Find us on Google+

Launches from Kourou temporarily suspended by social unrest

by
Launches from Kourou temporarily suspended by social unrest
A barricade outside the Guiana Space Center. Credit: France Guyane

The launch an Ariane 5 rocket with Brazilian and Korean communications satellites that was set for this week has been postponed indefinitely after protesters blocked access to the French Guiana spaceport.

The heavy-lift launcher was scheduled to lift off Tuesday, but widespread protests and a strike by workers from one of Arianespace’s subcontractors prevented the planned rollout of the Ariane 5 to its launch pad Monday.

Arianespace hoped to reschedule the launch for later in the week, but the company announced Thursday that the commercial flight will remain grounded until further notice.

“The evolution of the situation does not permit the restart of operations for the Ariane 5 launch scheduled for today,” Arianespace said in a statement Thursday.

The fully-assembled Ariane 5 rocket, topped by the SGDC and Koreasat 7 communications satellites for the Brazilian government and South Korea’s commercial operator KTsat, are secured inside the spaceport’s final assembly building, officials said.

Arianespace chief executive Stephane Israel tweeted Wednesday that officials will set a new target launch date as soon as possible.

The delay will likely cause Arianespace to push back the following launch from French Guiana. Once the Ariane 5 takes off, a Russian-made Soyuz rocket is next in line at the tropical space base, slated to loft the Boeing-built SES 15 communications satellite into orbit to provide in-flight Internet connectivity for airline passengers, and support government, networking and maritime customers across North America.

SES 15 also hosts a payload for the FAA’s Wide-Area Augmentation System to enhance airline navigation and safety across the United States.

Liftoff of SES 15 was scheduled for April 4, but it takes nearly two weeks to reconfigure the French Guiana spaceport and downrange tracking stations between launches.

File photo of an Ariane 5 rocket ready for rollout from the Guiana Space Center’s final assembly building to the ELA-3 launch zone. Credit: Stephen Clark/Spaceflight Now

Workers from Endel Engie, the company tasked with driving the Ariane 5 rocket from its assembly building to the launch pad at the Guiana Space Center, went on strike Monday and prevented the booster’s rollout. A union representative told French media that the strike was called to reopen wage negotiations.

Labor issues at the spaceport have pushed back launches before, most recently in 2011 when the operators of radar tracking systems in French Guiana went on strike, delaying an Ariane 5 flight by 24 hours.

The Endel Engie strike was part of a wider net of protests this week across French Guiana, a lightly-populated French department on the northeastern coast of South America. France Guyane, a local newspaper, reported Thursday that most businesses in Cayenne, the territory’s capital, were closed and large aircraft were prohibited from landing at the city’s airport.

Some schools in French Guiana were also closed this week, and an Air France flight from Paris to Cayenne turned around over the Atlantic Ocean and returned to France on Thursday.

Local workers are protesting high crime rates, hiring practices and economic conditions in French Guiana, along with the proposed privatization of the Kourou Medical and Surgical Center, or CMCK, in the town closest to the space center.

Protesters set up blockades on roads across French Guiana, including a barrier on the main highway leading into the Guiana Space Center, a facility managed by CNES, the French space agency, with financial support from the European Space Agency.

Protesters at the barrier outside the Guiana Space Center also included workers from a road transport union, who claim they are not receiving sufficient work during construction of ground facilities for the next-generation Ariane 6 rocket, according to France Guyane.

A CNES spokesperson declined to comment on the situation Thursday.

Davy Rimane, general secretary of a French Guiana electricians’ union, said the protest outside the Ariane 5 launch base was symbolic because the French government “only has eyes for the space center,” the French newspaper Le Figaro reported.

France Guyane reported Thursday that the Endel Engie strike was over, but drivers had to be helicoptered into the space center to get past blockades outside the southeastern gate of the spaceport.

The newspaper reported that local officials said there will be no launch until the conflicts are over.

The French government said Thursday that the plan to privatize the Kourou hospital has been suspended, and authorities invited local representatives to meet in Paris on Tuesday to hear their grievances.

Email the author.

Follow Stephen Clark on Twitter: @StephenClark1.

Source: Space Flight


Posted in Space Flight and tagged by with no comments yet.

Trump signs NASA authorization act, Pence to chair National Space Council

by
Trump signs NASA authorization act, Pence to chair National Space Council
President Trump signed the NASA Transition Authorization Act of 2017 on Tuesday, surrounded by members of Congress and astronauts. Credit: NASA/Bill Ingalls

President Donald Trump signed a new NASA authorization bill Tuesday, the first such space policy framework since early in the Obama administration, that largely continues the space agency’s efforts to foster a commercial economy in Earth orbit and explore deep space, with an eventual goal of landing humans on Mars.

The legislation sets high-level goals for NASA and directs the space agency to continue development of the Space Launch System heavy-lift rocket, the Orion crew capsule, and a deep space habitat to house astronauts on voyages beyond Earth orbit.

“I’m delighted to sign this bill,” Trump said in an Oval Office signing ceremony. “It’s been a long time since a bill like this has been signed, reaffirming our national commitment to the core mission of NASA: human space exploration, space science and technology. With this legislation, we support NASA scientists, engineers, astronauts and their pursuit of discovery.”

The NASA Transition Authorization Act of 2017, passed by the Senate and House on Feb. 17 and March 7, is the space agency’s first new authorization signed into law since October 2010. With minor tweaks, the bill maintains NASA’s trajectory toward deep space exploration and commercialization crafted during the Bush and Obama administrations in the aftermath of the space shuttle’s retirement.

Vice President Mike Pence said after Tuesday’s signing that he will chair a newly-chartered National Space Council, a White House-level space policy coordinating committee last active during President George H.W. Bush’s administration.

“In very short order, the president will be taking action to re-launch the National Space Council,” Pence said. “He’s asked me to chair that, as vice presidents have in the past, and we’re going to be bringing together the best and the brightest in NASA, and also in the private sector.”

In addition to maintaining support for the SLS and Orion programs, the authorization act has provisions for a detailed report on NASA’s plans to develop and demonstrate key technologies needed for a human mission to Mars, including a list of precursor missions in cis-lunar space, the region around the moon.

The policy framework calls for NASA to “develop a human exploration roadmap, including a critical decision plan, to expand human presence beyond low Earth orbit to the surface of Mars and beyond, considering potential interim destinations such as cis-lunar space and the moons of Mars.”

Lawmakers wrote in the authorization act that the multibillion-dollar SLS and Orion programs, along with contributions from the private sector, academia and the international community, is the “most practical approach to reaching the moon, Mars and beyond.”

NASA will also commission an independent, non-governmental study on a Mars human space mission that could be launched in 2033, examining the technical and budgetary requirements of such a flight.

The authorization act also supports the International Space Station through at least 2024, with provisions to study a possible extension to 2028 or 2030, and the commercial crew and cargo programs to transport astronauts and supplies to the orbiting research outpost.

“This bill will make sure that NASA’s most important and effective programs are sustained, and orders NASA to continue transitioning activities to the commercial sector, where we have seen great progress,” Trump said.

“I am grateful for the president’s action today which will restore stability and certainty to NASA and the future of the U.S. space program,” said Sen. Ted Cruz, R-Texas.

“It puts us on a dual track,” said Sen. Bill Nelson, D-Florida. “We have the commercial companies going to and from the International Space Station. We have NASA going out and exploring the heavens and going to Mars.”

But Elon Musk, the chief executive of SpaceX, said the bill would do little to accelerate a mission to Mars.

“This bill changes almost nothing about what NASA is doing,” Musk wrote on Twitter. “Existing programs stay in place and there is no added funding for Mars.”

SpaceX’s long-term goal is to send people to Mars, and Musk unveiled an audacious concept last year to begin setting up a habitat on the red planet with commercial interplanetary spaceships and huge rockets, not with the government-backed SLS and Orion.

“Perhaps there will be some future bill that makes a difference for Mars, but this is not it,” he later tweeted.

The bill signed by President Trump on Tuesday authorizes $19.5 billion for NASA in fiscal year 2017, but a separate appropriations bill is required to approve the agency’s budget and determine the level of funding each of NASA’s programs will receive.

The legislation questions the utility of NASA’s Asteroid Redirect Mission, a concept that would send a robotic spacecraft to pluck a large boulder off a near-Earth asteroid and return the sample to the vicinity of the human for visits by astronauts.

Congress has never fully supported the idea, and independent reviews have concluded the technologies that would be validated on such a mission, such as high-power solar-electric propulsion, could be tested in other ways before a crewed expedition to Mars.

In the authorization act, lawmakers ordered NASA to write a report on alternatives to the Asteroid Redirect Mission for demonstrating such technologies.

The White House’s fiscal year 2018 budget blueprint released earlier this month calls for the cancellation of the Asteroid Redirect Mission.

Lawmakers also authorized NASA to provide for lifetime medical monitoring and treatment of former astronauts for conditions potentially associated with their service in the space program.

NASA’s robotic missions also received support in the authorization act, which specifically identified the James Webb Space Telescope, the Wide Field Infrared Survey Telescope, the Mars 2020 rover and a probe to study Europa as top priorities. Congress also called for NASA to continue working on a “balanced” set of small, medium and large robotic science missions.

The space agency’s senior reviews, which decide which of NASA’s extended science missions should continue to receive federal funding, will occur every three years under the provisions of the authorization act, not every two years as they do now. Scientists say the change will give them more time analyzing data and operating missions, instead of writing proposals.

Some lawmakers criticized the authorization act for not specifically addressing NASA’s Earth science and heliophysics programs, but it garnered bipartisan support, passing the Senate by unanimous consent and the House with a voice vote.

Other parts of the authorization act direct NASA to identify spacecraft that could be aided by satellite servicing missions, and to solicit and review concepts to remove space junk from orbit.

Email the author.

Follow Stephen Clark on Twitter: @StephenClark1.

Source: Space Flight


Posted in Space Flight and tagged by with no comments yet.

Rosetta’s comet shows scars from swing through inner solar system

by
Rosetta’s comet shows scars from swing through inner solar system
This series of before-and-after views show the area of the Aswan cliff, which collapsed in July 2015 in conjunction with a strong outburst of gas and dust, seen by Rosetta in the long-range view at center. The same boulder is circled in all images to guide the eye when viewing the scene from different orientations. Credit: ESA/Rosetta/NavCam; ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Scientists examining imagery from Europe’s Rosetta spacecraft have logged numerous changes to the face of comet 67P/Churyumov-Gerasimenko, from collapsing cliffs to a growing crack through the comet’s neck that could foretell the eventual unraveling of the city-sized icy world.

The changes occurred as the comet traveled along the portion of its orbit closest to the sun, and comet 67P responded to the hotter conditions with dramatic outbursts of dust and ice, forcing the Rosetta spacecraft to move to a standoff position more than 100 miles away to keep out of the haze cloud.

Researchers said this week they have conclusively linked one of the outbursts to the collapse of a cliff on the comet, and scientists revealed other changes in the comet’s appearance noticed after its passage near the sun in 2015.

The European Space Agency’s Rosetta spacecraft arrived at the comet in August 2014, dropped a short-lived robot named Philae to its surface in November of that year, and spent more than two years observing the object’s behavior, completing the first long-term close-up exploration of a comet in history.

Ground controllers intentionally crash-landed Rosetta on the comet in September 2016, ending the mission as the probe’s power and fuel resources began to wane.

Scientists published two papers Tuesday in the journals Science and Nature Astronomy, describing the landscapes Rosetta saw before and after its perihelion, the point in its nearly six-and-a-half-year orbit nearest to the sun.

At perihelion in August 2015, comet 67P was about 115 million miles (186 million kilometers) from the sun, a point between the orbits of Earth and Mars

Artist’s concept of the Rosetta spacecraft during its descent to comet 67P/Churyumov-Gerasimenko. Credit: ESA/ATG medialab

The observations yielded new discoveries about how comets evolve, with powerful eruptions and outgassing that give them their fuzzy appearance through telescopes. Scientists believe comets contain primordial materials left over from the formation of the solar system, and they can glean important insights into the origins of the planets, and perhaps life itself, through studying the frozen mini-worlds.

Presenting their results at a press conference Tuesday at the Lunar and Planetary Science Conference near Houston, scientists showed images illustrating how the face of the comet changed during Rosetta’s two-year exploration. They identified eroded cliff walls, a lengthening crack between the two lobes of the duck-shaped comet, a giant rolling boulder, transient pitted patterns, and recurring ripples in the comet’s dune-like dusty veneer.

Before Rosetta, scientists only had comet imagery from high-speed flybys, and space missions had encountered just a single comet — Tempel 1 — more than once, revealing evidence of an eroding ridge on its surface.

“We had limited information on what other changes might happen on a comet — when do they actually start to kick in, and how long are these activities going on?” said Ramy El-Maarry, lead author of the paper published in Science and a member of the Rosetta science team at the University of Colorado, Boulder. “Also, (the) rate of change was something that we didn’t have information about before Rosetta.”

Maurizio Pajola, an astronomer at NASA’s Ames Research Center, said his team was able to connect a powerful outburst seen by Rosetta’s cameras on July 10, 2015, with the collapse of a cliff on the comet, the first time scientists have been able to make such a linkage.

“Rosetta’s images already suggested that cliff collapses are important in shaping cometary surfaces, but this particular event has provided the missing ‘before–after’ link between such a collapse, the debris seen at the foot of the cliff, and the associated dust plume, supporting a general mechanism where comet outbursts can indeed be generated by collapsing material,” said Matt Taylor, ESA’s Rosetta project scientist, in a statement.

“This is a really important point because we have different ideas on how outbursts can happen on the surface of a comet,” Pajola said Tuesday at the science conference in Texas. “There are different reasons, but this is one of the possibilities, and we can really validate it.”

Experts calculated that the outburst came from the comet’s Seth region, home to a cliff first seen in September 2014, soon after Rosetta drew close to comet 67P. The scarp had a 230-foot-long (70-meter), 3-foot-wide (1-meter) fracture near its edge.

Pajola and his team compared two images of the cliff captured July 4 and July 15. The first showed the feature — named the Aswan cliff — intact with the previously-observed crack, but the cliff’s shape and appearance had changed dramatically by the time Rosetta returned to take the second picture.

“We were like Sherlock Holmes,” Pajola said of the detective work. “We were trying to go back in time and trying to see when this cliff was collapsing.”

Anaglyph images of the Aswan cliff showing the overhang before (left) and after (right) it collapsed. The anaglyph images were prepared for evaluating the volume of overhang that detached in July 2015. Note the orientation between the two images is different. The images are best viewed using red–green/blue 3D glasses. ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; M. Pajola

Once comet 67P’s activity subsided as it headed toward the outer solar system again, Rosetta returned to the vicinity of the nucleus to record high-resolution snapshots of the surface, revealing the base of the ridge to be littered with boulders the size of cars that fell down the 440-foot (134-meter) face of the cliff.

Pajola said nearly 800,000 cubic feet (22,000 cubic meters) of rock, dust and ice fell away during the collapse, equivalent to roughly nine Olympic-sized swimming pools.

“The cliff collapse was not just a falling apart in two or three big pieces, but it was crumbling down, and while it was crumbling down, there was this outburst,” Pajola said.

Scientists estimate about 1 percent of the collapsed material was lost to space, escaping the comet’s tenuous gravity field and generating the bright cloud seen at the time by Rosetta.

According to Pajola, the cliff was in direct sunlight for only 90 minutes during each 12.4-hour day on the comet. But data from Rosetta indicated the surface temperature at the Aswan cliff rose from around minus 220 degrees Fahrenheit (minus 140 degrees Celsius) to 122 degrees Fahrenheit (50 degrees Celsius) in less than 20 minutes during each exposure to sunlight, a severe gradient not seen on other solar system bodies.

Scientists ruled out a sudden explosion triggered by solar heating because the collapse occurred when the Aswan cliff was in darkness. Instead, Pajola described how repeated thermal cycles could eat away at the ice buried inside the fracture at the top of the cliff.

“Thermal cracking can really propagate into the interior of the cliff,” Pajola said. “You’ve got to consider that this area was already damaged. It was already fractured before the cliff collapse.”

The ice inside the cliff acted like a glue holding the scarp together, and as heat reached inside the crack, the ice would have sublimated, or vaporized from a solid into a gas.

“All of a sudden, this glue is being lost,” Pajola said. “Sublimation happens, then there is this erosion, and since we are talking about an overhanging cliff, this block just freely falls down, and while it’s falling down, it’s crumbling apart.”

Scientists saw bright outcrops on the Aswan cliff after it caved in. Scientists interpret the markings, which were at least six times brighter than the rest of the comet, as water ice brought to the surface by the collapse.

The bright features dimmed in the months after the event as sunlight vaporized the water ice.

“We are seeing the fresh interior, and we are seeing that water ice is inside the comet,” Pajola said.

The collapsed cliff was just one of many changes on the comet outlined by El-Maarry and his co-authors in Science.

A prominent 1,640-foot-long (500-meter) crack in the nucleus’s neck grew by at least 100 feet (30 meters) during Rosetta’s time at comet 67P, and a new nearly 500-foot-long (150-meter) fracture also appeared, El-Maarry said.

These images show the growth of a 1,600-foot (500-meter) crack in the comet’s next over the course of Rosetta’s mission, and the appearance of a new fracture nearby. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Scientists attribute the large-scale fractures to the comet’s faster spin rate from torque introduced by jets activated by the warmer conditions at perihelion.

“The comet actually speeds up due to this activity around perihelion, and when it speeds up, models have shown that you’re going to introduce stresses into that body as it rotates, which tend to concentrate in the neck region,” El-Maarry said. “So these stresses would lead to the development of new fractures, or the evolution of pre-existing ones.”

By the end of the mission, the Rosetta team determined that comet 67P completed one rotation 21 minutes faster than it did when the spacecraft pulled alongside the comet in 2014.

“The comet probably is eventually going to split up as it’s going to speed up more and more,” El-Maarry said. “We have evidence of that, but when is that exactly going to happen, we, of course, have no idea.”

Scientists identified two boulders that moved during Rosetta’s campaign at the comet. One of the objects, roughly the size of a truck, moved around 50 feet (15 meters) between March 2015 and June 2016.

A much larger boulder, around 100 feet (30 meters) in size with a mass of 282 million pounds (130 million kilograms), trekked a distance more than the length of a football field. Rosetta’s science team believes the boulder was either lifted by a forceful outburst, or surface material at the base of the object holding it in position eroded away, allowing it to roll downslope.

With the weak gravity at comet 67P, the force required to lift the boulder would be equivalent to the forced needed to hoist a 550-pound (250-kilogram) object on Earth, according to El-Maarry.

These before-and-after images show the movement of a 100-foot (30-meter) boulder on comet 67P. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Rosetta also saw up to 10 feet (3 meters) of dust and other surface material removed in the comet’s Imhotep plains, excavating circular features and boulders that were only partially visible at the start of the mission’s campaign at comet 67P.

El-Maarry said the comet lost, on average, about 3 feet (1 meter) of surface material globally, but the loss was uneven across the nucleus, with some regions seeing much more erosion than others.

Several scarps on the comet retreated by up to 150 feet (50 meters), moving at a rate of several feet per day at peak heating near perihelion.

“Scarp retreats were observed before on Comet Tempel 1, inferred by comparing images taken during flybys of the comet by NASA’s Deep Impact in 2005, and Stardust-NExT in 2011,” El-Maarry said. “What we were able to do with Rosetta was to monitor similar changes continuously, and at a higher resolution. Our observations additionally tell us that scarp retreat seems to be a common process on comets, specifically in smooth-looking deposits.”

Rosetta observed transient changes, including the appearance of pitted patterns in 2015 that were erased by June 2016.

Recurrent ripples in the comet’s Hapi region were spotted early in Rosetta’s mission in late 2014, but the dune-like features disappeared by April 2015 to be replaced by a mysterious circular marking in mid-2015. By December 2015, the circular feature was gone, and the ripples were back.

“These pesky features just don’t want to go away, and they seem to be intent in appearing on the comet in exactly the same location,” El-Maarry said.

Scientists think the ripples are formed as sublimating gas coming from the comet’s northern neck flows over the Hapi region.

“It will act a little bit like wind,” El-Maarry said. “We think that the peculiar geometry of the comet, because it has this concave shape at the neck, is going to funnel this gas horizontally across the neck region, and that would be the reason why you’re creating the ripples specifically at that particular location.”

Most of the comet’s changes are driven by sunlight and heating, El-Maarry said, but the icy object did not undergo a large-scale makeover.

“We didn’t get fireworks, comet-splitting, things breaking up, and massive depressions being created,” El-Maarry said. “So we didn’t see major changes in the comet’s landscape.

“We’ve seen cliff collapses, but nothing that has changed the landscape of the comet,” he said. “That is telling us something. It means that we had much more activity earlier in the comet’s lifetime.”

Comet 67P was discovered in 1969 by Soviet astronomers Klim Churyumov and Svetlana Gerasimenko. An analysis of the comet’s orbit showed that an encounter with Jupiter in 1959 put it on its current trajectory, which takes comet 67P more than twice as close to the sun than during the previous century, placing it in a much warmer environment conducive to an increase in outbursts and other activity.

El-Maarry said scientists have little information about the behavior of the comet when it first entered the inner solar system. The “real fireworks” could have subsided over the last few decades as sunlight blew off more volatile constituents like carbon dioxide, he said.

Email the author.

Follow Stephen Clark on Twitter: @StephenClark1.

Source: Space Flight


Posted in Space Flight and tagged by with no comments yet.