Space and astronomy news
06/26/2016 11:22 AM
Good News, Martian Colonists Can Eat All the Radishes They Want
When your stated purpose is to send settlers to Mars by 2026, you're sure to encounter a lot of skepticism. And that is exactly what Dutch entrepreneur Bas Lansdorp has been dealing with ever since he first went public with MarsOne in 2012. In fact, in the past four years, everything from the project's schedule, technical and financial feasibility, and ethics have been criticized by scientists, engineers and people in the aerospace industry.
However, Lansdorp and his organization have persevered, stating that they intend to overcome all the challenges in sending people on a one-way trip to the Red Planet. And in their most recent statement, MarsOne has announced that they have addressed the all-important issue of what their settlers will eat. In an experiment that feels like it was ripped from the The Martian, MarsOne has completed testing different types of crops in simulated Martian soil, to see which ones could grow on Mars.
Located in the Dutch town of Nergena, MarsOne maintains a glasshouse complex where they have been conducting experiments. These experiments took place in 2013 and 2015, and involved Martian and Lunar soil simulants provided by NASA, along with Earth soil as a control group.
Using these, a team of ecologists and crop scientists from the Wageningen University & Research Center have been testing different kinds of seeds to see which ones will grow in a Lunar and Martian environment. These have included rye, radishes, garden cress and pea seed. And earlier this year, they added a crop of tomatoes and potatoes to the mix.
As Dr. Wieger Wamelink, the ecologist who led the experiments, told Universe Today via email:
"We started our first experiment in 2013 (published in Plos One in 2014) to investigate if it was possible to grow plants in Mars and moon soil simulants. We assume that plants will be grown indoors, because of the very harsh circumstances on both Mars and moon, very cold, no or almost no atmosphere and way to much cosmic radiation. That first experiment only had a few crops and mostly wild plants and clovers (for nitrogen binding from the atmosphere to manure the soil)."
After confirming that the seeds would germinate in the simulated soil after the first year, they then tested to see if the seeds from that harvest would germinate in the same soil to create another harvest. What they found was quite encouraging. In all four cases, the seeds managed to germinate nicely in both Martian and Lunar soil.
"Our expectation were very low," said Wamelink, "so we were very surprised that on the Mars soil simulant plants grew rather well and even better than on our nutrient poor control earth soil. There were also problems, the biggest that it was very difficult to keep the soil moist and that though on Mars soil simulant there was growth it was not very good, i.e. the amount of biomass formed was low."
And while they didn't grow as well as the control group, which was grown in Earth soil, they did managed to produce time and again. This was intrinsic to the entire process, in order to make sure that any crops grown on Mars would have a full life-cycle. Being able to grow crops, replant seeds, and grow more would eliminate the need to bring new seeds for every crop cycle, thus ensuring that Martian colonists could be self-sufficient when it came to food.
In 2015, they conducted their second experiment. This time around, after planting the seeds in the simulated soil, they added organic matter to simulate the addition of organic waste from a previous crop cycle. And on every Friday, when the experiments were running, they added nutrient solution to mimic the nutrients derived from fecal matter and urine (definite echoes of The Martian there!).
Once again, the results were encouraging. Once again, the crops grew, and the addition or organic matter improved the soil's water-holding capacity. Wamelink and his team were able to harvest from many of the ten crops they had used in the experiment, procuring another batch of radishes, tomatoes and peas. The only crop that did poorly was the batch of spinach they had added.
This year, the team's experiments were focused on the issue of food safety. As any ecologist knows, plants naturally absorb minerals from their surrounding environment. And tests have shown that soils obtained from the Moon and Mars show concentrations of heavy metals and toxins - such as arsenic, cadmium, copper, lead, and iron (which is what gives Mars its reddish appearance). As Wamelink described the process:
"Again we have ten crops, but slightly different crops from last year; we included green beans and potatoes (best food still and Mark Watney also seems to love potatoes). Also repeated was the addition of organic matter, to mimic the addition of the plant parts that are not eaten from a previous growth cycle. Also new is the addition of liquid manure, to mimic the addition of human faeces... We know that both Mars and moon soil simulants contain heavy metals, like led, copper, mercury and chrome. The plants do not care about this, however when they end up in the eaten parts then they could poison the humans that eat them. There we have to test if it is safe to eat them."
And again, the results were encouraging. In all cases, the crops showed that the concentrations of metals they contained were within human tolerances and therefore safe to eat. In some cases, the metal concentrations were even lower than that found those grown using potting soil.
"We now tested four species we harvested last year as a preliminary investigation and it shows that luckily there are no harmful quantities present in the fruits, so it is safe to eat them," said Wamelink. "We will continue these analyses, because for the FDA they have to be analysed in fresh fruits and vegetables, where we did the analyses on dried material. Moreover we will also look at the content of large molecules, like vitamins, flavonoids (for the taste) and alkaloids (for toxic components)."
However, the Wageningen UR team hopes to test all ten of the crops they have grown in order to make sure that everything grown in Martian soil will be safe to eat. Towards this end, Wageningen UR has set up a crowdfunding campaign to finance their ongoing experiments. With public backing, they hope to show that future generations will be able to be self-sufficient on Mars, and not have to worry about things like arsenic and lead poisoning.
As an incentive, donors will receive a variety of potential gifts, which include samples of the soil simulant used for the experiment. But the top prize, a a dinner based on the harvest, is being offered to people contributing €500 ($555.90 USD) or more. In what is being called the first "Martian meal" this dinner will take place once the experiment is complete and will of course include Martian potatoes!
Looking ahead, Wamelink and his associates also hope to experiment crops that do not rely on a seed-to-harvest cycle, and are not harvested annually.These include fruit trees so that they might be able to grow apples, cherries, and strawberries in Martian soil. In addition, Wamelink has expressed interest in cultivating lupin seeds as a means of replacing meat in the Martian diet.
And when it comes right down to it, neither MarsOne or the Wageningen UR team are alone in wanting to see what can be grown on Mars or other planets. For years, NASA has also been engaged in their own tests to see which crops can be cultivated on Mars. And with the help of the Lima-based International Potato Center, their latest experiment involves cultivating potatoes in samples of Peruvian soil.
For hundreds of years, the Andean people have been cultivating potatoes in the region. And given the arid conditions, NASA believes it will serve as a good facsimile for Mars. But perhaps the greatest draw is the fact cultivating potatoes in a simulated Martian environment immediately calls to mind Matt Damon in The Martian. In short, it's a spectacular PR move that NASA, looking to drum up support for its "Journey to Mars", cannot resist!
Naturally, experiments such as these are not just for the sake of meeting the challenges posed by MarsOne's plan for one-way crewed missions to Mars. Alongside the efforts of NASA and others, they are part of a much larger effort to address the challenges posed by the renewed era of space exploration we find ourselves embarking on.
With multiple space agencies and private corporations (like SpaceX) hoping to put buts back on the Moon and Mars, and to establish permanent bases on these planets and even in the outer Solar System, knowing what it will take for future generations of colonists and explorers to sustain themselves is just good planning.
Further Reading: Mars Exchange
The post Good News, Martian Colonists Can Eat All the Radishes They Want appeared first on Universe Today.
06/25/2016 02:00 PM
A Star Is About To Go 2.5% The Speed Of Light Past A Black Hole
Since it was first discovered in 1974, astronomers have been dying to get a better look at the Supermassive Black Hole (SBH) at the center of our galaxy. Known as Sagittarius A*, scientists have only been able to gauge the position and mass of this SBH by measuring the effect it has on the stars that orbit it. But so far, more detailed observations have eluded them, thanks in part to all the gas and dust that obscures it.
Luckily, the European Southern Observatory (ESO) recently began work with the GRAVITY interferometer, the latest component in their Very Large Telescope (VLT). Using this instrument, which combines near-infrared imaging, adaptive-optics, and vastly improved resolution and accuracy, they have managed to capture images of the stars orbiting Sagittarius A*. And what they have observed was quite fascinating.
One of the primary purposes of GRAVITY is to study the gravitational field around Sagittarius A* in order to make precise measurements of the stars that orbit it. In so doing, the GRAVITY team - which consists of astronomers from the ESO, the Max Planck Institute, and multiple European research institutes - will be able to test Einstein's theory of General Relativity like never before.
In what was the first observation conducted using the new instrument, the GRAVITY team used its powerful interferometric imaging capabilities to study S2, a faint star which orbits Sagittarius A* with a period of only 16 years. This test demonstrated the effectiveness of the GRAVITY instrument - which is 15 times more sensitive than the individual 8.2-metre Unit Telescopes the VLT currently relies on.
This was an historic accomplishment, as a clear view of the center of our galaxy is something that has eluded astronomers in the past. As GRAVITY’s lead scientist, Frank Eisenhauer - from the Max Planck Institute for Extraterrestrial Physics in Garching, Germany - explained to Universe Today via email:
"First, the Galactic Center is hidden behind a huge amount of interstellar dust, and it is practically invisible at optical wavelengths. The stars are only observable in the infrared, so we first had to develop the necessary technology and instruments for that. Second, there are so many stars concentrated in the Galactic Center that a normal telescope is not sharp enough to resolve them. It was only in the late 1990' and in the beginning of this century when we learned to sharpen the images with the help of speckle interferometry and adaptive optics to see the stars and observe their dance around the central black hole."
But more than that, the observation of S2 was very well timed. In 2018, the star will be at the closest point in its orbit to the Sagittarius A* - just 17 light-hours from it. As you can see from the video below, it is at this point that S2 will be moving much faster than at any other point in its orbit (the orbit of S2 is highlighted in red and the position of the central black hole is marked with a red cross).
When it makes its closest approach, S2 will accelerate to speeds of almost 30 million km per hour, which is 2.5% the speed of light. Another opportunity to view this star reach such high speeds will not come again for another 16 years - in 2034. And having shown just how sensitive the instrument is already, the GRAVITY team expects to be able make very precise measurements of the star's position.
In fact, they anticipate that the level of accuracy will be comparable to that of measuring the positions of objects on the surface of the Moon, right down to the centimeter-scale. As such, they will be able to determine whether the motion of the star as it orbits the black hole are consistent with Einstein's theories of general relativity.
"[I]t is not the speed itself to cause the general relativistic effects," explained Eisenhauer, "but the strong gravitation around the black hole. But the very high orbital speed is a direct consequence and measure of the gravitation, so we refer to it in the press release because the comparison with the speed of light and the ISS illustrates so nicely the extreme conditions.
As recent simulations of the expansion of galaxies in the Universe have shown, Einstein's theories are still holding up after many decades. However, these tests will offer hard evidence, obtained through direct observation. A star traveling at a portion of the speed of light around a supermassive black hole at the center of our galaxy will certainly prove to be a fitting test.
And Eisenhauer and his colleagues expect to see some very interesting things. "We hope to see a "kick" in the orbit." he said. "The general relativistic effects increase very strongly when you approach the black hole, and when the star swings by, these effects will slightly change the direction of the
While those of us here at Earth will not be able to "star gaze" on this occasion and see R2 whipping past Sagittarius A*, we will still be privy to all the results. And then, we just might see if Einstein really was correct when he proposed what is still the predominant theory of gravitation in physics, over a century later.
Further Reading: eso.org
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06/25/2016 12:45 PM
What are the Different Masses of the Planets?
It is a well known fact that the planets of the Solar System vary considerably in terms of size. For instance, the planets of the inner Solar System are smaller and denser than the gas/ice giants of the outer Solar System. And in some cases, planets can actually be smaller than the largest moons. But a planet's size is not necessarily proportional to its mass. In the end, how massive a planet is has more to do with its composition and density.
So while a planet like Mercury may be smaller in size than Jupiter's moon Ganymede or Saturn's moon Titan, it is more than twice as massive than they are. And while Jupiter is 318 times as massive as Earth, its composition and density mean that it is only 11.21 times Earth's size. Let's go over the planet's one by one and see just how massive they are, shall we?
Mercury is the Solar System's smallest planet, with an average diameter of 4879 km (3031.67 mi). It is also one of its densest at 5.427 g/cm3, which is second only to Earth. As a terrestrial planet, it is composed of silicate rock and minerals and is differentiated between an iron core and a silicate mantle and crust. But unlike its peers (Venus, Earth and Mars), it has an abnormally large metallic core relative to its crust and mantle.
All told, Mercury's mass is approximately 0.330 x 1024 kg, which works out to 330,000,000 trillion metric tons (or the equivalent of 0.055 Earths). Combined with its density and size, Mercury has a surface gravity of 3.7 m/s² (or 0.38 g).
Venus, otherwise known as "Earth's Sister Planet", is so-named because of its similarities in composition, size, and mass to our own. Like Earth, Mercury and Mars, it is a terrestrial planet, and hence quite dense. In fact, with a density of 5.243 g/cm³, it is the third densest planet in the Solar System (behind Earth and Mercury). Its average radius is roughly 6,050 km (3759.3 mi), which is the equivalent of 0.95 Earths.
And when it comes to mass, the planet weighs in at a hefty 4.87 x 1024 kg, or 4,870,000,000 trillion metric tons. Not surprisingly, this is the equivalent of 0.815 Earths, making it the second most massive terrestrial planet in the Solar System. Combined with its density and size, this means that Venus also has comparable gravity to Earth - roughly 8.87 m/s², or 0.9 g.
Like the other planets of the inner Solar System, Earth is also a terrestrial planet, composed of metals and silicate rocks differentiated between an iron core and a silicate mantle and crust. Of the terrestrial planets, it is the largest and densest, with an average radius of 6,371.0 km (3,958.8 mi) and a mean of density of 5.514 g/cm3.
And at 5.97 x 1024 kg (which works out to 5,970,000,000,000 trillion metric tons) Earth is the most massive of all the terrestrial planets. Combined with its size and density, Earth experiences the surface gravity that we are all familiar with - 9.8 m/s², or 1 g.
Mars is the third largest terrestrial planet, and the second smallest planet in our Solar System. Like the others, it is composed of metals and silicate rocks that are differentiated between a iron core and a silicate mantle and crust. But while it is roughly half the size of Earth (with a mean diameter of 6792 km, or 4220.35 mi), it is only one-tenth as massive.
In short, Mars has a mass of 0.642 x1024 kg, which works out to 642,000,000 trillion metric tons, or roughly 0.11 the mass of Earth. Combined with its size and density - 3.9335 g/cm³ (which is roughly 0.71 times that of Earth's) - Mars has a surface gravity of 3.711 m/s² (or 0.376 g).
Jupiter is the largest planet in the Solar System. With a mean diameter of 142,984 km, it is big enough to fit all the other planets (except Saturn) inside itself, and big enough to fit Earth 11.8 times over. But with a mass of 1898 x 1024 kg (or 1,898,000,000,000 trillion metric tons), Jupiter is more massive than all the other planets in the Solar System combined - 2.5 times more massive, to be exact.
However, as a gas giant, it has a lower overall density than the terrestrial planets. It's mean density is 1.326 g/cm, but this increases considerably the further one ventures towards the core. And though Jupiter does not have a true surface, if one were to position themselves within its atmosphere where the pressure is the same as Earth's at sea level (1 bar), they would experience a gravitational pull of 24.79 m/s2 (2.528 g).
Saturn is the second largest of the gas giants; with a mean diameter of 120,536 km, it is just slightly smaller than Jupiter. However, it is significantly less massive than its Jovian cousin, with a mass of 569 x 1024 kg (or 569,000,000,000 trillion metric tons). Still, this makes Saturn the second most-massive planet in the Solar System, with 95 times the mass of Earth.
Much like Jupiter, Saturn has a low mean density due to its composition. In fact, with an average density of 0.687 g/cm³, Saturn is the only planet in the Solar System that is less dense than water (1 g/cm³). But of course, like all gas giants, its density increases considerably the further one ventures towards the core. Combined with its size and mass, Saturn has a "surface" gravity that is just slightly higher than Earth's - 10.44 m/s², or 1.065 g.
With a mean diameter of 120,536 km, Uranus is the third largest planet in the Solar System. But with a mass of 86.8 x 1024 kg (86,800,000,000 trillion metric tons) it is the fourth most massive - which is 14.5 times the mass of Earth. This is due to its mean density of 1.271 g/cm3, which is about three quarters of what Neptune's is. Between its size, mass, and density, Uranus' gravity works out to 8.69 m/s2, which is 0.886 g.
Neptune is significantly larger than Earth; at 49,528 km, it is about four times Earth's size. And with a mass of 102 x 1024 kg (or 102,000,000,000 trillion metric tons) it is also more massive - about 17 times more to be exact. This makes Neptune the third most massive planet in the Solar System; while its density is the greatest of any gas giant (1.638 g/cm3). Combined, this works out to a "surface" gravity of 11.15 m/s2 (1.14 g).
As you can see, the planets of the Solar System range considerably in terms of mass. But when you factor in their variations in density, you can see how a planets mass is not always proportionate to its size. In short, while some planets may be a few times larger than others, they are can have many, many times more mass.
We have written many interesting articles about the planets here at Universe. For instance, here's Interesting Facts About the Solar System, What are the Colors of the Planets?, What are the Signs of the Planets?, How Dense are the Planets?, and What are the Diameters of the Planets?.
For more information, check out Nine Planets overview of the Solar System, NASA's Solar System Exploration, and use this site to find out what you would weigh on other planets.
Astronomy Cast has episodes on all of the planets. Here's Episode 49: Mercury to start!
The post What are the Different Masses of the Planets? appeared first on Universe Today.
06/24/2016 06:17 PM
Spectacular Launch of Most Powerful Atlas Completes Constellation of Navy’s Advanced Tactical Comsats – Gallery
Today’s (June 24) spectacular launch of the most powerful version of the venerable Atlas V rocket from the sunshine state completes the orbital deployment of a constellation of advanced tactical communications satellites for the U.S. Navy.
A United Launch Alliance (ULA) Atlas V rocket successfully launched the massive MUOS-5 satellite into clear blue skies from Space Launch Complex-41 on Cape Canaveral Air Force Station, Florida, at 10:30 a.m. EDT - on its way to a geosynchronous orbit location approximately 22,000 miles (37,586 km) above the Earth.
Note: Check back again for an expanding gallery of launch photos and videos
The Mobile User Objective System-5 (MUOS-5) satellite is the last in a five-satellite constellation that will provide military forces with significantly improved and assured communications worldwide. Lockheed Martin is the prime contractor for the MUOS system.
As launch time neared the weather odds improved to 100% GO and Atlas rumbled off the pad for on time launch that took place at the opening of a 44 minute window.
The launch was broadcast live on a ULA webcast.
The 206 foot tall Atlas rocket roared to space on an expanding plume of smoke and crackling fire from the first stage liquid and solid fueled engines generating over 2.5 million pounds of liftoff thrust.
Their contribution complete, all 5 solid rocket motors were jettisoned with seconds about 2 minutes after liftoff as the liquid fueled first stage continued firing.
The spent first stage separated about 5 minutes after liftoff, as the Centaur second stage fires up for the first of three times over almost three hours to deliver the hefty payload to orbit.
“We are honored to deliver the final satellite in the MUOS constellation for the U.S. Navy,” said Laura Maginnis, ULA vice president, Custom Services, in a statement.
“Congratulations to our navy, air force and Lockheed Martin mission partners on yet another successful launch that provides our warfighters with enhanced communications capabilities to safely and effectively conduct their missions around the globe.”
This is the fifth satellite in the MUOS series and will provide military users up to 16 times more communications capability over existing systems, including simultaneous voice, video and data, leveraging 3G mobile communications technology.
With MUOS-5 in orbit the system’s constellation is completed.
MUOS-5 will serve as an on orbit spare. It provides the MUOS network with near-global coverage. Communications coverage for military forces now extends further toward the North and South poles than ever before, according to Lockheed Martin officials.
“Like its predecessors, the MUOS-5 satellite has two payloads to support both new Wideband Code Division Multiple Access (WCDMA) waveform capabilities, as well as the legacy Ultra High Frequency (UHF) satellite system. On orbit, MUOS-5 will augment the constellation as a WCDMA spare, while actively supporting the legacy UHF system, currently used by many mobile forces today.”
The prior MUOS-4 satellite was launched on Sept. 2, 2015 - as I reported here.
The 20 story tall Atlas V launched in its most powerful 551 configuration and performed flawlessly.
The vehicle includes a 5-meter diameter payload fairing and five solid rocket boosters that augment the first stage. The Atlas booster for this mission was powered by the RD AMROSS RD-180 engine and the Centaur upper stage was powered by the Aerojet Rocketdyne RL10C-1 engine.
The RD-180 burns RP-1 (Rocket Propellant-1 or highly purified kerosene) and liquid oxygen and delivers 860,200 lb of thrust at sea level.
And the rocket needed all that thrust because the huge MUOS-5 was among the heftiest payloads ever lofted by an Atlas V booster, weighing in at some 15,000 pounds.
The Centaur upper stage was fired a total of three times.
For this mission the payload fairing was outfitted with an upgraded and advanced acoustic system to beet shield the satellite from the intense vibrations during the launch sequence.
This Atlas launch had been delayed several months to rectify a shortfall in the first stage thrust that occurred during the prior mission launching the Orbital ATK OA-6 cargo freighter in March 2016 on a contract mission for NASA to resupply the International Space Station (ISS).
The launch comes just two weeks after blastoff of the ULA Delta IV Heavy, the worlds most powerful rocket, on a mission to deliver a top secret spy satellite to orbit - as I witnessed and reported on here.
“I am so proud of the team for all their hard work and commitment to 100 percent mission success,” Maginnis added.
“It is amazing to deliver our second national security payload from the Cape in just two weeks. I know this success is due to our amazing people who make the remarkable look routine.”
The 15,000 pound MUOS payload is a next-generation narrowband tactical satellite communications system designed to significantly improve ground communications for U.S. forces on the move.
Here’s a detailed mission profile video describing the launch events:
Video caption: Atlas V MUOS-5 Mission Profile launched on June 24, 2016 from Cape Canaveral Air force Station. Credit: ULA
The launch was supported by the 45th Space Wing.
“Today’s successful launch is the culmination of the 45th Space Wing, Space and Missile Systems Center, Navy and ULA’s close partnership and dedicated teamwork,” said Brig. Gen. Wayne Monteith, 45th Space Wing commander and mission Launch Decision Authority, in a statement.
“We continue our unwavering focus on mission success and guaranteeing assured access to space for our nation, while showcasing why the 45th Space Wing is the ‘World's Premiere Gateway to Space."
Watch this exciting launch highlights video reel from ULA - including deployment of MUOS-5!
The MUOS-5 launch marked the 63rd Atlas V mission since the vehicle’s inaugural launch in August 2002. To date seven flights have launched in the 551 configuration. These include all four prior MUOS missions as well as NASA’s New Horizons mission to Pluto and the Juno mission to Jupiter.
Watch my up close remote launch video from the pad with hurling rocks:
Video caption: The sounds and fury of a ULA Atlas V 551 rocket blast off carrying Lockheed Martin built MUOS-5 tactical communications satellite to geosynchronous orbit for US Navy on June 24, 2016 at 10:30 a.m. EDT from Space Launch Complex 41 at Cape Canaveral Air Force Station, Fl, as seen in this up close video from remote camera positioned at pad. Credit: Ken Kremer/kenkremer.com
Watch this compilation of dramatic launch videos from Jeff Seibert.
Video Caption: MUOS-5 launch compilation on ULA Atlas 5 rocket on 6/24/2016 from Pad 41 of CCAFS. Credit: Jeff Seibert
The next Atlas V launch is slated for July 28 with the NROL-61 mission for the National Reconnaissance Office (NRO).
Stay tuned here for Ken's continuing Earth and Planetary science and human spaceflight news.
The post Spectacular Launch of Most Powerful Atlas Completes Constellation of Navy’s Advanced Tactical Comsats – Gallery appeared first on Universe Today.
06/24/2016 01:22 PM
Astronomy Cast Ep. 418: Error 418 – I’m a Teapot!
Visit the Astronomy Cast Page to subscribe to the audio podcast! We record Astronomy Cast as a live Google+ Hangout on Air every Monday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch here on Universe Today or from the Astronomy Cast Google+ page.
The post Astronomy Cast Ep. 418: Error 418 – I’m a Teapot! appeared first on Universe Today.
06/24/2016 12:47 PM
HiRISE Captures Curiosity on the Naukluft Plateau
Viewing orbital images of the rovers as they go about their business on the surface of Mars is pretty cool. Besides being of great interest to anyone keen on space in general, they have scientific value as well. New images from the High Resolution Imaging Science Equipment (HiRise) camera aboard the Mars Reconnaissance Orbiter (MRO) help scientists in a number of ways.
Recent images from HiRise show the Mars Science Laboratory (MSL) Curiosity on a feature called the Naukluft Plateau. The Plateau is named after a mountain range in Namibia, and is the site of Curiosity's 10th and 11th drill targets.
Orbital imagery of the rovers is used to track the activity of sand dunes in the areas the rovers are working in. In this case, the dune field is called the Bagnold Dunes. HiRise imagery allows a detailed look at how dunes change over time, and how any tracks left by the rover are filled in with sand over time. Knowledge of this type of activity is a piece of the puzzle in understanding the Martian surface.
But the ability to take such detailed images of the Martian surface has other benefits, as well. Especially as we get nearer to a human presence on Mars.
Orbital imaging is turning exploration on its ear. Throughout human history, exploration required explorers travelling by land and sea to reconnoiter an area, and to draw maps and charts later. We literally had no idea what was around the corner, over the mountain, or across the sea until someone went there. There was no way to choose a location for a settlement until we had walked the ground.
From the serious (SpaceX, NASA) to the fanciful (MarsOne), a human mission to Mars, and an eventual established presence on Mars, is a coming fact. The how and the where are all connected in this venture, and orbital images will be a huge part of choosing where.
Tracking the changes in dunes over time will help inform the choice for human landing sites on Mars. The types and density of sand particles may be determined by monitoring rover tracks as they fill with sand. This may be invaluable information when it comes to designing the types of facilities used on Mars. Critical infrastructure in the form of greenhouses or solar arrays will need to be placed very carefully.
Sci-Fi writers have exaggerated the strength of sand storms on Mars to great effect, but they are real. We know from orbital monitoring, and from rovers, that Martian sandstorms can be very powerful phenomena. Of course, a 100 km/h wind on Earth is much more dangerous than on Mars because of the density of the atmosphere. Martian air is 1% the density of Earth's, so on Mars the 100 km/h wind wouldn't do much.
But it can pick up dust, and that dust can foul important equipment. With all this in mind, we can see how these orbital images give us an important understanding of how sand behaves on Mars.
There's an unpredictability factor to all this too. We can't always know in advance how important or valuable orbital imagery will be in the future. That's part of doing science.
But back to the cool factor.
For the rest of us, who aren't scientists, it's just plain cool to be able to watch the rovers from above.
And, look at all the Martian eye candy!
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06/24/2016 12:00 PM
Weekly Space Hangout – June 24, 2016: Dr. James Green
Host: Fraser Cain (@fcain) Special Guest: Dr. James Green is the NASA Director of Planetary Science. Guests: Morgan Rehnberg (MorganRehnberg.com / @MorganRehnberg) Dave Dickinson (www.astroguyz.com / @astroguyz) Kimberly Cartier ( KimberlyCartier.org / @AstroKimCartier ) Their stories this week: Evidence for volcanic history on Mars Impact of Brexit on UK science uncertain FRIPON: A New All-Sky […]
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06/24/2016 09:55 AM
Centaurs Keep Their Rings From Greedy Gas Giants
When we think of ring systems, what naturally comes to mind are planets like Saturn. It's beautiful rings are certainly the most well known, but they are not the only planet in our Solar System to have them. As the Voyager missions demonstrated, every planet in the outer Solar System - from Jupiter to Neptune - has its own system of rings. And in recent years, astronomers have discovered that even certain minor planets - like the Centaur asteroids 10199 Chariklo and 2006 Chiron - have them too.
This was a rather surprising find, since these objects have such chaotic orbits. Given that their paths through the Solar System are frequently altered by the powerful gravity of gas giants, astronomers have naturally wondered how a minor planet could retain a system of rings. But thanks to a team of researchers from the Sao Paulo State University in Brazil, we may be close to answering that question.
In a study titled "The Rings of Chariklo Under Close Encounters With The Giant Planets", which appeared recently in The Astrophysical Journal, they explained how they constructed a model of the Solar System that incorporated 729 simulated objects. All of these objects were the same size as Chariklo and had their own system of rings. They then went about the process of examining how interacting with gas giant effected them.
To break it down, Centaurs are a population of objects within our Solar System that behave as both comets and asteroids (hence why they are named after the hybrid beasts of Greek mythology). 10199 Chariklo is the largest known member of the Centaur population, a possible former Trans-Neptunian Object (TNO) which currently orbits between Saturn and Uranus.
The rings around this asteroid were first noticed in 2013 when the asteroid underwent a stellar occultation. This revealed a system of two rings, with a radius of 391 and 405 km and widths of about 7 km 3 km, respectively. The absorption features of the rings showed that they were partially composed of water ice. In this respect, they were much like the rings of Jupiter, Saturn, Uranus and the other gas giants, which are composed largely of water ice and dust.
This was followed by findings made in 2015 that indicated that 2006 Chiron - another major Centaur - could have a ring of its own. This led to further speculation that there might be many minor planets in our Solar System that have a system of rings. Naturally, this was a bit perplexing to astronomers, since rings are fragile structures that were thought to be exclusive to the gas giants of our System.
As Professor Othon Winter, the lead researcher of the Sao Paulo team, told Universe Today via email:
"At first it was a surprise to find a Centaur with rings, since the Centaurs have chaotic orbits wandering between the giant planets and having frequent close encounters with them. However, we have shown that in most of the cases the ring system can survive all the close encounters with the giant planets. Therefore, Centaurs with rings might be much more common than we thought before."
For the sake of their study, Winter and his colleagues considered the orbits of 729 simulated clones of Chariklo as they orbited the Sun over the course of 100 million years. From this, Winter and his colleagues found that each Centaur averaged about 150 close encounters with a gas giant, within one Hill radius of the planet in question. As Winter described it:
"The study was made in two steps. First we considered a set of more than 700 clones of Chariklo. The clones had initial trajectories that were slightly different from Chariklo for statistical purposes (since we are dealing with chaotic trajectories) and computationally simulated their orbital evolution forward in time (to see their future) and also backward in time (to see their past). During these simulations we archived the information of all the close encounters (many thousands) they had with each of the giant planets."
"In the second step, we performed simulations of each one of the close encounters found in the first step, but now including a disk of particles around Chariklo (representing the ring particles). Then, at the end of each simulation we analyzed what happened to the particles. Which ones were removed from Chariklo (escaping its gravitational field)? Which ones were strongly disturbed (still orbiting around Chariklo)? Which ones did not suffer any significant effect?"
In the end, the simulations showed that in 90 percent of the cases, the rings of the Centaurs survived their close encounters with gas giants, whereas they were disturbed in 4 percent of cases, and were stripped away only 3 percent of the time. Thus, they concluded that if there is an efficient mechanism that creates the rings, then it is strong enough to let Centaurs keep them.
More than that, their research would seem to indicate that what was considered unique to certain planetary bodies may actually be more commonplace. "It reveals that our Solar System is complex not just as whole or for large bodies," said Winter, "but even small bodies may show complex structures and even more complex temporal evolution."
The next step for the research team is to study ring formation, which could show that they in fact picking them up from the gas giants themselves. But regardless of where they come from, its becoming increasingly clear that Centaurs like 10199 Chariklo are not alone. What's more, they aren't giving up their rings anytime soon!
Further Reading: iopscience.iop.org
The post Centaurs Keep Their Rings From Greedy Gas Giants appeared first on Universe Today.
06/23/2016 05:18 PM
Antares Return to Flight Launch Likely Slips to August, Cygnus Completes Atmospheric Reentry
The long awaited maiden launch of Orbital ATK’s revamped Antares commercial rocket utilizing new first stage engines, from its Virginia launch base, will likely slip from July to August a company spokesperson confirmed to Universe Today.
The target date for the ‘Return to Flight’ launch of Antares on a cargo resupply mission for NASA to the International Space Station (ISS) is “likely to result in an updated launch schedule in the August timeframe,” Orbital ATK spokeswoman Sean Wilson told Universe Today.
The company had most recently been aiming towards an Antares launch date around July 6 from NASA’s Wallops Flight Facility - for its next NASA contracted mission to stock the ISS via the Orbital ATK Cygnus cargo freighter on a flight known as OA-5.
Meanwhile the firms most recently launched Cygnus OA-6 cargo ship departed the space station and completed its planned destructive reentry into the Earth’s atmosphere on Wednesday, June 22.
But before Orbital ATK can resume Antares/Cygnus cargo flights to the ISS, it had to successfully hurdle through a critically important milestone on the path to orbit - namely a static hot fire test of the significantly modified first stage to confirm that its qualified for launch.
To that end the aerospace firm recently completed a successful 30 second long test firing of the re-engined first stage on May 31 at Virginia Space’s Mid-Atlantic Regional Spaceport (MARS) Launch Pad 0A - as I reported here earlier.
A thorough analysis of the hot fire test results and its implications is underway.
“Our Antares team recently completed a successful stage test and is wrapping up the test data analysis,” Wilson said.
“Final trajectory shaping work is also currently underway, which is likely to result in an updated launch schedule in the August timeframe.”
In the meantime, company engineers continue to ready the rocket and payload.
“We are continuing to prepare for the upcoming launch of the Antares rocket and Cygnus spacecraft for the OA-5 cargo logistics mission to the International Space Station from NASA’s Wallops Flight Facility,” Wilson noted.
It’s also clear that a decision on a launch date target is some weeks away and depends on the busy upcoming manifest of other ISS missions coming and going.
“A final decision on the mission schedule, which takes into account the space station traffic schedule and cargo requirements, will be made in conjunction with NASA in the next several weeks.”
And it also must take into account the launch of the intervening SpaceX ISS cargo flight that was just postponed two days to no earlier than July 18.
Another factor is the delayed launch of the next manned crew on a Russian Soyuz capsule from late June into July. Blastoff of the three person crew from Russia, the US and Japan is set for July 7. OA-5 will deliver some 3 tons of science experiments and crew supplies.
Antares launches had immediately ground to a halt following a devastating launch failure 20 months ago which destroyed the rocket and its critical payload of space station science and supplies for NASA in a huge fireball just seconds after blastoff - as witnessed by this author.
As a direct result consequence of the catastrophic launch disaster, Orbital STK managers decided to outfit the Antares medium-class rocket with new first stage RD-181 engines built in Russia.
The RD-181 replaces the previously used AJ26 engines which failed moments after liftoff during the last launch on Oct. 28, 2014 resulting in a catastrophic loss of the rocket and Cygnus cargo freighter.
The RD-181 flight engines are built by Energomash in Russia and had to be successfully tested via the static hot fire test to ensure their readiness.
As a result of switching to the new RD-181 engines, the first stage also had to be modified to incorporate new thrust adapter structures, actuators, and propellant feed lines between the engines and core stage structure, Mike Pinkston, Orbital ATK General Manager and Vice President, Antares Program told me in a prior interview.
So the primary goal of the stage test was to confirm the effectiveness of the new engines and all the changes in the integrated rocket stage.
It’s not entirely clear at this time whether the Antares launch delay to August is due to changes in the ISS manifest scheduling or any lingering questions from the hot fire test or both.
“A final decision on the mission schedule definitely takes into account the completion of data analysis combined with the busy space station traffic schedule and NASA’s cargo requirements,” Wilson told me in a response requesting clarification.
Following a quick look immediately following the May 31 test, Orbital ATK officials initially reported that all seemed well, with the caveat that further data review is needed.
“Early indications show the upgraded propulsion system, core stage and launch complex all worked together as planned,” said Mike Pinkston, Orbital ATK General Manager and Vice President, Antares Program.
“Congratulations to the combined NASA, Orbital ATK and Virginia Space team on a successful test.”
Orbital ATK engineers will now “review test data over the next several days to confirm that all test parameters were met. ”
The test used the first stage core planned to launch the OA-7 mission from Wallops late this year.
With the engine test completed, the OA-7 stage will be rolled back to the HIF processing hanger at Wallops and a new stage fully integrated with the Cygnus cargo freighter will be rolled out to the pad for the OA-5 ‘Return to Flight’ mission in August.
The mission of the OA-6 Cygnus ended on Wednesday, with a planned destructive reentry into the Earth’s atmosphere at 9:29 a.m. EDT.
Also known as the SS Rick Husband, it had spent 3 months in orbit since launching in March on a ULA Atlas V.
It departed the ISS on June 14 and continued several science experiments. Most notable was to successfully create the largest fire in space via the Spacecraft Fire Experiment-I (Saffire-I).
Stay tuned here for Ken's continuing Earth and Planetary science and human spaceflight news.
The post Antares Return to Flight Launch Likely Slips to August, Cygnus Completes Atmospheric Reentry appeared first on Universe Today.
06/23/2016 11:39 AM
Can Boeing Launch A Crewed Starliner By February 2018?
Boeing thinks it can have its Starliner spacecraft ready to fly crewed missions by February, 2018. This is 4 months later than the previous date of October 2017. It isn't yet clear what this will mean in Boeing's race against SpaceX to relieve NASA's dependence on Russian transportation to the ISS.
Currently, astronauts travel to the ISS aboard the Russian workhorse Soyuz capsule. Ever since the end of the Space Shuttle program, NASA has relied on Russia to transport astronauts to the station. Both Boeing and SpaceX have received funds to develop a crewed capsule, and both companies are working at a feverish pace to be the first to do so.
Boeing has a long history of involvement with NASA. It's the prime contractor for ISS operations, and is also the prime contractor for NASA's Space Launch System (SLS), which will be the most powerful rocket ever built and will power NASA's exploration of deep space. So Boeing is no stranger to complex development cycles and the types of delays that can crop up.
In a recent interview, Boeing's Chris Ferguson acknowledged that everything has to go well for the Starliner to meet its schedule. But things don't always go well in such a complex engineering program, and that's just the way things are.
The Starliner, and every other spacecraft, has to undergo extensive testing of each component before any flight can be attempted. Various suppliers are responsible for over 200 pieces of equipment, just in avionics alone, and each one of those pieces has to assembled, integrated, and tested. Not just by Boeing, but by NASA as well. This takes an enormous amount of time, and requires great rigor to carry out. In some cases, a problem with one piece of equipment can delay testing of other pieces. It's the nature of complex systems.
Another challenge that Boeing engineers face is limiting the mass of the spacecraft. Recent wind-tunnel testing of a Starliner model produced aero-acoustic issues when mated to a model of the Atlas 5, the rocket built by United Launch Alliance (ULA) which will carry the Starliner into space. Now Boeing is modifying the exterior lines of the vehicle to get the airflow just right.
The spacecraft also has to be tested for emergencies. Though the Starliner is designed to land on solid ground, it's also being tested for emergency landings on water.
NASA blames the delays in the development of the Starliner, and the SpaceX Dragon, on funding cuts from Congress. Administrator Charles Bolden has criticized Congress for consistent under-funding since the retirement of the Space Shuttle fleet in 2011. According to NASA, this has caused a 2 year delay in development of the Dragon and the Starliner. This delay, in turn, has meant that NASA has had to keep paying Russia for trips to the ISS. And like everything else, that cost keeps rising.
But it looks like the end, or maybe the beginning, is in sight for the Starliner. Boeing has paid deposits to ULA for four flights with the Atlas 5. A 2017 un-crewed test flight, a 2018 crewed test flight, and two crewed flights to the ISS.
Beyond that, the future looks a little hard to predict for Boeing and the Starliner. With both SpaceX and Blue Origin developing re-usable rockets, the future viability of the Atlas 5 might be in jeopardy. Compounding the uncertainty is NASA's stated plan to stop funding the ISS by 2024 or 2028.
By that time, NASA should be focused on establishing a presence in cislunar space, which would require different spacecraft.
But you can't wait forever to develop spacecraft. The only way to stay in the game is for Boeing to develop the spacecraft that are required right now, and let the knowledge and experience from that feed the development of the next spacecraft, whether for cislunar space or beyond.
In the big scheme of things, a four month delay for the first flight of the Starliner is not that big of a deal. If the Starliner is successful, and there's no reason to think it won't be, considering Boeing's track record, the four month delay in the initial flight won't even be remembered.
Whether its SpaceX or Boeing who get America back into space first, that moment will be celebrated, and all the delays and funding cuts will be left in the dust-bin of history.
The post Can Boeing Launch A Crewed Starliner By February 2018? appeared first on Universe Today.