Posted on by Evan Gough

Scientists Propose a New Kind of Planet: A Smashed Up Torus of Hot Vaporized Rock

Artist's impression of a Mars-sized object crashing into the Earth, starting the process that eventually created our Moon. Credit: Joe Tucciarone
Artist's impression of a Mars-sized object crashing into the Earth, starting the process that eventually created our Moon. Credit: Joe Tucciarone

There’s a new type of planet in town, though you won’t find it in well-aged solar systems like our own. It’s more of a stage of formation that planets like Earth can go through. And its existence helps explain the relationship between Earth and our Moon.

The new type of planet is a huge, spinning, donut-shaped mass of hot, vaporized rock, formed as planet-sized objects smash into each other. The pair of scientists behind the study explaining this new planet type have named it a ‘synestia.’ Simon Lock, a graduate student at Harvard University, and Sarah Stewart, a professor in the Department of Earth and Planetary Sciences at the University of California, Davis, say that Earth was at one time a synestia.

Rocky planets like Earth are accreted from smaller bodies over time. Objects with high energy and high angular momentum could form a synestia, a transient stage in planetary formation where vaporized rock orbits the rest of the body. In this image, each of the three stages has the same mass. Image: Simon Lock, Harvard University
Rocky planets like Earth are accreted from smaller bodies over time. Objects with high energy and high angular momentum could form a synestia, a transient stage in planetary formation where vaporized rock orbits the rest of the body. In this image, each of the three stages has the same mass. Image: Simon Lock, Harvard University

The current theory of planetary formation goes like this: When a star forms, the left-over material is in motion around the star. This left-over material is called a protoplanetary disk. The material coagulates into larger bodies as the smaller ones collide and join together.

As the bodies get larger and larger, the force of their collisions becomes greater and greater, and when two large bodies collided, their rocky material melts. Then, the newly created body cools, and becomes spherical. It’s understood that this is how Earth and the other rocky planets in our Solar System formed.

Lock and Stewart looked at this process and asked what would happen if the resulting body was spinning quickly.

When a body is spinning, the law of conservation of angular momentum comes into play. That law says that a spinning body will spin until an external torque slows it down. The often-used example from figure skating helps explain this.

If you’ve ever watched figure skaters, and who hasn’t, their actions are very instructive. When a single skater is spinning rapidly, she stretches out her arms to slow the rate of spin. When she folds her arms back into her body, she speeds up again. Her angular momentum is conserved.

This short video shows figure skaters and physics in action.

If you don’t like figure skating, this one uses the Earth to explain angular momentum.

Now take the example from a pair of figure skaters. When they’re both turning, and the two of them join together by holding each other’s hands and arms, their angular momentum is added together and conserved.

Replace two figure skaters with two planets, and this is what the two scientists behind the study wanted to model. What would happen if two large bodies with high energy and high angular momentum collided with each other?

If the two bodies had high enough temperatures and high enough angular momentum, a new type of planetary structure would form: the synestia. “We looked at the statistics of giant impacts, and we found that they can form a completely new structure,” Stewart said.

“We looked at the statistics of giant impacts, and we found that they can form a completely new structure.” – Professor Sarah Stewart, Department of Earth and Planetary Sciences at the University of California, Davis.

As explained in a press release from the UC Davis, for a synestia to form, some of the vaporized material from the collision must go into orbit. When a sphere is solid, every point on it is rotating at the same rate, if not the same speed. But when some of the material is vaporized, its volume expands. If it expands enough, and if its moving fast enough, it leaves orbit and forms a huge disc-shaped synestia.

Other theories have proposed that two large enough bodies could form an orbiting molten mass after colliding. But if the two bodies had high enough energy and temperature to vaporize some of the rock, the resulting synestia would occupy a much larger space.

“The main issue with looking for synestias around other stars is that they don’t last a long time. These are transient, evolving objects that are made during planet formation.” – Professor Sarah Stewart, UC Davis.

These synestias likely wouldn’t last very long. They would cool quickly and condense back into rocky bodies. For a body the size of Earth, the synestia might only last one hundred years.

The synestia structure sheds some light on how moons are formed. The Earth and the Moon are very similar in terms of composition, so it’s likely they formed as a result of a collision. It’s possible that the Earth and Moon formed from the same synestia.

These synestias have been modelled, but they haven’t been observed. However, the James Webb Space Telescope will have the power to peer into protoplanetary disks and watch planets forming. Will it observe a synestia?

“These are transient, evolving objects that are made during planet formation.” – Professor Sarah Stewart, UC Davis

In an email exchange with Universe Today, Dr. Sarah Stewart of UC Davis, one of the scientists behind the study, told us that “The main issue with looking for synestias around other stars is that they don’t last a long time. These are transient, evolving objects that are made during planet formation.”

“So the best bet for finding a rocky synestia is young systems where the body is close to the star. For gas giant planets, they may form a synestia for a period of their formation. We are getting close to being able to image circumplanetary disks in other star systems.”

Once we have the ability to observe planets forming in their circumstellar disks, we may find that synestias are more common than rare. In fact, planets may go through the synestia stage multiple times. Dr. Stewart told us that “Based on the statistics presented in our paper, we expect that most (more than half) of rocky planets that form in a manner similar to Earth became synestias one or more times during the giant impact stage of accretion.”

Posted on by Fraser Cain

Astronomy Cast Ep. 449: Robots in Space!

When you think of a robot, you’re probably imagining some kind of human-shaped machine. And until now, the robotic spacecraft we’ve sent out into space to help us explore the Solar System look nothing like that. But that vision of robots is coming back, thanks to a few new robots in development by NASA and other groups.

Visit the Astronomy Cast Page to subscribe to the audio podcast!

We usually record Astronomy Cast as a live Google+ Hangout on Air every Friday at 1:30 pm Pacific / 4:30 pm Eastern. You can watch here on Universe Today or from the Astronomy Cast Google+ page.

Posted on by Matt Williams

What is Neptune Made Of?

The interior structure of Neptune. Credit: Moscow Institute of Physics and Technology

Since it’s discovery in the mid-19th century, Neptune has consistently been a planet of mystery. As the farthest planet from our Sun, it has only been visited by a single robotic mission. And there are still many unanswered questions about what kind of mechanics power its interior. Nevertheless, what we have learned about the planet in the course of the past few decades is considerable.

For example, thanks to the Voyager 2 probe and multiple surveys using Earth-based instruments, scientists have managed to gain a pretty good understanding of Neptune’s structure and composition. In addition to knowing what makes up its atmosphere, planetary models have also predicted what the interior of the planet looks like. So just what is Neptune made of?

Structure and Composition:

Neptune, like the rest of the gas giant planets in the Solar System, can be broken up into various layers. The composition of Neptune changes depending on which of these layers you’re looking at. The outermost layer of Neptune is the atmosphere, forming about 5-10% of the planet’s mass, and extending up to 20% of the way down to its core.

Composition and interior structure of Neptune. Credit: NASA

Beneath the atmosphere is the planet’s large mantle. This is a superheated liquid region where temperatures can reach as high as 2,000 to 5,000 K (1727 – 4727 °C; 3140 – 8540 °F). The mantle is equivalent to 10 – 15 Earth masses and is rich in water, ammonia and methane. This mixture is referred to as icy even though it is a hot, dense fluid, and is sometimes called a “water-ammonia ocean”.

Increasing concentrations of methane, ammonia and water are found in the lower regions of the atmosphere. Unlike Uranus, Neptune’s composition has a higher volume of ocean, whereas Uranus has a smaller mantle. Like the other gas/ice giants, Neptune is believed to have a solid core, the composition of which is still subject to guesswork. However, the theory that it is rocky and metal-rich is consistent with current theories of planet formation.

In accordance with these theories, the core of Neptune is composed of iron, nickel and silicates, with an interior model giving it a mass about 1.2 times that of Earth. The pressure at the center is estimated to be 7 Mbar (700 GPa), about twice as high as that at the center of Earth, and with temperatures as high as 5,400 K. At a depth of 7000 km, the conditions may be such that methane decomposes into diamond crystals that rain downwards like hailstones.

Due to its smaller size and higher concentrations of volatiles relative to Jupiter and Saturn, Neptune (much like Uranus) is often referred to as an “ice giant” – a subclass of a giant planet. Also like Uranus, Neptune’s internal structure is differentiated between a rocky core consisting of silicates and metals; a mantle consisting of water, ammonia and methane ices; and an atmosphere consisting of hydrogen, helium and methane gas.

Uranus and Neptune, the Solar System’s ice giant planets. Credit: Wikipedia Commons

Neptune’s Atmosphere:

Neptune’s atmosphere forms about 5% to 10% of its mass and extends perhaps 10% to 20% of the way towards the core, where it reaches pressures of about 10 GPa – or about 100,000 times that of Earth’s atmosphere. At high altitudes, Neptune’s atmosphere is 80% hydrogen and 19% helium, with a trace amount of methane.

As with Uranus, this absorption of red light by the atmospheric methane is part of what gives Neptune its blue hue, although Neptune’s is darker and more vivid. Because Neptune’s atmospheric methane content is similar to that of Uranus, some unknown atmospheric constituent is thought to contribute to Neptune’s more intense coloring.

Neptune’s atmosphere is subdivided into two main regions: the lower troposphere (where temperature decreases with altitude), and the stratosphere (where temperature increases with altitude). The boundary between the two, the tropopause, lies at a pressure of 0.1 bars (10 kPa). The stratosphere then gives way to the thermosphere at a pressure lower than 10-5 to 10-4 microbars (1 to 10 Pa), which gradually transitions to the exosphere.

Neptune’s spectra suggest that its lower stratosphere is hazy due to condensation of products caused by the interaction of ultraviolet radiation and methane (i.e. photolysis), which produces compounds such as ethane and ethyne. The stratosphere is also home to trace amounts of carbon monoxide and hydrogen cyanide, which are responsible for Neptune’s stratosphere being warmer than that of Uranus.

Color and contrast-modified image that emphasizes Neptune’s atmospheric features. Neptune’s Great Dark Spot stands out as the most prominent feature on the left. Credit: Erich Karkoschka

For reasons that remain obscure, the planet’s thermosphere experiences unusually high temperatures of about 750 K (476.85 °C/890 °F). The planet is too far from the Sun for this heat to be generated by ultraviolet radiation, which means another heating mechanism is involved – which could be the atmosphere’s interaction with ion’s in the planet’s magnetic field, or gravity waves from the planet’s interior that dissipate in the atmosphere.

Because Neptune is not a solid body, its atmosphere undergoes differential rotation. The wide equatorial zone rotates with a period of about 18 hours, which is slower than the 16.1-hour rotation of the planet’s magnetic field. By contrast, the reverse is true for the polar regions where the rotation period is 12 hours.

This differential rotation is the most pronounced of any planet in the Solar System, and results in strong latitudinal wind shear and violent storms. The three most impressive were all spotted in 1989 by the Voyager 2 space probe, and then named based on their appearances.

The first to be spotted was a massive anticyclonic storm measuring 13,000 x 6,600 km and resembling the Great Red Spot of Jupiter. Known as the Great Dark Spot, this storm was not spotted five later (Nov. 2nd, 1994) when the Hubble Space Telescope looked for it. Instead, a new storm that was very similar in appearance was found in the planet’s northern hemisphere, suggesting that these storms have a shorter life span than Jupiter’s.

Reconstruction of Voyager 2 images showing the Great Black spot (top left), Scooter (middle), and the Small Black Spot (lower right). Credit: NASA/JPL

The Scooter is another storm, a white cloud group located farther south than the Great Dark Spot. This nickname first arose during the months leading up to the Voyager 2 encounter in 1989, when the cloud group was observed moving at speeds faster than the Great Dark Spot.

The Small Dark Spot, a southern cyclonic storm, was the second-most-intense storm observed during the 1989 encounter. It was initially completely dark; but as Voyager 2 approached the planet, a bright core developed and could be seen in most of the highest-resolution images.

Exploration:

The Voyager 2 probe is the only spacecraft to have ever visited Neptune. The spacecraft’s closest approach to the planet occurred on August 25th, 1989, which took place at a distance of 4,800 km (3,000 miles) above Neptune’s north pole. Because this was the last major planet the spacecraft could visit, it was decided to make a close flyby of the moon Triton – similar to what had been done for Voyager 1‘s encounter with Saturn and its moon Titan.

The spacecraft performed a near-encounter with the moon Nereid before it came to within 4,400 km of Neptune’s atmosphere on August 25th, then passed close to the planet’s largest moon Triton later the same day. The spacecraft verified the existence of a magnetic field surrounding the planet and discovered that the field was offset from the center and tilted in a manner similar to the field around Uranus.

Neptune’s rotation period was determined using measurements of radio emissions and Voyager 2 also showed that Neptune had a surprisingly active weather system. Six new moons were discovered during the flyby, and the planet was shown to have more than one ring.

While no missions to Neptune are currently being planned, some hypothetical missions have been suggested. For instance, a possible Flagship Mission has been envisioned by NASA to take place sometime during the late 2020s or early 2030s. Other proposals include a possible Cassini-Huygens-style “Neptune Orbiter with Probes”, which was suggested back in 2003.

Another, more recent proposal by NASA was for Argo – a flyby spacecraft that would be launched in 2019, which would visit Jupiter, Saturn, Neptune, and a Kuiper belt object. The focus would be on Neptune and its largest moon Triton, which would be investigated around 2029.

Given its distance from Earth, it is no secret why the Trans-Neptunian region remains mysterious to us. In the coming decades, several proposed missions are expected to travel there and explore its rich population of icy bodies and the giant planet for which it is named. From these studies, we are likely to learn a great deal about Neptune and the history of the Solar System.

We have written many interesting articles about Neptune on Universe Today. Here’s Who Discovered Neptune?, What is the Surface of Neptune Like?, What is the Surface Temperature of Neptune?, How Many Moons Does Neptune Have?, What’s the Atmosphere of Neptune Like?, What Color is Neptune?, The Orbit of Neptune: How Long is a Year on Neptune?

If you’d like more information on Neptune, take a look at Hubblesite’s News Releases about Neptune, and here’s a link to NASA’s Solar System Exploration Guide to Neptune.

We have recorded an entire episode of Astronomy Cast just about Neptune. You can listen to it here, Episode 63: Neptune.

Sources:

Posted on by Matt Williams

We Have More Details on the Outermost Trappist-1 Planet!

An artist’s conception shows the planet TRAPPIST-1h. (NASA / JPL-Caltech)

The announcement of a seven-planet system around the star TRAPPIST-1 earlier this year set off a flurry of scientific interest. Not only was this one of the largest batches of planets to be discovered around a single star, the fact that all seven were shown to be terrestrial (rocky) in nature was highly encouraging. Even more encouraging was the fact that three of these planets were found to be orbiting with the star’s habitable zone.

Since that time, astronomers have been seeking to learn all they can about this system of planets. Aside from whether or not they have atmospheres, astronomers are also looking to learn more about their orbits and surface conditions. Thanks to the efforts of a University of Washington-led international team of astronomers, we now have an accurate idea of what conditions might be like on its outermost planet – TRAPPIST-1h.

Continue reading “We Have More Details on the Outermost Trappist-1 Planet!”

Posted on by Matt Williams

Here’s How We Can Detect Plants on Extrasolar Planets

Artist’s impression of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri. The double star Alpha Centauri AB is visible to the upper right of Proxima itself. Credit: ESO

The past year has been an exciting time for those engaged in the hunt for extra-solar planets and potentially habitable worlds. In August of 2016, researchers from the European Southern Observatory (ESO) confirmed the existence of the closest exoplanet to Earth (Proxima b) yet discovered. This was followed a few months later (February of 2017) with the announcement of a seven-planet system around TRAPPIST-1.

The discovery of these and other extra-solar planets (and their potential to host life) was an overarching theme at this year’s Breakthrough Discuss conference. Taking place between April 20th and 21st, the conference was hosted by Stanford University’s Department of Physics and sponsored by the Harvard-Smithsonian Center for Astrophysics and Breakthrough Initiatives.

Continue reading “Here’s How We Can Detect Plants on Extrasolar Planets”

Posted on by Matt Williams

Do Gravitational Waves Permanently Alter the Nature of Spacetime?

In February 2016, LIGO detected gravity waves for the first time. As this artist's illustration depicts, the gravitational waves were created by merging black holes. The third detection just announced was also created when two black holes merged. Credit: LIGO/A. Simonnet.
Artist's impression of merging binary black holes. Credit: LIGO/A. Simonnet.

On February 11th, 2016, scientists at the Laser Interferometer Gravitational-wave Observatory (LIGO) announced the first detection of gravitational waves. This development, which confirmed a prediction made by Einstein’s Theory of General Relativity a century prior, opened new avenues of research for cosmologists and astrophysicists. It was also a watershed for researchers at Monash University, who played an important role in the discovery.

And now, a little over a year later, a team of researchers from the Monash Center for Astrophysics has announced another potential revelation. Based on their ongoing studies of gravitational waves, the team recently proposed a theoretical concept known as ‘orphan memory’. If true, this concept could revolutionize the way we think about gravitational waves and spacetime.

Researchers from Monash Center for Astrophysics are part of what is known as the LIGO Scientific Collaboration (LSC) – a group of scientists dedicated to developing the hardware and software needed to study gravitational waves. In addition to creating a system for vetting detections, the team played a key role in data analysis – observing and interpreting the data that was gathered – and were also instrumental in the design of the LIGO mirrors.

Looking beyond what LIGO and other experiments (like the Virgo Interferometer) observed, the research team sought to address how these detectors capabilities could be extended further by finding the “memory” of gravitational waves. The study that describes this theory was recently published in the Physical Review Letters under the title “Detecting Gravitational Wave Memory without Parent Signals“.

According to their new theory, spacetime does not return to its normal state after a cataclysmic event generates gravitational waves that cause it to stretch out. Instead, it remains stretched, which they refer to as “orphan memory” – the word “orphan” alluding to the fact the “parent wave” is not directly detectable. While this effect has yet to be observed, it could open up some very interesting opportunities for gravitational wave research.

At present, detectors like LIGO and Virgo are only able to discern the presence of gravitational waves at certain frequencies. As such, researchers are only able to study waves generated by specific types of events and trace them back to their source. As Lucy McNeill, a researchers from the Monash Center for Astrophysics and the lead author on the paper, said in a recent University press statement:

“If there are exotic sources of gravitational waves out there, for example, from micro black holes, LIGO would not hear them because they are too high-frequency. But this study shows LIGO can be used to probe the universe for gravitational waves that were once thought to be invisible to it.”

LIGO’s two facilities, located in Livingston, Louisiana, and Hanford, Washington. Credit: ligo.caltech.edu

As they indicate in their study, high-frequency gravitational-wave bursts (i.e. ones that are in or below the kilohertz  range) would produce orphan memory that the LIGO and Virgo detectors would be able to pick up. This would not only increase the bandwidth of these detectors exponentially, but open up the possibility of finding evidence of gravity wave bursts in previous searches that went unnoticed.

Dr Eric Thrane, a lecturer at the Monash School of Physics and Astronomy and another a member of the LSC team, was also one of the co-authors of the new study. As he stated, “These waves could open the way for studying physics currently inaccessible to our technology.”

But as they admit in their study, such sources might not even exist and more research is needed to confirm that “orphan memory” is in fact real. Nevertheless, they maintain that searching for high-frequency sources is a useful way to probe for new physics, and it just might reveal things we weren’t expecting to find.

“A dedicated gravitational-wave memory search is desirable. It will have enhanced sensitivity compared to current burst searches,” they state. “Further, a dedicated search can be used to determine whether a detection candidate is consistent with a memory burst by checking to see if the residuals (following signal subtraction) are consistent with Gaussian noise.”

Alas, such searches may have to wait upon the proposed successors to the Advanced LIGO experiment. These include the Einstein Telescope and Cosmic Explorer, two proposed third-generation gravitational wave detectors. Depending on what future surveys find, we may discover that spacetime not only stretches from the creation of gravitational waves, but also bears the “stretch marks” to prove it!

Further Reading: Physical Review Letters

 

Posted on by Fraser Cain

Astronomy Cast Ep. 448: Prepping for the Eclipse

On Monday, August 21, 2017, there’s going to be a total eclipse of the Sun, visible to path that goes right through the middle of the United States. You should be making plans to see this, and we’re here to help you know where to go and what to do.
Visit the Astronomy Cast Page to subscribe to the audio podcast!

We usually record Astronomy Cast as a live Google+ Hangout on Air every Friday at 1:30 pm Pacific / 4:30 pm Eastern. You can watch here on Universe Today or from the Astronomy Cast Google+ page.

Posted on by Ken Kremer

Two Veteran NASA Astronauts Michael Foale and Ellen Ochoa Inducted into U.S. Astronaut Hall of Fame at KSC

Two veteran retired NASA astronauts - Michael Foale and Ellen Ochoa - were inducted into the U.S. Astronaut Hall of Fame on May 22, 2017 during induction ceremony held below Space Shuttle Atlantis in the display pavilion at the Kennedy Space Center Visitor Complex in Florida. Credit: Ken Kremer/kenkremer.com
Two veteran retired NASA astronauts – Michael Foale and Ellen Ochoa – were inducted into the U.S. Astronaut Hall of Fame on May 19, 2017 during induction ceremony held below Space Shuttle Atlantis in the display pavilion at the Kennedy Space Center Visitor Complex in Florida. Credit: Ken Kremer/kenkremer.com

KENNEDY SPACE CENTER VISITOR COMPLEX, FL – In a moving ceremony, a pair of veteran NASA astronauts – Michael Foale and Ellen Ochoa – who once flew together on a space shuttle mission, were inducted into the U. S. Astronaut Hall of Fame at the Kennedy Space Center Visitor Complex, Florida, on May 19.

Between them, Foale and Ochoa flew to space a combined total of ten times – 6 for Foale and 4 for Ochoa.

They flew together as crewmates on the STS-56 space shuttle mission aboard Space Shuttle Discovery which launched from the Kennedy Space Center, Florida, on 8 April 1993.

The nine day STS-56 mission was Ochoa’s rookie flight and Foale’s second flight. It was the second of the shuttle’s ATLAS series of Earth science missions – dubbed Atlas-2 – whose purpose was to study the atmosphere and solar interactions.

“I was so happy to hear he and I were going to be inducted together,” Ochoa said during her acceptance speech. “He’d already had one mission and he passed along all kinds of helpful information that helped a rookie like me know where to focus and hopefully not be too surprised when the flight happened. Because being surprised in space is really not a good thing, as Mike found out.”

Ellen Ochoa counts as the first Hispanic woman to travel to space and currently serves as the 11th director of NASA’s Johnson Space Center in Houston.

Michael Foale counts as the only U.S. astronaut to serve on both the International Space Station (ISS) and Russian space station Mir.

Foale was on board Mir in June 1997 during one of the worst disasters in space when an out of control unmanned Russian Progress cargo ship collided with the station’s Spektr module causing its air depressurization and sent Mir tumbling and rolling. He and his two Russian crewmates rapidly went into action to seal the leak, to stabilize and save Mir and themselves. He spent four months on Mir during the Mir 23 and Mir 24 missions.

The induction ceremony was held in a truly magnificent setting below NASA’s retired Space Shuttle Atlantis orbiter now on permanent display in a dedicated pavilion at the Kennedy Space Center Visitor Complex in Florida.

Two veteran NASA astronauts joined the ranks of the U.S. Astronaut Hall of Fame, Ellen Ochoa, the first Hispanic woman to travel to space and current JSC Director, and Michael Foale, the only U.S. astronaut to serve on both the International Space Station and Russian space station Mir. Credit: NASA

Ochoa and Foale joined the ranks of 93 prestigious American space heroes who have previously received the same honor over the years since the U. S. Astronaut Hall of Fame was established in its current incarnation more than 30 years ago by the founders of the Astronaut Scholarship Foundation, the six surviving Mercury 7 astronauts.

The new duo comprise the 16th group of space shuttle astronauts to be inducted into the Hall of Fame.

Thus the Astronaut Hall of Fame now numbers 95 heroic and famous space explorers.

Foale and Ochoa unveiled their new ‘Hall of Fame’ commemorative plaques during the ceremony.

The plaques will be put on public display for all to see where they will join the others at the new U.S. Astronaut Hall of Fame (AHOF) pavilion – which had its Grand Opening in November 2016 as part of the new Heroes & Legends attraction located at the entrance to the Kennedy Space Center Visitor Complex.

The Astronaut Scholarship Foundation has awarded more than $4 million in merit-based scholarships to more than 400 brilliant students since its inception.

Group shot of 21 NASA astronauts posing with the two new NASA astronauts – Michael Foale and Ellen Ochoa – who were inducted into the U.S. Astronaut Hall of Fame on May 19, 2017 during induction ceremony held below Space Shuttle Atlantis in the display pavilion at the Kennedy Space Center Visitor Complex in Florida. Credit: Ken Kremer/kenkremer.com

Some 21 legendary NASA astronauts were on hand for the induction ceremony, including: Robert Cabana, Dan Brandenstein, Al Worden, Charlie Duke, Karol “Bo” Bobko, Brian Duffy, Scott Altman, Michael Bloomfield, Charles Bolden, Ken Bowersox, Curtis Brown, Michael Coats, Robert Crippen, Sam Durrance, Robert Gibson, Fred Gregory, Rhea Seddon, Brewster Shaw, Loren Shriver, Kathryn Thornton, and James Wetherbee.

Two veteran retired NASA astronauts – Michael Foale and Ellen Ochoa – were inducted into the U.S. Astronaut Hall of Fame on May 19, 2017 and show their medals to the media after induction ceremony held below Space Shuttle Atlantis in the display pavilion at the Kennedy Space Center Visitor Complex in Florida. Credit: Ken Kremer/kenkremer.com

Here is a description of their space flight accomplishments from NASA:

“Ochoa joined NASA in 1988 as a research engineer at NASA’s Ames Research Center in California after earning a doctorate in electrical engineering from Stanford University. She joined Johnson in 1990, when she was selected as an astronaut candidate. After completing astronaut training, she served on the nine-day STS-56 mission aboard the space shuttle Discovery in 1993, conducting atmospheric studies to better understand the effect of solar activity on Earth’s climate and environment.

Ochoa has flown in space four times, including the STS-66, STS-96 and STS-110 missions, logging nearly 1,000 hours in orbit. She is Johnson’s first Hispanic director and its second female director. She also has served as the center’s deputy director and director of Flight Crew Operations.”

“Foale, whose hometown is Cambridge, England, earned a doctorate in laboratory astrophysics from the University of Cambridge, Queens’ College. A naturalized U.S. citizen, Foale was selected as an astronaut candidate in June 1987. Before his first spaceflight, he tested shuttle flight software in the Shuttle Avionics Integration Laboratory simulator.

Foale was a crew member on six space missions, including STS-45, STS-56, STS-63, STS-84, STS-103 and Soyuz TMA-3. During STS-84, he helped reestablish the Russian Space Station Mir after it was degraded by a collision and depressurization. Foale logged more than 374 days in space, including four spacewalks totaling 22 hours and 44 minutes.

Foale also served as chief of the Astronaut Office Expedition Corps, assistant director (technical) of Johnson, and deputy associate administrator for exploration operations at NASA Headquarters in Washington. His last assignment at Johnson was as chief of the Soyuz Branch, Astronaut Office, supporting Soyuz and International Space Station operations and space suit development. Foale retired from NASA in 2013.”

Read this description of the U.S. Astronaut Hall of Fame Induction Process and Eligibility:

“Each year, inductees are selected by a committee of Hall of Fame astronauts, former NASA officials, flight directors, historians and journalists. The process is administered by the Astronaut Scholarship Foundation. To be eligible, an astronaut must have made his or her first flight at least 17 years before the induction. Candidates must be a U.S. citizen and a NASA-trained commander, pilot or mission specialist who has orbited the earth at least once.”

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

Ken Kremer

Grand opening ceremony for the ‘Heroes and Legends’ attraction on Nov. 11, 2016 at the Kennedy Space Center Visitor Complex in Florida and attended by more than 25 veteran and current NASA astronauts. It includes the new home of the U.S. Astronaut Hall of Fame, presented by Boeing. In addition to displays honoring the 93 Americans currently enshrined in the hall, the facility looks back to the pioneering efforts of Mercury, Gemini and Apollo. It provides the background and context for space exploration and the legendary men and women who pioneered the nation’s journey into space. Credit: Ken Kremer/kenkremer.com
Posted on by Fraser Cain

The Mars Project! Von Braun’s Ideas for a Mars Mission. Collaboration with Vintage Space

Humans to Mars!
Humans to Mars!

Did you know that it’s been almost 45 years since humans walked on the surface of the Moon? Of course you do. Anyone who loves space exploration obsesses about the last Apollo landings, and counts the passing years of sadness.

Sure, SpaceX, Blue Origins and the new NASA Space Launch Systems rocket offer a tantalizing future in space. But 45 years. Ouch, so much lost time.

What would happen if we could go back in time? What amazing and insane plans did NASA have to continue exploring the Solar System? What alternative future could we have now, 45 years later?

In order to answer this question, I’ve teamed up with my space historian friend, Amy Shira Teitel, who runs the Vintage Space blog and YouTube Channel. We’ve decided to look at two groups of missions that never happened.

In her part, Amy talks about the Apollo Applications Program; NASA’s original plans before the human exploration of the Moon was shut down. More Apollo missions, the beginnings of a lunar base, and even a human flyby of Venus.

In my half of the series, I look at Werner Von Braun’s insanely ambitious plans to send a human mission to Mars. Put it together with Amy’s episode and you can imagine a space exploration future with all the ambition of the Kerbal Space Program.

Keep mind here that we’re not going to constrain ourselves with the pesky laws of physics, and the reality of finances. These ideas were cool, and considered by NASA engineers, but they weren’t necessarily the best ideas, or even feasible.

So, 2 parts, tackle them in any order you like. My part begins right now.

Werner Von Braun, of course, was the architect for NASA’s human spaceflight efforts during the space race. It was under Von Braun’s guidance that NASA developed the various flight hardware for the Mercury, Gemini and Apollo missions including the massive Saturn V rocket, which eventually put a human crew of astronauts on the Moon and safely returned them back to Earth.

Wernher von Braun. Credit: NASA/Marshall Space Flight Center

Von Braun was originally a German rocket scientist, pivotal to the Nazi “rocket team”, which developed the ballistic V-2 rockets. These unmanned rockets could carry a 1-tonne payload 800 kilometers away. They were developed in 1942, and by 1944 they were being used in war against Allied targets.

By the end of the war, Von Braun coordinated his surrender to the Allies as well as 500 of his engineers, including their equipment and plans for future rockets. In “Operation Paperclip”, the German scientists were captured and transferred to the White Sands Proving Ground in New Mexico, where they would begin working on the US rocket efforts.

Von Braun and others standing in front a V-2 rocket engine at White Sands. Credit: U.S. Army/ Ordway Collection/Space Rocket Center

Before the work really took off, though, Von Braun had a couple of years of relative downtime, and in 1947 and 1948, he wrote a science fiction novel about the human exploration of Mars.

The novel itself was never published, because it was terrible, but it also contained a detailed appendix containing all the calculations, mission parameters, hardware designs to carry out this mission to Mars.

The Mars Project

In 1952, this appendix was published in Germany as “Das Marsproject”, or “The Mars Project”. And an English version was published a few years later. Collier’s Weekly Magazine did an 8-part special on the Mars Project in 1952, captivating the world’s imagination.

Here’s the plan: In the Mars Project, Von Braun envisioned a vast armada of spaceships that would make the journey from Earth to Mars. They would send a total of 10 giant spaceships, each of which would weigh about 4,000 tonnes.

Just for comparison, a fully loaded Saturn V rocket could carry about 140 tonnes of payload into Low Earth Orbit. In other words, they’d need a LOT of rockets. Von Braun estimated that 950 three-stage rockets should be enough to get everything into orbit.

Ships being assembled in orbit. Credit: Collier’s

All the ships would be assembled in orbit, and 70 crewmembers would take to their stations for an epic journey. They’d blast their rockets and carry out a Mars Hohmann transfer, which would take them 8 months to make the journey from Earth to Mars.

The flotilla consisted of 7 orbiters, huge spheres that would travel to Mars, go into orbit and then return back to Earth. It also consisted of 3 glider landers, which would enter the Martian atmosphere and stay on Mars.

Once they reached the Red Planet, they would use powerful telescopes to scan the Martian landscape and search for safe and scientifically interesting landing spots. The first landing would happen at one of the planet’s polar caps, which Von Braun figured was the only guaranteed flat surface for a landing.

A rocket-powered glider descending towards Mars. Credit: Collier’s

At this point, it’s important to note that Von Braun assumed that the Martian atmosphere was about as thick as Earth’s. He figured you could use huge winged gliders to aerobrake into the atmosphere and land safely on the surface.

He was wrong. The atmosphere on Mars is actually only 1% as thick as Earth’s, and these gliders would never work. Newer missions, like SpaceX’s Red Dragon and Interplanetary Transport Ship will use rockets to make a powered landing.

I think if Von Braun knew this, he could have modified his plans to still make the whole thing work.

Landed at the polar cap. Credit: Collier’s

Once the first expedition landed at one of the polar caps, they’d make a 6,400 kilometer journey across the harsh Martian landscape to the first base camp location, and build a landing strip. Then two more gliders would detach from the flotilla and bring the majority of the explorers to the base camp. A skeleton crew would remain in orbit.

Once again, I think it’s important to note that Von Braun didn’t truly understand how awful the surface of Mars really is. The almost non-existent atmosphere and extreme cold would require much more sophisticated gear than he had planned for. But still, you’ve got to admire his ambition.

Preparing the gliders for rocket-powered ascent. Credit: Collier’s

With the Mars explorer team on the ground, their first task was to turn their glider-landers into rockets again. They would stand them up and get them prepped to blast off from the surface of Mars when their mission was over.

The Martian explorers would set up an inflatable habitat, and then spend the next 400 days surveying the area. Geologists would investigate the landscape, studying the composition of the rocks. Botanists would study the hardy Martian plant life, and seeing what kinds of Earth plants would grow.

Zoologists would study the local animals, and help figure out what was dangerous and what was safe to eat. Archeologists would search the region for evidence of ancient Martian civilizations, and study the vast canal network seen from Earth by astronomers. Perhaps they’d even meet the hardy Martians that built those canals, struggling to survive to this day.

Once again, in the 1940s, we thought Mars would be like the Earth, just more of a desert. There’d be plants and animals, and maybe even people adapted to the hardy environment. With our modern knowledge, this sounds quaint today. The most brutal desert on Earth is a paradise compared to the nicest place on Mars. Von Braun did the best he could with the best science of the time.

Finally, at the end of their 400 days on Mars, the astronauts would blast off from the surface of Mars, meet up with the orbiting crew, and the entire flotilla would make the return journey to Earth using the minimum-fuel Mars-Earth transfer trajectory.

The planned trajectories to and from Mars. Credit: Collier’s

Although Von Braun got a lot of things wrong about his Martian mission plan, such as the thickness of the atmosphere and habitability of Mars, he got a lot of things right.

He anticipated a mission plan that required the least amount of fuel, by assembling pieces in orbit, using the Hohmann transfer trajectory, exploring Mars for 400 days to match up Earth and Mars orbits. He developed the concept of using orbiters, detachable landing craft and ascent vehicles, used by the Apollo Moon missions.

The missions never happened, obviously, but Von Braun’s ideas served as the backbone for all future human Mars mission plans.

I’d like to give a massive thanks to the space historian David S.F. Portree. He wrote an amazing book called Humans to Mars, which details 50 years of NASA plans to send humans to the Red Planet, including a fantastic synopsis of the Mars Project.

I asked David about how Von Braun’s ideas influenced human spaceflight, he said it was his…

“… reliance on a conjunction-class long-stay mission lasting 400 days. That was gutsy – in the 1960s, NASA and contractor planners generally stuck with opposition-class short-stay missions. In recent years we’ve seen more emphasis on the conjunction-class mission mode, sometimes with a relatively short period on Mars but lots of time in orbit, other times with almost the whole mission spent on the surface.”