Cassini – Scienceandsf -A Blog Published by Robert A. Lawler

Space New for October 2017.

Space X is once again heading our space news for the month. On October 11th the privately owned space corporation successfully reused one of its Falcon 9 first stage booster rockets for the third time . The rocket that put the Echo Star 105/SES-11 satellite into orbit had been used previously back on February the 19th to launch Space X’s Dragon resupply capsule on a mission to the International Space Station.

That launch back in February had been Space X’s first launch from NASA’s historic pad 39A, the same pad that had seen so many of the Apollo and Space Shuttle take offs. This was also Space X’s second successful launch in three days demonstrating the company’s increasing skill and competence in the task of launching payloads into space. The image below shows the liftoff of Space X’s Falcon 9.

Launch of Space X’s Falcon 9 (Credit: Space X)

Both of the first stages used in this week’s missions landed intact on Space X’s recovery barge. In fact Space X has now recovered their first stage boosters 18 times making the feat seem almost routine. By making both the recovery and reuse of their boosters routine Space X hopes to reduce the cost of getting into space, dollars per kilo to orbit, enough to greatly increase the amount of cargo going into space. This is something business types call ‘Economies of Scale’ which will help to drive down the cost of space travel even further.

One last word about Space X. Next year the company, along with their rival Boeing, is scheduled to begin test flights of their manned orbital capsules. According to NASA’s commercial crew program each company will perform one unmanned test flight to be followed by a manned flight late next year. Those flights will be the first time in seven years that astronauts will fly into orbit from American soil.

Another space event that got a bit of news play involved the close approach by the asteroid 2012 TC4. The asteroid, which is estimated to be about 30 meters across, came within 43,000 kilometers of Earth on the night of 12 October. Now 43,000 km may sound like a long way off but in terms of the solar system it’s a near miss. It is in fact only a little more than a tenth of the distance to the Moon. The image below shows a NASA illustration of what 2012 TC4 looked like as it passed by Earth.

Illustration of Asteroid 2012TC4 passing Earth (Credit: NASA)

In fact since 2012 TC4 was coming so close NASA decided to use the encounter as the first test of their ‘Planetary Defense System’. A system which one day may be used to deflect, or if necessary destroy, an asteroid on a collision course with our planet.

This initial test simply used NASA’s network of observatories to keep a closer watch on the asteroid’s trajectory as it went by. In 2024 however, NASA hopes to arrange a mission to actually alter the course of an asteroid. Not one on a collision course but another close encounter like 2012 TC4.

The mission is being called DART and the target is actually a pair of asteroids called Didymos that are bound together by their mutual gravity. The test will involve slamming a space probe into the smaller (~150m) asteroid in order to see how its orbit around its larger (800m) companion is effected. From the results of the experiment NASA hopes to learn just how much push would be needed to alter an asteroid’s course enough to prevent a collision in the future. The long term goal would be protect the Earth from disasters such as the one that killed off the dinosaurs.

One final item before I leave. Last month (13Sept17) I wrote a post about the final days of NASA’s Cassini spacecraft before it plunged into the atmosphere of the planet Saturn. Now the Jet Propulsion Labouratory (JPL) and NASA have released some of the details of the doomed space probe’s final minutes. According to JPL Cassini ‘put up a fight’ and fired it thrusters for 91 seconds trying desperately to keep its antenna pointed toward Earth and transmitted data until the last second.

By greatly exceeding its designer’s expectations it’s as if Cassini had acquired something of a personality, a determination to carry out its mission to the end. And it’s not just Cassini. The Voyager probes are still sending us information on interstellar space after more than 40 years and the Lost Horizon spacecraft is now preparing for a flyby of a Kuiper belt object. It’s almost as if these interplanetary explorers are becoming the first mechanical heroes.

Oh I know that’s kind of silly. Or is it, after all who knows what our space probes will be like a hundred years from now. Cassini’s final image, transmitted to Earth even as the probe was falling into Saturn’s atmosphere is below.

Cassini’s Final image (Credit: NASA-JPL)

End of the Cassini Mission to Saturn

Two days from now, on Friday the 15th of September 2017 the Cassini Spacecraft will make it’s final orbit around Saturn. After exploring Saturn and its moons for the past 13 years Cassini is now nearly out of fuel and NASA has decided to plunge the probe into the atmosphere of the ringed planet. The reason for ending the probe’s mission in this fiery fashion is to make certain that Cassini does not crash onto one of Saturn’s moons and possibly contaminate it with micro-organisms from Earth.

The Cassini-Huygens mission began almost 20 years ago on the 15th of October 1997 when the spacecraft was launched from Kennedy Space Center aboard a Titan IV-Centaur rocket. The probe’s long seven year journey to Saturn required gravity boosting flybys from Venus (twice), Earth and Jupiter in order to gain enough energy to reach the outer Solar System. The image below shows the Cassini-Huygens spacecraft prior to its launch.

Cassini-Huygens Spacecraft (Credit: NASA)

Entering orbit around Saturn on the first of July 2004 Cassini released the Huygens landing module on the 25th of December 2004 and Huygens successfully landed on the Moon Titan on January the 14th, 2005. The lander, which was built by the European Space Agency, operated for 90 minutes sending back images and instrument measurements from the surface of the second largest moon in the Solar System. The first image below is a picture of the Huygens lander and the second is an image from the surface of Titan.

The Surface of Titan (Credit: ESA-NASA-JPL)

During it’s short operating life the Huygens lander found that the atmosphere of Titan was denser than Earth’s by about 45% with a composition of 95% nitrogen and 5% methane at a temperature of 98.3 degrees Kelvin (-179.3 Celsius). The rocks in the surface image above are actually water ice at a temperature so cold they are as hard as rocks!

The discoveries on Titan by Huygens were augmented by those of the Cassini orbiter which found both large lakes of liquid methane along with signs of channels other indications of erosion caused by flowing liquid methane. Between them Cassini and Huygens portray Titan as a world very similar to our own except it is so cold that methane has replaced water.

Since then the Cassini orbiter has continued its mission, making several major discoveries. One of the most important has been the eruptions of water ‘volcanoes’ spewing out of the moon Enceladus. The energy causing these eruptions is thought to be generated by the tidal forces of Saturn and its other moons and is similar to the process that heats Jupiter’s moons Io and Europa. After discovering the ‘volcanos’ the Cassini spacecraft was even sent into them in an attempt to analyze their composition. The plumes are indeed water but with a small amount of complex hydro-carbons mixed in. Are these complex molecules a sign of the beginning of life on Enceladus? Only time, and a lander to the moon will tell. The picture below is an artists idea of the hydro-thermal activity on Enceladus.

Hydro-Thermal Activity on Enceladus (Credit: NASA-JPL-Caltech)

As far as I’m concerned however the best part of any mission to Saturn is simply the images of the planet and its system of rings. So without further ado I’ll just add a few below.

NASA has actually set up live internet coverage of Cassini’s final moments, although we can’t be quite certain exactly when that will happen. The show will start at 7AM Eastern Daylight Time on Friday the 15th and if you’d like to tune in, I will be, click on the link below to be taken to NASA’s Cassini End of Mission Activities website.

https://www.nasa.gov/press-release/nasa-announces-cassini-end-of-mission-media-activities

Has CERN discovered a new Particle. Maybe.

It was five years ago now that the Large Hadron Collider (LHC) at CERN announced the discovery of the Higgs Particle, filling in the last hole of what physicists call ‘The Standard Model’. For the next three years the LHC underwent an upgrade to increase it’s maximum energy to 13Tev, that 13 trillion electron volts. The upgrade was finished in 2015 and the LHC began another run of data collection on 3Jun2015.

Now the goal of this run is to look for new particles and new interactions beyond the standard model, something that will confirm or exclude the many different ‘Theories of Everything’ the mathematical types have come up with over the last 30-40 years. Supersymmetry, Dark Matter and String Theory are just the more well known models waiting and hoping for some sort of experimental conformation.

This past week a seminar was held at CERN giving preliminary results of the data collected by one of the LHC’s four detectors, the LHC-beauty or LHCb. The different detectors at the LHC each examine the products of the particle collisions by different techniques and the LHCb detector examines the number and behavior of particles called beauty quarks. (I was taught to call them bottom quarks but that was years ago, before their existence was even confirmed)

The researchers working with the LHCb have found a bump in their data that cannot be accounted for by any known particle, possible evidence of new physics. The researchers state that their results could be evidence of strange particles like LeptoQuarks, particles that share properties with both electrons and quarks.

As I said the results are preliminary, the researchers are currently estimating a 2.5 sigma confidence level, well below the 5 sigma level needed to announce a discovery. But more data is pouring in and the results of the LHC’s three other detectors could add further evidence. For now we’ll just have to wait and see. If you’d like to read more about the possible discovery at the LHC click on the link below.

https://www.scientificamerican.com/article/physicists-excited-by-latest-lhc-anomaly1/

Before I go I want to just mention that today, 22Apl17, the Cassini Spacecraft will make its final close flyby of the moon Titan before going into an orbit that will take it between Saturn and its rings. Only another 22 orbits of Saturn are planned before Cassini plunges into the Planet’s atmosphere to burn up. While it’s sad to lose the spacecraft after 13 years of discoveries the close ups of Saturn should give us a very exciting ride.

I have to do a quick update. Not five minutes after I posted this story I found a newly released picture by Cassini of the Earth as seen through Saturn’s Rings! Here it is, enjoy!

More Space News for April

Two days ago NASA held a press conference to announce some of the results that scientists have discovered from the Cassini spacecraft. Cassini is in orbit around the planet Saturn and is in the final few months of it’s twenty year long mission.

The press conference mainly dealt with some new discoveries about Saturn’s moon Enceladus which we knew from earlier observations was an ice covered world similar to Jupiter’s moon Europa. For several years now NASA astronomers have speculated that, again like Europa, Enceladus might have a liquid ocean beneath the ice covering, an ocean that could support life.

Now the heat energy that keeps the ocean warm would come from the flexing and squeezing of the moon’s interior caused by the interacting gravitational fields of Saturn and it’s other moon’s, the tidal pulls. The same process is known to cause the numerous volcanoes on Jupiter’s moon Io and are suspected to keep the ocean on Europa warm. The heat generated by this process could also provide the energy for life on Enceladus.

Images taken of Enceladus by Cassini have discovered plumes of water spewing out of the Moon like geysers and now Cassini has even succeeded in flying through those plumes and identifying some of the chemicals contained in them. In their announcement NASA scientists stated that Cassini has detected considerable amounts of both Carbon Dioxide and Methane both of which are commonly associated with living processes. The image below details the processes going on at the moon.

These results give us another possible home for life in our Solar system. Along with Mars and Europa, Enceladus is another world we need to explore further. A specialized mission to search for life on Enceladus may take years to develop and launch however, but someday we’ll know whether or not we have close neighbors living around the ringed planet.

If you’d like to read more about NASA’s announcement click on the link below.

https://www.nasa.gov/press-release/nasa-missions-provide-new-insights-into-ocean-worlds-in-our-solar-system

There has also been another announcement from NASA concerning grant money being funded to a series of new technology programs. These grants are called the NASA Innovative Advanced Concept or NIAC program and are intended to study possible future technologies for spaceflight. The initial Phase I grants are about $125,000 dollars while Phase II grants can be as much as a half a million dollars.

The Phase I grants can be very interesting, even far out concepts while the Phase II grants tend to be a bit more realistic. In the Phase I group are included four completely new type of propulsion technologies, two are intended for interstellar travel, along with a ‘vacuum balloon’ to drift over the surface of Mars and Solar Surfing!

The Phase II grants include a probe of the interior of the planet Venus and a fusion enabled Pluto orbiter and lander. If you’d like to read a bit more about these possible future space technologies click on the link below.

https://www.nasa.gov/directorates/spacetech/niac/2017_Phase_I_Phase_II

There’s always something new happening in space so I hope you’ll be coming back soon.

This Week in Space

Several news stories dealing with space exploration came out this week but didn’t receive much attention so I decided to take a moment to highlight them.

The first item on my list is the beginning of the final, and perhaps most exciting phase of the Cassini spacecraft’s mission to the planet Saturn. The Cassini mission is expected to end in September of next year with Cassini plunging into Saturn’s atmosphere but starting this week the spacecraft has begun a series of ring grazing orbits that will be followed by orbits closer to the giant planet than anything ever attempted.

In the picture below the gray lines indicate the ring grazing orbits while the blue lines are the planet grazing orbits. These orbits are dangerous, a collision with debris from the rings could easily destroy the spacecraft which is why NASA has waited till the end of the mission to attempt them. The possibility of close up observations of the ring system is too great a chance to miss however.

Hopefully in the next several weeks NASA will be able to release spectacular images of Saturn’s Rings. If you’d like to know more about the Cassini mission here’s a link to the official NASA website.

https://www.nasa.gov/mission_pages/cassini/main/index.html

Another interesting NASA story is the awarding of a contact to the California based company Space Systems/LORAL. I used to work for them back in the 1980s designing antennas for geostationary communications satellites. The contact is for the development of a satellite refueling spacecraft called the Restore-L spacecraft bus.

Refueling satellites in space is an idea that’s been talked about since the 80’s and I’m glad to see they are finally getting around to doing it. You see, all the satellites we put into space to sent you your direct TV signal or complete your overseas telephone call or keep an eye on the hurricane brewing in the Atlantic have only a limited amount of fuel to keep them in the proper orbit and, just as importantly pointing in the right direction. Once their fuel is gone these technological miracles costing hundreds of millions of dollars are just trash.

Having an unmanned spacecraft that could go to these satellites and refuel them is another step on the road to building the infrastructure of space, turning low Earth orbit (LEO) into a work environment of benefit to everyone here on Earth. If you’d like to read more about Restore-L here’s a link to the story.

http://perfscience.com/content/2145143-refueling-mission-spacecraft-project-wins-nasa-approval-127-million-payment

A closely related story is the selection by INTELLSAT, the international consortium managing most of the world’s communications satellites, of Orbital ATK as the provider for a Mission Extension Vehicle-1, MEV-1. The objective of the MEV-1 will be very similar to NASA’s Restore-L spacecraft in that the MEV-1 will go to satellites already in orbit and either refuel or repair them, thereby extending their useful life.

These twin spacecraft, are scheduled to be developed over the next three to four years and together they will provide a new capability for mankind in space. To read the original story from Spacecraft Insider click on the link below.

http://www.spaceflightinsider.com/organizations/orbital-sciences-corp/intelsat-taps-orbital-atks-mev-1-extend-life-orbiting-satellites/