Saturday, April 14, 2018

ISRO successfully launches IRNSS-1I Navigation Satellite on 12th April, 2018

In the 43rd flight of PSLV,  ISRO's PSLV-C41 has successfully launched the 1425 Kg IRNSS-1I Navigation Satellite on 12th April, 2018 from Satish Dhawan Space Center, Sriharikota.  The launch took place at 04:04 hrs IST

The vehicle lifted off from the first launch pad as planned and after a flight time of 19 minutes, the vehicle achieved a GTO orbit with perigee of 281.5 Km and apogee of 20,730 Km inclined at an angle of 19.2 degrees to the equator after which the IRNSS-1I satellite was separated from PSLV.

The IRNSS-1I is expected to replace IRNSS-1A, the first of the seven navigation satellites, that was rendered ineffective after its three rubidium atomic clocks failed..  The seven satellites are a part of the NavIC navigation satellite constellation.

The video of the launch is shown below.


India's GSLV-F08 successfully injects Communication Satellite GSAT-6A into orbit on 29th March, 2018

ISRO successfully placed a communication satellite GSAT-6A into a geosynchronous transfer orbit. The satellite was carried  onboard the GSLV-F08 launch vehicle from Satish Dhawan Space Center in Sriharikota on Thursday,  March 29th, 2018 at 16:56 hrs IST

The GSLV-F08 is the 12th flight of GSLV launch vehicle and sixth flight with indigenous cryogenic stage.  The launch took place from the second launch pad at Satish Dhawan Space Center

The GSAT-6A is a communication satellite that will complement the GSAT-6 which is already in orbit  The diameter of the antenna of this satellite is 6 meters - it can be unfurled and opened like an umbrella once it reaches the prescriibed orbit and improve India's communication capabilities.

The GSAT-6A is a high power S-band communication satellite and its mission life is about 10 years.

Friday, March 2, 2018

China's Space Lab may fall to Earth in March, 2018

Tiangong-1 was the first space lab built by China and launched in late September, 2011 to help the nation master the technologies needed to construct and operate a crewed space station. China aims to have such a station up by 2020.

The first Chinese orbital docking occurred between Tiangong-1 and an unpiloted Shenzhou spacecraft on 2nd Nov, 2011.  Two crewed missions later visited Tiangong-1. Shenzhou9 and Shenzhou 10 which launched in June 2012 and June 2013.  

The European Space Agency has issued a new re-entry forecast for China's Tiangong-1 Space Lab.   Th space lab weighing 8.5 tons is now expected to fall into Earth's atmosphere between 24th March, 2018 and 19th April, 2018.  The ESA officials say it is a rough estimate.    Re-entry will take place anywhere between 43 degrees north and 43 degrees south ( eg. Spain, France, Portugal, Greece etc) latitude. Areas outside these latitudes can be excluded.  The precise location and time of fall cannot be predicted by ESA..

What is a Blue Moon?

We all know that "Blue Moon" has nothing to do with the color of the Moon.  A "Blue Moon" is some infrequent phenomenon which involves the appearance of an additional full moon within a given period.  The period is something like two full moons appearing within a month's time.  

Normally there is a gap of 29.5 days between two full moons so it is very unusual for two ful moons to fit into a 3o or 31 day-long month ( means February will never have  a blue moon).  So a blue moon is a second full moon appearing within a single calendar month. This is the meaning of a blue moon.  So a blue moon does not have associate blue color but a blue moon is a full moon which appears within the same calendar.

The next monthly Blue Moon will be on 31st March, 2018.  The previous one was the Super Blue Moon on 31st January, 2018.  

Origin of the term "Blue Moon".

The phrase "Once in a blue moon" has been around for more than 450 years according to Philip Hiscock, a folklorist at the Memorial University of NewFoundland.  In a 2012 article in Sky&Telescope magazine, he explained that the earliest use of the term was much like saying the moon is made of green cheese - It indicated some thing absurd.  "He would argue that the moon is blue" was similar to saying "He would argue that black is white".


Friday, February 24, 2017

Astronomers discovered 7 earth-sized planets orbiting nearby star

Astronomers have discovered seven earth-sized planets orbiting same star which is 40 light-years away according to a study published on wednesday ( 22nd Feb 2017) in the journal of nature.  The discovery was announced at a news conference at NASA headquarters in Washington.  

This discovery which is outside of our solar system is a rare event because the planets have the winning combination of being similar to the size of Earth and being all temperate, meaning they could have water on their surfaces and potentially support life..

The seven planets were all found in a tight formation around an ultra cool dwarf star called TRAPPIST-1.  Some estimates indicate that they are rocky planets rather than being gaseous like Jupiter.   Three planets are in habitable zone of the star and may even have oceans on their surfaces.  These three planets are called as Trappist-1e, 1f and 1g.

The researchers believe that Trappist-1f is the best candidate for supporting life. It is little bit cooler than Earth but can be suitable with the right atmosphere and enough green house gases.

These planets are very close to each other and the star.   They are all within five times within a space five times smaller than the distance from Mercury to our Sun.  This proximity allows the researchers to make a study of the planets in depth as well, gaining insight about planetary systems other than our own.  The seven planets of Trappist-1 are compared with Mercury, Venus, Earth and Mars.

As we move away from the closest to the star to outwards,  the planets have respective orbits from one and half to nearly 13 Earth days.  The orbit of the farthest planet is still not known.   If you stand on surface of one of the planets, you would receive 200 times less light than you get from the Sun, but you would still receive just as much energy to keep you warm since the star is so close..   It would also afford some views, as the other planets would appear in the sky as big as the moon. 

If you stand on Trappist-1f,  the star would appear three times as big as the sun in our sky.  The researchers believe that because of red nature of the star, the light would be a salmon hue.  The researchers believe that the planets were formed together further from the star.  Then they would have moved into their current lineup.   Like our moon,  the researchers believe that the planets closest to the star are tidally locked.  This means that the planets always face one side to the star.  One side of the planet is night and other side always day;.

As per preliminary studies on climate,  the researchers believe that the three planets which are closest to the star may be too warm to support liquid water, while the outermost planet, Trappist-1h, is probably too distant and cold to support water on the surface.

Trappist-1 is a star which is half the temperature and a tenth of the mass of the Sun.  It is red, dim and just a bit larger than Jupiter.  But these tiny ultra cool stars are common in our galaxy.  By using a global network ground-based telescopes like TRAPPIST and space-based telescopes like Spitzer, the researchers continued looking toward the Trappist system and were able to determine the  orbits and orbital periods and distances of the planets from the star, their radius and their masses.  

The researchers are planning to define the atmosphere of each planet as well as determine whether they truly do have liquid water on their surface and search for life on these planets.  All this would happen in the next decade.  Even though 40 light years is not too distant, but it would take us millions of years to reach this star system.  But for research purpose, it is a close opportunity and the best target to search for life beyond our solar system.

James Webb Space Telescope will be launched i 2018 and positioned at a distance of 1 million miles from Earth with a view of the Universe.  It can observe large exoplanets and detect starlight filtered through their atmosphere.. They are also searching for similar star systems to conduct atmosphere research.  Four telescopes named SPECULOOS ( Search for habitable planets EClipsing ULtra-cOOl Stars) based in Chile will survey the southern sky for this purpose.  

This star system will probably outlive us because this type of star evolves so slowly.  When out Sun dies, TRAPPIST-1 will still be young star and will live for another trillion years.   After we are all gone, if there is another part of the Universe for life to carry on,  it may be in the TRAPPIST-1 system.

Thursday, February 16, 2017

ISRO successfully launches 104 satellites with PSLV-C37

The Indian Space Research Organisation made  history once again by successfully launching PSLV-C37 Rocket with 104 satellites on-board there by creating a record of the most number of satellites in a single launch.   This is the world record now..   

This is yet another feather in the ISRO's cap, which has also launched the cheapest mission to MARS named Mangalyaan.  The PSLV-C37 which was launched from Satish Dhawan Space Center at Sriharikota carried aboard the CARTOSAT-2Series satellite as well as 103 nano-satellites from various countries.  

The PSLV-C37 took off at 09:20 AM IST ( 03:58 GMT ) on 15th FEbruary, 2017 and cruised at a speed of 27,000 Kms per hour ejecting all the 104 satellites into the orbit in 30 minutes time. The main payload of PSLV-C37 was 714 Kg satellite for earth observation and it was also loaded with 103 nano satellites weighing around 664 kilograms in total.  Three of the nano satellites are from India and the others are from countries including Israel, Kazakhstan, Netherlands, Switzerland, United Arab Emirates and 96 from USA.   Now India holds the record of launching the most number of satellites in one go, surpassing Russia which launched 39 satellites in a single mission in June, 2014.

The business of putting satellites into orbit for a fee is growing as phone, internet and other companies seek greater and more high-tech communications.  ISRO is competing with other international players for a greater share of the space market and is well known for its low-cost space programme.

The two solar arrays of Cartosat-2Series satellite were deployed automatically immediately after separation and the ISRO Telemetry, Tracking and Command Network at Bangalore took over the control of the satellite.  The satellite will be made operational to its final configuration very soon and it will provide remote sensing services using its panchromatic ( black and white ) and multispectral ( color ) cameras.  Out of the 103 satellites carried by PSLV-C37, two ISRO nano satellite-1 ( INS-1) weighing 8.4 Kg and INS-2 weighing 9.7 Kg are technology demonstration satellites from India.  The remaining satellites are from other countries - USA ( 96),  Netherlands ( 1), Switzerland ( 1), Israel (1), Kazakhistan (1) and UAE (1).   With today's launch, the total number of customer satellites launched by India has reached 180.

The list of satellites 104 is given below...

CartoSat-2D – ISRO, India (1)
CartoSat-2D is fifth in the series of CartoSat-2 remote-sensing satellites that capture and
send panchromatic and multispectral images of India from space. These images can be used
to monitor the coastal land use, urban and rural planning, road networks and water distribution
, and to identify natural and man-made features. Weighing 714 kilograms, ISRO’s CartoSat-2D
 is the heaviest satellite onboard the PSLV-C37 and accounts for more than half the 1,377
kilogram payload of the rocket.
INS-1A – ISRO, India (1)
ISRO Nano Satellite-1A is an 8.4-kilogram research satellite that will stay operational for six
months, and carry two science payloads. One is the Surface BRDF Radiometer (SBR) payload
that can be used measure the Bidirectional Reflectance Distribution Function (BRDF) of targets
on the Earth's surface and will be able to take readings of the sunlight reflected off different
surface features. The other is the Single Event Upset Monitor (SEUM), which can be used to
track Single Event Upsets that happen due to high energy radiation in space environment in
Commercial, Off-the-Shelf (COTS) electronic components.
INS-1B – ISRO, India (1)
ISRO Nano Satellite-1B aboard the new PSLV-C37 rocket is also a modular satellite similar to
the INS-1B, but weighs 9.7 kilogram. It is expected to remain operational for 6-12 months and
 also carries two science payloads: the Earth Exosphere Lyman Alpha Analyser (EELA) and
 Origami Camera payload from ISRO's Space Application Centre (SAC). EELA keeps track of
 terrestrial exospheric line-of-sight neutral atomic hydrogen Lyman Alpha flux and can give an
 estimate for the interplanetary hydrogen Lyman Alpha background flux by means of deep
space observations. The Origami Camera, on the other hand, is a remote sensing colour
camera that can take high-resolution pictures of the Earth with a small package.
Flock-3p – Plant Labs, United States of America (88)
ISRO’s PSLV-C37 will take Planet Labs’ 88 Flock-3p nano-satellites to space, bringing the total
number of Dove satellites in space to 100. The satellites will be able to capture images of the
entire Earth surface once a day and take pictures in line-scanner formation at mid-morning
 pass times to minimise shadows in the images they capture.
Lemur-2 – Spire Global, United States of America (8)
Eight Lemur-2 nano-satellites operated by Spire Global of the USA, each of which carries a
 meteorological payload that can determine the atmospheric pressure, humidity and temp-
erature using signals from GPS satellites in Earth’s atmosphere. These nano-satellites also
 carry a payload that allows them to monitor and send forward tracking data from seafaring
Al-Farabi-1 – Al-Farabi Kazakh National University, Kazakhstan (1)
The Al-Farabi-1 is a nano-satellite developed by students of the Kazakhstan’s Al-Farabi
Kazakh National University. It weighs 1.7 kilograms and will work on calculating uplink /
downlink and ADCS Mission algorithms and testing of self-made components.
BGUSat – Ben Gurion University, Israel (1)
A 3U CubeSat nano-satellite developed by Israel’s Ben Gurion University, BGUSat carries
 two imaging payloads, an experimental GPS receiver and an optical communication expe-
riment. It measures 10x10x30 centimetres and weighs 5 kilograms. The BGUSat’s cameras
can track climate phenomena and its guidance system enables the operators choose the
 areas to shoot and research through a dedicated ground station at BGU. 
Nayif-1 – Emirates Institution for Advanced Science and Technology (EIAST), UAE (1)
Students at UAE’s Emirates Institution for Advanced Science and Technology (EIAST) deve-
loped the Nayif-1 nano-satellite and will be used for educational purposes.
DIDO-2 – SpacePharma, Israel and Switzerland (1)
DIDO-2 is a microgravity research nano-satellite that can be used to conduct biochemical
and physical experiments in micro-gravity. It will serve pharmaceutical companies, as well as
 other organisations, and will be able to send back data to Earth-based researchers via the
 on-board microscope.
PEASS – PEASS Consortium, Netherlands, Germany, Belgium, and Israel (1)
PiezoElectric Assisted Smart Satellite Structure or PEASS is a nano-satellite that can be
 used to evaluate and qualify ‘smart structures’ which combine composite panels, piezo-
electric materials, and next-generation sensors.
The launch video is shown below..

Here is a video of the onboard camera where we can see all the events till seperation of all the satellites.

Saturday, December 10, 2016

Indian Resource mapping satellite RESOURCESAT-2A blasted off from Sriharikota by PSLV-C36 Rocket

Once again India's PSLV delivered to orbit on Wednesday ( 7th December, 2016) the country's third space mission dedicated to mapping of natural resources creating a record year for Indian launch hitory.  

The Resurcesat-2A was launched by India's PSLV rocket ( PSLV-C36) in its 38th flight successfully at 10:25 hrs IST on 7th December, 2016.  The satellite weighed 1235 Kg.  

The 36 hur count down began on monday and the ground crew filled the PSLV's second and fourth stages with liquid fuels.   The PSLV-C36 lifted off at 04:55 GMT and climbed through a heavy rain shower and low clouds from the First Launch Pad of Satish Dhawan Space Center with 1.7 million pounds of thrust. 

The first four of the 12 meter auxiliary motors ( strap-on motors ) burned out and jettisoned around 70 seconds after lift-off followed by release of the last pair of boosters at T+92 seconds.   The first stage of the rocket consumed the solid propellant by T+1 minute and 50 seconds giving way to the Rocket's hydrazine-burning second stage Vikas Engine around 74 kilometers above Earth for a firing which lasted about 2 and 1/2 minutes with 1,80,000 pounds of thrust.   The onboard computers began closed-loop guidance during the second stage burn and the rocket's 3.2 meter diameter payload fairing fell down from the rocket at T+150 seconds.  

The PSLV headed eastwards first and then turned south in a "dogleg" maneuver to avoid flying over Sri Lanka accelerating to orbital velocity over Indian Ocean.   Once the Vikas Engine ( second stage ) emptied its 42 metric tonne supply of hydrazine and nitrogen tetroxide propellants, the third stage ignited around T+4 minutes 23 seconds for nearly two minutes and then coasted off until separating from the Rocket's fourth stage at around T+ 8 minutes 41 seconds.  

The twin engine liquid fueled fourth stage took control  of the mission at T+ 8 minutes 51 seconds for an eight minute firing to obtain proper velocity to enter the targeted polar orbit.  Resourcesat-2A was separated at around 18 minutes after lift-off.  

The Resourcesat-2A will track agriculture, water resources, soil contamination and the growth of Indian cities.  This is a follow up for Resourcesat 1 and Resourcesat 2 launched earlier in 2003 and 2011.  The spacecraft was put into an orbit of 823 Kms high at an inclination of 98.7 degrees to equator.

The PSLV-C36 launched on wednesday demonstrated several upgrades to the PSLV's avionics systems including the improved navigation system, a fiber-optic gyroscope, indigenously-produced computer processors and an automated fueling system to the fourth stage.  The streamlined automatic fuelling system saved one day in the launch preparations and also for a safe work environment for ground engineers to prepare the rocket.

Here is a video of PSLV-C36 Launch  ....