A ULA Atlas V rocket carrying the NROL-61 satellite is poised for blastoff from the pad at Space Launch Complex-41 at Cape Canaveral Air Force Station in Florida on July 28, 2016. Credit: Ken Kremer/kenkremer.com
A ULA Atlas V rocket carrying the NROL-61 satellite is poised for blastoff from the pad at Space Launch Complex-41 at Cape Canaveral Air Force Station in Florida on July 28, 2016. Credit: Ken Kremer/kenkremer.com
CAPE CANAVERAL AIR FORCE STATION, FL — The nation’s newest surveillance satellite is all set for a brilliant breakfast blastoff on Thursday July 28 atop a powerful Atlas V rocket from the Florida Space Coast – and both the booster and weather are in excellent shape at this time!
The goal is carry the top secret NROL-61 mission for the National Reconnaissance Office (NRO) to an undisclosed orbit which in support of US national defense and vital to US national security.
The NROL-61 mission is set to lift off on a United Launch Alliance (ULA) Atlas V rocket on Thursday morning July 28 from Space Launch Comple-41 at Cape Canaveral Air Force Station in Florida.
In an uncommon move, ULA and the military have announced the launch time is 8:37 a.m. EDT.
Virtually everything about the clandestine payload, its mission, purpose and goals are classified top secret.
The NRO is the government agency that runs a vast fleet of powerful orbital assets hosting a multitude of the most advanced, wide ranging and top secret capabilities.
The most recent NRO payload, known as NROL 37, was just launched by ULA last month on their Delta IV Heavy – the most powerful rocket in the world on June 11 – read my story here.
The excitement is building with the launch just a day away and visitors are checking into local area hotels hoping for a magnificent show from the venerable Atlas rocket with a perfect record of launch performance.
ULA managers completed the Launch Readiness Review and everything “is on track for launch.”
So you can now plan your day and watch Thursday’s launch live via a ULA broadcast which starts 20 minutes prior to the given launch time at 8:17 a.m. EDT.
Better yet if you are free and mobile you can watch this truly impressive feat with your own eyes by making your way to the many excellent viewing locations surrounding Cape Canaveral in every direction.
Here’s the rather cool ULA mission art with a webcast link.
ULA Webcast info for launch of Atlas V NROL-61 mission for the National Reconnaissance Office (NRO) on July 28, 2016. Credit: ULA/NRO
The NROL-61 patch depicts a green lizard, Spike, riding an Atlas V launch vehicle from the Cape Canaveral AFS. Spike was chosen as the mission mascot.
Mission artwork for Atlas V NROL-61 mission for the National Reconnaissance Office (NRO) is painted on nose cone of Atlas V rocket and depicts a green lizard, Spike, riding an Atlas V launch vehicle. Credit: Ken Kremer/kenkremer.com
The Florida weather outlook is looking quite promising at this time rather favorable. Air Force meteorologists are predicting an 80 percent chance of ‘GO’ with favorable weather conditions for Thursdays breakfast time blastoff.
The primary weather concern is for Cumulus Clouds.
In the event of a scrub delay for any reason, a backup launch opportunity exists on Friday, July 29. The weather odds are the same at 80% GO!
The rocket should put on a spectacular sky show since it is equipped with a pair of powerful solid rocket boosters spewing fire and an expanding plume of smoke and ash as is soars to orbit!
The Atlas rocket and payload were rolled put to launch pad 41 as planned Tuesday morning, July 26 – for a distance of about 1800 feet from the Vertical Integration Facility (VIF) where the rocket and payload were assembled, out to the pad.
It is now visibly erect at the pad from a number of viewing locations including Titusville and Playalinda Beach – positioned in between four lightning masts for protection from lightening.
Here’s a detailed mission profile video describing the launch events:
The NROL-61 mission counts as ULA’s sixth launch of 2016 and the 109th overall since the company was founded in 2006.
A ULA Atlas V rocket carrying the NROL-61 satellite is poised for blastoff from the pad at Space Launch Complex-41 at Cape Canaveral Air Force Station in Florida on July 28, 2016. Credit: Ken Kremer/kenkremer.com
The 20 story tall Atlas V will launch in its 421 configuration – the same as what will be used for manned launches with the crewed Boeing ‘Starliner’ space taxi carrying astronaut crews to the International Space Station.
This will be the sixth Atlas V to launch in the 421 configuration.
The Atlas 421 vehicle includes a 4-meter diameter payload fairing and two solid rocket boosters that augment the first stage. The Atlas booster for this mission was powered by the RD AMROSS RD-180 engine and the Centaur upper stage was powered by the Aerojet Rocketdyne RL10C-1 engine.
The RD-180 burns RP-1 (Rocket Propellant-1 or highly purified kerosene) and liquid oxygen and delivers 860,200 lb of thrust at sea level.
The strap on solids deliver approximately 500,000 pounds of thrust.
The solids will be jettisoned about 2 minutes after liftoff
The possible roles for the reconnaissance payload include signals intelligence, eavesdropping, imaging and spectroscopic observations, early missile warnings and much more.
The NRO was formed in response to the Soviet launch of Sputnik and secretly created on September 6, 1961.
“The purpose is overseeing all satellite and overflight reconnaissance projects whether overt or covert. The existence of the organization is no longer classified today, but we’re still pressing to perform the functions necessary to keep American citizens safe,” according to the official NRO website.
Watch for Ken’s continuing on site reports direct from Cape Canaveral Air Force Station, the Kennedy Space Center and the ULA Atlas launch pad.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
Learn more about SLS and Orion crew vehicle, SpaceX CRS-9 rocket launch, ISS, ULA Atlas and Delta rockets, Juno at Jupiter, Orbital ATK Antares & Cygnus, Boeing, Space Taxis, Mars rovers, NASA missions and more at Ken’s upcoming outreach events:
July 27-28: “ULA Atlas V NRO Spysat launch July 28, SpaceX launch to ISS on CRS-9, SLS, Orion, Juno at Jupiter, ULA Delta 4 Heavy NRO spy satellite, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings
Earth's axial tilt (or obliquity) and its relation to the rotation axis and plane of orbit. Credit: Wikipedia Commons
In ancient times, the scholars, seers and magi of various cultures believed that the world took a number of forms – ranging from a ziggurat or a cube to the more popular flat disc surrounded by a sea. But thanks to the ongoing efforts of astronomers, we have come to understand that it is in fact a sphere, and one of many planets in a system that orbits the Sun.
Within the past few centuries, improvements in both scientific instruments and more comprehensive observations of the heavens have also helped astronomers to determine (with extreme accuracy) what the nature of Earth’s orbit is. In addition to knowing the precise distance from the Sun, we also know that our planet orbits the Sun with one pole constantly tilted towards it.
Earth’s Axis:
This is what is known axial tilt, where a planet’s vertical axis is tilted a certain degree towards the ecliptic of the object it orbits (in this case, the Sun). Such a tilt results in there being a difference in how much sunlight reaches a given point on the surface during the course of a year. In the case of Earth, the axis is tilted towards the ecliptic of the Sun at approximately 23.44° (or 23.439281° to be exact).
Earth’s axis points north to Polaris, the northern hemisphere’s North Star, and south to dim Sigma Octantis. Credit: Bob King
Seasonal Variations:
This tilt in Earth’s axis is what is responsible for seasonal changes during the course of the year. When the North Pole is pointed towards the Sun, the northern hemisphere experiences summer and the southern hemisphere experiences winter. When the South Pole is pointed towards the Sun, six months later, the situation is reversed.
In addition to variations in temperature, seasonal changes also result in changes to the diurnal cycle. Basically, in the summer, the day last longer and the Sun climbs higher in the sky. In winter, the days become shorter and the Sun is lower in the sky. In northern temperate latitudes, the Sun rises north of true east during the summer solstice, and sets north of true west, reversing in the winter. The Sun rises south of true east in the summer for the southern temperate zone, and sets south of true west.
The situation becomes extreme above the Arctic Circle, where there is no daylight at all for part of the year, and for up to six months at the North Pole itself (known as a “polar night”). In the southern hemisphere, the situation is reversed, with the South Pole oriented opposite the direction of the North Pole and experiencing what is known as a “midnight sun” (a day that lasts 24 hours).
The four seasons can be determined by the solstices (the point of maximum axial tilt toward or away from the Sun) and the equinoxes (when the direction of tilt and the Sun are perpendicular). In the northern hemisphere, winter solstice occurs around December 21st, summer solstice around June 21st, spring equinox around March 20th, and autumnal equinox on or about September 22nd or 23rd. In the southern hemisphere, the situation is reversed, with the summer and winter solstices exchanged and the spring and autumnal equinox dates swapped.
Changes Over Time:
The angle of the Earth’s tilt is relatively stable over long periods of time. However, Earth’s axis does undergo a slight irregular motion known as nutation – a rocking, swaying, or nodding motion (like a gyroscope) – that has a period of 18.6 years. Earth’s axis is also subject to a slight wobble (like a spinning top), which is causing its orientation to change over time.
Known as precession, this process is causing the date of the seasons to slowly change over a 25,800 year cycle. Precession is not only the reason for the difference between a sidereal year and a tropical year, it is also the reason why the seasons will eventually flip. When this happens, summer will occur in the northern hemisphere during December and winter during June.
Artist’s rendition of the Earth’s rotation and the precession of the Equinoxes. Credit: NASA
Precession, along with other orbital factors, is also the reason for what is known as “length-of-day variation”. Essentially, this is a phenomna where the dates of Earth’s perihelion and aphelion (which currently take place on Jan. 3rd and July 4th, respectively) change over time. Both of these motions are caused by the varying attraction of the Sun and the Moon on the Earth’s equatorial region.
Needless to say, Earth’s rotation and orbit around the Sun are not as simple we once though. During the Scientific Revolution, it was a huge revelation to learn that the Earth was not a fixed point in the Universe, and that the “celestial spheres” were planets like Earth. But even then, astronomers like Copernicus and Galileo still believed that the Earth’s orbit was a perfect circle, and could not imagine that its rotation was subject to imperfections.
It’s only been with time that the true nature of our planet’s inclination and movements have come to be understood. And what we know is that they lead to some serious variations over time – both in the short run (i.e. seasonal change), and in the long-run.
Philae's view via its CIVA instrument after landing. Credit: ESA/Rosetta/Philae/CIVA
You can’t say they didn’t try, but the news is sad nonetheless. ESA announced the mission for the Philae lander – the first spacecraft to ever land on a comet — is officially over. The system that enables communications between the Rosetta spacecraft and Philae – which sitting in a shaded region on Comet 67P/Churyumov-Gerasimenko – is being switched off on July 27, 2016, at 09:00 UTC.
“It’s time for me to say goodbye,” Philae tweeted on Tuesday. “Tomorrow, the unit on @ESA_Rosetta for communication with me will be switched off forever…”
Philae has mostly been in hibernation after its dramatic touchdown (actually, three or maybe four touchdowns) on Nov. 12, 2014 when it separated from the orbiting Rosetta spacecraft, flew, landed, bounced and then repeated that process for more than two hours across the surface. The harpoons that were to anchor Philae to the surface failed to fire, and scientists estimated the lander may have bounced as high as 3.2 kilometers (2 miles) before becoming wedged in the shadows of a cliff on the odd-shaped comet. The solar-powered lander quickly ran out of power, just hours after landing. Philae’s final location has been plotted but never actually seen by Rosetta.
Slow animation of images taken by Philae’s Rosetta Lander Imaging System, ROLIS, trace the lander’s descent to the first landing site, Agilkia, on Comet 67P/Churyumov–Gerasimenko on November 12, 2014. Credits: ESA/Rosetta/Philae/ROLIS/DLR
After months of silence, the team heard briefly from Philae on June 13, 2015, when it transmitted information on its power and computer subsystems. It then made seven intermittent contacts with Rosetta in the following weeks, with the last coming on July 9, but the communications were too short and unstable to transmit or receive any meaningful scientific or engineering data.
Since then, the Support System Processor Unit (ESS) on Rosetta was kept on in the unlikely chance that Philae would wake up and try to reestablish contact. The hope was that when the comet was closer to the Sun, it might receive enough light to power up.
But the reason for turning it off now is due to Rosetta’s own impending end of mission, coming on September 30, 2016 when it will make a controlled impact at the Ma’at region on the comet’s “head.” Emily Lakdawalla of The Planetary Society put together this annotated image of sites where Philae touched down and likely landed, and where Rosetta will end up:
The 19 regions identified on Comet 67P/Churyumov–Gerasimenko are separated by distinct geomorphological boundaries. Following the ancient Egyptian theme of the Rosetta mission, they are named for Egyptian deities. They are grouped according to the type of terrain dominant within each region. Five basic categories of terrain type have been determined: dust-covered (Ma’at, Ash and Babi); brittle materials with pits and circular structures (Seth); large-scale depressions (Hatmehit, Nut and Aten); smooth terrains (Hapi, Imhotep and Anubis), and exposed, more consolidated (‘rock-like’) surfaces (Maftet, Bastet, Serqet, Hathor, Anuket, Khepry, Aker, Atum and Apis). All three landing sites (Philae initial and final sites and the planned resting place of the Rosetta orbiter) are located on the northern part of the “head” of the comet. Base map: ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA. Landing site locations: Emily Lakdawalla.
The team decided to keep “Rosetta’s listening channel on until it is no longer possible due to power constraints as we move ever further from the Sun towards the end of the mission,” said Patrick Martin, ESA’s Rosetta mission manager.
Martin said that by the end of this week, the spacecraft will be about 520 million km from the Sun, and will start facing a significant loss of power – about 4W per day. In order to continue scientific operations over the next two months and to maximize their return, it became necessary to start reducing the power consumed by the non-essential payload components on board.
But, Martin added that the mission of Philae and Rosetta will always be remembered as an incredible success.
“The combined achievements of Rosetta and Philae, rendezvousing with and landing on a comet, are historic high points in space exploration,” he said.
Philae did achieve 80% of its primary science goals in its short 64-hour active mission, as it took detailed images of the comet from above and on the surface, searched for organic compounds, and profiled the local environment and surface properties of the comet, “providing revolutionary insights into this fascinating world,” ESA said.
A depression on Ceres is possibly what’s left of one of the largest craters from Ceres’ earliest collisional history. Credit: SwRI/Simone Marchi.
Scientists have found a bit of a mystery at the dwarf planet Ceres. Yes, there are those intriguing bright spots inside numerous craters, which is a mystery that has mostly been solved (the bright areas likely made of bright salts leftover from the sublimation of a briny solution of sodium carbonate and ammonium chloride; read more details in this NASA article.)
But a new puzzle involves the craters themselves. In the rough and tumble environment of the asteroid belt, ancient Ceres was certainly pummeled by numerous large asteroids during its 4.5 billion-year lifetime. But yet, there are just a few large craters on Ceres.
How could that be?
“It is as though Ceres cures its own large impact scars and regenerates new surfaces, over and over,” said Dr. Simone Marchi, a senior research scientist at the Southwest Research Institute.
Scientists with NASA’s Dawn mission were surprised to find that Ceres has no clear signs of truly giant impact basins. This image shows both visible (left) and topographic (right) mapping data from Dawn. Credit: NASA/JPL-Caltech/SwRI.
Ceres has lots of little craters, but the Dawn spacecraft, orbiting Ceres since early 2015, has found only 16 craters larger than 100 km, and none larger than 280 km (175 miles) across. Scientists who model asteroid collisions in our Solar System predicted Ceres should have amassed up to 10 to 15 craters larger than 400 kilometers (250 miles) wide, and at least 40 craters larger than 100 km (62 miles) wide.
By comparison, Dawn’s other target of study, the smaller asteroid Vesta, has several large craters, including one 500 kilometers (300 miles) in diameter, covering almost the entire south pole region.
While they aren’t visible now, the scientists say there are clues that large impact basins may be hidden beneath Ceres’ surface.
“We concluded that a significant population of large craters on Ceres has been obliterated beyond recognition over geological time scales, likely the result of Ceres’ peculiar composition and internal evolution,” Marchi said.
The top of this false-color image includes a grazing view of Kerwan, Ceres’ largest impact crater. This well-preserved crater is 280 km (175 miles) wide and is well defined with red-yellow high-elevation rims and a deep central depression shown in blue. Kerwan gradually degrades as one moves toward the center of the image into an 800-km (500-mile) wide, 4-km (2.5-mile) deep depression (in green) called Vendimia Planitia. This depression is possibly what’s left of one of the largest craters from Ceres’ earliest collisional history. Credit: SwRI/Simone Marchi.
There are hints of about three shallow depressions around 800 km (500 miles) wide, and Marchi said they could be what are called or planitiae, or ancient impact basins, left over from large collisions that took place early in Ceres’ history.
There are a few possible reasons why the big craters have been erased, and the scientists now have to figure out which reason or combination of reasons best explain their findings. One reason could be because of large amounts of water or ice in Ceres’ interior, which has long been suspected. Does the absence of large craters lend any insight into Ceres’ water content?
“It might,” Marchi said via email. “There is evidence for ice locally at the surface but it is not clear how much water ice there is in the subsurface.”
Marchi said the craters allow scientists to “probe” down to different depths, depending on their sizes, and that the missing large craters (greater than 100 km in diameter) can provide information on the properties on just the upper 100-200 km or so of Ceres’s outer shell.
Because ice is less dense than rock, the topography could “relax” over time — like what happens if you push on your skin, then take the pressure off, and it relaxes back to its original shape, although this happened extremely more slowly on Ceres. The scientists said that over geological timescales of several million years the water or ice would slowly flow and the craters would smooth out.
Additionally, recent analysis of the center of Ceres’ Occator Crater — where the largest bright areas are located — suggests that the salts found there could be remnants of a frozen ocean under the surface, and that liquid water could have been present in Ceres’ interior.
A recent paper constrains the amount of subsurface ice to be no more than 30-40%.
“However, the lack of large craters cannot be solely explained by the presence of 30-40% of water,” Marchi told Universe Today.
Another reason for the lack of large craters could be hydrothermal activity, such as geysers or cryovolcanoes, which could have flowed across the surface, possibly burying pre-existing large craters. Smaller impacts would have then created new craters on the resurfaced area. Hydrothermal activity has been linked to bright areas on Ceres, as well.
A close look at some of the craters on Ceres show cracked-like surfaces and other areas that looks like there was flow of the surface that “softened” some of the features. Marchi said the team is still working to clarify the Ceres’ peculiar composition and how cryolava or “low viscous material” could have caused the crater rims and bowls to “relax.”
The bright central spots near the center of Occator Crater are shown in enhanced color in this view from NASA’s Dawn spacecraft. The view was produced by combining the highest resolution images taken in February 2016 (at image scales 115 feet (35 meters) per pixel of 35 meters with color images obtained in September 2015 at a lower resolution. Click for a highest-res view. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI
“This is still work in progress,” he told Universe Today. “Ceres is far more richer than Vesta in terms of smooth, flow features. Given that they are in the same environment (e.g. similar impact speed with asteroids), one would think that the production of impact melts would be the same. Thus the fact that we see more flow features on Ceres is a confirmation of its peculiar composition. This may facilitate production of impact “melt” (or ‘mud’ if there is enough water and clays).”
Another reason for the lack of large craters is that smaller, later impacts could have erased the bigger older impact basins. But if that were the case, the older basins would seemingly be more visible than they are now.
But the answer to this puzzle might all come back to the intriguing bright areas on Ceres.
“The presence of ammoniated phyllosilicates, carbonates and salts is truly amazing,” Marchi said. “I think this peculiar composition and Ceres’ internal structure are responsible for the lack of large craters, although we do not know precisely what the obliteration mechanism is.”
Marchi said the large crater obliteration was active well after the late heavy bombardment era, or about 4 billion year ago, so the resurfacing is inextricably linked to Ceres itself and its internal evolution, not impact events.
“All this shows over and over how peculiar Ceres is,” Marchi said. “Beside being a transition object (at inner/outer solar system boundary), it is peculiar in composition, and now also in cratering record.”
Finding out more about Ceres’ interior is one of the more intriguing aspects of Dawn’s continued mission there.
The eccentricity in Mars' orbit means that it is . Credit: NASA
With the Scientific Revolution, astronomers became aware of the fact that the Earth and the other planets orbit the Sun. And thanks to Copernicus, Galileo, Kepler, and Newton, the study of their orbits was refined to the point of mathematical precision. And with the subsequent discoveries of Uranus, Neptune, Pluto and the Kuiper Belt Objects, we have come to understand just how varied the orbits of the Solar Planets are.
Consider Mars, Earth’s second-closest neighbor, and a planet that is often referred to as “Earth’s Twin”. While it has many things in common with Earth, one area in which they differ greatly is in terms of their orbits. In addition to being farther from the Sun, Mars also has a much more elliptical orbit, which results in some rather interesting variations in temperature and weather patterns.
Perihelion and Aphelion:
Mars orbits the Sun at an average distance (semi-major axis) of 228 million km (141.67 million mi), or 1.524 astronomical units (over one and a half times the distance between Earth and the Sun). However, Mars also has the second most eccentric orbit of all the planets in the Solar System (0.0934), which makes it a distant second to crazy Mercury (at 0.20563).
This means that Mars’ distance from the Sun varies between perihelion (its closest point) and aphelion (its farthest point). In short, the distance between Mars and the Sun ranges during the course of a Martian year from 206,700,000 km (128.437 million mi) at perihelion and 249,200,000 km (154.8457 million mi) at aphelion – or 1.38 AU and 1.666 AU.
Speaking of a Martian year, with an average orbital speed of 24 km/s, Mars takes the equivalent of 687 Earth days to complete a single orbit around the Sun. This means that a year on Mars is equivalent to 1.88 Earth years. Adjusted for Martian days (aka. sols) – which last 24 hours, 39 minutes, and 35 seconds – that works out to a year being 668.5991 sols long (still almost twice as long).
Mars in also the midst of a long-term increase in eccentricity. Roughly 19,000 years ago, it reached a minimum of 0.079, and will peak again at an eccentricity of 0.105 (with a perihelion distance of 1.3621 AU) in about 24,000 years. In addition, the orbit was nearly circular about 1.35 million years ago, and will be again one million years from now.
Axial Tilt:
Much like Earth, Mars also has a significantly tilted axis. In fact, with an inclination of 25.19° to its orbital plane, it is very close to Earth’s own tilt of 23.439°. This means that like Earth, Mars also experiences seasonal variations in terms of temperature. On average, the surface temperature of Mars is much colder than what we experience here on Earth, but the variation is largely the same.
Mars eccentric orbit and axial tilt result in considerable seasonal variations. Credit and Copyright: Encyclopedia Britannica
All told, the average surface temperature on Mars is -46 °C (-51 °F). This ranges from a low of -143 °C (-225.4 °F), which takes place during winter at the poles; and a high of 35 °C (95 °F), which occurs during summer and midday at the equator. This means that at certain times of the year, Mars is actually warmer than certain parts of Earth.
Orbit and Seasonal Changes:
Mars’ variations in temperature and its seasonal changes are also related to changes in the planet’s orbit. Essentially, Mars’ eccentric orbit means that it travels more slowly around the Sun when it is further from it, and more quickly when it is closer (as stated in Kepler’s Three Laws of Planetary Motion).
Mars’ aphelion coincides with Spring in its northern hemisphere, which makes it the longest season on the planet – lasting roughly 7 Earth months. Summer is second longest, lasting six months, while Fall and Winter last 5.3 and just over 4 months, respectively. In the south, the length of the seasons is only slightly different.
Mars is near perihelion when it is summer in the southern hemisphere and winter in the north, and near aphelion when it is winter in the southern hemisphere and summer in the north. As a result, the seasons in the southern hemisphere are more extreme and the seasons in the northern are milder. The summer temperatures in the south can be up to 30 K (30 °C; 54 °F) warmer than the equivalent summer temperatures in the north.
Mars’ south polar ice cap, seen in April 2000 by the Mars Odyssey probe. Credit: NASA/JPL/MSSS
It also snows on Mars. In 2008, NASA’s Phoenix Landerfound water ice in the polar regions of the planet. This was an expected finding, but scientists were not prepared to observe snow falling from clouds. The snow, combined with soil chemistry experiments, led scientists to believe that the landing site had a wetter and warmer climate in the past.
And then in 2012, data obtained by the Mars Reconnaissance Orbiter revealed that carbon-dioxide snowfalls occur in the southern polar region of Mars. For decades, scientists have known that carbon-dioxide ice is a permanent part of Mars’ seasonal cycle and exists in the southern polar caps. But this was the first time that such a phenomena was detected, and it remains the only known example of carbon-dioxide snow falling anywhere in our solar system.
For starters, soil samples and orbital observation have demonstrated conclusively that roughly 3.7 billion years ago, the planet had more water on its surface than is currently in the Atlantic Ocean. Similarly, atmospheric studies conducted on the surface and from space have proven that Mars also had a viable atmosphere at that time, one which was slowly stripped away by solar wind.
Scientists were able to gauge the rate of water loss on Mars by measuring the ratio of water and HDO from today and 4.3 billion years ago. Credit: Kevin Gill
Weather Patterns:
These seasonal variations allow Mars to experience some extremes in weather. Most notably, Mars has the largest dust storms in the Solar System. These can vary from a storm over a small area to gigantic storms (thousands of km in diameter) that cover the entire planet and obscure the surface from view. They tend to occur when Mars is closest to the Sun, and have been shown to increase the global temperature.
The first mission to notice this was the Mariner 9 orbiter, which was the first spacecraft to orbit Mars in 1971, it sent pictures back to Earth of a world consumed in haze. The entire planet was covered by a dust storm so massive that only Olympus Mons, the giant Martian volcano that measures 24 km high, could be seen above the clouds. This storm lasted for a full month, and delayed Mariner 9‘s attempts to photograph the planet in detail.
And then on June 9th, 2001, the Hubble Space Telescope spotted a dust storm in the Hellas Basin on Mars. By July, the storm had died down, but then grew again to become the largest storm in 25 years. So big was the storm that amateur astronomers using small telescopes were able to see it from Earth. And the cloud raised the temperature of the frigid Martian atmosphere by a stunning 30° Celsius.
These storms tend to occur when Mars is closest to the Sun, and are the result of temperatures rising and triggering changes in the air and soil. As the soil dries, it becomes more easily picked up by air currents, which are caused by pressure changes due to increased heat. The dust storms cause temperatures to rise even further, leading to Mars’ experiencing its own greenhouse effect.
Mercury and the Moon over the ramparts of Assilah, Morocco. Photo by author
Have you caught sight of Mercury yet? This coming week is a good time to try, looking low to the west at dusk. We just managed to to nab it with binoculars for the first time during the current apparition this past Sunday from the rooftop of our Air BnB in Casablanca, Morocco.
Mercury is a tough grab under any circumstance, that’s for sure. Brilliant Venus and Jupiter make great guides to finding the elusive planet in late July, as it ping-pongs between the two. The waxing crescent Moon joins the scene in the first week of August, and for a very lucky few, actually occults (passes in front of ) the diminutive innermost world shortly after passing New.
Mercury (arrowed) near the Moon on the morning of June 3rd, 2016. Image credit: Dave Dickinson.
Here’s the low down on everything Mercurial, and circumstances for the coming weeks.
Mercury passes 18′ from the star Regulus on Saturday, July 30th at 19:00 Universal Time (UT), representing the closest passage of a planet near a first magnitude star for 2016.
The Moon then reaches New phase, marking the start of lunation 1158 on August 2nd at 20:45 UT. The Moon then moves on to occult Mercury on Thursday, August 4th at 22:00 UT, just over 48 hours later. The occultation is visible at dusk for observers based in southern Chile and southern Argentina. The rest of us see a close pass. Note that although it is a miss for North America, viewers based on the continent share the same colongitude and will see Mercury only a degree off of the northern limb of the Moon on the night of August 4th. Mercury shines at magnitude +0.01, and presents a 67% illuminated disk 6.3” in size, while the Moon is a slender 5% illuminated.
Occultations of Mercury for 2016. Credit: Occult 4.2. (click image to enlarge).
How early can you see the waxing crescent Moon? Catching the Moon with the naked eye under transparent clear skies isn’t usually difficult when it passes 20 hours old. This cycle, first sightings favor South Africa westward on the night of August 3rd.
Mercury reaches greatest elongation 27.4 degrees east of the Sun 12 days after this occultation on August 16th.
How rare is it? Well occultations of Mercury by the Moon are the toughest to catch of all the naked eye planets, owing to the fact that the planet never strays far from the Sun. Nearly all of these events go unwitnessed, as they occur mainly under daytime skies. And while you can observe Mercury in the daytime near greatest elongation with a telescope, safety precautions need to be taken to assure the Sun is physically blocked from view. Astronomers of yore did exactly that, hoping to glimpse fleeting detail on Mercury while it was perched higher in the sky above the murk of the atmosphere low to the horizon.
In fact, a quick search of ye ole web reveals very few convincing captures of an occultation of Mercury (see the video above). The closest grab thus far comes from astrophotographer Cory Schmitz on June 3rd 2016 based in South Africa:
Can you see it? The Moon about to occult Mercury on June 3rd. Image credit and copyright: Cory Schmitz.
Can’t wait til next week? The Moon crosses the Hyades open star cluster this week, occulting several stars along the way. The action occurs on the morning of Friday, July 29th culminating with an occultation of +1 magnitude Aldebaran by the 23% illuminated Moon. Texas and Mexico are well-placed to see this event under dark skies. A small confession: we actually prefer occultations of planets and stars by the waxing Moon, as the dark edge of the Moon is leading during ingress, making it much easier to witness and the exact moment the Moon blots out the object.
Still want more? The Moon actually goes on to occult Jupiter on August 6th for the South Pacific. Viewers farther west in southeast Asia might just spy this one in the daytime. This is the second occultation of Jupiter by the Moon in a series of four in 2016.
Looking west on the evening of August 4th. Image credit: Stellarium.
Keep and eye on those planets in August, as they’re now all currently visible in the dusk sky. The Moon, Regulus and Venus also form a tight five degree triangle on the evening of August 4th, followed by a slightly wider grouping of Venus, Jupiter and the Moon around August 25th.
More to come on that soon. Be sure to check the planet Mercury off of your life list this coming week, using the nearby waxing crescent Moon as a guide.
For the remainder of 2016, all payloads traveling to the US National Lab aboard the ISS will feature a mission patch with Marvel characters. Credit: NASA
In 2011, the US government created the Center for the Advancement of Science in Space (CASIS) to manage the US National Laboratory aboard the International Space Station,. With the purpose of ensuring that research opportunities provided by the ISS are used to their full potential, CASIS also seeks to inspire new generations of students to become involved in STEMs research and space exploration.
With the next generation in mind, CASIS recently announced the creation of a new mission patch that is sure to appeal to sci-fi fans and space enthusiasts! The patch features Groot and Rocket Raccoon, two characters from the Guardians of the Galaxy franchise, and was designed by Marvel Comic’s Custom Solution Group. For the remainder of 2016, it will represent all payloads that are destined for the ISS’ US National Laboratory.
The announcement came at the 2016 San Diego Comic Con, where tens of thousands of fans were gathered to witness the latest from their favorite sci-fi, fantasy, and comic book franchises. In between all the trailers and fanfare, members of CASIS held a panel discussion to talk about their collaboration with Marvel, and explained why it was these two Guardians characters that were selected to promote activities aboard the ISS.
This mission patch, featuring Groot and Rocket Racoon, will adorn all cargo going to CASIS labs in 2016. Credit: iss-casis.org
As Patrick O’Neill, a representative of CASIS, was quoted by The Verge as saying: “These are characters who have a bit of a space-based background to begin with. So both of [these] characters already embody some of the characteristics associated with what’s happening on the space station.”
The patch – which was designed by famed Marvel artist “Juan Doe” – features Groot and Rocket Racoon staring up at the ISS, which is floating overhead. In and around them, stars that are made to look like the flames from the Guardian of the Galaxy shield are positioned. In addition to being artistically creative, the symbolism could not be more clear: pop-culture icons and the ISS National Lab coming together to raise awareness about important scientific research!
During 2016, the U.S. National Lab plans to conduct over 100 science investigations aboard the ISS, with experiments involving the physical and material sciences, technological development, Earth observation and student inquiries. Thanks to its partnership with Marvel, the Guardians-inspired patch will adorn every payload that is sent to the ISS as part of these research initiatives.
Obviously, this partnership has been a good way for Marvel to promote one of the latest installments in its cinematic universe (not to mention its upcoming sequel). But for CASIS, it was also an opportunity to draw attention to the work of the U.S. National Lab. Traditionally, CASIS is responsible for providing seed money to research projects and product development. But a major aspect of their work also includes providing expertise, access, support, and educational outreach.
The Center for the Advancement of Science in Space (CASIS), shown here as part of the ISS. Credit: iss-casis.org
As Ken Shields, the CASIS Director of Operations and Educational Opportunities, said in a CASIS press release:
“A major mission for us here at CASIS is to find unique and innovative ways to bring notoriety to the ISS National Laboratory and the research that is being conducted on our orbiting laboratory. There are very few brands in the world who have as large an impact as Marvel, and we are thrilled to partner with them on this project and look forward to Rocket and Groot inspiring a new generation of researchers interested in the space station.”
Later this year, CASIS also hopes to use these characters in an upcoming educational flight contest intended to inspire children to become the next generation of scientists and engineers. News of the mission patch also came amidst announcements that Rocket and Groot will be star in their own Rocket Raccoon and Groot comic, and will be returning to the big screen next summer for Guardians of the Galaxy 2.
Obviously, this is going to be a good year for a certain tree alien and hyper-raccoon! And be sure to check out this video of the creation of the new mission patch, courtesy of CASIS:
We’ve covered the full range of exotic star-type objects in the Universe. Like Pokemon Go, we’ve collected them all. Okay fine, I’m still looking for a Tauros, and so I’ll continue to wander the streets, like a zombie staring at his phone.
Now, according to my attorney, I’ve fulfilled the requirements for shamelessly jumping on a viral bandwagon by mentioning Pokemon Go and loosely connecting it to whatever completely unrelated topic I was working on.
Any further Pokemon Go references would just be shameless attempts to coopt traffic to my channel, and I’m better than that.
It was pretty convenient, though, and it was easy enough to edit out the references to Quark on Deep Space 9 and replace them with Pokemon Go. Of course, there is a new Star Trek movie out, so maybe I miscalculated.
Anyway, now that we got that out of the way. Back to rare and exotic stellar objects.
The white dwarf G29-38. Credit: NASA
There are the white dwarfs, the remnants of stars like our Sun which have passed through the main sequence phase, and now they’re cooling down.
There are the neutron stars and pulsars formed in a moment when stars much more massive than our Sun die in a supernova explosion. Their gravity and density is so great that all the protons and electrons from all the atoms are mashed together. A single teaspoon of neutron star weighs 10 million tons.
And there are the black holes. These form from even more massive supernova explosions, and the gravity and density is so strong they overcome the forces holding atoms themselves together.
White dwarfs, neutron stars and black holes. These were all theorized by physicists, and have all been discovered by observational astronomers. We know they’re out there.
Is that it? Is that all the exotic forms that stars can take? That we know of, yes, however, there are a few even more exotic objects which are still just theoretical. These are the quark stars. But what are they?
Artist concept of a neutron star. Credit: NASA
Let’s go back to the concept of a neutron star. According to the theories, neutron stars have such intense gravity they crush protons and electrons together into neutrons. The whole star is made of neutrons, inside and out. If you add more mass to the neutron star, you cross this line where it’s too much mass to hold even the neutrons together, and the whole thing collapses into a black hole.
A star like our Sun has layers. The outer convective zone, then the radiative zone, and then the core down in the center, where all the fusion takes place.
Could a neutron star have layers? What’s at the core of the neutron star, compared to the surface?
The idea is that a quark star is an intermediate stage in between neutron stars and black holes. It has too much mass at its core for the neutrons to hold their atomness. But not enough to fully collapse into a black hole.
The difference between a neutron star and a quark star. Credit: Chandra
In these objects, the underlying quarks that form the neutrons are further compressed. “Up” and “down” quarks are squeezed together into “strange” quarks. Since it’s made up of “strange” quarks, physicists call this “strange matter”. Neutron stars are plenty strange, so don’t give it any additional emotional weight just because it’s called strange matter. If they happened to merge into “charm” quarks, then it would be called “charm matter”, and I’d be making Alyssa Milano references.
And like I said, these are still theoretical, but there is some evidence that they might be out there. Astronomers have discovered a class of supernova that give off about 100 times the energy of a regular supernova explosion. Although they could just be mega supernovae, there’s another intriguing possibility.
They might be heavy, unstable neutron stars that exploded a second time, perhaps feeding from a binary companion star. As they hit some limit, they converting from a regular neutron star to one made of strange quarks.
But if quark stars are real, they’re very small. While a regular neutron star is 25 km across, a quark star would only be 16 km across, and this is right at the edge of becoming a black hole.
A neutron star (~25km across) next to a quark star (~16km across). Original Image Credit: NASA’s Goddard Space Flight Center
If quark stars do exist, they probably don’t last long. It’s an intermediate step between a neutron star, and the final black hole configuration. A last gasp of a star as its event horizon forms.
It’s intriguing to think there are other exotic objects out there, formed as matter is compressed into tighter and tighter configurations, as the different limits of physics are reached and then crossed. Astronomers will keep searching for quark stars, and I’ll let you know if they find them.
The Triffid Nebula (on the left), with M21 open star cluster to the right. Credit and Copyright: NASA/Lorand Fenyes
Welcome back to Messier Monday! In our ongoing tribute to the great Tammy Plotner, we take a look at the Trifid Nebula (aka. Messier 20). Enjoy!
Back in 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 these objects so that others wouldn’t make the same mistake. Consisting of 100 objects, the Messier Catalog would come to be viewed by posterity as a major milestone in the study of Deep Space Objects.
One of these objects is the Trifid Nebula (aka. Messier 20, NGC 6514), a star-forming region of ionized gas located in the Scutum spiral arm of the Milky Way, in the direction of the southern Sagittarius constellation. A bright object that is a favorite amongst amateur astronomers, this object is so-named because it is a combination open star cluster, emissions nebula, reflection nebula, and a dark nebula that looks like it consists of three lobes.
Description:
Almost everyone who is familiar with space images has likely seen a beautiful color image of this emission and reflection nebula. However, when looking at M20 through a telescope, what you will see will be less colorful. Why? When it comes to photographs, exposure times and wavelengths cause different colors to become visible.
Composite image comparing visible-light views from Hubble of the Trifid Nebula with an infrared view from NASA’s Spitzer Space Telescope of the glowing Trifid Nebula. Credit: NASA/JPL-Caltech/J. Rho (SSC/Caltech)
Photographically, the red emission nebula contained within Messier 20 has a bright blue star cluster in it central portion. It glows red because the ultraviolet light of the stars ionizes the hydrogen gas, which then recombines and emits the characteristic red hydrogen-alpha light captured on film. Further away, the radiation from these hot, young stars becomes too weak to ionize the hydrogen. Now the gas and dust glows blue by reflection!
No matter how it is observed, the Trifid – or “three lobed” – nebula has a distinctive set of dark dust lanes which divide it. These also have a classification of their own, and were cataloged by E.E. Barnard as a dark nebula – Barnard 85 (B 85). In 1999 the Hubble Space Telescope took a look deep into the Trifid nebula at some of its star forming regions (see below).
What it found was a stellar jet poking its way into the cloud, like a fabulous twisted antenna. Inside the exhaust column is a new star waiting to be born, yet sometime over the next 10,000 years the central massive star will probably erode away all of its material before it can fully form. Nearby, a stalk stands waiting.
Close up on the interior of the Trifid Nebula, showing the star forming region and a stellar jet. Credit: NASA/HST
Like the jet, it is also a stellar nursery – one with an EGG (evaporating gaseous globule) at its tip – a condensed cloud of gas able to survive so far. As Jeff Hester of the Department of Physics & Astronomy explained:
“If our interpretation is correct, the microjet may be the last gasp from a star that was cut off from its supply lines 100,000 years ago. The vast majority of stars like our sun form not in isolation, but in the neighborhood of massive, powerful stars. HST observations of the Trifid Nebula provide a window on the nature of star formation in the vicinity of massive stars, as well as a spectacular snapshot of the “ecology” from which stars like our sun emerge.”
“We report the discovery of a new candidate barrel-shaped supernova remnant (SNR) lying adjacent to M20 and two shell-type features to the north and east of SNR W28. Future observations should clarify whether the nonthermal shell fragment is either part of W20 or yet another previously unidentified shell-type SNR.”
The Trifid nebula (M20, NGC NGC 6514) in pseudocolor. Image taken with the Palomar 1.5-m telescope. Credit: Jeff Hester (Arizona State University)/Palomar telescope
History of Observation:
Charles Messier discovered this object on June 5th, 1764. As he recorded of the object in his notes:
“In the same night I have determined the position of two clusters of stars which are close to each other, a bit above the Ecliptic, between the bow of Sagittarius and the right foot of Ophiuchus: the known star closest to these two clusters is the 11th of the constellation Sagittarius, of seventh magnitude, after the catalog of Flamsteed: the stars of these clusters are, from the eighth to the ninth magnitude, environed with nebulosities. I have determined their positions. The right ascension of the first cluster, 267d 4′ 5″, its declination 22d 59′ 10″ south. The right ascension of the second, 267d 31′ 35″; its declination, 22d 31′ 25″ south.”
While Messier did separate the two star clusters, he did not note so many different portions to the nebula – but, he did note nebulosity. In this circumstance, we cannot fault him. His purpose was to locate comets, after all; and the reason for the catalog was to list objects that were not. In later years, it would be Sir William Herschel who would take a closer look at Messier 20 and discover much more. As he wrote of the nebula:
“If it was supposed that double nebulae at some distance from each other would frequently be seen, it will now on the contrary be admitted that an expectation of finding a great number of attracting centers in a nebulosity of no great extent is not so probable; and accordingly observation has shewn that greater combinations of nebular than those of the foregoing article are less frequently to be seen. The following list however contains 20 treble, 5 quadruple, and 1 sextuple nebulae of this sort. Among the treble nebulae there is one, namely H V.10 [M20], of which the nebulosity is not yet separated. Three nebulae seem to join faintly together, forming a kind of triangle; the middle of which is less nebulous, or perhaps free of nebulosity; in the middle of the triangle is a double star of the 2nd or 3rd class; more faint nebulosities are following.”
A close detail of the Trifid Nebula, showing a “Pillar” region. Credit: NASA/Jeff Hester (Arizona State University).
While William went on to catalog four separate areas in his books, it was his son John to whom we owe the famous name that we know it by today. “A most remarkable object. Very large; trifid, three nebulae with a vacuity in the midst, in which is centrally situated the double star Sh 379, the nebula is 7′ in extent. A most remarkable object.”
Just remember when you observe that sky conditions are everything and that not even a large telescope can make it appear if the sky isn’t right. Even Admiral Smyth has his share of troubles spotting it. Said he of the Trifid Nebula:
“I lowered the telescope a couple of degrees, and gazed for the curious trifid nebula, 41 H. IV [H IV.41]; but though I could make out the delicate triple star in the centre of its opening, the nebulous matter resisted the light of my telescope, so that its presence was only indicated by a peculiar glow. Pretty closely preceding this is No. 20 M., an elegant cruciform group of stars, discovered in 1764, which he considered to be surrounded with nebulosity.”
Locating Messier 20:
Once you have become familiar with the Sagittarius region, finding Messier 20 is easy, since it is located just 2 degrees northwest of Messier 8 – the “Lagoon” Nebula. However, at magnitude 9, it isn’t an easy to spot with small binoculars, and not always easy for a small telescope either. Because we often see it depicted in pictures as bright and beautiful, we simply assume M20 will jump out of the sky; but you’ll find that its a lot fainter and more elusive than you might think.
The Sagittarius constellation. Credit: iau.org
If you are a beginner to astronomy, try starting at the teapot’s tip star (Lambda), “Al Nasl”, and starhopping in the finderscope northwest to the Lagoon. While the nebulosity might not show in your finder, the optical double star 7 Sagittari, will. From there you will spot a bright cluster of stars two degrees due north. These are the stars embedded withing the Trifid and the small, compressed area of stars to its northeast is the open star cluster of Messier 21.
Center your finderscope on the north and south oriented pair of stars and observe. Remember that you will need a moonless night and that sky conditions will need to be right to see the dark dustlanes! And here are the quick facts about M20, for your convenience:
Object Name: Messier 20 Alternative Designations: M20, NGC 6514, Trifid Nebula Object Type: Emission Nebula and Reflection Nebula with Open Star Cluster Constellation: Sagittarius Right Ascension: 18 : 02.6 (h:m) Declination: -23 : 02 (deg:m) Distance: 5.2 (kly) Visual Brightness: 9.0 (mag) Apparent Dimension: 28.0 (arc min)
The Saturn V (left) and the Falcon Heavy (right). Credit: NASA/SpaceX
Its an Epic Rocket Battle! Or a Clash of the Titans, if you will. Except that in this case, the titans are the two of the heaviest rockets the world has ever seen. And the contenders couldn’t be better matched. On one side, we have the heaviest rocket to come out of the US during the Space Race, and the one that delivered the Apollo astronauts to the Moon. On the other, we have the heaviest rocket created by the NewSpace industry, and which promises to deliver astronauts to Mars.
And in many respects, the Falcon Heavy is considered to be the successor of the Saturn V. Ever since the latter was retired in 1973, the United States has effectively been without a super-heavy lifter. And with the Space Launch System still in development, the Falcon Heavy is likely to become the workhorse of both private space corporations and space agencies in the coming years.
So let’s compare these two rockets, taking into account their capabilities, specifications, and the history of their development and see who comes out on top. BEGIN!
Launch of the modified Saturn V rocket carrying the Skylab space station. Credit: NASA
Development History:
The development of the Saturn V began in 1946 with Operation Paperclip, a US government program which led to the recruitment of Wernher von Braun and several other World War II-era German rocket scientists and technicians. The purpose of this program was to leverage the expertise of these scientists to give the US an edge in the Cold War through the development of intercontinental ballistic missiles (ICBMs).
Between 1945 and the mid-to-late 50s von Braun acted as an advisor to US armed forces for the sake of developing military rockets only. It was not until 1957, with the Soviet launch of Sputnik-1 using an R-7 rocket – a Soviet ICBM also capable of delivering thermonuclear warheads – that the US government began to consider the use of rockets for space exploration.
Thereafter, von Braun and his team began developing the Jupiter series of rockets – a modified Redstone ballistic missile with two solid-propellant upper stages. These proved to be a major step towards the Saturn V, hence why the Jupiter series was later nicknamed “an infant Saturn”. Between 1960 and 1962, the Marshall Space Flight Center began designing the rockets that would eventually be used by the Apollo Program.
After several iterations, the Saturn C-5 design (later named the Saturn V) was created. By 1964, it was selected for NASA’s Apollo Program as the rocket that would conduct a Lunar Orbit Rendezvous (LRO). This plan called for a large rocket to launch a single spacecraft to the Moon, but only a small part of that spacecraft (the Lunar Module) would actually land on the surface. That smaller module would then rendezvous with the main spacecraft – the Command/Service Module (CSM) – in lunar orbit and the crew would return home.
A Saturn V launching the historic Apollo 11 mission. Credit: NASA/Michael Vuijlsteke. Public Domain image.
Development of the Falcon Heavy was first announced in 2011 at the National Press Club in Washington D.C. In a statement, Musk drew direct comparisons to the Saturn V, claiming that the Falcon Heavy would deliver “more payload to orbit or escape velocity than any vehicle in history, apart from the Saturn V moon rocket, which was decommissioned after the Apollo program.”
Consistent with this promise of a “super heavy-lift” vehicle, SpaceX’s original specifications indicated a projected payload of 53,000 kg (117,000 lbs) to Low-Earth Orbit (LEO), and 12,000 kgg (26,000 lbs) to Geosynchronous Transfer Orbit (GTO). In 2013, these estimates were revised to 54,400 kg (119,900 lb) to LEO and 22,200 kg (48,900 lb) to GTO, as well as 16,000 kilograms (35,000 lb) to translunar trajectory, and 13,600 kilograms (31,000 lb) on a trans-Martian orbit to Mars, and 2,900 kg (6,400 lb) to Pluto.
In 2015, the design was changed – alongside changes to the Falcon 9 v.1.1 – to take advantage of the new Merlin 1D engine and changes to the propellant tanks. The original timetable, proposed in 2011, put the rocket’s arrival at SpaceX’s west-coast launch location – Vandenberg Air Force Base in California – at before the end of 2012.
The first launch from Vandenberg was take place in 2013, while the first launch from Cape Canaveral was to take place in late 2013 or 2014. But by mid-2015, delays caused by failures with Falcon 9 test flights caused the first launch to be pushed to late 2016. The rocket has also been relocated to the Kennedy Space Center Launch Complex in Florida.
Artist’s concept of the SpaceX Red Dragon spacecraft launching to Mars on SpaceX Falcon Heavy as soon as 2018. Credit: SpaceX
SpaceX also announced in July 0f 2016 that it planned to expand its landing facility near Cape Canaveral to take advantage of the reusable technology. With three landing pads now planned (instead of one on land and a drone barge at sea), they hope to be able to recover all of the spent boosters that will be used for the launch of a Falcon Heavy.
Design:
Both the Saturn V and Falcon Heavy were created to do some serious heavy lifting. Little wonder, since both were created for the sole purpose of “slipping the surly bonds” of Earth and putting human beings and cargo onto other celestial bodies. For its part, the Saturn V‘s size and payload surpassed all other previous rockets, reflecting its purpose of sending astronauts to the Moon.
With the Apollo spacecraft on top, it stood 111 meters (363 feet) tall and was 10 meters (33 feet) in diameter, without fins. Fully fueled, the Saturn V weighed 2,950 metric tons (6.5 million pounds), and had a payload capacity estimated at 118,000 kg (261,000 lbs) to LEO, but was designed for the purpose of sending 41,000 kg (90,000 lbs) to Trans Lunar Insertion (TLI).
Later upgrades on the final three missions boosted that capacity to 140,000 kg (310,000 lbs) to LEO and 48,600 kg (107,100 lbs) to the Moon. The Saturn V was principally designed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, while numerous subsystems were developed by subcontractors. This included the engines, which were designed by Rocketdyne, a Los Angeles-based rocket company.
Diagram of Saturn V Launch Vehicle. Credit: NASA/MSFC
The first stage (aka. S-IC) measured 42 m (138 feet) tall and 10 m (33 feet) in diameter, and had a dry weight of 131 metric tons (289,000 lbs) and a total weight of over 2300 metric tons (5.1 million lbs) when fully fueled. It was powered by five Rocketdyne F-1 engines arrayed in a quincunx (four units arranged in a square, and the fifth in the center) which provided it with 34,000 kN (7.6 million pounds-force) of thrust.
The Saturn V consisted of three stages – the S-IC first stage, S-II second stage and the S-IVB third stage – and the instrument unit. The first stage used Rocket Propellant-1 (RP-1), a form of kerosene similar to jet fuel, while the second and third stages relied on liquid hydrogen for fuel. The second and third stage also used solid-propellant rockets to separate during launch.
The Falcon Heavy is based around a core that is a single Falcon 9 with two additional Falcon 9 first stages acting as boosters. While similar in concept to the Delta IV Heavy launcher and proposals for the Atlas V HLV and Russian Angara A5V, the Falcon Heavy was specifically designed to exceed all current designs in terms of operational flexibility and payload. As with other SpaceX rockets, it was also designed to incorporate reusability.
The rocket relies on two stages, with the possibility of more to come, that measure 70 m (229.6 ft) in height and 12.2 m (39.9 ft) in width. The first stage is powered by three Falcon 9 cores, each of which is equipped with nine Merlin 1D engines. These are arranged in a circular fashion with eight around the outside and one in th middle (what SpaceX refers to as the Octaweb) in order to streamline the manufacturing process. Each core also includes four extensible landing legs and grid fins to control descent and conduct landings.
Chart comparing SpaceX’s Falcon 9 and Falcon Heavy rocket. Credit: SpaceX
The first stage of the Falcon Heavy relies on Subcooled LOX (liquid oxygen) and chilled RP-1 fuel; while the upper stage also uses them, but under normal conditions. The Falcon Heavy has a total sea-level thrust at liftoff of 22,819 kN (5,130,000 lbf) which rises to 24,681 kN (5,549,000 lbf) as the craft climbs out of the atmosphere. The upper stage is powered by a single Merlin 1D engine which has a thrust of 34 kN (210,000 lbf) and has been modified for use in a vacuum.
Although not a part of the initial Falcon Heavy design, SpaceX has been extending its work with reusable rocket systems to ensure that the boosters and core stage can be recovered. Currently, no work has been announced on making the upper stages recoverable as well, but recent successes recovering the first stages of the Falcon 9 may indicate a possible change down the road.
The consequence of adding reusable technology will mean that the Falcon Heavy will have a reduced payload to GTO. However, it will also mean that it will be able to fly at a much lower cost per launch. With full reusability on all three booster cores, the GTO payload will be approximately 7,000 kg (15,000 lb). If only the two outside cores are reusable while the center is expendable, the GTO payload would be approximately 14,000 kg (31,000 lb).
Cost:
The Saturn V rocket was by no means a small investment. In fact, one of the main reasons for the cancellation of the last three Apollo flights was the sheer cost of producing the rockets and financing the launches. Between 1964 and 1973, a grand total of $6.417 billion USD was appropriated for the sake of research, development, and flights.
A Saturn V rocket viewed from the rear, showing its five Rocketdyne F-1 engines. Credit: Infinity Science Center
Adjusted to 2016 dollars, that works out to $41.4 billion USD. In terms of individual launches, the Saturn V would cost between $185 and $189 million USD, of which $110 million was spent on production alone. Adjusted for inflation, this works out to approximately $1.23 billion per launch, of which $710 million went towards production.
By contrast, when Musk appeared before the US Senate Committee on Commerce, Science and Transportation in May 2004, he stated that his ultimate goal with the development of SpaceX was to bring the total cost per launch down to $1,100 per kg ($500/pound). As of April 2016, SpaceX has indicated that a Falcon Heavy could lift 2268 kg (8000 lbs) to GTO for a cost of $90 million a launch – which works out to $3968.25 per kg ($1125 per pound).
No estimates are available yet on how a fully-reusable Falcon Heavy will further reduce the cost of individual launches. And again, it will vary depending on whether or not the boosters and the core, or just the external boosters are recoverable. Making the upper stage recoverable as well will lead to a further drop in costs, but will also likely impact performance.
Specifications:
So having covered their backgrounds, designs and overall cost, let’s move on to a side-by-side comparison of these two bad boys. Let’s see how they stack up, pound for pound, when all things are considered – including height, weight, lift payload, and thrust.
Saturn V:
Falcon Heavy:
Height:
110.6 m (363 ft)
70 m (230 ft)
Diameter:
10.1 m (33 ft)
12.2 m (40 ft)
Weight:
2,970,000 kg
(6,540,000 lbs)
1,420,788 kg
(3,132,301 lb)
Stages:
3
2+
Engines
(1st Stage):
5 Rocketdyne F-1
3 x 9 Merlin 1D
2nd stage
5 Rocketdyne J-2
1 Merlin 1D
3rd stage
1 Rocketdyne J-2
Thrust
(1st stage):
34,020 kN
22,918 kN (sea level);
24,681 kN (vacuum)
2nd stage
4,400 kN
934 kN
3rd stage
1,000 kN
Payload (LEO):
140,000 kg
(310,000 lbs)
54,400 kg
(119,900 lbs)
Payload (TLI):
48,600 kg
(107,100 lbs)
16,000 kg
(35,000 lbs)
When put next to each other, you can see that the Saturn V has the advantage when it comes to muscle. It’s bigger, heavier, and can deliver a bigger payload to space. On the other hand, the Falcon Heavy is smaller, lighter, and a lot cheaper. Whereas the Saturn V can put a heavier payload into orbit, or send it on to another celestial body, the Falcon Heavy could perform several missions for every one mounted by its competitor.
But whereas the contributions of the venerable Saturn V cannot be denied, the Falcon Heavy has yet to demonstrate its true worth to space exploration. In many ways, its like comparing a retired champion to an up-and-comer who, despite showing lots of promise and getting all the headlines, has yet to win a single bout.
But should the Falcon Heavy prove successful, it will likely be recognized as the natural successor to the Saturn V. Ever since the latter was retired in 1973, NASA has been without a rocket with which to mount long-range crewed missions. And while heavy-lift options have been available – such as the Delta IV Heavy and Atlas V – none have had the performance, payload capacity, or the affordability that the new era of space exploration needs.
In truth, this battle will take several years to unfold. Only after the Falcon Heavy is rigorously tested and SpaceX manages to deliver on their promises of cheaper space launches, a return to the Moon and a mission to Mars (or fail to, for that matter) will we be able to say for sure which rocket was the true champion of human space exploration! But in the meantime, I’m sure there’s plenty of smack talk to be had by fans of both! Preferably in a format that rhymes!
![The Trifid nebula (M20, NGC NGC 6514) in pseudocolor. Image taken with the Palomar 1.5-m telescope. The field of view is 16’ ´ 16’. Red shows [S II] ll 6717+6731. Green shows Ha l 6563. Blue shows [O III] l 5007. The WFPC2 field of view is indicated. Image: Jeff Hester (Arizona State University), Palomar telescope.](https://www.universetoday.com/wp-content/uploads/2009/06/Trifid-Nebula-M20-e1469471610624-580x515.jpg)
