March 14, 2017March 14, 2017 by Fraser Cain

What’s on the Surface of Venus?

We’re always talking about Mars here on the Guide to Space. And with good reason. Mars is awesome, and there’s a fleet of spacecraft orbiting, probing and crawling around the surface of Mars.

The Red Planet is the focus of so much of our attention because it’s reasonably close and offers humanity a viable place for a second home. Well, not exactly viable, but with the right technology and techniques, we might be able to make a sustainable civilization there.

We have the surface of Mars mapped in great detail, and we know what it looks like from the surface.

But there’s another planet we need to keep in mind: Venus. It’s bigger, and closer than Mars. And sure, it’s a hellish deathscape that would kill you in moments if you ever set foot on it, but it’s still pretty interesting and mysterious to visit.

Would it surprise you to know that many spacecraft have actually made it down to the surface of Venus, and photographed the place from the ground? It was an amazing feat of Soviet engineering, and there are some new technologies in the works that might help us get back, and explore it longer.

Venera 10 image of Venusian surface (1975). 174-degree raw 6-bit logarithmically encoded telemetry seen above. Linearized and aperture corrected view in center, including data from a second 124-degree panorama. Bottom image had missing portions in-painted with Bertalmio’s algorithm.

Today, let’s talk about the Soviet Venera program. The first time humanity saw Venus from its surface.

Back in the 60s, in the height of the cold war, the Americans and the Soviets were racing to be the first to explore the Solar System. First satellite to orbit Earth (Soviets), first human to orbit Earth (Soviets), first flyby and landing on the Moon (Soviets), first flyby of Mars (Americans), first flyby of Venus (Americans), etc.

The Soviets set their sights on putting a lander down on the surface of Venus. But as we know, this planet has some unique challenges. Every place on the entire planet measures the same 462 degrees C (or 864 F).

Furthermore, the atmospheric pressure on the surface of Venus is 90 times greater than Earth. Being down at the bottom of that column of atmosphere is the same as being beneath a kilometer of ocean on Earth. Remember those submarine movies where they dive too deep and get crushed like a soda can?

Finally, it rains sulphuric acid. I mean, that’s really irritating.

Needless to say, figuring this out took the Soviets a few tries.

Their first attempts to even flyby Venus was Venera 1, on February 4, 1961. But it failed to even escape Earth orbit. This was followed by Venera 2, launched on November 12, 1965, but it went off course just after launch.

Venera 3 blasted off on November 16, 1965, and was intended to land on the surface of Venus. The Soviets lost communication with the spacecraft, but it’s believed it did actually crash land on Venus. So I guess that was the first successful “landing” on Venus?

Before I continue, I’d like to talk a little bit about landing on planets. As we’ve discussed in the past, landing on Mars is really really hard. The atmosphere is thick enough that spacecraft will burn up if you aim directly for the surface, but it’s not thick enough to let you use parachutes to gently land on the surface.

Landing on the surface of Venus on the other hand, is super easy. The atmosphere is so thick that you can use parachutes no problem. If you can get on target and deploy a parachute capable of handling the terrible environment, your soft landing is pretty much assured. Surviving down there is another story, but we’ll get to that.

Venera 4 came next, launched on June 12, 1967. The Soviet scientists had few clues about what the surface of Venus was actually like. They didn’t know the atmospheric pressure, guessing it might be a little higher pressure than Earth, or maybe it was hundreds of times our pressure. It was tested with high temperatures, and brutal deceleration. They thought they’d built this thing plenty tough.

The Venera 4 spacecraft. Venera spacecraft 3 to 6 were similar. Image supplied by NASA

Venera 4 arrived at Venus on October 18, 1967, and tried to survive a landing. Temperatures on its heat shield were clocked at 11,000 C, and it experienced 300 Gs of deceleration.

The initial temperature 52 km was a nice 33C, but then as it descended down towards the surface, temperatures increased to 262 C. And then, they lost contact with the probe, killed dead by the horrible temperature.

We can assume it landed, though, and for the first time, scientists caught a glimpse of just how bad it is down there on the surface of Venus.

Venera 5 was launched on January 5, 1969, and was built tougher, learning from the lessons of Venera 4. It also made it into Venus’ atmosphere, returned some interested science about the planet and then died before it reached the surface.

Venera 6 followed, same deal. Built tougher, died in the atmosphere, returned some useful science.

Venera 7 was built with a full understanding of how bad it was down there on Venus. It launched on August 17, 1970, and arrived in December. It’s believed that the parachutes on the spacecraft only partially deployed, allowing it to descend more quickly through the Venusian atmosphere than originally planned. It smacked into the surface going about 16.5 m/s, but amazingly, it survived, and continued to send back a weak signal to Earth for about 23 minutes.

For the first time ever, a spacecraft had made it down to the surface of Venus and communicated its status. I’m sure it was just 23 minutes of robotic screaming, but still, progress. Scientists got their first accurate measurement of the temperatures, and pressure down there.

Bottom line, humans could never survive on the surface of Venus.

Venera 8 blasted off for Venus on March 17, 1972, and the Soviet engineers built it to survive the descent and landing as long as possible. It made it through the atmosphere, landed on the surface, and returned data for about 50 minutes. It didn’t have a camera, but it did have a light sensor, which told scientists being on Venus was kind of like Earth on an overcast day. Enough light to take pictures… next time.

The Venera 9 spacecraft. Image supplied by NASA

For their next missions, the Soviets went back to the drawing board and built entirely new landing craft. Built big, heavy and tough, designed to get to the surface of Venus and survive long enough to send back data and pictures.

Venera 9 was launched on June 8, 1975. It survived the atmospheric descent and landed on the surface of Venus. The lander was built like a liquid cooled reverse insulated pressure vessel, using circulating fluid to keep the electronics cooled as long as possible. In this case, that was 53 minutes. Venera 9 measured clouds of acid, bromine and other toxic chemicals, and sent back grainy black and white television pictures from the surface of Venus.

In fact, these were the first pictures ever taken from the surface of another planet.

Images from Venera 9 (top) and Venera 10 (bottom). Public Domain Images, courtesy of NASA/National Space Science Data Center.

Venera 10 lasted for 65 minutes and took pictures of the surface with one camera. The lens cap on a second camera didn’t release. The spacecraft saw lava rocks with layers of other rocks in between. Similar environments that you might see here on Earth.

Venera 11 was launched on September 9, 1975 and lasted for 95 minutes on the surface of Venus. In addition to confirming the horrible environment discovered by the other landers, Venera 11 detected lightning strikes in the vicinity. It was equipped with a color camera, but again, the lens cap failed to deploy for it or the black and white camera. So it failed to send any pictures home.

Venera 12 was launched on September 14, 1978, and made it down to the surface of Venus. It lasted 110 minutes and returned detailed information about the chemical composition of the atmosphere. Unfortunately, both its camera lens caps failed to deploy, so no pictures were returned. And pictures are what we really care about, right?

Venera 13 was built on the same tougher, beefier design, and was blasted off to Venus on October 30, 1981, and this one was a tremendous success. It landed on Venus and survived for 127 minutes. It took pictures of its surroundings using two cameras peering through quartz windows, and saw a landscape of bedrock. It used spring-loaded arms to test out how compressible the soil was.

The surface of Venus as captured by Soviet Venera 13 lander in March of 1982. NASA/courtesy of nasaimages.org

Venera 14 was identical and launched just 5 days after Venera 13. It also landed and survived for 57 minutes. Unfortunately, its experiment to test the compressibility of the soil was a botch because one of its lens caps landed right under its spring-loaded arm. But apart from that, it sent back color pictures of the hellish landscape.

And with that, the Soviet Venus landing program ended. And since then, no additional spacecraft have ever returned to the surface of Venus.

It’s one thing for a lander to make it to the surface of Venus, last a few minutes and then die from the horrible environment. What we really want is some kind of rover, like Curiosity, which would last on the surface of Venus for weeks, months or even years and do more science.

And computers don’t like this kind of heat. Go ahead, put your computer in the oven and set it to 850. Oh, your oven doesn’t go to 850, that’s fine, because it would be insane. Seriously, don’t do that, it would be bad.

Engineers at NASA’s Glenn Research Center have developed a new kind of electrical circuitry that might be able to handle those kinds of temperatures. Their new circuits were tested in the Glenn Extreme Environments Rig, which can simulate the surface of Venus. It can mimic the temperature, pressure and even the chemistry of Venus’ atmosphere.

A before (top) and after (bottom) image of the electronics after being tested in the Glenn Extreme Environments Rig. Credit: NASA

The circuitry, originally designed for hot jet engines, lasted for 521 hours, functioning perfectly. If all goes well, future Venus rovers could be developed to survive on the surface of Venus without needing the complex and short lived cooling systems.

This discovery might unleash a whole new era of exploration of Venus, to confirm once and for all that it really does suck.

While the Soviets had a tough time with Mars, they really nailed it with Venus. You can see how they built and launched spacecraft after spacecraft, sticking with this challenge until they got the pictures and data they were looking for. I really think this series is one of the triumphs of robotic space exploration, and I look forward to future mission concepts to pick up where the Soviets left off.

Are you excited about the prospects of exploring Venus with rovers? Let me know your thoughts in the comments.

March 14, 2017 by Evan Gough

Are You Ready For The NanoSWARM?

CubeSats NODes 1 & 2 and STMSat-1 are deployed from the International Space Station during Expedition 47. Image: NASA

We’re accustomed to the ‘large craft’ approach to exploring our Solar System. Probes like the Voyagers, the Mariners, and the Pioneers have written their place in the history of space exploration. Missions like Cassini and Juno are carrying on that work. But advances in technology mean that Nanosats and Cubesats might write the next chapter in the exploration of our Solar System.

Nanosats and Cubesats are different than the probes of the past. They’re much smaller and cheaper, and they offer some flexibility in our approach to exploring the Solar System. A Nanosat is defined as a satellite with a mass between 1 and 10 kg. A CubeSat is made up of multiple cubes of roughly 10cm³ (10cm x 10cm x 11.35cm). Together, they hold the promise of rapidly expanding our understanding of the Solar System in a much more flexible way.

A cubesat structure, made by ClydeSpace, 1U in size. Credit: Wikipedia Commons/Svobodat

NASA has been working on smaller satellites for a few years, and the work is starting to bear some serious fruit. A group of scientists at JPL predicts that by 2020 there will be 10 deep space CubeSats exploring our Solar System, and by 2030 there will be 100 of them. NASA, as usual, is developing NanoSat and CubeSat technologies, but so are private companies like Scotland’s Clyde Space.

Clyde Space from Clyde Space on Vimeo.

INSPIRE and MarCO

NASA has built 2 Interplanetary NanoSpacecraft Pathfinder In Relevant Environment (INSPIRE) CubeSats to be launched in 2017. They will demonstrate what NASA calls the “revolutionary capability of deep space CubeSats.” They’ll be placed in earth-escape orbit to show that they can withstand the rigors of space, and can operate, navigate, and communicate effectively.

Following in INSPIRE’s footsteps will be the Mars Cube One (MarCO) CubeSats. MarCO will demonstrate one of the most attractive aspects of CubeSats and NanoSats: their ability to hitch a ride with larger missions and to augment the capabilities of those missions.

In 2018, NASA plans to send a stationary lander to Mars, called Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight). The MarCO CubeSats will be along for the ride, and will act as communications relays, though they aren’t needed for mission success. They will be the first CubeSats to be sent into deep space.

So what are some specific targets for this new class of small probes? The applications for NanoSats and CubeSats are abundant.

Other NanoSat and CubeSat Missions

NASA’s Europa Clipper Mission, planned for the 2020’s, will likely have CubeSats along for the ride as it scrutinizes Europa for conditions favorable for life. NASA has contracted 10 academic institutes to study CubeSats that would allow the mission to get closer to Europa’s frozen surface.

The ESA’s AIM asteroid probe will launch in 2020 to study a binary asteroid system called the Didymos system. AIM will consist of the main spacecraft, a small lander, and at least two CubeSats. The CubeSats will act as part of a deep space communications network.

ESA’s Asteroid Impact Mission is joined by two triple-unit CubeSats to observe the impact of the NASA-led Demonstration of Autonomous Rendezvous Technology (DART) probe with the secondary Didymos asteroid, planned for late 2022. Image: ESA

The challenging environment of Venus is also another world where CubeSats and NanoSats can play a prominent role. Many missions make use of a gravity assist from Venus as they head to their main objective. The small size of NanoSats means that one or more of them could be released at Venus. The thick atmosphere at Venus gives us a chance to demonstrate aerocapture and to place NanoSats in orbit around our neighbor planet. These NanoSats could take study the Venusian atmosphere and send the results back to Earth.

NanoSWARM

But the proposed NanoSWARM might be the most effective demonstration of the power of NanoSats yet. The NanoSWARM mission would have a fleet of small satellites sent to the Moon with a specific set of objectives. Unlike other missions, where NanoSats and CubeSats would be part of a mission centered around larger payloads, NanoSWARM would be only small satellites.

NanoSWARM is a forward thinking mission that is so far only a concept. It would be a fleet of CubeSats orbiting the Moon and addressing questions around planetary magnetism, surface water on airless bodies, space weathering, and the physics of small-scale magnetospheres. NanoSWARM would target features on the Moon called “swirls“, which are high-albedo features correlated with strong magnetic fields and low surficial water. NanoSWARM CubeSats will make the first near-surface measurements of solar wind flux and magnetic fields at swirls.

This is an image of the Reiner Gamma lunar swirl from NASA’s Lunar Reconnaissance Orbiter.
Credits: NASA LRO WAC science team

NanoSWARM would have a mission architecture referred to as “mother with many children.” The mother ship would release two sets of CubeSats. One set would be released with impact trajectories and would gather data on magnetism and proton fluxes right up until impact. A second set would orbit the Moon to measure neutron fluxes. NanoSWARM’s results would tell us a lot about the geophysics, volatile distribution, and plasma physics of other bodies, including terrestrial planets and asteroids.

Space enthusiasts know that the Voyager probes had less computing power than our mobile phones. It’s common knowledge that our electronics are getting smaller and smaller. We’re also getting better at all the other technologies necessary for CubeSats and NanoSats, like batteries, solar arrays, and electrospray thrusters. As this trend continues, expect nanosatellites and cubesats to play a larger and more prominent role in space exploration.

And get ready for the NanoSTORM.

March 13, 2017April 5, 2020 by Matt Williams

Exploring the Universe For Magnetic Fields

At one time, Mars had a magnetic field similar to Earth, which prevented its atmosphere from being stripped away. Credit: NASA

In the past few decades, astronomers and geophysicists have benefited immensely from the study of planetary magnetic fields. Dedicated to mapping patterns of magnetism on other astronomical bodies, this field has grown thanks to missions ranging from the Voyager probes to the more recent Mars Atmosphere and Volatile EvolutioN (MAVEN) mission.

Looking ahead, it is clear that this field of study will play a vital role in the exploration of the Solar System and beyond. As Jared Espley of NASA’s Goddard Space Flight Center outlined during a presentation at NASA’s Planetary Science Vision 2050 Workshop, these goals include advancing human exploration of the cosmos and the search for extraterrestrial life.

March 13, 2017March 14, 2017 by Ken Kremer

March Launch Madness: Triple Headed Space Spectacular Starts Overnight with SpaceX March 14 – Watch Live

SpaceX Falcon 9 rocket carrying EchoStar 23 telecomsat raised erect atop Launch Complex 39A at the Kennedy Space Center as seen from inside the pad on March 13, 2017 ahead of liftoff slated for 14 Mar 2017 at 1:34 a.m. Credit: Ken Kremer/Kenkremer.com

KENNEDY SPACE CENTER, FL – It’s March Madness for Space fans worldwide! A triple header of space spectaculars starts overnight with a SpaceX Falcon 9 launching in the wee hours of Tuesday, March 14 from the Florida Space Coast.

Indeed a trio of launches is planned in the next week as launch competitor and arch rival United Launch Alliance (ULA) plans a duo of nighttime blastoffs from their Delta and Atlas rocket families – following closely on the heels of the SpaceX Falcon 9 launching a commercial telecommunications satellite.

Of course it’s all dependent on everything happening like clockwork!

And there is no guarantee of that given the unpredictable nature of the fast changing weather on the Florida Space Coast and unknown encounters with technical gremlins which have already plagued all 3 rockets this month.

Each liftoff has already been postponed by several days this month. And the rocket launch order has swapped positions.

At any rate, SpaceX is now the first on tap after midnight tonight on Tuesday, March 14.

The Delta IV and Atlas V will follow on March 17 and March 21 respectively – if all goes well.

So to paraphrase moon walker Buzz Aldrin;

‘Get Your Ass to the Florida Space Coast – Fast !’

The potential for a grand slam also exists at the very end of the month. But let’s get through at least the first launch of Falcon first.

SpaceX Falcon 9 rocket stands at launch pad 39a poised to liftoff with EchoStar 23 TV sat on the Kennedy Space Center ahead of liftoff slated for 14 Mar 2017 at 1:34 a.m. Credit: Julian Leek

Liftoff of the two stage SpaceX Falcon 9 carrying the EchoStar 23 telecommunications satellite is now slated for a post midnight spectacle next Tuesday, Mar. 14 from launch pad 39A on the Kennedy Space Center at the opening of the launch window at 1:34 a.m. EDT.

The two and a half hour launch window closes at 4:04 a.m. EDT.

You can watch the launch live on a SpaceX dedicated webcast starting about 20 minutes prior to the 1:34 a.m. liftoff time.

The SpaceX webcast will be available starting at about 20 minutes before liftoff, at approximately 1:14 a.m. EDT.

Watch at: SpaceX.com/webcast

Following a successful static fire test last week on Mar. 9 of the first stage boosters engines, the SpaceX Falcon 9 was integrated with the EchoStar 23 direct to home TV satellite and rolled back out to pad 39A

The Falcon 9 rocket was raised erect into launch position by the time I visited the pad this afternoon, Monday March 13, to set up my cameras.

The weather outlook is not great at this moment, with rain and thick clouds smothering the coastline and central Florida.

The planned Mar. 14 launch comes barely three weeks after the Falcon’s successful debut on Feb. 19 on the NASA contracted Dragon CRS-10 mission that delivered over 2.5 tons of cargo to the six person crew living and working aboard the International Space Station (ISS).

Raindrops keep falling on the lens, as inaugural SpaceX Falcon 9/Dragon disappears into the low hanging rain clouds at NASA’s Kennedy Space Center after liftoff from pad 39A on Feb. 19, 2017. Dragon CRS-10 resupply mission is delivering over 5000 pounds of science and supplies to the International Space Station (ISS) for NASA. Credit: Ken Kremer/kenkremer.com

Launch Complex 39A was repurposed by SpaceX from launching Shuttles to Falcons. It had lain dormant for launches for nearly six years since Space Shuttle Atlantis launched on the final shuttle mission STS 135 in July 2011.

SpaceX bilionaire CEO Elon Musk announced last week that he wants to launch a manned Moonshot from pad 39A by the end of next year using his triple barreled Falcon Heavy heavy lift rocket – derived from the Falcon 9.

The second launch of the trio on tap is a United Launch Alliance Delta 4 rocket carrying the WGS-9 high speed military communications satellite for the U.S. Air Force.

Liftoff of the ULA Delta is slated for March 17 from Space Launch Complex-37 at 7: 44 p.m. EDT.

A United Launch Alliance (ULA) Delta IV rocket carrying the WGS-8 mission lifts off from Space Launch Complex-37 at 6:53 p.m EDT on Dec. 7, 2016 from Cape Canaveral Air Force Station, Fla. Credit: Ken Kremer/kenkremer.com

The S.S. John Glenn is scheduled to as the Orbital ATK Cygnus OA-7 spacecraft for NASA on a United Launch Alliance (ULA) Atlas V rocket launch no earlier than March 21 from Space launch Complex-41 (SLC-41) on Cape Canaveral Air Force Station, Florida.

Orbital ATK Cygnus OA-7 spacecraft named the SS John Glenn for Original 7 Mercury astronaut and Sen. John Glenn, undergoes processing inside the Payload Hazardous Servicing Facility at NASA’s Kennedy Space Center in Florida on March 9, 2017 for launch slated for March 21 on a ULA Atlas V. Credit: Ken Kremer/Kenkremer.com

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

Ken Kremer

SpaceX Falcon 9 EchoStar 23 mission patch. Credit: SpaceX

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Learn more about SpaceX EchoStar 23 and CRS-10 launch to ISS, ULA SBIRS GEO 3 launch, EchoStar launch GOES-R launch, Heroes and Legends at KSCVC, OSIRIS-REx, InSight Mars lander, ULA, SpaceX and Orbital ATK missions, Juno at Jupiter, SpaceX AMOS-6, ISS, ULA Atlas and Delta rockets, Orbital ATK Cygnus, Boeing, Space Taxis, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events at Kennedy Space Center Quality Inn, Titusville, FL:

Mar 13-15: “SpaceX EchoStar 23, CRS-10 launch to ISS, ULA Atlas SBIRS GEO 3 launch, EchoStar 19 comsat launch, GOES-R weather satellite launch, OSIRIS-Rex, SpaceX and Orbital ATK missions to the ISS, Juno at Jupiter, ULA Delta 4 Heavy spy satellite, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

SpaceX conducts successful static hot fire test of Falcon 9 booster atop Launch Complex 39A at the Kennedy Space Center on Mar 9, 2017 as seen from Space View Park, Titusville, FL. Liftoff with EchoStar 23 comsat is planned for 14 March 2017. Credit: Ken Kremer/Kenkremer.com

March 13, 2017April 4, 2017 by Matt Williams

Strange Loner Planet Gets Astronomers’ Attention

Artist’s impression of the free-floating object known as CFBDSIR J~214947.2-040308.9. Credit: ESO/L. Calçada/P. Delorme/R. Saito/VVV Consortium.

In the hunt for exoplanets, some rather strange discoveries have been made. Beyond our Solar System, astronomers have spotted gas giants and terrestrial planets that appear to be many orders of magnitude larger than what we are used to (aka. “Super-Jupiters” and “Super-Earths”). And in some cases, it has not been entirely clear what our instruments have been detecting.

For instance, in some cases, astronomers have not been sure if an exoplanet candidate was a super-Jupiter or a brown dwarf. Not only do these substellar-mass stars fall into the same temperature range as massive gas giants, they also share many of the same physical properties. Such was the conundrum addressed by an international team of scientists who recently conduced a study of the object known as CFBDSIR 2149-0403.

Located between 117 and 143 light-years from Earth, this mysterious object is what is known as a “free-floating planetary mass object”. It was originally discovered in 2012 by a team of French and Canadian astronomers led by Dr. Phillipe Delorme of the University Grenoble Alpes using the Canada-France Brown Dwarfs Survey – a near infrared sky survey with the Canada-France Hawaii Telescope at Mauna Kea.

*The Canada France Hawaii Telescope, near the summit of Mauna Kea, Hawaii. Credit: cfht.hawaii.edu/*

The existence of this object was then confirmed using data by the Wide-field Infrared Survey Explorer (WISE), and was believed at the time to be part of a group of stars known as the AB Doradus Moving Group (30 stars that are moving through space). The data collected on this object placed its mass at between 4 and 7 Jupiter masses, its age at 20 to 200 million years, and its surface temperature at about 650-750 K.

This was the first time that such an object had constraints placed upon its mass and age using spectral data. However, questions remained about its true nature – whether it was a low mass, high-metallicity brown dwarf or a isolated planetary mass. For the sake of their study, Delorme and the international team conducted a multi-wavelength, multi-instrument observational characterization of CFBDSIR 2149-0403.

This consisted of x-ray data from the X-Shooter instrument on the ESO’s Very Large Telescope (VLT), near-infrared data from the VLT’s Hawk-1 instrument, and infrared data from the Spitzer Space Telescope and the CFHT’s Wide-field InfraRed Camera (WIRCam). As Delorme told Tomasz Nowakowski of Phys.org:

“The X-Shooter data enabled a detailed study of the physical properties of this object. However, all the data presented in the paper is really necessary for the study, especially the follow-up to obtain the parallax of the object, as well as the Spitzer photometry. Together, they enable us to get the bolometric flux of the object, and hence constraints that are almost independent from atmosphere model assumptions.”

*An artist’s conception of a T-type brown dwarf star. Credit: Wikimedia Commons/Tyrogthekreeper*

From the combined data, they were able to characterize the absolute flux of the CFBDSIR 2149-0403, obtain readings on its spectrum, and even determine the radial velocity of the object. They were therefore able to determine that it not likely a member of a moving population of stars, as was previously expected.

“We now reject our initial hypothesis that CFBDSIR 2149-0403 would be a member of the AB Doradus moving group,” said Delorme. “This removes the most robust age constraint we had. Though determining that certainly improved our knowledge of the object it also made it more difficult to study, by adding age as a free parameter.”

As for what it is, they narrowed that down to one of two possibilities. Basically, it could be a planetary-mass object with a mass of between 2 and 13 Jupiters that is less than 500 million years in age, or a high metallicity brown dwarf that is between 2 and 40 Jupiter masses and two to three billion years in age. Ultimately, they acknowledge that this uncertainty is due to the fact that our theoretical understanding of cool, low-gravity, and metallicity-enhanced bodies is not robust enough yet.

Much of this has to do with the fact that brown dwarfs and super gas giants have common physical parameters that produce very similar effects in the spectra of their atmospheres. But as astronomers gain more of an understanding of planetary formation, which is made possible by the discovery of so many extra-solar planetary systems, we might just find where the line between the smallest of stars and the largest of gas giants is drawn.

Further Reading: arXiv, Phys.org

March 13, 2017April 4, 2017 by Nancy Atkinson

Closest Star Around A Black Hole Discovered

This artist's impression depicts a white dwarf star found in the closest known orbit around a black hole. As the circle around each other, the black hole's gravitational pull drags material from the white dwarf's outer layers toward it. Astronomers found that the white dwarf in X9 completes one orbit around the black hole in less than a half an hour. They estimate the white dwarf and black hole are separated by about 2.5 times the distance between the Earth and Moon — an extraordinarily small span in cosmic terms. (Credit: NASA/CXC/M.Weiss)

Imagine being caught in the clutches of a black hole, being whirled around at dizzying speeds and having your mass slowly but continually sucked away. That’s the life of a white dwarf star that is doing an orbital dance with a black hole. And this dancing duo could be the first ultracompact black hole X-ray binary identified in our galaxy.

“This white dwarf is so close to the black hole that material is being pulled away from the star and dumped onto a disk of matter around the black hole before falling in,” said Arash Bahramian from the University of Alberta in Edmonton, Canada, and Michigan State University, first author of a new paper.

If you were the white dwarf in this predicament, you may wish for a quick end to it all. But somehow, the star does not appear to be in danger of falling in or being torn apart by the black hole.

“We don’t think it will follow a path into oblivion, but instead will stay in orbit,” Bahramian added.

Data from the Chandra X-ray Observatory, the NuSTAR mission and the Australian Telescope Compact Array (ATCA) shows evidence that this star whips around the black hole about twice an hour, and it may be the tightest orbital dance ever witnessed for a likely black hole and a companion star.

This seemingly unique binary system – with a great name, X9 — is located in the globular cluster 47 Tucanae, a dense cluster of stars in our galaxy about 14,800 light years from Earth.

Astronomers have been studying this system for a while.

“For a long time, it was thought that X9 is made up of a white dwarf pulling matter from a low mass Sun-like star,” Bahramian wrote in a blog post.

But 2015, radio observations with the ATCA showed the pair likely contains a black hole pulling material from a companion star called a white dwarf, a low-mass star that has exhausted most or all of its nuclear fuel.

“In 2015, Dr. Miller-Jones and collaborators observed strong radio emission from X9 indicating the presence of a black hole in this binary,” Bahramian continued. “They suggested that this might mean the system is made up of a black hole pulling matter from a white dwarf.”

Astronomers found an extraordinarily close stellar pairing in the globular cluster 47 Tucanae, a dense collection of stars located on the outskirts of the Milky Way galaxy, about 14,800 light years from Earth. Credit: X-ray: NASA/CXC/University of Alberta/A.Bahramian et al.

Looking at archived Chandra data, it showed changes in X-ray brightness in the same manner every 28 minutes, and Bahramian and his PhD supervisor Craig Heink think this is likely the length of time it takes the companion star to make one complete orbit around the black hole. Chandra data also shows evidence for large amounts of oxygen in the system, a characteristic feature of white dwarfs. They feel a strong case can be made that the companion star is a white dwarf. And this star would then be orbiting the black hole at just 2.5 times the distance between the Earth and the Moon.

“Eventually so much matter may be pulled away from the white dwarf that it ends up only having the mass of a planet,” said Heinke, also of the University of Alberta. “If it keeps losing mass, the white dwarf may completely evaporate.”

The researchers think this system would be a good candidate for future gravitational wave observatories to observe. It has to low of a frequency that is too low to be detected with Laser Interferometer Gravitational-Wave Observatory, LIGO, that made ground-breaking detections of gravitational waves last year. Systems like this could tell us more about gravitational waves, as well as providing more information about black hole binary systems.

“We’re going to watch this binary closely in the future, since we know little about how such an extreme system should behave”, said co-author Vlad Tudor of Curtin University and the International Centre for Radio Astronomy Research in Perth, Australia. “We’re also going to keep studying globular clusters in our galaxy to see if more evidence for very tight black hole binaries can be found.”

Further reading:
Chandra press release
ICRAR press release
Blog post
Paper: The ultracompact nature of the black hole candidate X-ray binary 47 Tuc X9

March 13, 2017March 27, 2017 by Tammy Plotner

Messier 37 – the NGC 2099 Open Star Cluster

The open star cluster Messier 38, in proximity to Messier 36 and Messier 37. Credit: Wikisky

Welcome back to Messier Monday! In our ongoing tribute to the great Tammy Plotner, we take a look at the open star cluster known as Messier 37. Enjoy!

During the 18th century, famed French astronomer Charles Messier noted the presence of several “nebulous objects” in the night sky. Having originally mistaken them for comets, he began compiling a list of them so that others would not make the same mistake he did. In time, this list (known as the Messier Catalog) would come to include 100 of the most fabulous objects in the night sky.

One of these objects is the open star cluster known as Messier 37 (aka M37 and NGC 2099). Located in the direction of the Auriga constellation, Messier 37 is one of three open star clusters (including Messier 36 and Messier 38) in this portion of the night sky – and also the brightest.

Description:

Of the trio of Messier star clusters in this area, M37 is by far the most stellar populated. It contains at least 150 stars that are around magnitude 12 and easily resolved by even small telescopes – and science is still counting actual members! At around 347 – 550 million years old, you’ll find at least a dozen red giants living here about 4,500 light years away from Earth… and they do it in a neighborhood that spans anywhere from 20 to 25 light years across!

*The open star cluster Messier 37. Credit: Wikisky*

Just how many stars might be inside this intermediate-aged cluster? As R. Sagar and Nilakshi of the Indian Institute for Astrophysics said in their 2002 study:

“The CCD observations of the rich open star cluster NGC 2099 and its surrounding field region have been carried out up to a limiting magnitude of V ~ 22 mag in B, V and I passbands for the first time. A total of ~ 12 000 stars have been observed in the area of about 24 arcmin x 34 arcmin in the cluster region, as well as ~ 2180 stars in the ~ 12arcmin x 12arcmin area of the field region located ~ 45arcmin away from the cluster center.”

Out of this huge number of stars, astronomers have been able to observe white dwarfs, too. This helps us to understand how they develop and what affects their helium or hydrogen content. Jasonjot Singh Kalirai et al. had the following to say in a 2004 study:

“Spectra have been obtained of 21 white dwarfs (WDs) in the direction of the young, rich open star cluster NGC 2099. This represents an appreciable fraction (>30%) of the cluster’s total WD population. The mean derived mass of the sample is 0.8 M—about 0.2 M larger than the mean seen among field WDs. A surprising result is that all of the NGC 2099 WDs have hydrogen-rich atmospheres (DAs); none exhibit helium-rich ones (DBs) or any other spectral class. We explore possible reasons for the lack of DBs in these clusters and conclude that the most promising scenario for the DA/DB number ratio discrepancy in young clusters is that hot, high-mass WDs do not develop large enough helium convection zones to allow helium to be brought to the surface and turn a hydrogen-rich WD into a helium-rich one.”

So, we’re setting the stage with number of stars and types. We have white dwarfs – but what about variables? Y.B. Kang (et al), put it this way in a 2007 study:

“Time-series CCD photometric observations of the intermediate-age open cluster NGC 2099 were performed to search for variable stars. We also carried out BV photometry to study physical properties of variables in the cluster. Using V-band time-series data, we carefully examined light variations of about 12,000 stars in the range of 10 < V < 22 mag. A total of 24 variable stars have been identified; seven stars are previously known variables and 17 stars are newly identified. On the basis of observational properties such as light curve shape, period, and amplitude, we classified the new variable stars as nine delta Scuti-type pulsating stars, seven eclipsing binaries, and one peculiar variable star. Judging from the position of delta Scuti-type stars in the color-magnitude diagram, only two stars are likely to have the cluster membership. One new variable KV10 shows peculiar light variations with a delta Scuti-type short period of about 0.044 day as well as a long period of 0.417 day.”

*M37 (NGC 2099) open cluster. Credit: Wikipedia Commons*

So what does knowing about these two types of stars help with our understanding of stellar evolution? That’s one of the goals of the RACE-OC project. As S. Messina (et al) said in 2008:

“Rotation and solar-type magnetic activity are closely related to each other in main-sequence stars of G or later spectral types. The presence and level of magnetic activity depend on star’s rotation, and rotation itself is strongly influenced by strength and topology of the magnetic fields. Open clusters represent especially useful targets to investigate the connection between rotation and activity. The open cluster NGC 2099 has been studied as a part of the RACE-OC project (Rotation and ACtivity Evolution in Open Clusters), which is aimed at exploring the evolution of rotation and magnetic activity in the late-type members of open clusters of different ages. We collected time series CCD photometric observations of this cluster in January 2004, and we determined the presence of periodicities in the flux variation related to the stellar rotation by Fourier analysis. We investigate the relations between activity manifestations, such as the light curve amplitude, and global stellar parameters. Results: We have discovered 135 periodic variables, 122 of which are candidate cluster members. Determination of rotation periods of G- and K-type stars has allowed us to better explore the evolution of angular momentum at an age of about 500 Myr. In our analysis, we have also identified 3 new detached eclipsing binary candidates among cluster members. A comparison with the older Hyades cluster (~625 Myr) shows that the newly-determined distribution of rotation periods is consistent with the scenario of rotational braking of main-sequence spotted stars as they age. However, a comparison with the younger M 34 cluster (~200 Myr) shows that the G8-K5 members of these clusters have the same rotation period distribution. That is, G8-K5 members in NGC 2099 seem to have experienced no significant braking in the age range from ~200 to ~500 Myr. Finally, NGC 2099 members have a smaller level of photospheric magnetic activity, as measured by light curve amplitude, than in younger stars of the same mass and rotation, suggesting that the activity level also depends on some other age-dependent parameters.”

History of Observation:

Although this great star cluster was originally recorded Giovanni Batista Hodierna before 1654, it would be 230 years before his records would be uncovered, so when Charles Messier first logged as Messier 37, it was believed to be an independent discovery.

“In the same night [September 2 to 3, 1764], I have observed a second cluster of small stars which were not very distant from the preceding, near the right leg of Auriga and on the parallel of the star Chi of that constellaiton: the stars there are smaller than that of the preceding cluster: they are also closer to each other, and contain a nebulosity. With an ordinary refractor of 3 feet and a half, one has difficulty to see these stars; but one distinguishes them with an instrument of greater effectivity. I have determined the position fo this cluster, which may have an extension of 8 to 9 minutes of arc: its right ascension was 84d 15′ 12″, and its declination 32d 11′ 51″ north.”

While William Herschel would return in later years to study Messier’s object, he did not publish his notes – but gives some great observing advice:

“A useful, coarse step; it will serve to learn to see nebulae, because it contains many small stars mixed with others in various magnitudes, many of which are not to be seen without great and long attention.” Messier 37 would be later given its NGC catalog designation by John Herschel who was the first to make a guess at its true stellar population: “Very fine large cluster, all resolved into stars of 10th to 13th magnitude. It fills 1 1/2 field, but the straggling stars extend very far. There may be 500 stars.”

As always, Admiral Smyth was the most poetical about his observing, and of M37 he writes:

“A magnificent object, the whole field being strewed as it were with sparkling gold-dust; and the group is resolvable into about 500 stars, from the 10th to the 14th magnitudes, besides the outliers. It was found and fixed by Messier in 1764, who described it as “a mass of small stars, much enveloped in nebulous matter.” This nebulous matter, however, yields to my telescope, and resolves into infinitely minute points of lucid light, among the distinct little individuals.”

*The location of Messier 37 in the constellation Auriga. Credit: IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg)*

Locating Messier 37:

Locating Messier 37 is relatively easy once you understand the constellation of Auriga. Looking roughly like a pentagon in shape, start by identifying the brightest of these stars – Capella. Due south of it is the second brightest star which shares its border with Beta Tauri, El Nath. By aiming binoculars at El Nath, go north about 1/3 the distance between the two and enjoy all the stars! You will note two very conspicuous clusters of stars in this area, and so did Le Gentil in 1749.

Binoculars will reveal the pair in the same field, as will telescopes using lowest power. The dimmest of these is the M38, and will appear vaguely cruciform in shape. At roughly 4200 light years away, larger aperture will be needed to resolve the 100 or so fainter members. About 2 1/2 degrees to the southeast (about a finger width) you will see the much brighter M36.

More easily resolved in binoculars and small scopes, this “jewel box” galactic cluster is quite young and about 100 light years closer. If you continue roughly on the same trajectory about another 4 degrees southeast you will find open cluster M37. This galactic cluster will appear almost nebula-like to binoculars and very small telescopes – but comes to perfect resolution with larger instruments.

While all three open star clusters make fine choices for moonlit or light polluted skies, remember that high sky light means less faint stars which can be resolved – robbing each cluster of some of its beauty. Messier 37 is the brightest and easternmost of the trio and you’ll very much notice its density.

When you view this cluster with binoculars, you’ll be seeing it much as Messier did… But use the power of a telescope if you can. Because this cloud of stars is quite worth your time and attention!

Object Name: Messier 37
Alternative Designations: M37, NGC 2099
Object Type: Galactic Open Star Cluster
Constellation: Auriga
Right Ascension: 05 : 52.4 (h:m)
Declination: +32 : 33 (deg:m)
Distance: 4.4 (kly)
Visual Brightness: 6.2 (mag)
Apparent Dimension: 24.0 (arc min)

We have written many interesting articles about Messier Objects here at Universe Today. Here’s Tammy Plotner’s Introduction to the Messier Objects, , M1 – The Crab Nebula, M8 – The Lagoon Nebula, and David Dickison’s articles on the 2013 and 2014 Messier Marathons.

Be to sure to check out our complete Messier Catalog. And for more information, check out the SEDS Messier Database.

Sources:

March 13, 2017 by Susie Murph

Carnival of Space #500

Carnival of Space. Image by Jason Major.

This week’s Carnival of Space is hosted by Stefan Lamoureux at the Links Through Space blog.

Click here to read Carnival of Space #500.
Continue reading “Carnival of Space #500”

March 11, 2017March 14, 2017 by Ken Kremer

Next Cygnus Cargo Ship Christened the SS John Glenn to Honor First American in Orbit

The Orbital ATK Cygnus spacecraft named for Sen. John Glenn, one of NASA's original seven astronauts, stands inside the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida behind a sign commemorating Glenn on March 9, 2017. It launched on April 18, 2017 on a ULA Atlas V. Credit: Ken Kremer/Kenkremer.com

KENNEDY SPACE CENTER, FL – The next Cygnus cargo ship launching to the International Space Station (ISS) has been christened the ‘S.S. John Glenn’ to honor legendary NASA astronaut John Glenn – the first American to orbit the Earth back in February 1962.

John Glenn was selected as one of NASA’s original seven Mercury astronauts chosen at the dawn of the space age in 1959. He recently passed away on December 8, 2016 at age 95.

The naming announcement was made by spacecraft builder Orbital ATK during a ceremony with the ‘S.S. John Glenn’, held inside the Kennedy Space Center (KSC) clean room facility where the cargo freighter is in the final stages of flight processing – and attended by media including Universe Today on Thursday, March 9.

“It is my humble duty and our great honor to name this spacecraft the S.S. John Glenn,” said Frank DeMauro, vice president and general manager of Orbital ATK’s Advanced Programs division, during the clean room ceremony in the inside the Payload Hazardous Servicing Facility high bay at NASA’s Kennedy Space Center in Florida.

The next Orbital ATK Cygnus supply ship was christened the SS John Glenn in honor of Sen. John Glenn, one of NASA’s original seven astronauts as it stands inside the Payload Hazardous Servicing Facility at NASA’s Kennedy Space Center on March 9, 2017. Launch slated for March 21 on a ULA Atlas V. Credit: Ken Kremer/Kenkremer.com

The S.S. John Glenn is scheduled to liftoff as the Orbital ATK Cygnus OA-7 spacecraft for NASA on a United Launch Alliance (ULA) Atlas V rocket launch no earlier than March 21 from Space launch Complex-41 (SLC-41) on Cape Canaveral Air Force Station, Florida.

The space station resupply mission dubbed Cygnus OA-7 is dedicated to Glenn and his landmark achievement as the first American to orbit the Earth on Feb. 20, 1962 and his life promoting science, human spaceflight and education.

“John Glenn was probably responsible for more students studying math and science and being interested in space than anyone,” said former astronaut Brian Duffy, Orbital ATK’s vice president of Exploration Systems, during the clean room ceremony on March 9.

“When he flew into space in 1962, there was not a child then who didn’t know his name. He’s the one that opened up space for all of us.”

The Orbital ATK Cygnus OA-7 supply ship named in honor of Sen. John Glenn, one of NASA’s original seven astronauts stands inside the Payload Hazardous Servicing Facility at KSC. Launch slated for March 21 on a ULA Atlas V. Credit: Julian Leek

Glenn’s 3 orbit mission played a pivotal role in the space race with the Soviet Union at the height of the Cold War era.

“He has paved the way for so many people to follow in his footsteps,” said DeMauro.

All of Orbital ATK’s Cygnus freighters have been named after deceased American astronauts.

Glenn is probably America’s most famous astronaut in addition to Neil Armstrong, the first man to walk on the moon during Apollo 11 in 1969.

John Glenn went on to become a distinguished U.S. Senator from his home state of Ohio on 1974. He served for 24 years during 4 terms.

He later flew a second mission to space aboard the Space Shuttle Discovery in 1998 as part of the STS-95 crew at age 77. Glenn remains the oldest person ever to fly in space.

“Glenn paved the way for America’s space program, from moon missions, to the space shuttle and the International Space Station. His commitment to America’s human space flight program and his distinguished military and political career make him an ideal honoree for the OA-7 mission,” Orbital ATK said in a statement.

“The OA-7 mission is using the Enhanced Cygnus Pressurized Cargo Module (PCM) to deliver cargo to the International Space Station,” said DeMauro.

Cygnus will carry 7,700 pounds (3500 kg) of cargo to the station with a total volumetric capacity of 27 cubic meters.

“All these teams have worked extremely hard to get this mission to this point and we are looking forward to a great launch.”

Orbital ATK Cygnus OA-7 supply ship named the SS John Glenn undergoes processing inside the Payload Hazardous Servicing Facility at KSC on March 9, 2017. Launch slated for March 21 on a ULA Atlas V. Credit: Ken Kremer/Kenkremer.com

This is the third Cygnus to launch on an Atlas V rocket from the Cape. The last one launched a year ago on March 24, 2016 during the OA-6 mission. The first one launched in December 2015 during the OA-4 mission.

“We’re building the bridge to history with these missions,” said Vernon Thorp, ULA’s program manager for Commercial Missions.

“Every mission is fantastic and every mission is unique. At the end of the day every one of these missions is critical.”

The other Cygnus spacecraft have launched on the Orbital ATK commercial Antares rocket from NASA Wallops Flight Facility on Virginia’s eastern shore.

A United Launch Alliance (ULA) Atlas V rocket carrying the Orbital ATK Cygnus OA-6 mission lifted off from Space Launch Complex 41 at 11:05 p.m. EDT on March 22, 2016 from Cape Canaveral Air Force Station, Fla. Credit: Ken Kremer/kenkremer.com

Overall this is Orbital ATK’s seventh commercial resupply services mission (CRS) to the space station under contract to NASA.

OA-7 also counts as NASA’s second supply mission of the year to the station following last month’s launch of the SpaceX Dragon CRS-10 capsule on Feb. 19 and which is currently berthed to the station at a Earth facing port on the Harmony module.

Historic maiden blastoff of SpaceX Falcon 9 rocket from Launch Complex 39A at the Kennedy Space Center) at 9:38 a.m. EDT on Feb 19, 2017, on Dragon CRS-10 resupply mission to the International Space Station (ISS) for NASA. Credit: Ken Kremer/kenkremer.com

The Cygnus OA-8 mission will launch again from NASA Wallops in the summer of 2017, DeMauro told me.

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

Ken Kremer

Posing with the newly christened SS John Glenn for the Cygnus OA-7 resupply mission to the ISS are Vern Thorp, United Launch Alliance Program program manager for Commercial Missions, Ken Kremer, Universe Today and Frank DeMauro, Orbital ATK vice president and general manager of Orbital ATK’s Advanced Programs division inside the Payload Hazardous Servicing Facility cleanroom at NASA’s Kennedy Space Center on March 9, 2017. Credit: Ken Kremer/Kenkremer.com

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March 11, 2017March 11, 2017 by Matt Williams

Exploring Titan with Aerial Platforms

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

Last week, from Monday Feb. 27th to Wednesday March 1st, NASA hosted the “Planetary Science Vision 2050 Workshop” at their headquarters in Washington, DC. During the course of the many presentations, speeches and addresses that made up the workshop, NASA and its affiliates shared their many proposals for the future of Solar System exploration.

A very popular theme during the workshop was the exploration of Titan. In addition to being the only other body in the Solar System with a nitrogen-rich atmosphere and visible liquid on its surface, it also has an environment rich in organic chemistry. For this reason, a team led by Michael Pauken (from NASA’s Jet Propulsion Laboratory) held a presentation detailing the many ways it can be explored using aerial vehicles.

The presentation, which was titled “Science at a Variety of Scientific Regions at Titan using Aerial Platforms“, was also chaired by members of the aerospace industry – such as AeroVironment and Global Aerospace from Monrovia, California, and Thin Red Line Aerospace from Chilliwack, BC. Together, they reviewed the various aerial platform concepts that have been proposed for Titan since 2004.

*Artist depiction of the ESA’s Huygens lander setting down on Titan, which took place on January 14th. Credit: ESA*

While the concept of exploring Titan with aerial drones and balloons dates back to the 1970s and 80s, 2004 was especially important since it was at this time that the Huygens lander conducted the first exploration of the moon’s surface. Since that time, many interesting and feasible proposals for aerial platforms have been made. As Dr. Pauken told Universe Today via email:

“The Cassini-Huygens mission revealed a lot about Titan we didn’t know before and that has also raised a lot more questions. It helped us determine that imaging the surface is possible below 40-km altitude so it’s exciting to know we could take aerial photos of Titan and send them back home.”

These concepts can be divided into two categories, which are Lighter-Than-Air (LTA) craft and Heavier-Than-Air (HTA) craft. And as Pauken explained, these are both well-suited when it comes to exploring a moon like Titan, which has an atmosphere that is actually denser than Earth’s – 146.7 kPa at the surface compared to 101 kPa at sea level on Earth – but only 0.14 times the gravity (similar to the Moon).

“The density of Titan’s atmosphere is higher than Earth’s so it is excellent for flying lighter-than-air vehicles like a balloon,” he said. “Titan’s low gravity is a benefit for heavier-than-air vehicles like helicopters or airplanes since they will ‘weigh’ less than they would on Earth.”

Titan’s atmosphere makes Saturn’s largest moon look like a fuzzy orange ball in this natural-color view from the Cassini spacecraft. Cassini captured this image in 2012. Credit: NASA/JPL-Caltech/Space Science Institute

“The Lighter-than-air LTA concepts are buoyant and don’t need any energy to stay aloft, so more energy can be directed towards science instruments and communications. The Heavier-than-air concepts have to consume power to stay in the air which takes away from science and telecom. But HTA can be directed to targets more quickly and accurately the LTA vehicles which mostly drift with the winds.”

TSSM Montgolfiere Balloon:

Plans for using a Montgolfiere balloon to explore Titan go back to 2008, when NASA and the ESA jointly developed the Titan Saturn System Mission (TSSM) concept. A Flagship Mission concept, the TSSM would consist of three elements including a NASA orbiter and two ESA-designed in-situ elements – a lander to explore Titan’s lakes and a Montgolfiere balloon to explore its atmosphere.

The orbiter would rely on a Radioisotopic Power System (RPS) and Solar Electric Propulsion (SEP) to reach the Saturn system. And on its way to Titan, it would be responsible for examining Saturn’s magnetosphere, flying through the plumes of Enceladus to analyze it for biological markers, and taking images of Enceladus’ “Tiger Stripes” in the southern polar region.

*Artist’s concept of a Mongolfiere balloon and a deployable lander at Titan. Credit: NASA*

Once the orbiter had achieved orbital insertion with Saturn, it would release the Montgolfiere during its first Titan flyby. Attitude control for the balloon would be provided by heating the ambient gas with RPS waste heat. The prime mission would last a total of about 4 years, comprised of a two-year Saturn tour, a 2-month Titan aero-sampling phase, and a 20-month Titan orbiting phase.

Of the benefits to this concept, the most obvious is the fact that a Montgolfiere vehicle powered by RPS could operate within Titan’s atmosphere for many years and would be able to change altitude with only minimal energy use. At the time, the TSSM concept was in competition with mission proposals for the moons of Europa and Ganymede.

In February of 2009, both the TSSM and the the Europa Jupiter System Mission (EJSM) concept were chosen to move forward with development, but the EJSM was given first priority. This mission was renamed the Europa Clipper, and is slated for launch in 2020 (and arriving at Europa by 2026).

Titan Helium Balloon:

Subsequent research on Montgolfiere balloons revealed that years of service and minimal energy expenditure could also be achieved in a much more compact balloon design. By combining an enveloped-design with helium, such a platform could operate in the skies of Titan for four times as long as balloons here on Earth, thanks to a much slower rate of diffusion.

Artist’s concept of the Mechanical Compression Altitude Control (MCAC) balloon, which is comprised of a number of segments that are compressed by shortening a tether that runs down the axis of the balloon. Credit: Thin Red Line Aerospace.

Altitude control would also be possible with very modest amounts of energy, which could be provided either through pump or mechanical compression. Thus, with an RPS providing power, the platform could be expected to last longer that comparable balloon designs. This envelope-helium balloon could also be paired with a glider to create a lighter-than-air vehicle capable of lateral motion as well.

Examples of the this include the Titan Winged Aerobot (TWA, shown below), which was investigated as part of NASA’s Phase One 2016 Small-Business Innovation Research (SBIR) program. Developed by the Global Aerospace Corporation, in collaboration with Northrop Grumman, the TWA is a hybrid entry vehicle, balloon, and maneuverable glider with 3-D directional control that could satisfy many science objectives.

Like the Mongtolfiere concept, it would rely on minimal power provided by a single RPS. Its unique buoyancy system would also allow it to descend and ascend without the need for propulsion systems or control surfaces. One drawback is the fact that it cannot land on the moon’s surface to conduct research and then take off again. However, the design does allow for low-altitude flight, which would allow for the delivery of probes to the surface.

Other concepts that have been developed in recent years include heavier-than-air aircraft, which center around the development of fixed-wing vehicles and rotorcraft.

*Concept for a Titan Winged Aerobot, a hybrid balloon glider that does not require significant power either to stay aloft or to achieve lateral motion. Credit: Global Aerospace Corp/Northrup Grumman*

Fixed Wing Vehicles:

Concepts for fixed-wing aircraft have also been proposed in the past for a mission to Titan. A notable example of this is the Aerial Vehicle for In-situ and Airborne Titan Reconnaissance (AVIATR), an unmanned aerial vehicle (UAV) that was proposed by Jason Barnes and Lawrence Lemke in 2011 (of the University of Idaho and Central Michigan University, respectively).

Relying on an RPS that would use the waste heat of decaying Plutonium 238 to power a small rear-mounted turbine, this low-power craft would take advantage of Titan’s dense atmosphere and low gravity to conduct sustained flight. A novel “climb-then-glide” strategy, where the engine would shut down during glide periods, would also allow for power to be stored for optimal use during telecommunication sessions.

This addresses a major drawback of fixed-wing vehicles, which is the need to subdivide power between the needs of maintaining flight and conducting scientific research. However, the AVIATR is limited in one respect, in that it cannot descend to the surface to conduct science experiments or collect samples.

Rotorcraft:

Last, but not least, is the concept for a rotorcraft. In this case, the aerial platform would be a quadcopter, which would be well-suited to Titan’s atmosphere, would allow for easy ascent and descent, and for studies to be conducted on the surface. It would also take advantage of developments made in commercial UAVs and drones in recent years.

*Artist’s concept of the Titan Aerial Daughtercraft (TAD) flying above one of Titan’s methane lake. Credit: NASA*

This mission concept would consist of two components. On the one hand, there’s the rotorcraft – known as a Titan Aerial Daughtercraft (TAD) – which would rely on a rechargeable battery system to power itself while conducting short-duration flights (about an hour at a time). The second component is the “Mothercraft”, which would take the form of a lander or balloon, which the TAD would return to between flights to recharge from an onboard RPS.

Currently, NASA’s Jet Propulsion Laboratory is developing a similar concept, known as the Mars Helicopter “Scout”, for use on Mars – which is expected to be launched aboard the Mars 2020 mission. In this case, the design calls for two coaxial counter-rotating rotors, which would provide the best thrust-to-weight ratio in Mars’ thin atmosphere.

Another rotorcraft concept is being pursued by Elizabeth Turtle and colleagues from John Hopkins APL and the University of Idaho (including James Barnes). With support from NASA and members of Goddard Space Flight Center, Pennsylvania State University, and Honeybee Robotics, they have proposed a concept known as the “Dragonfly“.

Their aerial vehicle would rely on four-rotors to take advantage of Titan’s thick atmosphere and low gravity. Its design would also allow it to easily obtain samples and determine the composition of the surface in multiple geological settings. These findings will be presented at the upcoming 48th Lunar and Planetary Science Conference – which will be taking place from March 20th to 24th in The Woodlands, Texas.

*Artist’s concept of the Titan Aerial Daughter quadcopter and its “Mothercraft” balloon. Credit: NASA/STMD*

While the exploration of Titan is likely to take a back seat to the exploration of Europa in the coming decades, it is anticipated that a mission will be mounted before the mid-point of this century. Not only are the scientific goals very much the same in both cases – a chance to explore a unique environment and search for life beyond Earth – but the benefits will be comparable as well.

With every potentially life-bearing body we explore, we stand to learn more about how life began in our Solar System. And even if we do not find any life in the process, we stand to learn a great deal about the history and formation of the Solar System. On top of that, we will be one step closer to understanding humanity’s place in the Universe.

Further Reading: USRA