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

Mars Exploration Rovers

Tomorrow NASA will be launching the Mars Science Laboratory (MSL) to begin an eight month journey to the red planet.  Today we take a look at it’s predecessors the highly successful Mars Exploration Rovers.

Mars Exploration Rovers (MER)

Launched in 2003 the twin rovers Spirit and Opportunity were sent to explore the surface and geology of Mars.  The two rovers were launching within a month of each other and used an airbag landing to arrive on the surface of Mars eight months later in early 2004.

Each rover was designed to operate for 90 sols (Sol is a day on Mars, which is almost 40m longer than a day on earth).  The rovers far exceeded there designed life with Spirit finally giving up after ~2208 sols.  Opportunity is still operational today over 2777 sols after arriving on the planet.

The rovers have provided a wealth of information from the surface of Mars and have demonstrated that we can operate in distant environments for extended periods of time.

While the rovers have been active for a long time they certainly have had some luck along the way and have to rest during the winter months due to not having enough solar energy to charge the battery.

Several times during the mission NASA noticed that the power levels on the rovers suddenly increased having declined due to the buildup of dust on the solar panels.  They determine later that these were because of wind gusts called dust devil’s that had hit the rover cleaning off the dust, this was confirmed in 2010 when Opportunity spotted a wind gust (dust devil).

Since arriving on the planet each of the rovers has sent back a large amount of pictures,  including panoramic views of the environment around the rover.  These images are available on NASA’s Mars Rover web site.

We don’t know how much longer Opportunity will operate for, soon it will enter it’s next winter hibernation period.  However as long as it has power, is communicating and NASA has funding we can expect more from the amazing rover.

Opportunity's View Approaching Rim of Endeavour Crater

NASA Budget

This week the new Budget was signed into law and NASA’s funding for the Commercial Crew development has been slashed.  So what does this mean for the future?

As we are currently looking at Commercial Space and the different teams who are involved it seems appropriate to review this further and see what real impact this has.

The final budget for Commercial Crew has come out at $406 million which is less then half the original $850 million requested.  The Senate and House appropriations committees passed legislation calling for commercial crew funding levels of $500 million and $312 million, respectively.  A conference committee between lawmakers agreed to a compromise budget at $406 million.

This has serious implications for the Commercial Crew Development program, NASA currently has four companies working towards milestones each which has specific financial rewards associated with them.  While the money for the current set of milestones is already secure the reduce budget does have implications for future milestones.  Either NASA will have to reduce the number of companies they are working with or slow down the pace of development.  Neither of these options is ideal as it results in the US and NASA not having a crew capability for longer.

Given that NASA are currently paying $63 million per flight to the space station and have at least 4 crew per year launching by 2015 NASA would have spent between $1 billion and $2 billion getting crew there.  NASA Administrator Charlie Bolden cautioned legislators that reducing the funding would likely add another 2 years to the program meaning that at the current rate another $500 million to $1 billion will be spent on Soyuz flights.

Several of the companies that are currently working towards Commercial Crew have stated that they can launch for less than the $63 million so this new budget makes no sense for the future of US access to space or the goal of reducing costs.

Personally I hope that none of the companies will stop the work they have begun on Commercial Crew and will step up and show the government that they can reduce the cost of access to space and once again give the US the access to space that it has given up at the present time.

 

 

Commercial Space – Part Six

Today we continue our look at Commercial Space with Boeing and there contribution to the CCDev/CCDev2 programs.

Boeing

Working with Bigelow the CST-100 will provide crew and cargo missions to the International Space Station.   The CST-100 was first announced by Robert Bigelow in June 2010, just last month NASA announced that Boeing had signed an agreement to use one of the Shuttle OPF buildings as there construction site for the CST modules.

Drawing on their expertise with the Apollo, Space Shuttle and ISS they have quickly demonstrated that they can deliver on the design and with the recent funding from NASA have several milestones that have to be achieved as they work towards being operational by 2015.  Clearly the partnership with Bigelow will benefit both companies;  as Boeing will have a second destination for CST and Bigelow will have a supplier for their stations.

Boeing have recently been conducting drop tests  of their test module to evaluate the design of the airbag cushioning system that will be deployed just before landing.  So far Boeing are the only company to use this design and will be interested to see how different the landing will be to some of the other modules.  I think overall SpaceX’s design seems to offer the best solution for landing but only time will tell as they continue to test and actual use the systems.

Boeing has designed CST to be compatible with Atlas V, Delta IV and Falcon 9 with Atlas V being the initial launch vehicle during testing.

At present there is no set date for when orbital testing will be performed.

Commercial Space – Part Five

Today we look at Blue Origin and there contribution to the CCDev/CCDev2 programs.

Blue Origin

Blue Origin are working on the New Shepherd sub-orbital craft to provide customer’s trip to the edge of space, allow a period of time of weightlessness before returning to the launch site.  Unlike Virgin Galactic’s SpaceShipTwo this will be a capsule based craft and will return using parachutes.

In the future they are will be launching the Biconic Space Vehicle for orbital operations.  This craft will use some of the components from New Shepherd as well as a re-usable first stage booster. From what I can determine neither of these have actually been built and I was not able to determine when they would be.  SpaceX recently announced that they are working on re-usable booster components to reduce costs but as yet have no date when they would even begin testing.

While Blue Origin are making progress they seem to be a long way behind some of the other players in the CCDev/CCDev2 arena and while coming later to the industry shouldn’t hurt them too much as we need more competition they will have a lot more to prove at that point to catch up.

Commercial Space – Part Four

Now we move onto the NASA Commercial Crew Development (CCDev/CCDev2) providers.

Sierra Nevada Corporation (SNC)

SNC are currently working on the Dream Chaser spacecraft, designed to lift off on top a man-rated launcher with Delta-V as the current preferred booster.  The craft is designed to transport up to seven astronauts as well as cargo.  Exact weight’s are not currently available.

Artist's illustration of the Dream Chaser crew transportation vehicle docked to the ISS. Source: Sierra Nevada Space Systems 2010

The ship will dock with the space station and then glide back to a landing once the mission is complete. Due to it’s design it should be able to land at any commercial airstrip and unlike the Space Shuttle it’s reaction control system uses ethanol and therefore can be handled immediately after landing.

Dream Chaser has several other advantages over the shuttle, first it is designed to last as long as 210 days in space, where as the shuttle only allowed a couple of weeks.  Second the heat shield is made up of ablative tiles ( created by NASA ) which can be replaced in large groups and don’t need to be replaced as often.

As with the COTS program CCDev and CCDev2 are milestone driven programs, SNC have recently announced that they have achieved several of the early milestones and are working towards drop tests using Virgin Galactic’s WhiteKnightTwo aircraft in 2012.

With the creation of the CCDev/CCDev2 programs the future for spaceflight is very exciting and will only result in cheaper missions for everyone.