Pale Blue Dot

This week during the 219th meeting of the American Astronomical Society a number of announcements were made about recent discoveries, today we will take a looks at some of these.

One of the most significant is the announcement that almost every star in the galaxy has at least one planet orbiting it. Recently we discussed the results of the Kepler data that had been released to date that estimated that there could be as many as 7 sextillion planets in the universe. However with this new announcement this would increase to 300 sextillion planets at least and we know for certain that there are multi-planetary systems out there, including the one we live in. One estimate suggested there are 1.6 planets for every star; therefore we are looking at potentially 480 sextillion planets in the universe.

Based on this information we can speculate that there are 1500 planets within a 50 light-year radius of earth. While we still don’t have the technology to get to these any time soon we do have instruments powerful enough to start investigate these in a lot more detail. The next few years in planetary hunting are going to be very exciting as more and more of the Kepler candidates are confirmed and as more and more powerful telescope come online.

The Kepler team recently announced that they are finding that smaller planets are actually more common than the larger gas giant planets. Combined with the above announcements the possibility of finding other habitable worlds has increased significantly.

In another announcement astronomers at the California Institute of Technology announced the discovery of the smallest Explanets so far. Measuring 0.57 to 0.78 times the size of earth the three planets orbit the star KOI-961, which is 130 light-years away in the Cygnus constellation. The team used the Kepler data combined with additional observations of the star, due to the star’s similarity to Barnard’s star they were also able to use information gathered from previous observations of this year which is much closer at only 6 light-years from Earth.

Following the previous announcement of a circumbinary planet, one that orbit’s two stars. The Kepler team announced two additional circumbinary systems. It would seem that these systems are not rare exceptions, and one day we could well see a double sun-set just like Luke did in Star Wars. Again we don’t have the technology to visit these systems today but I believe one day humans will.

The final announcement we will look at today is the discovery of a ring like system similar to Saturn’s transiting a distant star. Unlike a planetary transit these are harder to detect because the light dip will be different depending on the structure of the rings. The team studied light curve data from SuperWASP (Wide Angle Search for Planets) and All Sky Automated Survey (ASAS).

So why the reference to The Pale Blue Dot, I am reminded as we discover more and more planets in the Universe that we live on a tiny island in the vast sea of the Universe.  As a christian I believe that we are the only intelligent species out there, however I also believe that there are many habitable worlds and one day we will go out from our tiny place and visit them.  I don’t know what the future holds for the discovery of planets but I believe within the next 5 years we will directly image planets orbiting other stars and be able to read their chemical signatures.

Active NASA missions

As we close out another year we are going to take a look at some of the other NASA missions that are active in the Solar System exploring other planets.  While the future looks a little uncertain at the moment due to the growing budget crisis there are plenty of spacecraft still in operation.

Voyager 1 & 2

Artist concept of NASA's Voyager spacecraft. Image credit: NASA/JPL-Caltech

We start our journey with two of the longest serving craft in the NASA fleet, Voyager 1 & 2 launched in 1977 have been traveling away from earth ever since and continue to function.  Their primary mission was to explore Jupiter and Saturn after making a number of discoveries at each their missions where extended.  Voyager 2 went on to explore Uranus and Neptune.  They are now traveling at the very edge of our solar system in the region called the Heliosheath where the influence of the solar wind from the sun is almost complete diminished.  We don’t currently know when the craft will actually exit the solar system however it is expected to be close.  At the time of writing Voyager 1 was 17 billion km from the sun and Voyager 2 was 14 billion km away.  At this distance it takes more than  a day for a signal to travel to the craft and back at the speed of light.  The craft are expected to operate until ~ 2020 when they will no longer have enough power for their instruments.  Follow the progress of the Voyager’s at there website.

Cassini-Huygens Mission

Next we take a look at the Cassini-Huygens spacecraft which is currently in orbit around Saturn.  Launched in 1997 the craft spent almost 7 years travelling to the Saturn system before entering into orbit.  Cassini-Huygens is actually two physical spacecraft and Orbiter which is named Cassini and is still in orbit today and a lander named Huygens which descendant into the atmosphere of Saturn’s moon Titan shortly after the combined craft arrived at Saturn.  Initially designed for a four year mission in orbit around Saturn the mission has been extended several times with the current plan to crash the orbiter into Saturn in 2017.  Follow the progress of Cassini at it’s website.

Diagram of the Cassini Spacecraft

Dawn

Artist's concept of Dawn with Vesta and Ceres. Image credit: William K. Hartmann Courtesy of UCLA

Next we visit a spacecraft that will be the first two orbit two different objects in the Solar System, currently in orbit around the asteroid Vesta providing a wealth of information about the rocky object, once it’s mission is complete it will then travel onto the dwarf planet Ceres and again go into orbit.  Both objects are found in the asteroid belt between Mars and Jupiter and are believed to have been created when the Solar System was created.  The decade long mission including travel time will allow scientists to learn more about the creation processes.  Follow Dawn’s progress at it’s website.

Messenger

The Messenger spacecraft is the first to orbit Mercury after spending more than 6 years traveling to the planet and covering more than 7.9 billion kilometers.  Unlike most of the other planets traveling to Mercury was a lot more complex due to how close it is to the Sun instead of a direct approach which would have constant accelerated the craft Messenger had to flyby Earth, Venus and Mercury several times before finally inserting into orbit.

Follow Messenger’s progress at it’s website.

New Horizons

The New Horizon’s spacecraft will be the first to fly-by Pluto, launched in 2006 the craft is rapidly approaching Pluto but still has just under 1300 days until closest approach.  New Horizons is often erroneously given the title of Fastest Spacecraft Ever Launched, when in fact the Helios probes are the holders of that title. To be more specific New Horizons achieved the highest launch velocity and thus left Earth faster than any other spacecraft to date. It is also the first spacecraft launched directly into a solar escape trajectory, which requires an approximate velocity of 16.5 km/s (36,900 mph), plus losses, all to be provided by the launcher. In January 2007 New Horizon’s speed was increased by a gravity assist from Jupiter sending it hurtling towards Pluto at 8,900 mph faster.  However due to the gravitation influence of the Sun even at that distance the craft has slowed as it progresses towards Pluto.  New Horizon’s is now closer to Pluto than any previous spacecraft has been, the next significant event in the journey won’t occur until August 2014 when it will cross Neptune’s orbit. Flyby of Pluto will occur in July 2015 when all the science instruments will be pointed at the planet to gather as much information as possible.

After the successful completion of the primary mission to Pluto the craft may approach other Kuiper belt objects before leaving the Solar System in 2029.

Follow New Horizon’s progress at it’s website.

Juno

The last spacecraft we will look at today is the newest craft Juno, launched in August 2011 the craft began a five year journey to Jupiter to explore the origin and evolution of Jupiter.  Expected to arrive in July 2018 the craft will then orbit Jupiter 33 times gathering information about the amount of water in it’s atmosphere, measure the composition, temperature, cloud motions of the giant planet.  Map Jupiter’s magnetic and gravity fields and explore the magnetosphere near the the planet’s poles.

Follow Juno’s progress at it’s website.

And then there were six

This morning Oleg Kononenko, Andre Kuipers and Don Pettit successfully launched from Kazakhstan aboard their Soyuz TMA-03M spacecraft heading to the space station to complete the full Expedition 30 crew and once again return the station to a six man crew.

Despite the bitter cold weather, the crew launched on time and will now spend two days chasing the station before the automated docking to the Rassvet module.  As with all the Soyuz craft the crew will have the ability to manually dock if needed.

Oleg Kononenko
Oleg Kononenko, 47, will serve as a flight engineer for Expedition 30 and commander for Expedition 31. He first flew as a Soyuz and International Space Station commander for the Expedition 17 crew in 2008. He also performed two spacewalks during the increment, acquiring more than 12 hours of extravehicular experience.

Andre Kuipers
European Space Agency astronaut Andre Kuipers, 58, will return to space for his second spaceflight mission. A medical doctor, he flew aboard the Soyuz spacecraft in 2004 as part of the DELTA mission. During the flight, he performed 21 science experiments. He will serve as a flight engineer for this mission.

Donald Pettit
NASA astronaut Donald Pettit, 56, holds a doctorate in chemical engineering,
will be embarking on his third spaceflight and second long-duration mission.
He previously served as flight engineer during Expedition 6 in 2002 and 2003 and
as mission specialist on STS-126 in 2008. He will again serve as flight engineer during
the upcoming mission.

Once on the space station the crew will be running a number of scientific experiments as well as all the maintenance tasks needed to keep the station operating at peak efficiency. There are no planned U.S. spacewalks during this Expedition but the crew is always ready should the need occur to perform one.  With the recently announced SpaceX dragon flight in February 2012 the Expedition 30 crew will be the first to receive a spacecraft from a commercial company.

The full overview of the science being performed by the crew can be found here.

NASA Discovers First Earth-size Planets

Two weeks ago NASA announced the first planet is the habitable zone of another star.  Yesterday they announced the discovery of the first Earth-size planets orbiting a sun-like star outside our solar system.

The planets, called Kepler-20e and Kepler-20f, are too close to their star to be in the so-called habitable zone but they are the smallest exoplanets ever confirmed around a star like our sun.

The discovery marks the next important milestone in the ultimate search for planets like Earth. The new planets are thought to be rocky. Kepler-20e is slightly smaller than Venus, measuring 0.87 times the radius of Earth. Kepler-20f is a bit larger than Earth, measuring 1.03 times its radius. Both planets reside in a five-planet system called Kepler-20, approximately 1,000 light-years away in the constellation Lyra.

Kepler-20e orbits its parent star every 6.1 days and Kepler-20f every 19.6 days. These short orbital periods mean very hot, inhospitable worlds. Kepler-20f, at 800 degrees Fahrenheit, is similar to an average day on the planet Mercury. The surface temperature of Kepler-20e, at more than 1,400 degrees Fahrenheit, would melt glass.

Kepler Planet Lineup

On a separate note, NASA announced that the Kepler spacecraft experienced a processor reset on 12/7 most likely due to a galactic cosmic-ray burst.  They were able to quickly recover the spacecraft which is now operating as expected.  This again highlights the extreme dangers of working in space and some of the factors that must be taking into consideration when designing space missions especially when talking about human deep space missions.

Stratolaunch Systems

Today we return to our commercial space series as we look at a new player to the field.

Paul G. Allen and Burt Rutan announced yesterday that they were once again partnering to revolutionize the space launch industry.  Their last adventure led to the Ansari X Prize winning SpaceShipOne craft which achieved three sub-orbital flights to win the prize in 2004 and is the pre-cursor to Virgin Galactic’s SpaceShipTwo.

The Stratolaunch System (SLS) will consist of four primary elements: a carrier aircraft, a multi-stage booster, a mating and integration system, and an orbital payload.  Initially the payloads will be unmanned but longer term after the system has been proven manned missions will also be included.  To achieve this SLS will be a partnership between Scaled Composites (carrier aircraft), SpaceX (multi-stage booster) and Dynetics (mating and integration system).

The carrier aircraft will be a much larger version of the WhiteKnightTwo craft used by Virgin with a wing-span of 385 feet and be powered by six 747 engines.  The craft will weight more than 1.2 million pounds, require a 12,000 foot runaway of takeoff and landing and will be the biggest aircraft ever built.

The multi-stage booster will be derived from SpaceX’s Falcon 9 rocket.

The mating and integration system (MIS) will have the capacity to carrier up to 500,000 pounds.  As well as providing the interface point to the Booster.

Unfortunately the system will not be ready much before 2016 but again the future looks bright for the US launch industry in the future.  With the backing of Paul G. Allen there is little doubt that they will succeed.

More details are available on there web site including animations of the SLS.

 

 

 

 

 

Kepler – A Search for Habitable Planets

This week the Kepler mission confirmed its First Planet in Habitable Zone of a Sun-like Star, they increased the number of planet candidates to 2365, they celebrated 1000 days in space and finally held their first science conference.  Today we take a look at the Kepler mission and what it has discovered so far.

The Kepler mission was launched on 6th March 2009, once in orbit and after complete a series of validation tests began scientific observations.  Unlike other missions, which look at different regions of the sky based on requests, the Kepler mission is pointing at a single region of sky observing the light from 100,000 stars.  Kepler is looking for signs of transiting planets which cause the brightness of the star to change very minutely.  Once detected it is possible to determine the orbital size of the planet based on how long the change is observed.  To be sure that the observations are correct Kepler needs to see at least three transit which is why it is pointing at the same point most of the time.

Why most of the time? Kepler has to point back to earth once a month to transmit the data it has capture, during this time it cannot observe the stars.  Personally I think this is a design flaw and I hope a successor to Kepler will address this.

Why are they Planet Candidates?  Kepler can only detect the changes in light from a star, therefore once a change has been detected and verified it needs to be confirmed.  Working with different teams around the work they are able to use the other telescopes to actually observe the stars to determine what is really there.

What has Kepler found so far?  Of the 2365 candidates announced so far 31 planets have been confirmed orbiting in 22 systems.  Included in these is the first known planet to orbit around a binary star system (Kepler 16b), the first near earth sized planet detected in habitual zone of the star (Kepler 22b).  Kepler is now starting to see planets that have longer orbital periods, most of the early candidates all have very short periods but the recently annouced Kepler 22b has a 290 day orbit.

What does the future hold?  Kepler has been designed to operate for at least 3.5 years, assuming there are no problems the craft will hopefully continue to operate long after that and provide further lots more candidates with longer orbital periods.

Is that all the planets? No Kepler is only observing one region of the sky and focused on 100,000 stars, it is only able to detect the change in brightness caused by a planet transiting the star.

First this is a very very very small percentage of the known stars in the universe, estimated to be 300,000,000,000,000,000,000,000, or 300 sextillion.  So far in 1,000 days of obervation we have detected 2365 candidates from the 100,000 stars (0.02365%).  If we use the same percentage of the estimate there could be as many as 7,000,000,000,000,000,000,000 or 7 sextillion planets in the universe.

Second Kepler can only see the planets that move directly in front of the star from our line of sight.  We know for a fact from other observations using other methods that there are exoplanets that Kepler cannot see, therefore we could conclude from this that each known method could have the same number of candidates in the universe.  This continue to increase as Kepler finds more candidates.

What’s next? The next big observatory that is planned to be launched is the James Webb Space Telescope which will have the power to see some of these planet candidates and allow us to really see the finer details of these planets.  At present there is no details of a planned follow up to Kepler but hopefully the number of candidates already returned will encourage NASA to look into one.

 

 

 

Falling Behind

China are on the verge of surpassing the US for second place in the number of spacecraft launched in a single year.  Last year we were tied for second place and so far this year have one more mission than China but with no more planned US launches this year and at least one more for China could be tied again or risk losing out to them.

And the picture looks bleak until the commercial launchers come online.  SpaceX and Orbital are still in the testing phase and while both plan to be online with cargo flights next year to ISS there is no guarantee that this will happen.  The next demo flight for SpaceX has been delayed a number of times so far while SpaceX and NASA make sure everything is in place for the mission.  While we can understand the need to ensure the spacecraft will not pose a threat to the station it also makes us more reliant on Russia until these craft are up and running.

The crew situation is even worse, until SLS or Commercial Crew are online which at the moment looks to be 3-4 years away we are completely dependent on Russia to get to ISS and in the mean time China and making huge progress on there crew missions.  With the successful completion of the Shenzhou 8 mission which included two dockings to the Tiangong 1 space station, they are now planning a crewed mission to the station and have already selected the crew.

As I said a couple of weeks ago after the new NASA budget was announced we are cutting funding for commercial space and therefore risk falling further behind.  Having to pay Russia $63m per seat to get to the space station that we spend billions of dollars building is short sighted and the continued under-spending on commercial space is not going to rectify this any time soon.

The History of Mars Exploration (NASA)

To follow up the successful launch of MSL, which NASA confirmed last night was inserted into an almost perfect trajectory towards Mars, today we take a look at the history of successful Mars Exploration missions by NASA.

The History of Mars Exploration

Year Name Type Summary
1964 Mariner 4 Flyby First spacecraft to flyby of Mars and return close-up pictures of the surface.  Returned 21 images during the flyby.
1969 Mariner 6 Flyby Returned 75 images during flyby and provided data used to program Mariner 7 for it’s flyby five days later.
1969 Mariner 7 Flyby Returned 126 images during it’s flyby.
1971 Mariner 9 Orbiter First spacecraft to orbit another planet, returned 7,329 images while operational.  Still in orbit today and will remain so until about 2022.
1975 Viking 1 Orbiter/Lander First spacecraft to land on Mars, was operational for 2245 sols, contact was lost when a faulty command sequence sent from the ground overwrote the antenna pointing software. The Viking 1 Lander was named the Thomas Mutch Memorial Station in January 1982 in honor of the leader of the Viking imaging team.
1975 Viking 2 Orbiter/Lander Twin of Viking 1 and second spacecraft to land on Mars.  Viking two was operation for 1281 sols, during which time it returned over 16,000 images and a large amount of scientific data.
1996 Mars Global Surveyor Orbiter Arrived at Mars 9/12/1997, began mapping operations in 1996, lose of contact 11/2/2006
1996 Mars Pathfinder Lander/Rover Lander on Mars 7/4/1997, deployed rover Sojourner to explore the surface around the lander.  The lander sent more than 16,500 pictures and made 8.5 million measurements of the atmospheric pressure, temperature and wind speed. Lander renamed Carl Sagan Memorial Station.
2001 Mars Odyssey Orbiter Arrived at Mars 10/24/2001, began orbital operations 2/19/2002.  Still operational today.  As well as providing a large amount of images and scientific data the craft is used as a relay for MER and Phoenix.
2003 Mars Exploration Rover – Spirit Rover See MER Post
2003 Mars Exploration Rover – Opportunity Rover See MER Post
2005 Mars Reconnaissance Orbiter Orbiter Arrived at Mars 3/10/2006, began orbital operations in 11/2006.  Still operational today with a variety of scientific instruments.  Also provides relay capabilities to MER.  MRO’s telecommunications systems will transfer more data back to earth than all previous spacecraft sent to the planet combined, more than 26 terabits.
2007 Phoenix Mars Lander Lander PML arrived on Mars 5/28/2008 and was operational for 155 sols, the original mission was designed for 90 sols.  The instruments were designed to look for microbial life and water.  Returned more than 25 gigabits of scientific data for analysis.

Mars Science Laboratory – Curiosity

This morning the massive Mars Science Laboratory (MSL) launched torwards Mars.  Scheduled to land in August 2012 the rover will bring a host of scientific instruments to the planet and continue the exploration that started in 1975 with the Viking landers.

Mars Science Laboratory (MSL)

By far the largest rover every launched to another planet the MSL is a risky mission.  The rover is five times bigger and carriers more than ten times the mass of scientific instruments than the MER rovers.  In additional MSL will attempt the first precision landing on Mars, which will be achieved by a sky crane that will lower the rover to the surface before flying off and crashing into the surface.

Unlike it’s predecessors, which were solar powered, MSL will use an radioisotope thermoelectric generators (RTGs).  This will allow the rover to operate day and night and also has the advantage that the heat generated by the process can be used to keep the components warm meaning more electricity will be available to the instruments.

Once on the surface the rover will wake up and begin it’s mission, designed to operate for at least a martian year (668 Martian sols/686 Earth days) MSL will using it’s various scientific instruments to determine the habitability of Mars for microbial life.

MSL is carrying an impressive array of instruments which will enable it to take samples of Martian rocks and analyze them.  Rather than repeat the information I have included a link to the Mars Science Laboratory site.

The plan is to land MSL at Gale Crater which spans 96 miles (154 kilometers) in diameter and holds a mountain rising higher from the crater floor than Mount Rainier rises above Seattle. Gale is about the combined area of Connecticut and Rhode Island. Layering in the mound suggests it is the surviving remnant of an extensive sequence of deposits. The crater is named for Australian astronomer Walter F. Gale.[1]

Now all we have to do is wait until next August when Curiosity lands.

Sources
1 – http://www.jpl.nasa.gov/news/news.cfm?release=2011-222#1