Carnival of Space #502

Carnival of Space #502

This week’s Carnival of Space is hosted by Allen Versfeld at his Urban Astronomer blog.

Click here to read Carnival of Space #502.

And if you’re interested in looking back, here’s an archive to the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to carnivalofspace@gmail.com, and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, sign up to be a host. Send an email to the above address.

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Stars Born in Winds from Supermassive Black Holes

Stars Born in Winds from Supermassive Black Holes

Observations using ESO’s Very Large Telescope have revealed stars forming within powerful outflows of material blasted out from supermassive black holes at the cores of galaxies. These are the first confirmed observations of stars forming in this kind of extreme environment. The discovery has many consequences for understanding galaxy properties and evolution. The results are published in the journal Nature.
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NASA Test Fires New Engine Controlling ‘Brain’ for First SLS MegaRocket Mission

NASA Test Fires New Engine Controlling ‘Brain’ for First SLS MegaRocket Mission

NASA engineers conduct a test of the first RS-25 engine controller that will be used on an actual Space Launch System flight on the A-2 Test Stand at Stennis Space Center on March 23, 2017. The RS-25 engine, with the flight controller, was test fired for a full-duration 500 seconds. Credits: NASA/SSC

Engineers carried out a critical hot fire engine test firing with the first new engine controlling ‘brain’ that will command the shuttle-era liquid fueled engines powering the inaugural mission of NASA’s new Space Launch System (SLS) megarocket.

The first integrated SLS launch combining the SLS-1 rocket and Orion EM-1 deep space crew capsule could liftoff as soon as late 2018 on a mission around the Moon and back.

The full duration static fire test involved an RS-25 engine integrated with the first engine controller flight unit that will actually fly on the maiden SLS launch and took place on Thursday, March 23 at the agency’s Stennis Space Center in Bay St. Louis, Mississippi.

The 500 second-long test firing was conducted with the engine controller flight unit installed on RS-25 development engine no. 0528 on the A-2 Test Stand at Stennis.

The RS-25 engine controller is the ‘brain’ that commands the RS-25 engine and communicates between the engine and the SLS rocket. It is about the size of a dorm refrigerator.

RS-25 new engine controller. Credit: NASA/SSC

The newly developed engine controller is a modern version from the RS-25 controller that helped propel all 135 space shuttle missions to space.

“This an important – and exciting – step in our return to deep space missions,” Stennis Director Rick Gilbrech said. “With every test of flight hardware, we get closer and closer to launching humans deeper into space than we ever have traveled before.”

The modernized RS-25 engine controller was funded by NASA and created in a collaborative effort of engineers from NASA, RS-25 prime contractor Aerojet Rocketdyne of Sacramento, California, and subcontractor Honeywell of Clearwater, Florida.

“The controller manages the engine by regulating the thrust and fuel mixture ratio and monitors the engine’s health and status – much like the computer in your car,” say NASA officials.

“The controller then communicates the performance specifications programmed into the controller and monitors engine conditions to ensure they are being met, controlling such factors as propellant mixture ratio and thrust level.”

A quartet of RS-25 engines, leftover from the space shuttle era and repeatedly reused, will be installed at the base of the core stage to power the SLS at liftoff, along with a pair of extended solid rocket boosters.

The four RS-25 core stage engine will provide a combined 2 million pounds of thrust at liftoff.

In addition to being commanded by the new engine controller, the engines are being upgraded in multiple ways for SLS. For example they will operate at a higher thrust level and under different operating conditions compared to shuttle times.

To achieve the higher thrust level required, the RS-25 engines must fire at 109 percent of capability for SLS compared to operating at 104.5 percent of power level capability for shuttle flights.

The RS-25 engines “also will operate with colder liquid oxygen and engine compartment temperatures, higher propellant pressure and greater exhaust nozzle heating.”
SLS will be the world’s most powerful rocket and send astronauts on journeys into deep space, further than human have ever travelled before.

For SLS-1 the mammoth booster will launch in its initial 70-metric-ton (77-ton) Block 1 configuration with a liftoff thrust of 8.4 million pounds – more powerful than NASA’s Saturn V moon landing rocket.

NASA engineers conduct a test of the first RS-25 engine controller that will be used on an actual Space Launch System flight on the A-2 Test Stand at Stennis Space Center on March 23, 2017. The RS-25 engine, with the flight controller, was test fired for a full-duration 500 seconds. Credits: NASA/SSC

The next step is evaluating the engine firing test results, confirming that all test objectives were met and certifying that the engine controller can be removed from the RS-25 development engine and then be installed on one of four flight engines that will help power SLS-1.

During 2017, two additional engine controllers for SLS-1 will be tested on the same development engine at Stennis and then be installed on flight engines after certification.

Finally, “the fourth controller will be tested when NASA tests the entire core stage during a “green run” on the B-2 Test Stand at Stennis. That testing will involve installing the core stage on the stand and firing its four RS-25 flight engines simultaneously, as during a mission launch,” says NASA.

Numerous RS-25 engine tests have been conducted at Stennis over more than 4 decades to certify them as flight worthy for the human rated shuttle and SLS rockets.

NASA engineers successfully conducted a development test of the RS-25 rocket engine Thursday, Aug. 18, 2016 at NASA’s Stennis Space Center near Bay St. Louis, Miss. The RS-25 will help power the core stage of the agency’s new Space Launch System (SLS) rocket for the journey to Mars. Credit: Ken Kremer/kenkremer.com

Although NASA is still targeting SLS-1 for launch in Fall 2018 on an uncrewed mission, the agency is currently conducting a high level evaluation to determine whether the Orion EM-1 capsule can be upgraded in time to instead fly a human crewed mission with two astronauts before the end of 2019 – as I reported here.

The Orion EM-1 capsule is currently being manufactured at the Neil Armstrong Operations and Checkout Building at the Kennedy Space Center by prime contractor Lockheed Martin.

Orion crew module pressure vessel for NASA’s Exploration Mission-1 (EM-1) is unveiled for the first time on Feb. 3, 2016 after arrival at the agency’s Kennedy Space Center (KSC) in Florida. It is secured for processing in a test stand called the birdcage in the high bay inside the Neil Armstrong Operations and Checkout (O&C) Building at KSC. Launch to the Moon is slated in 2018 atop the SLS rocket. Credit: Ken Kremer/kenkremer.com

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

Aerojet Rocketdyne technicians inspect the engine controller that will be used for the first integrated flight of NASA’s Space Launch System and Orion in late 2018. The engine controller was installed on RS-25 development engine no. 0528 for testing at Stennis Space Center on the A-2 Test Stand on March 23, 2017. The RS-25 engine, with the flight controller, was test fired for a full-duration 500 seconds. Credits: NASA/SSC

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See Mercury At Dusk, New Comet Lovejoy At Dawn

See Mercury At Dusk, New Comet Lovejoy At Dawn

Mercury requests the company of your gaze now through the beginning of April, when it shines near Mars low in the west after sunset. Created with Stellarium

March has been a busy month for planet and comet watchers. Lots of action. Venus, the planet that’s captured our attention at dusk in the west for months, is in inferior conjunction with the Sun today. Watch for it to rise before the Sun in the eastern sky at dawn in about a week.

Mercury like Venus and the Moon shows phases when viewed through a telescope. Right now, the planet is in waning gibbous phase. Stellarium

As Venus flees the evening scene, steadfast Mars and a new planet, Mercury keep things lively. For northern hemisphere skywatchers, this is Mercury’s best dusk apparition of the year. If you’d like to make its acquaintance, this week and next are best. And it’s so easy! Just find a spot with a wide open view of the western horizon, bring a pair of binoculars for backup and wait for a clear evening.

Plan to watch starting about 40 minutes after sundown. From most locations, Mercury will appear about 10° or one fist held at arm’s length above the horizon a little bit north of due west. Shining around magnitude +0, it will be the only “star” in that part of the sky. Mars is nearby but much fainter at magnitude +1.5. You’ll have to wait at least an hour after sunset to spot it.

Have a telescope? Check out the planet using a magnification around 50x or higher. You’ll see that it looks like a Mini-Me version of the Moon. Mercury is brightest when closest to full. Over the next few weeks, it will wane to a crescent while increasing in apparent size.

If you have any difficulty finding brilliant Jupiter and its current pal, Spica, just start with the Big Dipper, now high in the northeastern sky at nightfall. Use the Dipper’s handle to “arc to Arcturus” and then “jump to Jupiter.” Credit: Bob King

If you like planets, don’t forget the combo of Jupiter and Spica at the opposite end of the sky. Jupiter climbs out of bed and over the southeastern horizon about 9 p.m. local time in late March, but to see it and Spica, Virgo’s brightest star, give it an hour and look again at 10 p.m. or later. Quite the duo!

You’re not afraid of getting up with the first robins are you? If you set your alarm to a half hour or so before the first hint of dawn’s light and find a location with an open view of the southeastern horizon, you might be first in your neighborhood to spot Terry Lovejoy’s brand new comet. His sixth, the Australian amateur discovered C/2017 E4 Lovejoy on the morning of March 10th in the constellation Sagittarius at about 12th magnitude.

C/2017 E4 Lovejoy glows blue-green this morning March 26. Structure around the nucleus including a small jet is visible. The comet is currently in Aquarius and quickly moving north and will reach perihelion on April 23. Credit: Terry Lovejoy

The comet has rapidly brightened since then and is now a small, moderately condensed fuzzball of magnitude +9, bright enough to spot in a 6-inch or larger telescope. Some observers have even picked it up in large binoculars. Lovejoy’s comet should brighten by at least another magnitude in the coming weeks, putting it within 10 x 50 binocular range.

This map shows the sky tomorrow morning before dawn from the central U.S. (latitude about 41° north). Created with Stellarium

Good news. E4 Lovejoy is moving north rapidly and is now visible about a dozen degrees high in Aquarius just before the start of dawn. I’ll be out the next clear morning, eyepiece to eye, to welcome this new fuzzball from beyond Neptune to my front yard. The map above shows the eastern sky near dawn and a general location of the comet. Use the more detailed map below to pinpoint it in your binoculars and telescope.

This chart shows the comet’s position nightly (5:30 a.m. CDT) through April 9. On the morning of April 1 it passes just a few degrees below the bright globular cluster M5. Click to enlarge, save and then print out for use at the telescope. Map: Bob King, Source: Chris Marriott’s SkyMap

Spring brings with it a new spirit and the opportunity to get out at night free of the bite of mosquitos or cold. Clear skies!

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What About a Mission to Titan?

What About a Mission to Titan?

As you probably know, NASA recently announced plans to send a mission to Jupiter’s moon Europa. If all goes well, the Europa Clipper will blast off for the world in the 2020s, and orbit the icy moon to discover all its secrets.

And that’s great and all, I like Europa just fine. But you know where I’d really like us to go next? Titan.

Titan, as you probably know, is the largest moon orbiting Saturn. In fact, it’s the second largest moon in the Solar System after Jupiter’s Ganymede. It measures 5,190 kilometers across, almost half the diameter of the Earth. This place is big.

It orbits Saturn every 15 hours and 22 days, and like many large moons in the Solar System, it’s tidally locked to its planet, always showing Saturn one side.

Titan image taken by Cassini on Oct. 7, 2013 (Credit: NASA/JPL-Caltech/Space Science Institute)

Before NASA’s Voyager spacecraft arrived in 1980, astronomers actually thought that Titan was the biggest moon in the Solar System. But Voyager showed that it actually has a thick atmosphere, that extends well into space, making the true size of the moon hard to judge.

This atmosphere is one of the most interesting features of Titan. In fact, it’s the only moon in the entire Solar System with a significant atmosphere. If you could stand on the surface, you would experience about 1.45 times the atmospheric pressure on Earth. In other words, you wouldn’t need a pressure suit to wander around the surface of Titan.

You would, however, need a coat. Titan is incredibly cold, with an average temperature of almost -180 Celsius. For you Fahrenheit people that’s -292 F. The coldest ground temperature ever measured on Earth is almost -90 C, so way way colder.

You would also need some way to breathe, since Titan’s atmosphere is almost entirely nitrogen, with trace amounts of methane and hydrogen. It’s thick and poisonous, but not murderous, like Venus.

Titan has only been explored a couple of times, and we’ve actually only landed on it once.

The first spacecraft to visit Titan was NASA’s Pioneer 11, which flew past Saturn and its moons in 1979. This flyby was followed by NASA’s Voyager 1 in 1980 and then Voyager 2 in 1981. Voyager 1 was given a special trajectory that would take it as close as possible to Titan to give us a close up view of the world.

Saturn’s moon Titan lies under a thick blanket of orange haze in this Voyager 1 picture. Credit: NASA

Voyager was able to measure its atmosphere, and helped scientists calculate Titan’s size and mass. It also got a hint of darker regions which would later turn out to be oceans of liquid hydrocarbons.

The true age of Titan exploration began with NASA’s Cassini spacecraft, which arrived at Saturn on July 4, 2004. Cassini made its first flyby of Titan on October 26, 2004, getting to within 1,200 kilometers or 750 miles of the planet. But this was just the beginning. By the end of its mission later this year, Cassini will have made 125 flybys of Titan, mapping the world in incredible detail.

Cassini saw that Titan actually has a very complicated hydrological system, but instead of liquid water, it has weather of hydrocarbons. The skies are dotted with methane clouds, which can rain and fill oceans of nearly pure methane.

And we know all about this because of Cassini’s Huygen’s lander, which detached from the spacecraft and landed on the surface of Titan on January 14, 2005. Here’s an amazing timelapse that shows the view from Huygens as it passed down through the atmosphere of Titan, and landed on its surface.

Huygens landed on a flat plain, surrounded by “rocks”, frozen globules of water ice. This was lucky, but the probe was also built to float if it happened to land on liquid instead.

It lasted for about 90 minutes on the surface of Titan, sending data back to Earth before it went dark, wrapping up the most distant landing humanity has ever accomplished in the Solar System.

Although we know quite a bit about Titan, there are still so many mysteries. The first big one is the cycle of liquid. Across Titan there are these vast oceans of liquid methane, which evaporate to create methane clouds. These rain, creating mists and even rivers.

This false-color mosaic of Saturn’s largest moon Titan, obtained by Cassini’s visual and infrared mapping spectrometer, shows what scientists interpret as an icy volcano. Credit: NASA/JPL/University of Arizona

Is it volcanic? There are regions of Titan that definitely look like there have been volcanoes recently. Maybe they’re cryovolcanoes, where the tidal interactions with Saturn cause water to well up from beneath crust and erupt onto the surface.

Is there life there? This is perhaps the most intriguing possibility of all. The methane rich system has the precursor chemicals that life on Earth probably used to get started billions of years ago. There’s probably heated regions beneath the surface and liquid water which could sustain life. But there could also be life as we don’t understand it, using methane and ammonia as a solvent instead of water.

To get a better answer to these questions, we’ve got to return to Titan. We’ve got to land, rove around, sail the oceans and swim beneath their waves.

Now you know all about this history of the exploration of Titan. It’s time to look at serious ideas for returning to Titan and exploring it again, especially its oceans.

Planetary scientists have been excited about the exploration of Titan for a while now, and a few preliminary proposals have been suggested, to study the moon from the air, the land, and the seas.

The spacecraft, balloon, and lander of the Titan Saturn System Mission. Credit: NASA Jet Propulsion Laboratory

First up, there’s the Titan Saturn System Mission, a mission proposed in 2009, for a late 2020s arrival at Titan. This spacecraft would consist of a lander and a balloon that would float about in the atmosphere, and study the world from above. Over the course of its mission, the balloon would circumnavigate Titan once from an altitude of 10km, taking incredibly high resolution images. The lander would touch down in one of Titan’s oceans and float about on top of the liquid methane, sampling its chemicals.

As we stand right now, this mission is in the preliminary stages, and may never launch.

The Aerial Vehicle for In-situ and Airborne Titan Reconnaissance (AVIATR) concept for an aerial explorer for Titan. Credit: Mike Malaska

In 2012, Dr. Jason Barnes and his team from the University of Idaho proposed sending a robotic aircraft to Titan, which would fly around in the atmosphere photographing its surface. Titan is actually one of the best places in the entire Solar System to fly an airplane. It has a thicker atmosphere and lower gravity, and unlike the balloon concept, an airplane is free to go wherever it needs powered by a radioactive thermal generator.

Although the mission would only cost about $750 million or so, NASA hasn’t pushed it beyond the conceptual stage yet.

On the left is TALISE (Titan Lake In-situ Sampling Propelled Explorer), the ESA proposal. This would have it’s own propulsion, in the form of paddlewheels. Credit: bisbos.com

An even cooler plan would put a boat down in one of Titan’s oceans. In 2012, a team of Spanish engineers presented their idea for how a Titan boat would work, using propellers to put-put about across Titan’s seas. They called their mission the Titan Lake In-Situ Sampling Propelled Explorer, or TALISE.

Propellers are fine, but it turns out you could even have a sailboat on Titan. The methane seas have much less density and viscosity than water, which means that you’d only experience about 26% the friction of Earth. Cassini measured windspeeds of about 3.3 m/s across Titan, which half the average windspeed of Earth. But this would be plenty of wind to power a sail when you consider Titan’s thicker atmosphere.

And here’s my favorite idea. A submarine. This 6-meter vessel would float on Titan’s Kraken Mare sea, studying the chemistry of the oceans, measuring currents and tides, and mapping out the sea floor.

It would be capable of diving down beneath the waves for periods, studying interesting regions up close, and then returning to the surface to communicate its findings back to Earth. This mission is in the conceptual stage right now, but it was recently chosen by NASA’s Innovative Advanced Concepts Group for further study. If all goes well, the submarine would travel to Titan by 2038 when there’s a good planetary alignment.

Okay? Are you convinced? Let’s go back to Titan. Let’s explore it from the air, crawl around on the surface and dive beneath its waves. It’s one of the most interesting places in the entire Solar System, and we’ve only scratched the surface.

If I’ve done my job right, you’re as excited about a mission to Titan as I am. Let’s go back, let’s sail and submarine around that place. Let me know your thoughts in the comments.

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Juno’s Monday Jupiter Flyby Promises New Batch of Images & Science

Juno’s Monday Jupiter Flyby Promises New Batch of Images & Science

Juno is only part way through its mission to Jupiter, and already we’ve seen some absolutely breathtaking images of the gas giant. On Monday, the Juno spacecraft will flyby Jupiter again. This will be the craft’s 5th flyby of the gas giant, and it’ll provide us with our latest dose of Jupiter science and images. The first 4 flybys have already exceeded our expectations.

Juno will approach to within 4,400 km of Jupiter’s cloud tops, and will travel at a speed of 207,600 km/h. During this time of closest approach, called a perijove, all of Juno’s eight science instruments will be active, along with the JunoCam.

The JunoCam is not exactly part of the science payload. It was included in the missions to help engage the public with the mission, and it appears to be doing that job well. The Junocam’s targets have been partly chosen by the public, and NASA has invited anyone who cares to to download and process raw Junocam images. You can see those results throughout this article.

This image of Jupiter’s dancing cloud tops was captured during perijove 3. Image: NASA / JPL-Caltech / SwRI / MSSS / Kootenay Nature Photos © cc nc sa

This is Juno’s 5th flyby, but only its 4th science pass. During Juno’s first encounter with Jupiter, the science instruments weren’t active. Even so, after only 3 science passes, we have learned some things about Jupiter.

“We are excited to see what new discoveries Juno will reveal.” – Scott Bolton, NASA’s Principal Investigator for the Juno Mission

“This will be our fourth science pass — the fifth close flyby of Jupiter of the mission — and we are excited to see what new discoveries Juno will reveal,” said Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio. “Every time we get near Jupiter’s cloud tops, we learn new insights that help us understand this amazing giant planet.”

We’ve already learned that Jupiter’s intense magnetic fields are much more complicated than we thought. We’ve learned that the belts and zones in Jupiter’s atmosphere, which are responsible for the dazzling patterns on the cloud tops, extend much deeper into the atmosphere than we thought. And we’ve discovered that charged material expelled from Io’s volcanoes helps cause Jupiter’s auroras.

The South Pole of Jupiter, taken during perijove 3. Image: NASA / JPL-Caltech / SwRI / MSSS / Luca Fornaciari © cc nc sa

Juno has the unprecedented ability to get extremely close to Jupiter. This next flyby will bring it to within 4,400 km of the cloud tops. But to do so, Juno has to pay a price. Though the sensitive equipment on the spacecraft is protected inside a titanium vault, Jupiter’s powerful radiation belts will still take a toll on the electronics. But that’s the price Juno will pay to perform its mission.

Jupiter’s dazzle as revealed by JunoCam and Shane Drever. Image: NASA / JPL-Caltech / SwRI / MSSS / Shane Drever © cc nc sa

Other missions, like Cassini, have been measured in years, while Juno’s will be measured in orbits. And once it’s completed its final orbit, it will be sent to its destruction in Jupiter’s atmosphere.

But before that happens, there’s a lot of science to be done, and a lot of stunning images to be captured.

Here’s an interview with the man leading the Juno Mission: Understanding Juno’s Orbit: An Interview with NASA’s Scott Bolton.

Here is the page for the JunoCam: https://www.missionjuno.swri.edu/junocam

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Nighttime Delta IV Blastoff Powers Military Comsat to Orbit for U.S. Allies: Photo/Video Gallery

Nighttime Delta IV Blastoff Powers Military Comsat to Orbit for U.S. Allies: Photo/Video Gallery

Blastoff of ULA Delta IV rocket carrying the Wideband Global SATCOM (WGS-9) comsat to orbit for the U.S. Air Force from Space Launch Complex-37 on Cape Canaveral Air Force Station, Fl, on Mar. 18, 2017. Credit: Ken Kremer/kenkremer.com

CAPE CANAVERAL AIR FORCE STATION, FL – The second round of March Launch Madness continued with the thunderous nighttime blastoff of a ULA Delta IV rocket powering a super swift military communications satellite to orbit in a collaborative effort of U.S. Allies from North America, Europe and Asia and the U.S. Air Force.

The next generation Wideband Global SATCOM-9 (WGS-9) military comsat mission for the U.S. Force lifted off atop a United Launch Alliance (ULA) Delta IV from Space Launch Complex-37 (SLC-37) on Saturday, March 18 at 8:18 p.m. EDT at Cape Canaveral Air Force Station, Florida.

Check out this expanding gallery of spectacular launch photos and videos gathered from my space journalist colleagues, myself and spectators ringing the space coast under crystal clear early evening skies.

ULA Delta IV rocket streaks to orbit carrying WGS-9 tactical communications satellite for the U.S. Air Force and international partners from Cape Canaveral Air Force Station, Fl, at 8:18 p.m. EDT on Mar. 18, 2017. Credit: Julian Leek

Note that Round 3 of March Launch Madness is tentatively slated for March 29 with the SpaceX liftoff of the first ever reused Falcon 9 first stage from historic pad 39 on NASA’s Kennedy Space Center.

The WGS-9 satellite was paid for by a six nation consortium that includes Canada, Denmark, Luxembourg, the Netherlands, New Zealand and the United States. It joins 8 earlier WGS satellites already in orbit.

The partnership was created back in 2012 when the ‘WGS-9 Memorandum of Understanding (MOU)’ was signed by Defense organizations of the six countries.

The WGS-9 MOU agreement to fund the satellite enabled the expansion of the WGS system with this additional satellite added to the existing WGS constellation.

“The agreement provides all signatories with assured access to global wideband satellite communications for military use,” according to the US Air Force.

Watch this launch video compilation from Jeff Seibert:

Video Caption: Launch of WGS-9 satellite continues USAF Breaking Barriers heritage. This ULA Delta 4 launch of the WGS-9 satellite marks the start of the 70th anniversary of the United States Air Force. That was also the year that U.S. Air Force Captain Chuck Yeager broke the sound barrier. Credit: Jeff Seibert

The 217 foot tall Delta IV Medium+ rocket launched in the 5,4 configuration with a 5 meter diameter payload fairing that stands 47 feet tall, and 4 solid rocket boosters to augment the first stage thrust of the single common core booster.

The payload fairing was emblazoned with decals commemorating the 70th anniversary of the USAF, as well as Air Force, mission and ULA logos.

Blastoff of ULA Delta IV rocket carrying the Wideband Global SATCOM (WGS-9) comsat to orbit for the U.S. Air Force from Space Launch Complex-37 on Cape Canaveral Air Force Station, Fl, on Mar. 18, 2017. Credit: Ken Kremer/kenkremer.com

Orbital ATK manufactures the four solid rocket motors. The Delta IV common booster core was powered by an RS-68A liquid hydrogen/liquid oxygen engine producing 705,250 pounds of thrust at sea level.
A single RL10B-2 liquid hydrogen/liquid oxygen engine powered the second stage, known as the Delta Cryogenic Second Stage (DCSS).

The booster and upper stage engines are both built by Aerojet Rocketdyne. ULA constructed the Delta IV Medium+ (5,4) launch vehicle in Decatur, Alabama.

Launch of USAF WGS-8 milsatcom on ULA Delta IV rocket from pad 37 on Cape Canaveral Air Force Station, Fl, on Mar. 18, 2017. Credit: Julian Leek

The DCSS will also serve as the upper stage for the maiden launch of NASA heavy lift SLS booster on the SLS-1 launch slated for late 2018. That DCSS/SLS-1 upper stage just arrived at the Cape last week – as I witnessed and reported here.

Saturday’s launch marks ULA’s 3rd launch in 2017 and the 118th successful launch since the company was formed in December 2006 as a joint venture between Boeing and Lockheed Martin.

Blastoff of ULA Delta IV rocket carrying the Wideband Global SATCOM (WGS-9) comsat to orbit for the U.S. Air Force from Space Launch Complex-37 on Cape Canaveral Air Force Station, Fl, on Mar. 18, 2017. Credit: Ken Kremer/kenkremer.com

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

Launch of USAF WGS-8 milsatcom on ULA Delta IV rocket from pad 37 on Cape Canaveral Air Force Station, Fl, on Mar. 18, 2017. Dawn Leek Taylor

Two AF Generals and a Delta! Major General David D. Thompson, Vice Commander Air Force Space Command, Peterson Air Force Base, CO, and Brig. Gen. Wayne R. Monteith, Commander of the 45th Space Wing Commander and Eastern Range Director at Patrick Air Force Base, Fla, celebrate successful Wideband Global SATCOM (WGS-9) launch for the U.S. Air Force on ULA Delta IV from Cape Canaveral Air Force Station, Fl, on Mar. 18, 2017, with the media gaggle on base post launch with Delta pad 37 in background right. Credit: Ken Kremer/kenkremer.com

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Watch Stars Orbit The Milky Way’s Supermassive Black Hole

Watch Stars Orbit The Milky Way’s Supermassive Black Hole

The Milky Way’s supermassive black hole, called Sagittarius A* (or Sgr A*), is arrowed in the image made of the innermost galactic center in X-ray light by NASA’s Chandra Observatory. To the left or east of Sgr A* is Sgr A East, a large cloud that may be the remnant of a supernova. Centered on Sgr A* is a spiral shaped group of gas streamers that might be falling onto the hole. Credit: NASA/CXC/MIT/Frederick K. Baganoff et al.

When your ordinary citizen learns there’s a supermassive black hole with a mass of 4 million suns sucking on its teeth in the center of the Milky Way galaxy, they might kindly ask exactly how astronomers know this. A perfectly legitimate question. You can tell them that the laws of physics guarantee their existence or that people have been thinking about black holes since 1783. That year, English clergyman John Michell proposed the idea of “dark stars” so massive and gravitationally powerful they could imprison their own light.

This time-lapse movie in infrared light shows how stars in the central light-year of the Milky Way have moved over a period of 14 years. The yellow mark at the image center represents the location of Sgr A*, site of an unseen supermassive black hole.
Credit: A. Eckart (U. Koeln) & R. Genzel (MPE-Garching), SHARP I, NTT, La Silla Obs., ESO

Michell wasn’t making wild assumptions but taking the idea of gravity to a logical conclusion. Of course, he had no way to prove his assertion. But we do. Astronomers  now routinely find bot stellar mass black holes — remnants of the collapse of gas-guzzling supergiant stars — and the supermassive variety in the cores of galaxies that result from multiple black hole mergers over grand intervals of time.

Some of the galactic variety contain hundreds of thousands to billions of solar masses, all of it so to speak “flushed down the toilet” and unavailable to fashion new planets and stars. Famed physicist Stephen Hawking has shown that black holes evaporate over time, returning their energy to the knowable universe from whence they came, though no evidence of the process has yet been found.

On September 14, 2013, astronomers caught the largest X-ray flare ever detected from Sgr A*, the supermassive black hole at the center of the Milky Way, using NASA’s Chandra X-ray Observatory.  This event was 400 times brighter than the usual X-ray output from the source and was possibly caused when Sgr A*’s strong gravity tore apart an asteroid in its neighborhood, heating the debris to X-ray-emitting temperatures before slurping down the remains.The inset shows the giant flare. Credit: NASA

So how do we really know a massive, dark object broods at the center of our sparkling Milky Way? Astronomers use radio, X-ray and infrared telescopes to peer into its starry heart and see gas clouds and stars whirling about the center at high rates of speed. Based on those speeds they can calculate the mass of what’s doing the pulling.

The Hubble Space Telescope took this photo of the  5000-light-year-long jet of radiation ejected from the active galaxy M87’s supermassive black hole, which is aboutt 1,000 times more massive than the Milky Way’s black hole. Although black holes are dark, matter whirling into their maws at high speed is heated to high temperature, creating a bright disk of material and jets of radiation. Credit: NASA/The Hubble Heritage Team (STScI/AURA)

In the case of the galaxy M87 located 53.5 million light years away in the Virgo Cluster, those speeds tell us that something with a mass of 3.6 billion suns is concentrated in a space smaller than our Solar System. Oh, and it emits no light! Nothing fits the evidence better than a black hole because nothing that massive can exist in so small a space without collapsing in upon itself to form a black hole. It’s just physics, something that Mr. Scott on Star Trek regularly reminded a panicky Captain Kirk.

So it is with the Milky Way, only our black hole amounts to a piddling 4 million-solar-mass light thief confined within a spherical volume of space some 27 million miles in diameter or just shy of Mercury’s perihelion distance from the Sun. This monster hole resides at the location of Sagittarius A* (pronounced A- star), a bright, compact radio source at galactic center about 26,000 light years away.

Video showing a 14-year-long time lapse of stars orbiting Sgr A*

The time-lapse movie, compiled over 14 years, shows the orbits of several dozen stars within the light year of space centered on Sgr A*. We can clearly see the star moving under the influence of a massive unseen body — the putative supermassive black hole. No observations of Sgr A* in visible light are possible because of multiple veils of interstellar dust that lie across our line of sight. They quench its light to the tune of 25 magnitudes.

Merging black holes (the process look oddly biological!). Credit: SXS

How do these things grow so big in the first place? There are a couple of ideas, but astronomers don’t honestly know for sure. Massive gas clouds around early in the galaxy’s history could have collapsed to form multiple supergiants that evolved into black holes which later then coalesced into one big hole. Or collisions among stars in massive, compact star clusters could have built up stellar giants that evolved into black holes. Later, the clusters sank to the center of the galaxy and merged into a single supermassive black hole.

Whichever you chose, merging of smaller holes may explain its origin.

On a clear spring morning before dawn, you can step out to face the constellation Sagittarius low in the southern sky. When you do, you’re also facing in the direction of our galaxy’s supermassive black hole. Although you cannot see it, does it not still exert a certain tug on your imagination?

The post Watch Stars Orbit The Milky Way’s Supermassive Black Hole appeared first on Universe Today.

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