Curiosity Rover finds strong evidence of ancient lake on MARS surface

Those people who are eagerly monitoring the Curiosity Rover activities on MARS definitely may be knowing about Mount Sharp - a mountain on MARS and primary target of Curiosity Rover of NASA.  The Mount Sharp was built by sediments deposited in a large lake bed over tens of millions of years - says rover science team.

The Mount Sharp also known as Aeolis Mons officially forms the central peak within a very large crater called as Gale Crater which is 155 Km in diameter.  The Mount Sharp is 5 Km tall, its lower flanks exposing hundreds of rock layers.  The rock layers - alternating between lake river and wind deposits - bear witness to the repeated filling and evaporation of a lake much larger than any previously examined close-up.

The NASA team of scientists are exploring to solve the mystery of Mount Sharp.  Where there is a mountain now, there may have been a series of lakes in the past - says one of the team member, Dr. John Grotzinger.

The Curiosity rover is now investigating the lowest sedimentary layers of Mount Sharp, a section of rock 150 meters high.  Rivers carried sand and silt to the lake depositing the sediments at the mouth of the river to from deltas similar to those found at river mouths on Earth. 

“As Curiosity climbs higher on Mount Sharp, we will have a series of experiments to show patterns in how the atmosphere and the water and the sediments interact. We may see how the chemistry changed in the lakes over time.”    “This is a hypothesis supported by what we have observed so far, providing a framework for testing in the coming year.”  Dr Grotzinger said.

NASA's Curiosity finds life's building blocks on MARS surface

The Curiosity rover of NASA has found organic chemicals which are the carbon-containing building blocks of life on the Red Planet - MARS.  The discovery does not confirm the existence of life on MARS or has existed earlier on MARS.  But this marks the first time that organics have been confirmed on MARS.  The Curiosity Project Scientist Mr. John Grotzinger of California Institute of Technology said "This is really a great moment for the Mission".  

The SAM ( Sample Analysis at MARS ) instrument has detected chlorobenzene and several other carbon compounds containing chlorine in the samples from a rock called "Cumberland" which was drilled by Curiosity in May, 2013.

The SAM instrument uses a tiny oven to cook the samples, and then analyze the gases that come out.  The NASA scientists say that it is impossible at present whether the Cumberland organics were produced by living organisms.  But this discovery will definitely help them to guide the planning efforts for NASA's 2020 Mars Rover mission which aims to collect samples on MARS to be returned to Earth.  

The NASA scientists also discovered the detection of methane levels in MARS atmosphere.  Curiosity landed on MARS in August, 2012.  It is now exploring the foothills of Mount Sharp, which rises 5.5 Kilometers above the surface of MARS from the center of the huge Gale crater.

ISRO Successfully launches its heaviest launch vehicle GSLV MARK-III

ISRO successfully tested the atmospheric re-entry of a crew module after its heaviest launch vehicle GSLV Mark-III lifted off from Sriharikota on 18th December, 2014.  This success helps India to realize its ambition to send humans into space.


The Crew module separated exactly after 5.4 minutes after lift-off at 09:30 AM IST from the second launch pad of Satish Dhawan Space Center, Sriharikota.  The module separated from the rocket at a height of 126 Km and re-entered into earth's atmosphere.  The Crew module safely splashes down into the sea near Andaman and Nicobar islands.

The Crew module descended in a ballistic mode and splashed down in Bay of Bengal around 180 Kms away from Indira point, the southern tip of Andaman and Nicobar islands.  The LVM3-X rocket with active S200 and L110 propulsion stages and a passive C25 stage with dummy engine carried the CARE ( Crew module Atmospheric Re-entry Experiment ) as its payload.

The Crew module weighs 3.7 tonnes and it is a 2.7 meter tall cup cake shaped with a diameter of 3.1 meters.  The module which features aluminum alloy internal structure with composite panels and ablative thermal protection systems, was made to safely drop down into the sea by specially made parachutes.  The experiment witnessed the largest parachute in action every made in the country.  The main parachute which helped the Crew module touch the waters at a speed of 7 meters per second was 31 meters in diameter.

The GSLV Mark-III accelerated the CARE module to a velocity of around 5.3 kilometers per second ( 12,000 miles per hour ) and a projected apogee of 126 kilometers which was achieved at the time of separation of the stage.  The CARE module activated its control systems immediately after separating from the rocket.  

Here is a video of the GLSV Mark-III launch.

NASA installs the first zero gravity 3D printer in International Space Station

NASA has successfully installed the World's first zero gravity 3D printer on the International Space Station to help the astronauts experiment with additive manufacturing in micro gravity.  

NASA astronaut Barry Wilmore installed the 3D printer, designed and built by Made In Space, inside the Microgravity Science Glovebox (MSG) on the ISS.  The printer was launched in September aboard the SpaceX 4 resupply mission to the ISS.

Philae lander lands on the comet

A small robotic lander released from European Space Agency's Rosetta probe touched down on the comet 67P/Churyumov-Gerasimenko on wednesday 12th November, 2014 after 7-hour descent, by gently colliding and tumbling to the surface of the comet.  

The Philae lander hit the surface of two and half mile wide comet at a speed of 2 miles per hour.  The gravity on the comet is 1,00,000 times less than that of on earth.  Shortly after its deployment, Philae sent the first photo of the comet. 

This is one of the great success for ESA which launched Rosetta spacecraft more than 10 years ago from the Kourou launch port in French Guiana.  After launching in March, 2004 the spacecraft and Philae lander travelled more than 6 billion kilometers to catch up the comet which orbits the sun at speeds of upto 1,35,00 Km per hour

Here is a video about Philae lander by ESA.

Robotic Probe landing on a comet for the first time next week

European scientists and engineers are getting ready for a soft landing of a robotic probe on the surface of a comet for the first time.  This will happen next week.

The ESA's spacecraft "Rosetta" is just a few days away from releasing its Philae lander onto the surface of Comet 67P/Churyumov-Gerasimenko.  Scientists are getting to soft land the lander on 12th November,2014 on the surface of the comet.  

If the mission is successful, the Philae landing will be the first time humans have ever soft landed a probe on a comet's surface.  The lander will study the surface of the comet and the Rosetta probe will study the comet from the orbit.  

It is not easy to land the lander on the surface of the comet.  It has taken 10 years for the probe to catch up with the comet.  A number of specific commands must be executed in order to ensure that Rosetta does not crash into the comet and Philae will arrive at its landing site safely.  Rosetta should release the Philae when the two spacecrafts are flying about 22.5 kilometers from the center of the comet.  The scientists have to wait 10 hours before finding out whether the landing would be successful. 

The scientists and the teams are fully prepared to accomplish the difficult task of landing Philae on comet.  TheRosetta is expected to stay with the comet as it makes its closest approach with the sun in August, 2015.  The spacecraft will beam back scientific data to Earth which could help scientists understand about comets and early solar system. The instruments on Rosetta already revealed that comets smell like rotten eggs. 

The Rosetta was launched to space in 2004 on a  6.4 billion kilometers journey to the comet.  It has reached the comet in August, 2014.  Here is an artist's impression of Philae lander on the surface of comet.



Here is a video showing how the Rosetta will land the Philae lander on the comet. 

3rd navigation Satellite ( IRNSS-1C) launched by India on 16th October, 2014

The third navigation satellite, IRNSS-1C was launched by India on thursday early morning at 01:32 hrs IST ( 16th October, 2014).  The ISRO's work horse Polar Satellite Launch Vehicle, PSLV gave the country and the ISRO yet another text book launch at exactly 20.25 minutes after the PSLV-C26 lifted off with IRNSS-1C Satellite from Sriharikota at 01:32 hrs IST.  The spacecraft was placed into its intended orbit.

The IRNSS-1C is a part of Indian Regional Navigation Satellite System (IRNSS) which is a constellation of Geosynchronous satellites which the ISRO has been deploying to provide navigation data to India and the surrounding region.  The first satellite of the series IRNSS-1A was launched last July with seven satellites scheduled for completion by end of 2015.

The IRNSS-1C has a total mass of 1,425 Kgs including the weight of the fuel.  The spacecraft has a mass of only 600 Kgs without fuel.  The remaining 825 Kg is the weight taken up by the propellant for the apogee motors and manoeuvring engines.  The spacecraft is designed for a life period of 10 years operations.  The spacecraft generates 1600 watts of power through its twin solar arrays.  The satellite broadcasts L5 and S band navigation signals.  

This is the 27th successful mission of PSLV.  Hon'ble Minister of State Dr. Jitendra Singh witnessed the launch from the Mission Control Center at Sriharikota.   After the lift-off of PSLV-C26 with the ignition of the first stage, the important flight events, namely, stage and strap-on ignitions, heat-shield separation, stage and strap-on separations and satellite injection, took place as planned. After a flight of about 20 minutes 18 seconds, IRNSS-1C Satellite, weighing 1425 kg, was injected to an elliptical orbit of 282.56 km X 20,670 km, which is very close to the intended orbit. 

Russian Rocket Soyuz ST-B launches Galileo Satellites into wrong orbit

Arianspace has confirmed on Friday 22nd August, 2014 that two satellites for Europe's Galileo Navigation network were released into wrong orbit after launching aboard a Soyuz St-B rocket from french Guiana.

The Russian Rocket Soyuz ST-B has launched the Galileo satelllites from European Space port in Kourou, French Guiana on Friday 22nd August, 2014.  How ever the launch of two FOC-M1 ( FM01 and FM02) satellites which took place at 12:27 UTC did not result in a correct orbital injection.  Controllers are now looking for options to save the satellites.

There was no clarity whether the two satellites have enough fuel to make up for the orbit injection errors.  The Russian built Soyuz ST-B launch vehicle carrying the Galileo satellites blasted off from French Guiana in South America at 08:27 AM EDT ( !2:27 GMT).  The Soyuz rocket's three booster stages gave way to a Russian Fregat-MT upper stage less than 10 minutes after lift off.  The Fregat was programmed to fire two times to propel the Galileo satellites into a circular medium earth orbit tilted at an angle of 55 degrees to the equator.   

The Fregat upper stage consists of six spherical tanks arrayed in a circle ( four for propellant, two containing avionics) with trusses passing through the tanks to provide structural support.  The stage is independent from the Soyuz's lower three stages having its own guidance, navigation, control, tracking and telemetry systems.  The Fregat uses earth storable propellants ( UDMH/NTO) and can be restarted up to 20 times in flight - enabling it to carry out complex mission profiles.  It can provide 3-axis stabilization or perform a spin-up of the spacecraft payload.

US military orbital tracking data indicated that the Galileo satellites launched by Soyuz on Friday were flying in lower orbit than planned.  The officials confirmed launch anomaly on Friday.  Arianspace said that investigations into the launch anomaly are underway and more information will be provided after analysis of the flight data.

The $7.2 billion Galileo network will consist of 30 satellites when completed.  At least 24 satellites are required for independent global navigation coverage.  ESA officials said before Firday's launch that two more Galileo satellites were being prepared for lift off on another Soyuz launcher in December, 2014.  Another 8 spacecrafts were on track for launches on Soyuz or Arian 5 next year.( 2015).

Here is a video of the launch of GAlileo satellites......

SpaceX Rocket explodes during Test Flight

SpaceX is one of the private companies which is the most successful non-Government company in Space programs.  It was the first private company to launch a spacecraft to orbit and recover it and it was the first to launch a satellite into a geo synchronous orbit.  It is amazing that SpaceX has come so far without any set back.  But the failure happened on Friday, 23rd August, 2014 during an unmanned internal test and no payload was lost.

 SpaceX rocket exploded shortly after launching during a test flight in Texas, according to Bruce Gietzen of KXXV-TV.   Gietzen followed up by reporting there were no injuries. The rocket, which was unmanned, was launched from the SpaceX rocket-development facility in McGregor, Texas.  

Mr. John Taylor, a spokesman for SpaceX said that the prototype rocket automatically detonated after detection of an anamoly during a test flight on Friday 23rd August, 2014 in McGregor, Texas.   He said that the rocket was a three-engine version of the F9R ( FAlcon Rocket ) test vehicle, a prototype intended to pave way for fully reusable launch vehicles which would fly themselves back home. The rocket is similar to Falcon 9 which the SpaceX uses to launch unmanned cargo spacecraft to the International Space Station.  

The Flight Termination System automatically terminated the mission during the flight when an anamoly was detected.    SpaceX will review the flight record to learn more about the rocket's performance before its next test flight.  Here is a video of the launch and the explosion....

Robotic Russian CArgo Ship launched for a trip to International Space Station

An unmanned Russian spacecraft filled with three tons of cargo for the six crew members living on the International Space Station launched on 23rd July, 2014.  

The unmanned Progress 56 spacecraft launched atop a Russian built Soyuz rocket from Baikanur Cosmodrome in Kazakhistan at 5:44 PM EDT ( 21:44 GMT) and 3:44 local time on Thursday, 23rd Jult, 2014.  

The Progress 56 carrying around 2,587 Kilograms of food and other supplies for the Expedition 40 crew who are currently aboard ISS.  The spacedcraft is also delivering 800 Kg of Propellant,  26 Kg of air, 22 Kg of Oxygen, 420 Kg of Water and 1,320 Kg of supplies, spare parts and experimental hardware according to NASA.

The Progress ships normally takes around 2 days to reach ISS but the Russian craft launched on 24th July, 2014 has been accelerated and reached in 6 hours to the Science Laboratory.

The International Space Station was flying about 260 miles above north east of Kazakhistan at the time of launch and passed directly over4 the launch site three minutes later.  After a series of thruster firings by progress have adjusted the orbit to put the Russian space freighter on track for a rendezvous with the ISS and an automatic docking to the earth facing port of Piris docking compartment.  Progress 56 is slated to spend about three months docked to the complex before undocking to make way for ISS Progress 57.

The ISS Progress 55 cargo craft, which undocked from Pirs on Monday, is now a safe distance from the complex for a series of engineering tests prior to being sent to a destructive re-entry over the Pacific Ocean on July 31.

The station's crew began the workday at 6 a.m. Wednesday, four hours later than the usual 2 a.m. reveille to accommodate the late-night arrival of Progress.

Commander Steve Swanson and Flight Engineer Alexander Gerst participated in more Ocular Health exams as flight surgeons track the vision health of the astronauts aboard the station.

NASA recently identified that some astronauts experience changes in their vision, which might be related to effects of microgravity on the cardiovascular system. Researchers are working to understand and prevent these changes in astronauts. With guidance from the Ocular Health team on the ground, Gerst performed an ultrasound scan of Swanson's eyes.

Flight Engineer Reid Wiseman then pitched in to help out with Wednesday's exams and conducted an ultrasound scan of Gerst's eyes. Swanson and Gerst later measured each other's blood pressure and collected electrocardiogram data for Ocular Health.

Swanson also temporarily removed the Multi-user Droplet Combustion Apparatus from the Combustion Integrated Rack's combustion chamber to replace some igniter tips.

A video of the launch is shown below.

Five Foreign Satellites launched by Indian PSLV-C23 Rocket on 30th June, 2014

Indian Space Research Organization, ISRO bagged another success of its work horse launch vehicle PSLV.  The PSLV-C23 carrying five foreign satellites including French Satellite SPOT-7 successfully placed the satellites into their intended orbits on 30th June, 2014.


The Rocket lifted off from Satish Dhawan Space Center, Sriharikota exactly at 09:52 Hrs IST on Monday, 30th June, 2014.

PSLV-C23 injected SPOT-7, a French earth observing satellite, and four other foreign satellites, including two from Canada and one each from Germany and Singapore, into the desired orbits. This marks exclusive commercial launch by India and the 26th consecutive successful launch of PSLV.

The launch of PSLV-C23 was originally planned at 09:49 hrs IST but was delayed by 3 minutes to 09:52 Hrs IST to avoid possibility of some space debris getting in the way of the satellites.

Prime Minister of India, Sri Narendra Modi  arrived at Sriharikota on Sunday, 29th June, 2014 and has witnessed the PSLV-C23 Launch from Sriharikota.   The other dignitaries who accompanied Sri Narendra Modi are Chief Minister of AP Sri. Chandra Babu Naidu, Governor of Andhra Pradesh, Sri Narasimhan and Central
Prime Minister Narendra Modi, who arrived in Sriharikota on Sunday, witnessed the PSLV-C23 launch.

Modi on Sunday tweeted his government is committed to give impetus to the country's space programme.

The live Video of the PSLV-C23 launch is shown below.
 

2nd Navigation Satellite launched by India on 4th April, 2014

The second navigation satellite of India, IRNSS-1B was launched on Friday 4th April, 2014 by Polar Satellite Launch Vehicle PSLV-C24.  The launch vehicle lifted off at 11:44 hrs GMT ( 17:14 hrs IST) from Satish Dhawan Space Center which is India's primary launch site.  

The launch vehicle is propelled by a solid fueled first stage and six strap-on motors.  The second stage of the rocket is the liquid engine.  The third and fourth stages of the vehicle accelerated the spacecraft to the orbital velocity.  The spacecraft was separated  20 minutes after lift off.

Initial data indicated that the launch vehicle placed the spacecraft in an orbit with a perigee of 20610 Kilometers.  It was placed with an inclination of 19.2 degrees.  The PSLV is the most powerful launch vehicle of ISRO and the Friday's mission has used the PSLV-XL version.

The IRNSS-1B is the second satellite of the Indian Regional Navigation Satellite System which is a 7-satellite network flying in high altitude orbit over Indian ocean. The spacecraft weighs 1,432 Kilo grams including the full load of propellant.  The satellite will maneuver itself into a 36,000 high geosynchronous orbit at 55 degrees east longitude with inclination of 29 degrees to the equator. The spacecraft will be drifting north and south of the equator, tracing a figure of eight pattern over Indian Ocean, Arabian Sea and South Asia.

The spacecraft is designed for a 10-year lift time.  Five more satellites are scheduled to be launched by mid of 2015.  The program of regional navigation system will reach users within India and surrounding regions extending about 1500 Kilometers from the Indian main land. The IRNSS services will be freely available to the public but some of the features will be restricted to the Government users.

The IRNSS-1B launched on 4th April, 2014 carries L-band and S-band navigation payloads and a rubidium atomic clock to keep the time.  A C-band transponder and a laser reflectors will help the engineers to find out the distance to the satellite in orbit which is a requirement for precise navigation services.

Four IRNSS satellites will be operating in inclined orbits ( geosynchronous orbits ) while three satellites will be orbiting in the geostationary orbit over the equator.  The navigation services will be helpful for marine traffic, emergency response officials, vehicle tracking applications, mobile communications, mapping and civilian drivers.

A Planet beyond Pluto - Scientists discover a new planet of Solar System

Scientists at the Carnegie Institute for Science has discovered a new and distant dwarf planet beyond Pluto in our solar system recently in third week of March, 2014.  The planet is named as 2012 VP113.  The scientists believe that the existence of this planet indicates that there may be another actual planet there which may be ten times bigger than the Earth.

The dwarf planet seems to be around 450 Kms.  wide  and orbits roughly 12.4 billion kilometers away from the Sun.  This distance is roughly 83 Astronomical Units away from Sun.  One astronomical unit or AU is 155.838 million Kilometers.

If the size of the dwarf planet is confirmed, it could be qualified as a dwarf planet in the same category of Pluto.  The researchers said that the discovery proves the existence of the inner Oort cloud, which is a region of icy bodies that lies far beyond the orbit of Nepture,.   The planet is currently named as 2012VP113 as announced on 26th March, 2014.  

The size of 2012 VP113 is half the size of Sedna discovered earlier.  Dwarf planets such as 2012 VP113 and Sedna, which travels as far as 949 AUs away from the sun on its 11,400-year orbit, form a placid "inner" Oort Cloud distinct from the outer one, the study suggests. Comets that plunge into the inner solar system are thought to be dispatched from the outer Oort Cloud by gravitational nudges from stars passing near our solar system.

 

Astronaut and 2 Cosmonauts arrive at International Space Station after 2 day delay

 A NASA astronaut and two Cosmonauts arrived finally at the International Space Station two days later than originally planned.

A Russian Soyuz spacecraft carrying NASA astronaut Mr. Steve Swanson and Soviet Cosmonauts Mr. Alexander Skvortsov and Oleg Artemyev docked with the orbiting ISS at 7:53 PM EDT ( 23:53 GMT) on Thursday, March, 27, 2014. 

The three crew members blasted off on Tuesday afternoon ( March 25, 2014) and expected to arrive six hours later.  But there was a failure in the Soyuz to complete one of the automated burns required to pull off this "fast track" trip, forcing mission controllers to revert to a more traditional two-day chase and rendezvous.

 NASA officials said that all the systems on board Soyuz were functioning normally.  Arrival of these three crew members brings the space station back up to its full complement of six crew members.  The new crew members join the NASA's Rick Mastracchio, Japanese astronaut Koichi Wakata and Cosmonaut Mikhail Tyurin.

 

Japan launches next generation satellite to track rainfall and snow

The H-IIA rocket blasted off from a southern Japanese island at 3:37 am on Friday, 28th February, 2014  (1837 GMT Thursday) as scheduled, with the Global Precipitation Measurement (GPM) core observatory aboard. 


The Global Precipitation Measurement (GPM) Core Observatory, which is jointly developed by NASA and the JAXA (Japanese Aerospace Exploration Agency) was launched by Japan and the rocket blasted off from Japan's Tanegashima Space Center on 28th February, 2014.


The GPM satellite is designed to collect data from several other satellites in orbit and add that to its own measurement to build up a detailed picture of precipitation around Earth.  Weather forecasters say that with more detailed and  complete map of rain and precipitation they will be better able to predict events like typhoons and floods.  

The GPM will provide near real-time observations of precipitation every 3 hours all over the world which improves scientists' understanding of climate changes and global water cycle.

The H-IIA rocket blasted off from a southern Japanese island at 3:37 am on Friday (1837 GMT Thursday) as scheduled, with the Global Precipitation Measurement (GPM) core observatory aboard, JAXA said.
The satellite, jointly developed by Japan and the United States, is designed to collect data from several other satellites in orbit and add that to its own measurements to build up a detailed picture of precipitation around the planet.
Weather forecasters say that with a more detailed and complete map of rain they will be better able to predict extreme events such as typhoons and floods.
On Thursday, Japanese astronaut Koichi Wakata, who is now aboard the International Space Station along with NASA astronaut Rick Mastracchio and Russia's Mikhail Tyurin, told his 74,000 Twitter followers he was hoping for a smooth launch.


Read more at: http://phys.org/news/2014-02-japan-readies-hi-tech-global-rainfall.html#jCp

China Moon rover Jade Rabbit in trouble

We all know that China has landed a moon rover - Jade Rabbit on the surface of the Moon on 14th December, 2013.  The rover has already sent its first pictures at that time.  

But unfortunately the China's Jade Rabbit is experiencing some troubles.  The rover is experiencing a mechanical control abnormality.  The rover is experiencing the problems due to moon's complicated lunar surface environment.   We all know that the rover has landed on Moon as a part of China's Chang'e -3 Mission which is the first soft landing on Moon since 1976.  The rover was expected to operate for around 3 months. China has recently announced that Jade Rabbit also known as Yutu has successfully explored the Moon surface with its mechanical arm.

The malfunction emerged before the rover entered its scheduled dormancy period on 25th Jan, 2014.  The scientists are trying to repair the rover. The rover was due to become dormant for 14 days during the lunar night when there will be no sunlight available to power the solar panels.  As you alll know that the lunar cycle consists of 28 Earth days.  For those 14 days the Moon is illuminated by the Sun which is called as Lunar Day and for the other 14 days the Moon is in shadow which is called Lunar Night.  During the Lunar day, the rover is free to move around for those 14 days as the solar panels are powered by sun light.    But during the lunar night, the temperatures reach below -170 degrees celcius and the rover enters into a state of hibernation.  In this mode, a radio isotope heater unit ( which is a few grams of radio active plutonium) keeps the core systems warm enough so that they do not freeze to death.

But a mechanical control abnormality caused by the complicated lunar surface environment is preventing the rover from hibernating.  China has several successful manned space flights but the malfunctioning rover presents the first public mishap in China's ambitious space programme.

It is expected that the Jade Rabbit will not function in future and this is the end of its life.
 

Interesting Facts about Space Debris

Space Debris or Orbital debris or Space junk or Space Waste is nothing but a collection of defunct objects in orbit around Earth.   The space debris includes all the materials like spent rocket stages, old satellites, fragments from disintegration and collisions.  As we know that orbits overlap with launch of new spacecrafts, the space debris may collide with the newly launched and operational spacecrafts.

There are more than 19,000 pieces of space debris larger than 5 cm. which are tracked and another 3,00,000 pieces smaller than 1 cm below 2000 Km altitude around the earth,.  Most of the space debris is less than 1 cm. which include dust from solid rocket motors, paint flakes etc.  

Safety from debris over 10 cm (3.9 in) comes from maneuvering a spacecraft to avoid a collision. If a collision occurs, resulting fragments over 1 kg (2.2 lb) can become an additional collision risk.  Here are some important facts about Space debris.


What is Space Debris?

There are two types of Space debris - Natural and Artificial. 

 
• Natural space debris consists of small pieces of cometary and asteroidal material called meteoroids. We see these as meteors when they travel through the Earth's atmosphere.
• Artificial space debris is any non-functional man-made object in space (usually orbiting the Earth).

Where Does Artificial Space Debris Come From?

• Satellites which have reached the end of their life
• Failed Satellites and spacecrafts
• Rocket stages that have used to launch satellites into space
• Nose cones, payload covers, shrouds, bolts and other launch hardware
• Solid propellant slag
• Space activity cast-aways (accidental or deliberate), eg wrenches, human waste
• Deterioration fragments, eg peeling paint
• Fragments from exploding batteries, fuel tanks (not totally empty), etc
• Fragments from collisions, both accidental and deliberate

When was the First Piece of Artificial Space Debris Created?

         The first piece of artificial space debris was created on 4th October, 1957 when the last stage of the rocket which launched Sputnik-1 remained in orbit.

Is Space Debris a Problem?

The main worry about space debris is a possible collision with active or functioning satellites or spacecrafts.  

How Likely is a Collision with Space Debris?

Prior to 1957, many astronomers warned that natural space debris (ie meteoroids) would pose such a high collision risk that man's use of space might be severely compromised. Fortunately, this turned out to be not so. The collision probability from meteoroids is very low, although not negligible. The larger the spacecraft and the longer it remains in space, the greater the chance that it will suffer a collision. 

  At the present time, only a handful of dangerous collisions with artificial space debris are known to have occurred. However, the production of this type of debris is increasing at such a rate that it gives concern for the future.

What Other Problems are Due to Space Debris?

• Small pieces of space debris (less than 1/10 mm) are prolific enough to cause erosion of optical surfaces. This is like sandblasting, and can ruin telescope mirrors, and decrease the efficiency of solar cells.
• Particles such as paint flakes (under 1 mm) can cause small craters in walls and windows. Almost 100 Space Shuttle windscreens have had to be replaced (as of 2008) due to pits caused by such impacts.

What is the Minimum Size for Dangerous Damage?

It is believed that any fragment of space debris larger than 1 cm.  will penetrate the walls of existing satellites/spacecraft.

Why are Space Debris Impacts so Dangerous?

It may be surprising to know that a paint flake can cause a crater in a wind screen.  Yes it us true.  The reason is the velocity of space debris impacts. A typical impact occurs at a closing velocity of 10 km/sec or 36,000 Kms per hour! 

  Such impacts are called hyper velocity impacts to indicate their extreme nature. At these velocities a piece of debris has more kinetic energy (energy due to its motion) than an equal mass of high explosive. An impact with a one kilogram object will thus cause more damage than the explosion of one kilogram of TNT.

Can You Express a Space Debris Collision in Everyday Terms?

• A 2 mm space debris fragment colliding at 10 km/s is like being hit with a cricket ball at 100 km/hour
• A 10 mm fragment at the same speed is like being hit by a large motorbike at 100 km/hour

Why are Collision Velocities so High?

Velocities of objects in space are determined by the laws of physics and the gravitational field of the body around which the objects orbit.   An object has to move with a velocity of 7 Km per second around Earth to remain in the Earth orbit.    The objects are in many different orbits around the Earth, some traveling in opposite direction to others.  With these high velocities, it is natural that the collisional velocities will be very high.

  In the case of natural space objects (meteoroids) that orbit around the Sun, these travel at even greater velocities. To remain in its orbit around the Sun, the Earth has to move at 30 km/sec. Other objects that come near the Earth may have relative velocities ranging anywhere from 11 km/sec to 72 km/sec. The average collisional velocity between a meteoroid and a satellite is about 20 km/sec.

How Much Debris is in Space Now?

As of 2008 the number of pieces of artificial space debris in orbit around the Earth is estimated to be:

Size Range		Number of Fragments
1 - 10 mm		50,000,000
10 - 100 mm		300,000
> 100 mm		12,000

Is Anything Being Done About Space Debris?

In June 2007 the United Nations General Assembly adopted a set of 7 orbital debris mitigation guidelines for member states (countries) to follow. However, these are legally non-binding under international law. 

  Most space-faring countries realise that space debris is a problem and have their own programs to try and reduce the creation of more space debris in future space activities. NASA has the most proactive program in this area. The problem is that these programs do not reduce the amount of debris that is currently in orbit.

Can Satellites be Protected from Space Debris?

There are two ways that satellites and spacecraft may be protected from orbital space debris impacts:

• Computer programs can search for possible collisions between large space debris objects and high value spacecraft. When they detect the likelihood of such a collision, the spacecraft is manuevred (by small thruster rockets) out of harm's way.  Such manuevres are now being carried out for large spacecraft such as the International Space Station and the Space Shuttle. However, these operations are expensive and can disturb delicate experiments. Also, not every satellite has the ability to maneuvre. Space tracking networks can only track space objects larger than about 100 mm. Since even a 10 mm object can severely damage a satellite it is obvious that collision avoidance will never be 100% effective.


• Debris shields can be designed to provide additional protection for a spacecraft. One obvious way is simply to increase the thickness of the vehicle walls. However, this adds a lot of mass to the craft and makes it a lot more expensive to launch it into space. Specially designed shields take advantage of the fact that two thin walls separated by a space are more resistant to debris penetration than a single thicker wall. This type of design is called a Whipple shield after the astronomer Fred Whipple who came up with the idea in the 1950's. The outer wall absorbs a lot of the debris energy so that the inner wall is not punctured. This type of shield and modifications to this design are currently installed on the International Space Station. However, once again this does not offer 100% protection.

What About Debris Already in Orbit?

Although the probability of collision with a piece of orbital space debris is currently very low, it will not remain so forever, even if no more debris is put into orbit. The reason for this is that collisions between objects in space will slowly but surely increase the number of dangerous debris fragments. These in turn will produce more debris and so on in a chain reaction. In a few hundred years, the amount of debris will be so great that space operations will be severely limited. In 1989 science fiction writer Frederick Pohl predicted a similar situation in his novel "Homegoing". Set many years in the future, mankind had generated so much space debris that he was confined to the surface of the Earth.

What can be Done to Remove Debris from Space?

          A number of solutions have been proposed to this problem: 

• Objects in low altitude orbits (below about 500 km) are affected by atmospheric drag. This lowers their orbit until they re-enter the atmosphere and are thus naturally removed from orbit. The lower the orbit the faster it decays.


• Space "tugs" could be employed to "catch" large space debris objects and either lower their altitudes for natural decay, or bring them back to Earth.


• Giant "sponge" like objects could be deployed to "catch" or "soak up" small debris pieces. After a time, the sponge would be removed from orbit.


• Attach tails or tethers to large pieces of space debris to increase the drag they experience and lower their orbits.


• Use large ground based lasers to "push" small pieces of debris into lower orbits.
All of these schemes will be very expensive and use technology that is still to be developed. The laser scheme looks as if it might be the most promising. However, political problems might outweigh technical problems.

Is Anyone Actively Involved in Debris Reduction?

There is currently no agency involved in active removal of existing space debris from orbit. However, an Australian firm based in Canberra (EOS) has been given a Federal Government research grant to investigate laser removal of space debris.

What Happens to Space Debris Reentering Earth's Atmosphere?

Most pieces of space debris will burn up as they enter the Earth's atmosphere. This ablation process starts around a height of 100 km and is usually complete by the time the object has descended to about 20 km. Very heavy or refractory pieces (and occasionally very light pieces) may not burn up completely, and some part of the object may make it down to the ground. However, even these objects have lost most of their "space" velocity and hit the ground at no more than 100 metres per second.

Are Returning Objects Hazardous?

It has been estimated that one piece of space debris may make it down to the Earth's surface almost every day. Most of these are very small and most will fall into the ocean or an unpopulated region of the Earth's surface. Very few are ever recovered, much to the disappointment of reentry scientists. The probability of being hit by a piece of space debris is extremely low and a lot less than the probability of your being hit by a car while crossing a road. 

Occasionally a large reentering derelict satellite may contain hazardous cargo. Two cases of radioactive debris have actually made it to the ground (these were from radioactive power sources). Such reentries are known well in advance (although the exact point of landfall can never be known precisely), and trained teams can be sent to secure the site and ensure no danger to any people in the area. Australia has a contingency plan set up to deal with such an event.

Can Anything be Done to Reduce Reentry Risk?

If a satellite has maneuvring capability and still has remaining fuel at the end of its life, it can be set up so that it reenters over a large area of ocean. NASA carries out a reentry survivability analysis for all large spacecraft, and if this indicates that a significant fraction of the object may survive the reentry process, they will attempt to control the reentry of such objects into a safe area. If a large object is non-controllable, it may be possible to destroy the object through collision with an anti satellite missile launched from the ground. Such a collision produces many thousands of pieces of space debris, each of which will burn up when it reenters the atmosphere. However, as long as this is done at a sufficiently low altitude (below 300 km), the additional space debris produced will all decay from orbit (through atmospheric drag) within a month or two. However, the cost of such an operation is very expensive, and it could be argued whether this approach is worthwhile, considering the very low probability of damage or injury.

How Long Does it Take for Space Debris to Decay?

By "decay" we mean a reduction in orbital height due to atmospheric drag. The decay lifetime of a space object depends on its altitude, the level of solar activity, and its mass to cross-sectional area.  Objects with a large mass to area ratio will remain in orbit longer as they are less affected by drag.  High solar activity increases the density of the atmosphere in low Earth orbits and reduces satellites' decay lifetimes.  

On the average a satellite in an initial 300 km high orbit will have a decay lifetime of only a few months. One in a 500 km orbit has a lifetime of around 10 years, and one at 1000 km altitude will stay in orbit for thousands of years.

Are there any Other Future Problems with Space Debris?

Some astronomers have been worried about orbital space debris proliferation because of two concerns: 

 
• Increased numbers of medium to large scale space debris will cause light trails across astronomical images, decreasing their scientific and asthetic value. The trails also may confuse automatic computer analysis of large numbers of images.
• Extremely large numbers of very small objects (fractions of a millimetre) are expected to increase the background or ambient night-time sky glow, limiting the extent to which astronomers can see faint objects (eg very distant galaxies).

SpaceX launched a Telecom Satellite on 6th January, 2014

SpaceX has launched its second rocket within 5 weeks of the first launch of SpaceX.  The SpaceX Falcon 9 rocket lifted off from Cape Canaveral on Monday, 6th January, 2014 and successfully puts a broadcasting satellite for aThai communication operator.

The mission lasted for half an hour and it is just one month after the first launch by SpaceX into a geostationary transfer orbit.   The 224-foot-tall rocket lifted off in a blaze of golden exhaust at 2206 GMT (5:06 p.m. EST), and its on-board guidance computer maneuvered the slender white booster east from Cape Canaveral's Complex 40 launch pad, soaring over the Atlantic Ocean and through a deck of overcast clouds less than a minute into the flight.

Cameras were mounted on the rocket.  So SpaceX company webcasted the streamed video showing the smooth ascent of the rocket into the upper atmosphere before the Falcon 9 rocket shed its first stage 3 minutes after lift off.    The second stage's Merlin 1D engine, fitted with an expansive nozzle optimized for firing in a vacuum, ignited to propel the Thaicom 6 spacecraft into a temporary orbit. The second stage shut down its engine and coasted across the Atlantic before restarting to boost Thaicom 6 into a targeted orbit reaching as high as 90,000 kilometers, or 55,923 miles.

SpaceX has confirmed that the launch was successful in their twitter account.  The tweet says "Falcon 9 has successfully deployed Thaicom 6 into its target orbit".  The launch was actually planned on 3rd January, 2014 but it was delayed due to a technical snag.  The perigee of the orbit was 295 Kms or 183 miles and the inclination was 22.5 degrees at the time of deployment of the spacecraft.

 The SpaceX company is planning to make the Falcon9's first stage reusable eventually guiding the spent stages back to a rocket assisted touch down on a landing pad near the launch site.

Isro successfully launches indigenous cryogenic engine-powered GSLV-D5 Rocket

The heavy rocket of ISRO - GSLV D5 lifts off successfully from Space port of India - Sriharikota at 4:18 PM on 5th January, 2014.

The 29 hour count down for the launch of GSLV-D5 started at 11:18 AM on Saturday, 4th January, 2014.  The GSLV-D5 rocket powered by an indigenous Cryogenic Engine was launched from Satish Dhawan Space Center, Srihiarkota.


The GSAT-14 spacecraft was placed into a geosynchronous transfer orbit 17 minutes after lift off,.  This launch is very crucial for India as the launch took place after two back-to-back failures of GSLV flights in 2010 - the first one with indigenous cryogenic engine on 15th April and the next with a Russian Cryogenic engine on 25th December.  The last GSLV launch was on 19th August, 2013 but it was called off minutes before take off due to leakage of liquid fuel from the second stage. 

More detailed news about GSLV-D5 launch  can be read by clicking here.

A video of the GSLV-D5 launch can be seen below.