Hubble Space Telescope Sees Evidence of Water Vapor Venting off Jovian Moon Europa

NASA’s Hubble Space Telescope has observed water vapor above the frigid south polar region of Jupiter’s moon Europa, providing the first strong evidence of water plumes erupting off the moon’s surface.

Previous scientific findings from other sources already point to the existence of an ocean located under Europa’s icy crust. Researchers are not yet certain whether the detected water vapor is generated by water plumes erupting on the surface, but they are confident this is the most likely explanation.

Europa

This graphic shows the location of water vapor detected over Europa’s south pole that provides the first strong evidence of water plumes erupting off Europa’s surface, in observations taken by NASA’s Hubble Space Telescope in December 2012. Hubble didn’t photograph plumes, but spectroscopically detected auroral emissions from oxygen and hydrogen. The aurora is powered by Jupiter’s magnetic field. This is only the second moon in the solar system found ejecting water vapor from the frigid surface. The image of Europa is derived from a global surface map generated from combined NASA Voyager and Galileo space probe observations.

Should further observations support the finding, it would make Europa the second moon in the solar system known to have water vapor plumes. The findings were published in the Thursday, Dec. 12, online issue of Science Express, and reported at the meeting of the American Geophysical Union in San Francisco.

“By far the simplest explanation for this water vapor is that it erupted from plumes on the surface of Europa,” said lead author Lorenz Roth of Southwest Research Institute in San Antonio, Texas. “If those plumes are connected with the subsurface water ocean we are confident exists under Europa’s crust, then this means that future investigations can directly investigate the chemical makeup of Europa’s potentially habitable environment without drilling through layers of ice. And that is tremendously exciting.”

In 2005, NASA’s Cassini orbiter detected jets of water vapor and dust spewing off the surface of Saturn’s moon Enceladus. Although ice and dust particles subsequently have been found in the Enceladus plumes, only water vapor gases have been measured at Europa so far.

Hubble’s spectroscopic observations provided the evidence for Europa plumes in December 2012. Time sampling of auroral emissions measured by Hubble’s imaging spectrograph enabled the researchers to distinguish between features created by Jupiter’s magnetospheric particles and local enhancements of gas, and to also rule out more exotic explanations such as serendipitously observing a rare meteorite impact. The imaging spectrograph detected faint ultraviolet light from an aurora, powered by Jupiter’s intense magnetic field, near the moon’s south pole. Atomic oxygen and hydrogen produce a variable auroral glow and leave a telltale sign that they are products of water molecules being broken apart by electrons along magnetic field lines.

“We pushed Hubble to its limits to see this very faint emission. These could be stealth plumes, because they might be tenuous and difficult to observe in the visible light,” said Joachim Saur of the University of Cologne in Germany. Saur, who is principal investigator of the Hubble observation campaign, co-wrote the paper with Roth. Roth suggested long cracks on Europa’s surface, known as lineae, might be venting water vapor into space. Cassini has seen similar fissures that host Enceladus’ jets.

The Hubble team found that the intensity of Europa’s plumes, like that Enceladus’s plumes, varies with the moon’s orbital position. Active jets have been seen only when Europa is farthest from Jupiter. But the researchers could not detect any sign of venting when Europa is closer to Jupiter.

One explanation for the variability is these lineae experience more stress as gravitational tidal forces push and pull on the moon and open vents at larger distances from Jupiter. The vents are narrowed or closed when the moon is closest to the gas giant planet.

“The apparent plume variability supports a key prediction that Europa should tidally flex by a significant amount if it has a subsurface ocean,” said Kurt Retherford, also of Southwest Research Institute.

Europa’s and Enceladus’ plumes have remarkably similar abundances of water vapor. Because Europa has roughly 12 times more gravitational pull than Enceladus, the vapor, whose temperature is measured at minus 40 degrees Celsius, does not escape into space as it does at Enceladus. Instead, it falls back onto the surface after reaching an altitude of 125 miles, according to the Hubble measurements. This could leave bright surface features near the moon’s south polar region, the researchers hypothesize.

“If confirmed, this new observation once again shows the power of the Hubble Space Telescope to explore and opens a new chapter in our search for potentially habitable environments in our solar system,” said John Grunsfeld, an astronaut who participated in Hubble servicing missions and now serves as NASA’s associate administrator for science in Washington, D.C. “The effort and risk we took to upgrade and repair the Hubble becomes all the more worthwhile when we learn about exciting discoveries like this one from Europa.”

Europa

This is an artist’s concept of a plume of water vapor thought to be ejected off of the frigid, icy surface of the Jovian moon Europa, located 500 million miles from the Sun. Hubble Space Telescope spectroscopic measurements lead scientists to calculate that the plume rises to an altitude of 125 miles and then probably rains frost back onto the moon’s surface. Previous findings already point to a subsurface ocean under Europa’s icy crust.

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National Space Society Congratulates SpaceX on First Successful GEO Transfer Mission

The Washington DC-based National Space Society (NSS) congratulates Space Exploration Technologies (SpaceX) on the successful launch of the SES-8 telecommunications satellite. It was launched Tuesday, December 3, 2013 from Space Launch Complex 40 (SLC-40) at the Cape Canaveral Air Force Station at 5:41 PM Eastern Time.

The SES-8 is a GEOStar-2 satellite built by Orbital Sciences. The hybrid Ku- and Ka-band spacecraft weighs 3,138 kg (6,918 lbs) and will provide communications coverage of the South Asia and Asia Pacific regions.

This is the first mission to geo-synchronous orbit for SpaceX, and the second flight of the Falcon 9 v1.1. The upgraded version of the Falcon 9 has 60% more thrust than the Falcon 9 v1.0, and can loft payloads of up to 4,950 kg (10,690 lb) to geostationary transfer orbit.

Bruce Pittman, NSS Senior Vice President, said, “This milestone injects a new US competitor into the international commercial satcom launch market, and is an important step toward lowering the cost of access to space, which in turn will help drive space development and settlement.”

This flight of the Falcon v1.1 represents a major step forward commercially for SpaceX, and also demonstrates progress toward the certification of the Falcon 9 for Department of Defense payloads. Critical to geostationary transfer missions, for the first time the upgraded Falcon 9 second stage re-ignited for a 5-minutes 20-seconds burn to put the SES-8 into the correct orbit. SES is the world’s second largest telecommunications satellite company, fielding 54 geostationary satellites.

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SpaceX Successfully Completes First Mission to Geostationary Transfer Orbit

Space Exploration Technologies (SpaceX) has successfully completed its first geostationary transfer mission, delivering an SES-8 satellite to its targeted 295 x 80,000 km orbit.  Falcon 9 executed a picture-perfect flight, meeting 100% of mission objectives.

Falcon 9 lifted off from Space Launch Complex 40 (SLC-40) at 5:41 PM Eastern Time on December 3.  Approximately 185 seconds into flight, Falcon 9’s second stage’s single Merlin vacuum engine ignited to begin a five minute, 20 second burn that delivered the SES-8 satellite into its parking orbit. Eighteen minutes after injection into the parking orbit, the second stage engine relit for just over one minute to carry the SES-8 satellite to its final geostationary transfer orbit.  The restart of the Falcon 9 second stage is a requirement for all geostationary transfer missions.

“The successful insertion of the SES-8 satellite confirms the upgraded Falcon 9 launch vehicle delivers to the industry’s highest performance standards,” said Elon Musk, CEO and Chief Designer of SpaceX.   “As always, SpaceX remains committed to delivering the safest, most reliable launch vehicles on the market today.  We appreciate SES’s early confidence in SpaceX and look forward to launching additional SES satellites in the years to come.”

The mission marked SpaceX’s first commercial launch from its central Florida launch pad and the first commercial flight from the Cape Canaveral Air Force Station in over four years.  SpaceX has nearly 50 launches on manifest, of which over 60% are for commercial customers.

This launch also marks the second of three certification flights needed to certify the Falcon 9 to fly missions for the U.S. Air Force under the Evolved Expendable Launch Vehicle (EELV) program. When Falcon 9 is certified, SpaceX will be eligible to compete for all National Security Space missions.

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Roadmap to Space Settlement 2014 International Student Art Contest

The National Space Society (NSS) is looking for student artists to create illustrations for the NSS Roadmap to Space Settlement. Submitted artwork should REALISTICALLY illustrate one of this year’s two themes: Asteroid Settlement or Building a Space Settlement.


1. Asteroid Settlement

(Milestone 18)

“Asteroid Settlement” challenges students to design a space settlement on or in an asteroid or several asteroids. Asteroids can be located in many places in our solar system and can have many different types of orbits. Some have near-planet orbits, like those that regularly pass by Earth or Mars. Others stay in the asteroid belt. Asteroids also offer valuable resources and can be used as mining installations. To learn more about asteroids click here.


2. Building a Space Settlement

(Milestones 13, 17, 18, or 19)

“Building a Settlement” challenges students to think about how humans will build either orbital space settlements or surface settlements that are on or beneath the surface of the Moon or Mars. What tools and equipment will be used? How will astronauts do the physical building? Will scaffolding be needed? Then, students should take their ideas and interpret them into original works of visual art that depict the actual construction of their settlement.

All full-time students at any grade level between the ages of 13 and 25 are eligible. The deadline for submissions is March 16, 2014. Original artwork from entries submitted to the NSS/NASA Space Settlement Design Contest (including previous years) is especially encouraged.

See our contest web pages for information about prizes and submission requirements. Below is an example of art work that illustrates both of this year’s themes in a single image.

Bryan Versteeg, spacehabs.com
Image: Bryan Versteeg, spacehabs.com

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National Space Society Position on Space Solar Power in Economist Magazine Debate

The Economist magazine has conducted an open, on-line forum on the topic, “Can Solar Energy Save the World,” which concluded on Friday, November 8, 2013. The Washington DC-based National Space Society (NSS) has voted “YES” in this debate.

NSS urges that the European Union (EU) allow Space Solar Power to be given equal treatment with other sources of renewable energy as part of the European system of feed-in tariffs, which have worked for ground-based solar power to create a viable new market for energy. Feed-in tariffs are a guaranteed offer of a price and a market to generators of renewable electricity and not a tax on imported goods.

Dr. Paul Werbos, Chair of the NSS Policy Committee, said “What are some good strategies to really help develop space resources? The best strategy is one which tries to ‘kill two or three birds with one stone.’ And so, at nss.org/EU [and reproduced below], you will see a new position statement aimed at three goals — to create new jobs where they are badly needed in the EU, to accelerate low-cost forms of solar farms on Earth, and to set the wheels in motion for serious market-oriented investment in space solar power.”

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National Space Society Statement on Space Solar Power (SSP) and Feed-In Tariffs

Germany has long had a feed-in tariff system (EEG), which, among other things, guarantees a market and a price for large scale wind and solar farms. Some critics argue that these should simply be abolished, because of the damage they claim has been done to the German economy; however, the German economy seems to be doing quite well, compared to other major developed economies on Earth. The feed-in tariff is not a tax or a tariff like the tariffs we pay for imported goods; it is essentially just a guaranteed offer of a price and a market to generators of renewable electricity.

Just as we urge opening up the launch services market to more competition and new technologies, the National Space Society (NSS) also urges opening up the European electricity market to more large sources of renewable electricity. For the sake of lower energy prices, greater competition and greater economic stability, we propose that the feed-in tariff for large solar farms be extended to all solar farms in the European Union, and also to all rectennas to be located in the European Union supplying electricity from energy beamed from space.

Even just a year ago, the possibility seemed to be remote that industry might build such rectennas; however, the new design and analysis at www.nasa.gov/pdf/716070main_Mankins_2011_PhI_SPS_Alpha.pdf, combined with potentially useful efforts on key technologies to reduce the cost of access to space such as the DARPA XS-1 program and private sector efforts like SpaceX and others, suggest that we should not rule out such a development.

In the market based approach, we do not choose which technology we believe in more; rather, we offer the same incentive to all forms of benign solar energy anywhere in the EU, and let suppliers decide for themselves what to invest in and where. A firm price guarantee can be very useful in stimulating the kind of private sector investment and jobs which all major economies need today. For the EU, especially, a new supply of renewable electricity would be a great thing for consumers, who otherwise would be paying for more expensive offshore wind or imported natural gas — so long as solar suppliers on Earth or in space can meet the offer price. As in the past, this should be a standing law, allowing suppliers to decide on their own schedule for deployment.

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Near-Extinction Event in 1883 Indicates Threat from Space May Be Greater Than We Thought

NSS Board of Directors member Al Globus reports:

We have known for some time that Near Earth Objects (NEOs) are a serious threat to civilization. We also know, more-or-less, how to reduce that threat significantly at very reasonable cost. We have thought, however, that comets were much less of a threat which is a good thing, as they are much harder to deal with.

Unfortunately, it appears that a large comet may have missed Earth by only a few hundred kilometers in 1883. If the comet fragments “had collided with Earth we would have had 3275 Tunguska events in two days, probably an extinction event” [MIT Review].

We know that comet Comet Shoemaker–Levy 9 struck Jupiter in 1994. Comet C/2013 A1 is currently believed to have a 1-in-8,000 chance of striking Mars in October 2014, passing within 120,000 km. That’s close enough to endanger satellites orbiting the Red Planet.

It appears that either we are in a period of unusually frequent close encounters with comets, or cometary threats to our existence are fairly common. Defense against comets is much more difficult than against NEOs. Comets spend most of their lifetime in the far outer portions of the solar system where they are hard to observe, and when they do come through the inner solar system they are usually moving very fast, giving little time to respond even if we detect the threat before a collision.

NASA spends about $20 million/year of NEO detection, most of which pays for ground telescopes. For one percent of NASA’s budget ($160 million per year) we could have an absolutely outstanding NEO detection and deflection program. The immediate need is for an infra-red space telescope to find most of them, for example, the B612 Sentinel. As NEO defense is essential to our survival, it is a little silly, and potentially criminally negligent, that we spend orders of magnitude more money on very interesting, but much less important, projects.

Cometary defense, however, is not cheap. Detecting a cometary threat in time to do something about it requires extremely capable telescopes. Comets are dirty snowballs which tend to break into pieces making them very difficult to deflect. If further analysis finds comets to be a significantly greater threat than currently believed, be prepared to open the checkbook.

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Clues to the SpaceX “Big Rocket”

NSS Board of Directors member John K. Strickland reports:

A major clue to the “Big Rocket” from SpaceX (bigger than the Falcon Heavy) was recently revealed when an agreement with the Stennis Space Center to test the Raptor engine showed that its vacuum thrust is almost 600,000 lbs. We had been expecting a much smaller engine for upper stage use. This means the methane oxygen engine could be used on both the first and second stages of the Big Rocket.

We could assume that the same configuration as the Falcon 9 is used, with the upper stage having a single engine with a nozzle extension to allow greater thrust in space, and with the engine-out capability of the 9 engine Falcon 9, duplicating its basic eight-and-one first stage configuration with the new engines. This would mean that the Big Rocket’s total thrust would be about 5.4 million lbs of thrust (about 2500 tons at sea level), more than 2/3 that of the Saturn V, and with more efficient engines to boot.

Methane engines have a higher specific impulse than the RP1 and oxygen used in the Merlins. The new engine will also use combined cycle or closed loop combustion, a significant improvement over the existing Merlin engine design. This means the engines can produce more thrust with the same amount of fuel, part of Musk’s deliberate process of “continuous improvement.”

One observer wondered if the rocket could use 11 such engines, 10 in a circle and one in the middle. This would depend on the width and spacing requirements of both the engines and the first stage circumference. With this configuration, the total thrust would be 6.6 million lbs.

This means that the Big Rocket is not just a publicity gambit, as some critics have alleged. The 27 foot diameter given for the Big Rocket now makes sense. Such a rocket could launch cargo or vehicles up to 40 feet in diameter in a reverse fairing.

An article in the Oct 28 edition of Space News says that parts for the Raptor methane-oxygen engine will be tested at Stennis early in 2014. This indicates that Raptor development is well under way. It is unclear how long it will take to build a new test stand for a 600,000 lb thrust engine, six times what current stands there can test.

The engine is described as “highly reusable.” One would then think that the HLV Big Rocket it is designed to work with would also be “highly reusable.” The SpaceX spokesperson said that it was the first in what would be a family of engines. Based on the known development times for the Falcon family, the Big Rocket should be ready to fly (and land for another flight) well before 2020.

It is unclear if such engines will be tested at any other locations, and also what the schedule might be for the actual rockets that would use them. A short, fat booster is structurally much easier to get down into the troposphere intact than a long skinny booster like the Falcon 9.

References:

http://www.nasaspaceflight.com/2013/10/spacex-press-abort-test-raptor-engine/

http://www.spacenews.com/article/launch-report/37859spacex-could-begin-testing-methane-fueled-engine-at-stennis-next-year

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Participate in the International SunSat Competition – Over $40,000 in Prizes Will Be Awarded!

The National Space Society in affiliation with Ohio University is pleased to announce that the International SunSat Design Competition is now registering competitive teams.  This two-year project is designed to link global scientific communities with university-based (and other) digital media labs for the purposes of advancing knowledge of space-based solar power satellites (SunSats) and illustrating their many Earth-energy applications.

International SunSat Competition

If you are a space scientist, engineer, academic, business or digital media professional with an idea for moving space solar power closer to implementation, consider forming a team to join in this effort. And please forward this message to others.

In the first cycle of this competition, two First Place prizes of $10,000 and three Second Place prizes of $5,000 are expected to be awarded at the May 2014 International Space Development Conference in Los Angeles. For registered teams successfully completing the Feb. 2014 "significant progress point," an additional $1,000 incentive can be earned, and $1,000 travel assistance will be awarded to winners.

Winning entries of 2014 and 2015 will be published in the Space Journal as Issue No.18: Top SSP Designs.

To learn more, check  the SunSat Visualization Guidebook and look at the SunSat Design Competition website.

To see where the idea of a SSP Design Competition came from, take a look at SpaceJournal Issue No.16: Solar Power Satellites.

To see how Ohio University’s Game Research in Immersive Design (GRID) Lab, with the help of Georgia Institute of Technology, University of North Dakota and others in academia, has experimented with making the advanced science and technology concepts of SSP more accessible to the public, view SpaceJournal Issue No.17: Creative Visualization of Space Solar Power.

This competition is managed by Ohio University, the host institution for the Online Journal of Space Communication, but guided and juried by members of the National Space Society and the Society of Satellite Professionals International.

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Grasshopper Takes Final Leap

From SpaceX: On Monday, October 7th, Grasshopper completed its highest leap to date, rising to 744m altitude. The view above is taken from a single camera hexacopter, getting closer to the stage than in any previous flight.

Grasshopper is a 10-story Vertical Takeoff Vertical Landing (VTVL) vehicle designed to test the technologies needed to return a rocket back to Earth intact. While most rockets are designed to burn up on atmosphere reentry, SpaceX rockets are being designed not only to withstand reentry, but also to return to the launch pad for a vertical landing. The Grasshopper VTVL vehicle represents a critical step towards this goal.

Grasshopper consists of a Falcon 9 rocket first stage tank, Merlin 1D engine, four steel and aluminum landing legs with hydraulic dampers, and a steel support structure.

SpaceX says this is the last Grasshopper flight and “next up will be low altitude tests of the Falcon 9 Reusable (F9R) development vehicle in Texas followed by high altitude testing in New Mexico.”

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Cygnus spacecraft docks with ISS

The Orbital Sciences Cygnus spacecraft was grappled by the International Space Station’s robotic arm at 7:01 (EDT) this morning after a flawless approach and in-orbit demonstration sequence. Cygnus will now be guided to the berthing port on the nadir side of the Harmony node, where the Expedition 37 crew will complete the installation. That process is expected to be complete late this morning. Cygnus will remain attached to the ISS for 30 days before departing with disposal cargo on board.

This makes Orbital Sciences the second private company to successfully complete the COTS program and dock a cargo spacecraft with the ISS. The Cygnus spacecraft is not designed with return capability nor to carry astronauts.

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