is inspired by the better-known Messier 20, the Trifid Nebula, which lies very much further south in the sky and displays strikingly similar swirling clouds of gas and dust.

The Trifid of the North is a large, dusty region that is currently forming new stars. These stars are very hot and therefore appear to be very blue. During their short lives they radiate strongly into the gas surrounding them, causing it to glow brightly. Many regions like the Trifid of the North — named H II regions — are clumpy and strangely shaped due to the powerful winds emanating from the stars within them. H II regions also have relatively short lives, furiously forming baby stars until the immense winds from these bodies blow the gas and dust away, leaving just stars behind.

The image, captured by the NASA/ESA Hubble Space Telescope, shows the bright body of the nebula, with dark dust lanes snaking across the frame. The Trifid of the North glows strongly due to the many stars within it, like young binary EM* LkHA 101. Visible to the bottom right of the image, this binary is thought to be surrounded by a hundred or so fainter and less massive stars, making up a recently formed cluster. It lies behind a cloud of dust so thick that it is almost invisible to astronomers at optical wavelengths. Infrared imaging has now penetrated this dusty veil and is uncovering the secrets of this binary star, which is about five thousand times brighter than our own sun.