Archive for the ‘Space’ Category

UPDATE! Indian Mars orbiter supplementary firing successful

November 12, 2013

The supplementary burn made this morning to correct for the incompleteness of the 4th burn yesterday appears to have been successful. The objective was to reach an orbit (apogee) of 100,000 km and this seems to have been achieved with some margin to spare. The observed change is to an orbit with an apogee of 118,462 km. The next step on 18th November is to raise the apogee to just under 200,000 km and then insert the craft into the Trans-Mars trajectory on 1st December.

So far, so good and the success of the correction by the supplementary burn is both impressive and encouraging.

ISRO: 

  • Fourth supplementary orbit raising manoeuvre of Mars Orbiter Spacecraft, starting at 05:03:50 hrs(IST) on Nov 12, 2013, with a burn Time of 303.8 seconds has been successfully completed.The observed change in Apogee is from 78276km to 118642km.

The launch and subsequent orbit manoeuvre burns so far are summarised here:

  1. The Mars Orbiter Spacecraft, India’s first interplanetary spacecraft, was launched into an elliptical earth orbit with a perigee of 248.4 km and an apogee of 23,550 km, inclined at an angle of 19.27 deg to the equator by India’s Polar Satellite Launch Vehicle in its twenty fifth flight (PSLV-C25). The achieved orbit was very close to the intended one. The launch was conducted from Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota on November 05, 2013. The launch of Mars Orbiter Spacecraft occurred as scheduled from the First Launch Pad at 2:38 pm IST after a fifty six and a half hour count down. 
  2. The first orbit-raising manoeuvre of India’s Mars Orbiter Spacecraft was performed at 01:17 hrs Indian Standard Time (IST) early this morning (November 07, 2013) when the 440 Newton Liquid Engine of the spacecraft was fired for 416 seconds by commanding it from Spacecraft Control Centre (SCC) at ISRO Telemetry, Tracking and Command Network (ISTRAC) at Peenya, Bangalore. With this engine firing, the spacecraft’s apogee (farthest point to Earth) has been raised to 28,825 km, while its perigee (nearest point to Earth) is at 252 km. 
  3. The second orbit raising manoeuvre of Mars Orbiter Spacecraft, starting at 02:18:51 hrs(IST) on Nov 08, 2013, with a burn time of 570.6 seconds has been successfully completed.The observed change in Apogee is from 28814 km to 40186 km.
  4. The third orbit raising manoeuvre of Mars Orbiter Spacecraft, starting at 02:10:43 hrs(IST) on Nov 09, 2013, with a burn time of 707 seconds has been successfully completed.The observed change in Apogee is from 40186km to 71636km.
  5. In the fourth orbit-raising operation conducted on Nov 11, 2013, the apogee (farthest point to Earth) of Mars Orbiter Spacecraft was raised from 71,623 km to 78,276 km by imparting an incremental velocity of 35 metres/second (as against 130 metres/second originally planned to raise apogee to about 100,000 [1 lakh] km). The spacecraft is in normal health. A supplementary orbit-raising operation is planned for November 12, 2013, at 0500 hrs IST to raise the apogee to nearly 1 lakh km. 
mangalyaan trajectory

mangalyaan trajectory: image ISRO

Related posts: 

Indian Mars orbiter’s fourth burn in earth orbit only partially succesful

India’s frugal Mars orbiter mission completes 3rd burn in earth orbit

Frugal engineering for India’s Mars mission

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Indian Mars orbiter’s fourth burn in earth orbit only partially succesful

November 11, 2013
The Indian Mars Orbiter Mission met its first setback last night when the planned 4th burn in earth orbit was achieved but did not or could not impart the extra velocity that was planned. The orbit rose from about 71,000 km (apogee) to 78,000 km instead of the planned 100,000 km. A supplementary burn is planned for the early hours of 12th November (burns are scheduled for when the spacecraft is near perigee and within clear and easy range of tracking stations).
The current position of the spacecraft is between India and Saudi Arabia

ISRO Press Release:

In the fourth orbit-raising operation conducted this morning (Nov 11, 2013), the apogee (farthest point to Earth) of Mars Orbiter Spacecraft was raised from 71,623 km to 78,276 km by imparting an incremental velocity of 35 metres/second (as against 130 metres/second originally planned to raise apogee to about 100,000 [1 lakh] km). The spacecraft is in normal health. A supplementary orbit-raising operation is planned tomorrow (November 12, 2013) at 0500 hrs IST to raise the apogee to nearly 1 lakh km. 

During the orbit-raising operations conducted since November 7, 2013, ISRO has been testing and exercising the autonomy functions progressively, that are essential for Trans-Mars Injection (TMI) and Mars Orbit Insertion (MOI).  

During the first three orbit-raising operations, the prime and redundant chains of gyros, accelerometers, 22 Newton attitude control thrusters, attitude and orbit control electronics as well as the associated logics for their fault detection isolation, and reconfiguration have been exercised successfully. The prime and redundant star sensors have been functioning satisfactorily. The primary coil of the solenoid flow control valve was used successfully for the first three orbit-raising operations. 

During the fourth orbit-raising operations held today (November 11, 2013), the redundancies built-in for the propulsion system were exercised, namely, (a) energising the primary and redundant coils of the solenoid flow control valve of 440 Newton Liquid Engine and (b) logic for thrust augmentation by the attitude control thrusters, when needed. However, when both primary and redundant coils were energised together, as one of the planned modes, the flow to the Liquid Engine stopped. The thrust level augmentation logic, as expected, came in and the operation continued using the attitude control thrusters. This sequence resulted in reduction of the incremental velocity. 

While this parallel mode of operating the two coils is not possible for subsequent operations, they could be operated independently in sequence.

Mangalyaan current position 20131111 0830CET

Mangalyaan current position 20131111 0830CET

TOIThe first orbit-raising manoeuvre of India’s Mars Orbiter Mission was performed at 01:17 hrs Indian Standard Time (IST) early on November 07, 2013) when the 440 Newton Liquid Engine of the spacecraft was fired for 416 seconds by commanding it from Spacecraft Control Centre (SCC) at Isro Telemetry, Tracking and Command Network (ISTRAC) at Peenya, Bangalore. With this engine firing, the spacecraft’s Apogee (the farthest point to Earth) was raised to 28,825km.

The second orbit raising manoeuvre of MOM was at 02:18:51 hrs(IST) on Nov 8, 2013.The change observed in Apogee was from 28,814km to 40,186km. 

The third orbit raising manoeuvre of Mars Orbiter Mission spacecraft, starting at 02:10:43 hrs on Nov 09, 2013, was successful. The change observed in the Apogee was from 40,186 km to 71,636km.

India’s frugal Mars orbiter mission completes 3rd burn in earth orbit

November 9, 2013

There has been some criticism  (within and outside India) from the usual suspects about the frugally-engineered, Indian, Mangalyaan Mars Orbiter mission as “being too expensive” for a developing country like India. I tend to discount these voices which merely continue the long, retrograde and shameful tradition of the Luddites. Some of these voices are of those who would like humankind to return to the trees. Others are of those who feel threatened by the idea of “backward nations” moving into space.

Reaching Mars is not that easy. More missions have failed than have succeeded. The full list of Mars missions is here. There are many crucial steps left for the Mangalyaan mission to achieve and success is far from assured.

TOI: India’s Mars Rover Mission (MOM) named ‘Mangalyaan’ is the 42nd mission aimed at understanding Mars. Out of the 41 missions so far, 25 have been declared failures and only 16 have been a success. Even the latest Phobos-Grunt/Yinghuo-1 launched by Russia/China was a failure as it got stranded in the earth’s orbit. 

Close on the heels of ‘Mangalyaan’ being sent into space by India, the United States (US) is also gearing up for the MAVEN mission to be launched on November 18, 2013. The mission is intended to be a step towards ‘unravelling the planetary puzzle about Mars’. The US is also gearing up for the Mars Rover 2020 mission to understand ‘Martian atmosphere’.

Underlying all missions is the vision of Mars one day being inhabited by humans. And that vision transcends the petty and mean criticism of those who can only see a “glass half empty”.

Last night the 3rd of five rocket burns was completed to lift the earth orbit of Mangalyaan from 40,186 km to 71,636 km (apogee). The fourth and fifth burns are planned for November 11th and 16th to raise the apogee to 100,000 km and then to 192,000 km. The 6th burn will be to leave Earth’s orbit and  insert the spacecraft into a trajectory towards Mars. The Trans-Mars injection is expected around 12.42 AM on December 1st.

ISRO: The third orbit raising manoeuvre of Mars Orbiter Spacecraft, starting at 02:10:43 hrs(IST) on Nov 09, 2013, with a burn time of 707 seconds has been successfully completed. The observed change in Apogee is from 40186km to 71636km.

ISRO’s Mission Profile.

The Launch Vehicle – PSLV-C25 will inject the Spacecraft into an Elliptical Parking Orbit with a perigee of 250 km and an apogee of 23,500 km. With six Liquid Engine firing, the spacecraft is gradually maneuvered into a hyperbolic trajectory with which it escapes from the Earth’s Sphere of Influence (SOI) and arrives at the Mars Sphere of Influence. When spacecraft reaches nearest point of Mars (Peri-apsis), it is maneuvered in to an elliptical orbit around Mars by firing the Liquid Engine. The spacecraft then moves around the Mars in an orbit with Peri-apsis of 366 km and Apo-apsis of about 80000 km. 

The mission consists of following three phases:

1. Geo Centric Phase
The spacecraft is injected into an Elliptic Parking Orbit by the launcher. With six main engine burns, the spacecraft is gradually maneuvered into a departure hyperbolic trajectory with which it escapes from the Earth’s Sphere of Influence (SOI) with Earth’s orbital velocity + V boost. The SOI of earth ends at 918347 km from the surface of the earth beyond which the perturbing force on the orbiter is mainly due to the Sun. One primary concern is how to get the spacecraft to Mars, on the least amount of fuel. ISRO uses a method of travel called a Hohmann Transfer Orbit – or a Minimum Energy Transfer Orbit – to send a spacecraft from Earth to Mars with the least amount of fuel possible. 

2. Helio Centric Phase
The spacecraft leaves Earth in a direction tangential to Earth’s orbit and encounters Mars tangentially to its orbit. The flight path is roughly one half of an ellipse around sun. Eventually it will intersect the orbit of Mars at the exact moment when Mars is there too. This trajectory becomes possible with certain allowances when the relative position of Earth, Mars and Sun form an angle of approximately 44o. Such an arrangement recur periodically at intervals of about 780 days. Minimum energy opportunities for Earth-Mars occur in November 2013, January 2016, May 2018 etc. 

3. Martian Phase
The spacecraft arrives at the Mars Sphere of Influence (around 573473 km from the surface of Mars) in a hyperbolic trajectory. At the time the spacecraft reaches the closest approach to Mars (Periapsis), it is captured into planned orbit around mars by imparting ∆V retro which is called the Mars Orbit Insertion (MOI) manoeuvre. The Earth-Mars trajectory is shown in the above figure. ISRO plans to launch the Mars Orbiter Mission during the November 2013 window utilizing minimum energy transfer opportunity.

Frugal engineering for India’s Mars mission

November 6, 2013

India has been struggling to bridge the gap to more developed nations without necessarily having to follow exactly the same path as that followed by other nations. Especially to achieve the development objectives in less time than it has taken those who did it first. Doing more with less is the name of the game and “Frugal engineering” (or “frugal innovation”) is defining a new paradigm for development.

There may perhaps not be any better example of the dictum that necessity is the mother of invention than can be found in India. Whether it is a refrigerator, ECG device or an automobile, Indian engineers have brought innovative products to market by designing them outside-in. …….

It may seem a contradiction, but some infrastructure gaps in India have positively affected Indian innovation: they have forced entrepreneurs and companies to adopt technologies that make relying on existing infrastructure (creaking and unreliable as it is in many ways) simply irrelevant. Indian engineers have invented a battery-powered, ultra-low-cost refrigerator resistant to power cuts; an automatic teller machine for rural areas; and even a flour mill powered by a scooter. People in the West, with its constant access to electricity, have little motivation to pursue such innovations. The Indian mobile phone industry is the poster child for leapfrogging over infrastructural constraints. A limited fixed-line infrastructure created an opportunity for mobile phones to reach many more people. Mobile telephony is also relatively cheap, sharable, and easily repaired. And thus, a new frontier of global innovation opened in India. …… 

The Indian mission to Mars which launched yesterday is another example of frugal engineering at work.

Hindustan Times:

India’s successful Mangalyaan launch is as much a financial accomplishment as a technical milestone. The entire Mars mission has cost the Indian Space Research Organisation a mere around Rs. 450 crore ($75 million) and took 15 months to put together. Much of the Martian price tag is for ground stations and relay upgrades that will be used for other Isro projects. The actual satellite costs a mere $25 million ( Rs. 153 crore), says Pallav Bagla of Science magazine. Comparison: Nasa’s similar MAVEN Mars project will cost 10 times more and will take three times longer.

Isro is widely cited as an example of “frugal engineering” …..  A US state department scientific adviser once said that Isro had reduced satellite assembly costs to a tenth of Nasa’s.

Isro’s accomplishments are remarkable given its tiny budget: $700 million ( Rs. 4,270 crore) in 2012-13. Despite a space programme whose financial base is the ninth largest, India is generally rated the world’s number six space power.

Of this, only 7% is allotted for planetary exploration. Isro’s prime directive has and continues to be the finding of technical means to support socio-economic goals such as education, medicine, water and disaster management.

Isro also defrays government support through a commercial arm, Antrix. Through the sale of satellite imagery, satellite launches and so on, Antrix earned a pre-tax Rs. 2 billion in 2010 alone. …..

400m asteroid (2013 TV135) could collide with Earth on 26th August 2032

October 18, 2013

Not quite another doomsday prediction but the Russian Vice Premier Dmitry Rogozin was moved to tweet about the threat to blow up the Earth.

Ria Novosti: 

Ukrainian astronomers have discovered a large asteroid that could hit Earth in 2032, though the impact risk is minimal, according to current estimates.

The 410-meter-wide (1,350-foot) minor planet, which has been named 2013 TV135, was first discovered last weekend by the Crimean Astrophysical Observatory in southern Ukraine, according to the International Astronomer Union’s Minor Planet Center.

As of Thursday, the discovery had been confirmed by five more astronomy groups, including in Italy, Spain, the UK and Russia’s Siberian republic of Buryatia, the center said on its website.

The asteroid has been classified as potentially hazardous, a formal tag given to celestial bodies whose orbits bring them closer than 7.5 million km from Earth’s orbit. The minimal distance between the orbits of 2013 TV135 and Earth is currently put at 1.7 million km.

However, it also has a 1 in 63,000 chance of colliding with Earth on August 26, 2032, according to available estimates.

“Here’s a super-task for our space industry,” Russian Deputy Prime Minister Dmitry Rogozin, who has lobbied for Russia to develop asteroid defense systems, said of the asteroid on Twitter on Thursday.

The 2013 TV135 has been given a 1 out of 10 rating on the Torino Scale, which estimates asteroid impact hazards. Only one other asteroid currently has the same rating, with collision risks for all others being “effectively zero,” according to NASA’s Near Earth Object Program.

The 2013 TV135 colliding with Earth would create an explosion estimated to be equivalent to 2,500 megatons of TNT – 50 times greater than the biggest nuclear bomb ever detonated.

Asteroids due to pass close to Earth in the next 200 years are shown in this graphic:

Asteroids That Buzz Planet Earth

Asteroids which will come closest to the Earth in the next 200 years

 

The sun, the clouds and the climate

September 5, 2013

The Svensmark theory is that variations in the Sun’s electromagnetic  behaviour leads to varaiations of the cosmic ray flux reaching earth which in turn impacts cloud formation on earth and that connects to global warming or cooling.  A more active sun leads to fewer cosmic rays which gives fewer clouds and more warming on earth.

Graphic from Jonova

The CLOUD experiments at CERN have shown that cosmic rays can in fact lead to cloud formation. Now Svensmark and his colleagues have published further evidence from the SKY2 experiments which confirm the connection.

H. Svensmark, Martin B. Enghoff and Jens Olaf Pepke Pedersen, Response of cloud condensation nuclei (>50 nm) to changes in ion-nucleation,   Physics Letters A 377 (2013) 2343–2347,

Full paper is available here: svensmark et al 2013

Abstract: In experiments where ultraviolet light produces aerosols from trace amounts of ozone, sulfur dioxide, and water vapor, the relative increase in aerosols produced by ionization by gamma sources is constant from nucleation to diameters larger than 50 nm, appropriate for cloud condensation nuclei. This result contradicts both ion-free control experiments and also theoretical models that predict a decline in the response at larger particle sizes. This unpredicted experimental finding points to a process not included in current theoretical models, possibly an ion-induced formation of sulfuric acid in small clusters.

The Technical University of Denmark has issued a Press Release:

Danish experiment suggests unexpected magic by cosmic rays in cloud formation

Researchers in the Technical University of Denmark (DTU) are hard on the trail of a previously unknown molecular process that helps commonplace clouds to form. Tests in a large and highly instrumented reaction chamber in Lyngby, called SKY2, demonstrate that an existing chemical theory is misleading.

Back in 1996 Danish physicists suggested that cosmic rays, energetic particles from space, are important in the formation of clouds. Since then, experiments in Copenhagen and elsewhere have demonstrated that cosmic rays actually help small clusters of molecules to form. But the cosmic-ray/cloud hypothesis seemed to run into a problem when numerical simulations of the prevailing chemical theory pointed to a failure of growth. 

Fortunately the chemical theory could also be tested experimentally, as was done with SKY2, the chamber of which holds 8 cubic metres of air and traces of other gases. One series of experiments confirmed the unfavourable prediction that the new clusters would fail to grow sufficiently to be influential for clouds. But another series of experiments, using ionizing rays, gave a very different result, as can be seen in the accompanying figure. 

The reactions going on in the air over our heads mostly involve commonplace molecules. During daylight hours, ultraviolet rays from the Sun encourage sulphur dioxide to react with ozone and water vapour to make sulphuric acid. The clusters of interest for cloud formation consist mainly of sulphuric acid and water molecules clumped together in very large numbers and they grow with the aid of other molecules.

Atmospheric chemists have assumed that when the clusters have gathered up the day’s yield, they stop growing, and only a small fraction can become large enough to be meteorologically relevant. Yet in the SKY2 experiment, with natural cosmic rays and gamma-rays keeping the air in the chamber ionized, no such interruption occurs. This result suggests that another chemical process seems to be supplying the extra molecules needed to keep the clusters growing. 

“The result boosts our theory that cosmic rays coming from the Galaxy are directly involved in the Earth’s weather and climate,” says Henrik Svensmark, lead author of the new report. “In experiments over many years, we have shown that ionizing rays help to form small molecular clusters. Critics have argued that the clusters cannot grow large enough to affect cloud formation significantly. But our current research, of which the reported SKY2 experiment forms just one part, contradicts their conventional view. Now we want to close in on the details of the unexpected chemistry occurring in the air, at the end of the long journey that brought the cosmic rays here from exploded stars.”

Simulating what could happen in the atmosphere, the DTU’s SKY2 experiment shows molecular clusters (red dots) failing to grow enough to provide significant numbers of “cloud condensation nuclei” (CCN) of more than 50 nanometres in diameter. This is what existing theories predict. But when the air in the chamber is exposed to ionizing rays that simulate the effect of cosmic rays, the clusters (blue dots) grow much more vigorously to the sizes suitable for helping water droplets to form and make clouds. (A nanometre is a millionth of a millimetre.)

Black Holes are not as voracious as they are made out to be

August 30, 2013

I don’t understand the physics of black holes.

But I certainly had the impression that the relentless pull of gravity meant that they ruthlessly devoured everything in their paths and that they were bottomless pits. Everything beyond the event horizon – by definition – was entirely unknown and the stuff – possibly – of new Universes.

Not so – according to NASA. “Contrary to what some people think, black holes do not actually devour everything that’s pulled towards them. Sgr A* is apparently finding much of its food hard to swallow.” And so the black hole spits out what it can’t swallow!

Q. D. Wang, M. A. Nowak, S. B. Markoff, F. K. Baganoff, S. Nayakshin, F. Yuan, J. Cuadra, J. Davis, J. Dexter, A. C. Fabian, N. Grosso, D. Haggard, J. Houck, L. Ji, Z. Li, J. Neilsen, D. Porquet, F. Ripple, and R. V. Shcherbakov. Dissecting X-ray–Emitting Gas Around the Center of Our GalaxyScience, 2013; 341 (6149): 981-983 DOI:10.1126/science.1240755

NASA Press Release:

New Chandra images of Sagittarius A* (Sgr A*), which is located about 26,000 light-years from Earth, indicate that less than 1 percent of the gas initially within Sgr A*’s gravitational grasp ever reaches the point of no return, also called the event horizon. Instead, much of the gas is ejected before it gets near the event horizon and has a chance to brighten, leading to feeble X-ray emissions.

These new findings are the result of one of the longest observation campaigns ever performed with Chandra. The spacecraft collected five weeks’ worth of data on Sgr A* in 2012. The researchers used this observation period to capture unusually detailed and sensitive X-ray images and energy signatures of super-heated gas swirling around Sgr A*, whose mass is about 4 million times that of the sun.

“We think most large galaxies have a supermassive black hole at their center, but they are too far away for us to study how matter flows near it,” said Q. Daniel Wang of the University of Massachusetts in Amherst, who led of a study published Thursday in the journal Science. “Sgr A* is one of very few black holes close enough for us to actually witness this process.”

The researchers found that the Chandra data from Sgr A* did not support theoretical models in which the X-rays are emitted from a concentration of smaller stars around the black hole. Instead, the X-ray data show the gas near the black hole likely originates from winds produced by a disk-shaped distribution of young massive stars.

“This new Chandra image is one of the coolest I’ve ever seen,” said co-author Sera Markoff of the University of Amsterdam in the Netherlands. “We’re watching Sgr A* capture hot gas ejected by nearby stars, and funnel it in towards its event horizon.”

To plunge over the event horizon, material captured by a black hole must lose heat and momentum. The ejection of matter allows this to occur.

“Most of the gas must be thrown out so that a small amount can reach the black hole”, said Feng Yuan of Shanghai Astronomical Observatory in China, the study’s co-author. “Contrary to what some people think, black holes do not actually devour everything that’s pulled towards them. Sgr A* is apparently finding much of its food hard to swallow.”

The gas available to Sgr A* is very diffuse and super-hot, so it is hard for the black hole to capture and swallow it. The gluttonous black holes that power quasars and produce huge amounts of radiation have gas reservoirs much cooler and denser than that of Sgr A*. ….

For Chandra images, multimedia and related materials, visit: http://www.nasa.gov/chandra

Soyuz docks with ISS in record time

March 29, 2013

An update to my previous post.

Deutsche Welle:

A Soyuz capsule carrying three astronauts has docked at the International Space Station, just six hours after blasting off. Typically, manned Soyuz flights to the ISS last more than two days.

Russian cosmonauts Pavel Vinogradov and Alexander Misurkin and US astronaut Chris Cassidy took the express route to the International Space Station overnight Thursday, docking in the early hours of Friday morning.

They will join three other crew members and remain on board for five months.

“It’s such a beautiful sight, hard to believe my eyes,” the 59-year-old Vinogradov, making his third visit to space, said in footage broadcast on NASA TV.

Lift-off today for 6 hour fast-track journey to the ISS

March 28, 2013

The International Space Station‘s orbit varies between altitudes of 330 – 410 km and it orbits the Earth about 15 times a day. So a journey taking 6 hours to scale about 70 km of altitude per hour may not seem so impressive compared to the speeds on a German autobahn. But a trip which used to be completed on the 3rd day and 34 orbits after lift-off is going to be covered in 5hrs 49 mins and 4 orbits after launch later today. For its 3-man crew, the Soyuz craft can only carry enough fuel and supplies for at most a 4 day journey, so this fast-track approach will represent a major saving of fuel and supplies.

Soyuz is the longest serving manned spacecraft...

Soyuz is the longest serving manned spacecraft design in history (1967– ) , upgraded regularly (Photo credit: Wikipedia)

From Space.com

(Following three unmanned, cargo-only test flights, the Expedition 35/36 crew is the first to try the technique. For the Soyuz crew of three, the fast track rendezvous is much the same as before, except that tasks are compressed.)

NASA astronaut Chris Cassidy and Russian cosmonauts Alexander Misurkin and Pavel Vinogradov are due to arrive at the orbiting laboratory just six hours after they launch at 4:43 p.m. EDT (2043 GMT). The liftoff will begin a months-long mission in orbit for the three men.

The trio will blast off from the Central Asian spaceport of Baikonur Cosmodrome in Kazakhstan aboard a Russian Soyuz spacecraft. The mission’s Soyuz rocket rolled out to the launch pad on Tuesday (March 26) to prepare for today’s liftoff.

In the nearly 13 years since crews first began launching to the International Space Station, it has taken Russian Soyuz capsules and U.S. space shuttles about two days to reach the orbiting lab after liftoff. Now, NASA and Russia’s Federal Space Agency are testing out a new, accelerated schedule. The quick journey, which takes just four orbits of Earth, has been carried out by recent unmanned cargo spacecraft visiting the space station, but never by a crew.

Cassidy, Misurkin and Vinogradov are planning to join the station’s Expedition 35 mission for a roughly six-month stay. The current residents of the outpost are commander Chris Hadfield of Canada, Russian cosmonaut Roman Romanenko, and NASA astronaut Tom Marshburn.

Infographic: How astronauts are traveling to the International Space Station in hours instead of days.

Comet C/2013 A1 (Siding Spring) could impact Mars on 19th October 2014

March 21, 2013

Comet Shoemaker–Levy 9  broke apart and collided with Jupiter in July 1994, providing the first direct observation of an extraterrestrial collision of Solar System objects.

The collision provided new information about Jupiter and highlighted its role in reducing space debris in the inner Solar System.

But a much closer event could be in the offing for next year. A newly discovered comet has been found to have an orbit which takes it extraordinarily close to Mars in October 2014 and the possibility of an impact is 1 in 600. The size of the comet is still uncertain but some estimates are of the nucleus being 50 km in diameter. An impact crater on Mars – if an impact occurs – could then be about 500 km in diameter.

C/2013 A1 (Siding Spring) is a comet originating from the Oort cloud and was only discovered in January this year by Robert H. McNaught at Siding Spring Observatory in Australia,  using a 0.5-meter  Schmidt telescope. By looking at observations made before the comet was identified as a comet on 3rd January, NASA states “Pre-discovery observations located in the archives have extended the observation interval back to Oct. 4, 2012”.

NASA/JPL Near-Earth Object Program Office 
March 5, 2013

On Oct. 19, 2014, Comet 2013 A1 (Siding Spring) will pass extraordinarily close to Mars, almost certainly within 300,000 km of the planet and possibly much closer. Our current best estimate has it passing about 50,000 km from the surface of Mars. This is about 2.5 times the distance of Mars’ outermost satellite Deimos or less than twice the Earth close approach distance of 2012 DA14 on February 15, 2013. Since the observation span available for orbit determination is still relatively short, the current orbit is quite uncertain and the nominal close approach distance will change as additional observations are included in future orbit estimates. Currently, Mars lies directly within the range of possible paths for the comet and we can’t exclude the possibility that the comet might impact Mars. Our current estimate for the impact probability is less than one in six hundred and we expect that future observations will allow us to completely rule out a Mars impact.

This computer graphic depicts the orbit of comet 2013 A1 (Siding Spring) through the inner solar system. Image credit: NASA/JPL-Caltech

This computer graphic depicts the orbit of comet 2013 A1 (Siding Spring) through the inner solar system. Image credit: NASA/JPL-Caltech

Although the current heliocentric orbit is hyperbolic (i.e., eccentricity greater than one), the orbit is elliptic when expressed in the frame of the solar system’s barycenter. After more than a million year journey, this comet is arriving from our solar system’s distant Oort cloud. It could be complete with the volatile gases that short period comets often lack due to their frequent returns to the sun’s neighborhood.

During the close Mars approach, the comet will likely achieve a total visual magnitude of zero or brighter as seen from Mars-based assets. The attached illustration shows the comet’s approximate, apparent visual magnitude and its solar elongation angle as a function of time as seen from Mars. Because the comet’s apparent magnitude is so uncertain, the brightness curve was cut off at apparent visual magnitude zero. However, the comet may get brighter than magnitude zero as seen from Mars. From Earth, the comet will not likely reach naked eye brightness but it could brighten to visual magnitude 8 as seen from the southern hemisphere in mid-September 2014.

This illustration, prepared by Jon Giorgini, shows the apparent total visual magnitude and solar elongation angle as seen from the center of Mars

This illustration, prepared by Jon Giorgini, shows the apparent total visual magnitude and solar elongation angle as seen from the center of Mars image NASA


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