Recently in Science Category

During a routine call up of NASA's planet-hunting Kepler mission on 14 May, the spacecraft was found to have fallen into a safe mode with an attitude error. During an attempt to return to reaction wheel control as the spacecraft rotated into communication, and commanded a stop rotation, it appeared that all three wheels responded and that rotation had been successfully stopped.  However reaction wheel 4 remained at full torque while the spin rate dropped to zero. According to NASA, this is a clear indication that there has been an internal failure within the reaction wheel, likely a structural failure of the wheel bearing. The spacecraft was then transitioned back to Thruster-Controlled Safe Mode.  NASA may now elect to retire the spacecraft which has exceeded its three year old design life by over a year.  During its service the spacecraft has discovered hundreds of planets orbiting distant stars.

Orbital Sciences Corporation has been selected by NASA to design built and test a spacecraft for the Ionospheric Connection Explorer (ICON) mission .  Orbital will provide its LEOStar-2 spacecraft platform for the two-year mission under a contract valued at $50 million.  The mission, which will be led by the University of California at Berkeley, is currently planned for launch in 2017.   

The mission of the ICON satellite is to study the interface between the upper reaches of the Earth's atmosphere and outer space in response to a recent scientific discovery that the ionosphere, positioned at the edge of space where the Sun ionizes the air to create charged particles, is significantly influenced by storms in the lower atmosphere.  ICON will also help NASA better understand how atmospheric winds control ionospheric variability.

ICON was awarded under NASA's Explorer series of lower-cost and highly-productive space science satellites. 

The mission of the Herschel Space Observatory was formally declared over after liquid helium coolant ran out.  Launched, in May 2009, the European Space Agency's Herschel Space Observatory along with its 3.5 metre diameter mirror and extremely sensitive scientific instruments made it the most powerful infrared observatory ever launched.Astronomers used its infra-red images to make ground-breaking discoveries about the formation and evolution of stars, galaxies and planets. 

Artist's impression of Herschel Space Observatory. Courtesy: ESA

Herschel carried over 2000 litres of liquid helium when launched by ESA in May 2009, allowing its instruments to be cooled to a few degrees above absolute zero (-273 C).  Two of the instruments also contained internal coolers to get their detectors even colder - only a third of a degree above absolute zero.  Over the course of the mission the helium slowly evaporated, with the tank having now finally run dry. Because none of the instruments can work without helium-cooling, Herschel's operational life is now over. 

The SPIRE (Spectral and Photometric Imaging Receiver) instrument, responsible for keeping all the spacecraft's instrumentation cool, making images of the sky simultaneously in three submillimetre 'colours' and measuring the spectral features of atoms and molecules, was led by the UK. The spacecraft itself moved away from its halo orbit around the L2 Lagrangian poont and placed in a parking orbit around the Sun, but the analysis and evaluation of the data will continue for years to come.

 

All contact with the experimental cubesat Strand 1 has been lost since late March. The exact cause of the failure has not been disclosed,  Launched on 25 February as one of the payloads on board an Indian PSLV C Series CA (Core Alone) launch vehicle, the Strand1 (Surrey Training Research adn Nanosatellite Demonstrator 1) satellite was built by Surrey Satellite Technology Limited (SSTL) in conjunction with the University of Surrey.  Its mission was to test out Android software as well as the  GPS and camera systems of modern mobile Google Nexus 1 smartphone to see if such a phone could be used in space as a communications system, computer, camera, acelerometer and magnetometer.  The 3U cubesat satellite of 4kg mass also tested out water/alcohol resistojet, pulsed plasma thruster technologies.

US President Barack Obama has formally made his Fiscal Year 2014 budget request for NASA.  At $17.7 billion investment the budget is largely unchanged in cash terms from 2012 levels and is $1 billion higher than the 2013 budget, but taking inflation into account, it still still represents a decline.  The plan, which assumes that the sequestration limits will no longer be in effect, commits to continuing with the the Orion space capsule and its SLS heavy lift booster rocket programmes, and contributing towards the final development of the James Webb Space Telescope, leading to its planned launch in 2018.

NASA's asteroid initiative will use new capture and navigation technologies.  Courtesy: NASA 

One surprise in the budget request was confirmation that NASA is looking seriously at "dragging" an asteroid into near Earth space.  Funding worth $105 million has been allocated to to this "asteroid retrieval" mission along with the the solar electic and guidance technlogies which would be needed to allow such a mission to be undertaken.  If such a mission is successful, the idea is that NASA astronauts would then be able to explore this asteroid and even that mining operations coud be set up. 

Following on from the success of its Kepler mission in descovering planets, NASA has selected the TESS (Transiting Exoplanet Survey Satellite) mission for construction and then launch in 2017 as part of its Explorer programme.  Orbital Sciences Corporation has been awarded a contract to construct the spacecraft which will be equiped with wide-angle optical telescopes which will monitor any decrease in stellar brightness which is a signature clue that a planet has just passed in front of a star. The spacecraft will be operated from an elliptical orbit around Earth and have a two year lifespan.

Engineers at the Jet Propulsion Laboratory at Pasadena have put the Mars Curiosity Rover into a one month hibernation starting on 4 April.  The reason is that the planetary alignment of Mars puts the sun and its atmosphere of highly charged particles more or less directly in the way of direct communications between Mars and Earth which makes commanding the spacecraft difficult.  A basic signal transmitted from the rover effectively saying "I am still alive" can still be received but commanding the rover has been suspended until 1 May.

Mars Rover Curiosity will be asleep for a while.  Courtesy: NASA/JPL

 

 

 

Scientists from the Dartmouth College, New Hampshire, USA have presented their findings at the 44th Lunar and Planetary Science Conference, that the event that killed the dinosaurs may have been a comet impact rather than a meteorite or asteroid strike.

While dust and debris from an impact with a space object is still blamed for the rapid cooling on the Earth which is thought to have killed off most of the dinosaur population, a re-examimnation of the amount of rare metals (Iridium and Osmium) found in the layer released during the impact as the the 180km-wide Chicxulub crater in the Yukatan peninsular in Mexico was created now suggest that a much smaller object struck but with a much higher velocity.  The result of this is that the scientists now suggest that a comet more fits the bill for this strike than an errant asteroid.

Comet strikes on planets are well known.  In 1994, the broken up comet Shoemaker-Levy 9 (D/1993 F2) struck Jupiter causing "scarring" in the planets atmosphere.   Next year, a comet is making a close flyby of the planet Mars.  While expected to miss, scientists cannot be totally sure of Comet Siding Spring's (2012 A1) trajectory given that comets often vent jets (as the ice sublimates) which can act as thrusters altering their trajectories as they get close to the sun.

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