Archive for the ‘Space’ Category

MOM successfully enters Mars orbit – first time ever on a maiden Mars mission

September 24, 2014

In what appears to have been a remarkably flawless and precise operation ISRO’s MOM has entered Mars orbit. It is the first time that a country has succeeded to get a spacecraft to enter Martian orbit on its maiden attempt.

“We have the signal.

1099 m/s.

Expected – 1098.7 m/s”

(The Mars Orbit Insertion burn had a planned duration of 24 minutes and 14 seconds, slowing the spacecraft down by 1,098.7 meters per second to be captured in an elliptical orbit around Mars.)

The operations took place while the spacecraft was behind Mars. It seemed an endless wait for it to reappear. It was then a seemingly endless 12.5 minutes from when telemetry was reactivated and the signals were received confirming that the maneuvers had been successful.

The precise orbit achieved now awaits further tracking information.

Foto

Prime Minister Narendra Modi arrived at ISRO in time to witness the critical and historical phases of the orbit insertion procedures (and he is to be highly commended for preferring real things to the meaningless, pointless and futile climate change talkshop at the UN).

He was more than a little pleased.

Narendra Modi at ISRO after MOM achieved orbit — screen grab by The Hindu

A major step not just for India’s confidence in its technological capabilities but also for its geopolitical positioning against China.

BBC: If all goes well and the satellite orbits the Red Planet, India’s space agency will become the fourth in the world after those of the United States, Russia and Europe to undertake a successful Mars mission. …..

…… After India’s successful unmanned Chandrayaan mission to the Moon in 2008 that brought back the first clinching evidence of the presence of water there, the Mars mission, according to K Radhakrishnan, chairman of the Indian Space Research Organisation (Isro), is a “natural progression”. …….

India sees the Mars mission as an opportunity to beat its regional rival China in reaching the planet, especially after a Russian mission carrying the first Chinese satellite to Mars failed in November 2011. Japan also failed in a similar effort in 1998.

China has beaten India in space in almost every aspect so far: it has rockets that can lift four times more weight than India’s, and in 2003, successfully launched its first human space flight which India has not yet embarked on. China launched its maiden mission to the Moon in 2007, ahead of India.

So if India’s mission succeeds, it will have something to feel proud about.

Culmination nears for India’s Mars Orbiter Mission

September 23, 2014

In 8 hours – if everything goes as planned – the MOM would have been inserted into Mars orbit of 423 km at periareion and 80,000 Kilometers at apoareion  at an inclination of 150 degrees and with an orbital period of a little more than three days. Though a number of experiments are planned, the most important objectives of the mission – to demonstrate technology and capability – will largely have been accomplished on getting into orbit.

Frugal engineering and with a cost of about 10% of that of NASA’s MAVEN will have taken ISRO’s MOM into Mars orbit – and at the first attempt.

But the next few hours will be tense and nervous not only for ISRO mission staff but for the many millions of Indians who will be following the live webcast at http://webcast.isro.gov.in/. The critical operations will take place while the MOM spacecraft is occluded on the far side of Mars and when signals will be taking over 12 minutes to reach earth.

Spaceflight101: 

The critical Mars Orbit Insertion Burn Sequence will begin three hours ahead of the planned maneuver time when the spacecraft automatically switches over to its Medium Gain Antenna for communications since the High Gain Antenna will be pointing away from Earth during the retrograde burn.
21 minutes ahead of ignition, the spacecraft will begin the re-orientation to the proper attitude for the burn, pointing LAM to the direction of travel. The re-orientation is accomplished using the vehicle’s Reaction Wheels. Five minutes and 13 seconds ahead of the burn, the spacecraft passes into darkness – for the first time since leaving Earth last year. In advance, MOM will fully charge its battery to be in a safe configuration for the eclipse.
Three minutes ahead of the burn, the vehicle’s eight 22-Newton thrusters are enabled to start providing attitude control which they will continue to do throughout the main engine burn, keeping MOM pointing forward. Ignition of the Liquid Apogee Motor is planned at 1:47:32 UTC on Wednesday, September 24, 7:17 Indian Standard Time. The Mars Orbit Insertion burn has a planned duration of 24 minutes and 14 seconds, slowing the spacecraft down by 1,098.7 meters per second to be captured in an elliptical orbit around Mars. During the burn, the engines will consume 249.5 Kilograms of propellant leaving only about 40 Kilograms of propellant for the rest of the mission.
Should something go wrong during the burn, MOM is programmed to react appropriately in order to achieve a stable orbit around Mars – even if that means to spend all the vehicle’s propellant to do so. In the event the Liquid Apogee Motor is not ignited or its burn is cut short, MOM would automatically switch to the 22-Newton thrusters to supply as much delta-v as possible. Due to their lower thrust, the 22N thrusters would need to fire much longer than LAM along a greater stretch around the periapsis pass which will increase propellant consumption and leave MOM in a higher orbit.
MOI timeline

Graphic ISRO (via spaceflight101)

MOM test fires liquid motor for orbit insertion on Wednesday

September 22, 2014

A sigh of relief today as the liquid fueled motor was successfully test fired for 4 seconds after having last been used 9 months ago.

The 440 Newton Liquid Apogee Motor (LAM) of India’s Mars Orbiter Spacecraft, last fired on December 01, 2013, was successfully fired for a duration of 3.968 seconds at 1430 hrs IST today (September 22, 2014). This operation of the spacecraft’s main liquid engine was also used for the spacecraft’s trajectory correction and changed its velocity by 2.18 metre/second. With this successful test firing, Mars Orbiter Insertion (MOI) operation of the spacecraft is scheduled to be performed on the morning of September 24, 2014 at 07:17:32 hrs IST by firing the LAM along with eight smaller liquid engines for a duration of about 24 minutes.

The MOM is now in (or just entering) Mars’ sphere of influence and is effectively falling freely towards Mars. The orbit insertion procedure is described here.

Mars Orbit Insertion for MAVEN and MOM

graphic: indiaspaceactivity

On 24th 0127 GMT, even as it is falling with speed of 4 kms/sec, the craft is reoriented so that the thrusters face forward  ( for the next orbit maneuver of retro thrust to reduce the speed and to direct it in the required orbit ). The re-orientation is completed @ 0147 GMT. MOM would by this time be falling with a speed of  4.48Km/sec.

After the disturbances due to reorientation have died, i.e. 5 seconds later,  the Retro action starts with the firing of  LAM using 8 thrusters ..  the fall speed by now is 4.68 km/s. Even as the thrusters start their effort to reduce the speed of MOM, the fallingspeed continues to increase due to the gathered momentum upto 5.89 km/s and thenspeed  starts falling. The LAM firing also directs the craft in the desired direction so that it achieves the required orbit around Mars. The LAM operation ends @0216GMT.

As shown in figure there the MOM speed would increase from 3.18 Kms/sec to 5.89Kms/sec @  0216GMT.

Now notice that MOM approached Mars parellel to  equator unlike MAVEN which approached over North pole.  The reason for these two approaches is that the final orbits of MAVEN and MOM are inclined @ 75 deg and @ 19 deg respectively. This is evident from the ‘ cross roads ‘ seen between MOM and MAVEN release in the combination diagram shown above.

In the above flow of sequence we did not have time to  mention a couple of more chilling facts: @ nearly the same time when LAM operation starts MOM would go behind Mars as seen from Earth. Secondly , even if it was visible, whatever happens at MOM will be known to Earth only after 12 minutes due to the distance between Earth and MOM. So all this (and next described operations ) are being done under the unsupervised pre-loaded command sequences. So the success indicates how well are we in anticipating the situation through modelling.

A detailed look at dynamics of acceleration during this critical operation is shown in this graphic. (numbers are in kms/sec/sec ) corrosponding to sky blue curve. (X axis is time axis from 0110GMT to 0310GMT of 24 Sep. )
Violet curve is the speed normalized to fit in this graph with that of acceleration. Actual speed variation shown corresponds to 3.88 km/sec at left to 5.89km/s at peak near center which falls to 4 km/s at lsft edge.

We have also marked the events of reorientation (between red dots) and retro rocket firing (between Green dots ) on acceleration curve.

Notice that the LAM retro action started at first green dot on left ( 0152 GMT ) ..  it has tried to reduce the speed but the fall is more powerful, so MOM speed continues to increase despite retro action. This continues and for sometime eventhough the acceleration has started reducing ( blue line coming down ), the gathered momentum  makes the craft to increase its speed for sometime. Finally however the thrusters succeed in reducing the speed ( reversal near center of violet line ) ..  the thrusters are also turned off at that moment.(green dot near the center of graph ). Now the total operation of MOI is over.

Incidentally, the point where speed reversal has taken space forms the lowest point near the surface of MOM prior to first perigee which would occur after the craft completes one revolution.

Maven to enter Mars orbit tonight and MOM on Wednesday

September 21, 2014

UPDATE:

NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft successfully entered Mars’ orbit at 10:24 p.m. EDT Sunday, Sept. 21, where it now will prepare to study the Red Planet’s upper atmosphere as never done before. MAVEN is the first spacecraft dedicated to exploring the tenuous upper atmosphere of Mars.

==============================================

NASA’s Maven will be inserted into Mars orbit later tonight at 2130 pm Eastern time and will be covered live by NASA TV.

India’s MOM should be inserted into Mars Orbit on Wednesday.

(Related: Alternate paths to Mars: NASA’s MAVEN compared to India’s MOM)

Maven planned Mars orbit insertion 20140921 - NASA

Maven planned Mars orbit insertion 20140921 – NASA

The orbit insertion factsheet from NASA is here: MAVEN Orbit Insertion Fact Sheet – NASA

The orbit-insertion maneuver will begin with the brief firing of six small thruster engines to steady the spacecraft. The engines will ignite and burn for 33 minutes to slow the craft, allowing it to be pulled into an elliptical orbit with a period of 35 hours.

Following orbit insertion, MAVEN will begin a six-week commissioning phase that includes maneuvering the spacecraft into its final orbit and testing its instruments and science-mapping commands. Thereafter, MAVEN will begin its one-Earth-year primary mission to take measurements of the composition, structure and escape of gases in Mars’ upper atmosphere and its interaction with the sun and solar wind….

MAVEN launched Nov. 18, 2013, from Cape Canaveral Air Force Station in Florida, carrying three instrument packages. It is the first spacecraft dedicated to exploring the upper atmosphere of Mars. The mission’s goal is to determine how the loss of atmospheric gas to space played a role in changing the Martian climate through time.

ISRO’s press briefing for the MOM Mars orbit insertion is here: MOM press briefing on Mars Orbit Insertion

MOM Mars Orbit insertion planned for 20140924  ISRO

MOM Mars Orbit insertion planned for 20140924 ISRO

It’s coming, but don’t invest just yet in mining Helium-3 on the moon

August 16, 2014

Helium (4He) is the second most abundant element in the known Universe (after hydrogen) but only makes up 5.2 parts per million (ppm) of the Earth’s atmosphere. Helium-3 (3He) is an isotope of helium with two protons and one neutron. It is not radioactive and very rare on Earth (7 parts per trillion) but exists in recoverable concentrations in the lunar topsoil (in the top 2 -3 m of lunar regolith). It is even more abundant on the gas giants Jupiter, Saturn, Uranus and Neptune.

Lunar soil sample #75501 brought back by Apollo 17 in 1972 revealed the presence of He-3 and since then every country planning moon missions has the vision of mining for 3He on the moon and of vast quantities of energy production by means of a aneutronic fusion process on earth. (For old fogies like me, 1972 was the year of Watergate!)

In fusion reactions neutrons are “nasty”. They are very hard to contain and make other materials radioactive on collision. The first generation fuels of Deuterium and Tritium (reactions 1 and 2 below) produce many neutrons. A second generation with Deuterium and 3He only produces a few. A 3He – 3He reaction would produce none.

Kulcinski: Fusion Energy could provide that new energy source in the middle of the 21st Century. ….. However, ……  the DT Tokamak does not appear to be the ultimate answer. The problem lies in both the DT fuel cycle, which emits 80% of its energy in highly damaging and radioisotope producing neutrons, and in the complex design of the Tokamak.

fusion reactions after Kulcinski

fusion reactions after Kulcinski

But the promise of having 3He available to produce power is immense.

(more…)

MOM and MAVEN approach Mars

August 12, 2014

Both the Indian Mars Orbiter Mission (MOM – Mangalyaan, budget $70 million) and NASA’s MAVEN (budget $672 million) are now approaching Mars. Both are doing well according to their latest status updates.

MOM was launched on 5th November last year and MAVEN on 18th November, 2013. Whereas MAVEN on its Atlas 5 rocket could directly enter into a  Hohmann Transfer Orbit with periapsis at Earth’s orbit and apoapsis at the distance of the orbit of Mars, MOM had to take the low-cost, scenic route. Because of the relatively low payload capability of the PSLV launch rocket, MOM had to spend 26 days in ever-increasing earth orbits. MOM had to fire its Liquid Motor six times to work its way up to departing Earth orbit using a standard Hohmann Transfer Orbit on 1st December.

Alternate paths to Mars: NASA’s MAVEN compared to India’s MOM

MAVEN - MOM trajectories

MAVEN – MOM trajectories

 

When they were launched MAVEN was expected to reach Mars on 22nd September 2014 and MOM 2 days later on 24th September 2014. The time lines have shifted slightly subsequent to the mid-course corrections carried out and MOM is now expected to reach Mars orbit about a week ahead of MAVEN. I suspect that the time of Mars Orbit Insertion is still a little fluid, but both are about 1 month away. MOM is currently about 6 minutes away in radio signal distance.

Discovery News:

India’s Mars Orbiter Mission (MOM) is more than 80 percent of the way to Mars and performing well, according to a Facebook update posted July 21 by the Indian Space Research Organization. MOM is expected to enter orbit on Sept. 14.

The second craft, NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN), is also performing well. MAVEN is scheduled to embark on its final approach to the Red Planet on Sept. 21, one week after MOM’s arrival, principal investigator Bruce Jakosky said. After months of checkouts and tests, the spacecraft will now be left quiet until close to the big day.

NASA’s MAVEN has now gone into a “pre-Mars Orbit Insertion moratorium.” All systems required for a safe Mars Orbit Insertion remain powered on. But other systems like the instruments are shut down until late September because they are not needed for a successful MOI. We want the spacecraft system to be as “quiet” as possible and in the safest condition during the critical event on September 21st”.

Related: Frugal engineering for India’s Mars mission

Rosetta finds its new stone

August 8, 2014

The Original Rosetta Stone – BBC

The new stone is a comet identified as 67P/Churyumov-Gerasimenko

  • It was first observed in 1969 and named after its Russian discoverers
  • The comet is in an elliptical 6.45-year orbit that takes it from beyond Jupiter at its furthest point, to between the orbits of Mars and Earth at its closest to the Sun.
  • It is approximately 3.5 x 4 km in size, has a rotational period of 12.7 hours and a mass of 3.14±0.21×1012 kg
  • The surface temperature appears to be around -70ºC, which is warmer than expected
  • It is currently about 405 million km from earth (about 22.5 light-minutes) and moving at 55,000 km/hr

The European Space Agency’s Rosetta craft has now arrived at 67P/Churyumov-Gerasimenko after a 10 year, 6.4 billion km long journey and has entered orbit around its new stone

Rosetta is a cornerstone mission to chase, go into orbit around, and land on a comet. It will study the Jupiter-family comet 67P/Churyumov-Gerasimenko with a combination of remote sensing and in situ measurements. The spacecraft will orbit the comet and release the Philae lander, which carries a suite of instruments for imaging and sampling the comet nucleus. The mission will track the comet through perihelion, examining its behaviour before, during and after.

Rosetta Trajectories by Christian Simoes astronoo.com

Rosetta Trajectories by Christian Simoes astronoo.com

The spacecraft was launched from Kourou aboard an Ariane 5G+ on 2 March 2004. It required four gravity assists for its journey, one by Mars and three by Earth. Rosetta had already flown by the asteroids 2867 Steins (in 2008) and 21 Lutetia (in 2010), before entering deep space hibernation in June 2011.

Rosetta’s main goals will be reached in 2014. Following a planned exit from hibernation on 20 January, the spacecraft’s instruments were checked as it continued on its journey to 67P/Churyumov-Gerasimenko. The spacecraft arrives at the comet in August 2014, and deploys the lander in November 2014.

Comet 67P-CG on 3rd August 2014 ESA

Comet 67P-CG on 3rd August 2014 ESA

Rosetta is just 100 km from the comet’s surface, but it will edge closer still. Over the next six weeks, it will describe two triangular-shaped trajectories in front of the comet, first at a distance of 100 km and then at 50 km.

At the same time, more of the suite of instruments will provide a detailed scientific study of the comet, scrutinising the surface for a target site for the Philae lander.

100 days to Mars for ISRO’s Mangalyaan

June 16, 2014

Four days ago

  • The second Trajectory Correction Manoeuvre (TCM-2) of India’s Mars Orbiter Spacecraft was successfully performed on June 11, 2014 at 1630 hrs IST. TCM-2 was performed by firing the spacecraft’s 22 Newton thrusters for a duration of 16 seconds.
  • At present, the radio distance between the Spacecraft and the Earth is 102 million km. A radio signal from the Earth to the Spacecraft now takes about 340 seconds. The spacecraft so far has traveled a distance of 466 million km as part of its total Journey of 680 million km.
  • ISRO is continuously monitoring Mars Orbiter Spacecraft using Indian Deep Space Network (IDSN). The spacecraft and its five scientific instruments are in good health.

And 100 days from today on 24th September, ISRO’s frugally engineered  Mars Orbiter Mission (called Mangalyaan meaning Mars craft) should be inserted into Mars orbit. The highly over-rated movie “Gravity” had a larger budget at $100 million than ISRO’s $75 million for its Mars mission.

China’s Jade Bunny apparently stuck on the moon

January 26, 2014

(I see that Chinese news reports usually translate “Yutu” as “Jade Rabbit” but from this version of the legend I prefer “Jade Bunny” as being more appropriate to the lunar creatures who went to Chang’e’s assistance and where the reincarnation of her husband Hou Yi was the Jade Bunny)

In a setback – apparently due to the difficult lunar terrain, the Jade Bunny lunar rover has suffered a “mechanical control abnormality” – which I take to mean that it is stuck and not responding to commands. China Daily has the story

China’s moon rover, Yutu (Jade Rabbit), has experienced a mechanical control anomaly, and scientists are organizing repairs. The abnormality occurred due to “complicated lunar surface environment,” the State Administration of Science, Technology and Industry for National Defence (SASTIND) said on Saturday, without giving further details. The abnormality emerged before the rover entered its second dormancy at dawn on Saturday asthe lunar night fell, according to SASTIND.

The lander, another part of the Chang’e-3 probe, also “fell asleep” earlier on Friday. The pair went dormant for two weeks about one month ago when the first lunar night of the mission occurred.

 ….. The Chang’e-3 lunar probe soft-landed on the Moon on December 14. Yutu separated from the lander hours later.

The success of the Chang’e-3 mission makes China the third country to soft-land a spacecraft on lunar soil after the United States and the former Soviet Union.

Lunar panorama: Chang’e 3 lander in Out of this World

Jade Bunny on the moon on 22nd December 2013 (photo Xinhua)

Jade Bunny on the moon on 22nd December 2013
(photo Xinhua)

Poltergeists on Mars

January 21, 2014

Mysterious forces and poltergeists are at work  on Mars (which in due course will be found not to be so mysterious after all). But stories about moving rocks, and possible aliens are not new. The latest however is just doing the rounds based on the pictures SOL 3528 and 3540.

Rock appears mysteriously in front of Mars Opportunity rover

Rock appears mysteriously in front of Mars Opportunity rover

(Phys.org)The lead scientist for NASA’s Mars rover exploration team (Steve Squyres) has announced that recent images beamed back by the Opportunity rover show a rock sitting in a place nearby where there wasn’t one just twelve days prior. The image, he says, has caused quite a commotion with the rover team as possible explanations for the sudden appearance of the rock are bandied about. The announcement was part of a meeting at California Institute of Technology to celebrate a decade of service by the tiny rover. …… 

….. How it got there has NASA’s best scratching their heads. Thus far, they have two main likely explanations: either the rock was tossed to that spot after a meteorite impact nearby, or far more likely, it came to rest there as a result of clumsy maneuvering by Opportunity itself. The rover is having trouble getting around these days as one of its actuators has failed. This means one wheel winds up scrapping the ground during turns, producing what Squyres described as “chatter” which he said could have caused some debris to be flung to where the rock is now.

But these stories have been appearing since – at least – about 2009 (based for example on pictures SOL 1833 onwards). Moving rocks on Mars have a long history of fanciful – and some not so fanciful – notions. A whole bunch can be found here and here. But it would seem that most of the conspiracy theories and “Life on Mars” stories are connected to the selling of particular books.

As far as stories are concerned, the first ever fictional account of Mars was probably Across the Zodiac (1880) by Percy Greg. But for me, The War of the Worlds (published in 1898) by H. G. Wells  and Edgar Rice Burroughs and his Martian Trilogy – published between 1912 and 1943 and which I first read in 1959 – are not easily surpassed.


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