Russian Mars probe trapped in orbit
Hope is fading for the Russian Phobos-Grunt mission to Mars, as the probe has been trapped in low Earth orbit since Wednesday. The 13-ton (11.8-tonne) unmanned spacecraft was launched from the Baikonur Cosmodrome in Kazakhstan on November 9, atop a Ukrainian Zenit-2 booster. Baikonur ground control lost track of the probe when it failed to appear in its predicted orbit. According to the Russian Space Agency, the Phobos-Grunt's engines failed to fire twice, leaving the probe in a low, rapidly decaying orbit. Despite continuing efforts, ground control has been unable to get the probe to respond to commands and can only receive telemetry data from it. If the Russians are unable to regain control, the Phobos-Grunt is expected to make an uncontrolled re-entry into the Earth's atmosphere, along with its 8.3 tons (7.5 tonnes) of highly toxic propellant and radioactive cobalt-57.
The cause of the Phobos-Grunt's failure to fire its engines still remains unknown. Russian officials continue to hope that the problem is a software glitch, which means that ground control can reprogram the computers and attempt to fire the engines again. However, if the problem is in the hardware, then the mission is a failure. Originally, the Russian Space Agency was only able to signal the probe while it passed over Baikonur or a ground station near Moscow, but NASA and the European Space Agency have offered their help in trying to maintain contact. The one bright spot is that the solar panels aboard the machine have been confirmed as deployed, otherwise the onboard batteries would have been exhausted in a little over three days.
Mission to Phobos
At 13.2 tons, the Phobos-Grunt (Grunt means "earth," "dirt" or "ground" in Russian) is the largest deep-space probe since the American Cassini spacecraft was launched to Saturn was launched in 1997. The US$163 million mission was intended to be Russia's return to the high table of space exploration. The first Russian deep-space probe in 15 years, the objective of the bus-sized craft is, as the name implies, to orbit Phobos - one of the tiny moons of Mars, that some scientists suspect are captured asteroids. Once on station, the probe would release a landing craft that would descend to the moon's surface, collect soil samples and then launch a return vehicle containing seven ounces (200 g) of dirt to Earth for recovery in 2014. In addition, the Phobos-Grunt would deploy the Chinese Mars orbiter Yinghuo-1 - China's first deep-space mission.
On a more controversial note, part of the Phobos-Grunt science package is a biological experiment devised by America's Planetary Society, which is designed to study the effects of deep-space travel on samples of bacteria, plant seeds and microorganisms known as water bears. Some critics have stated that the inclusion of living creatures violates international space treaties because of the danger of the probe crashing on Mars and contaminating the environment, but the Russians have replied that the chances of this occurring and the safeguards used make this likelihood too remote to be regarded as such.
At any rate, all such worries are moot so long as the Phobos-Grunt remains trapped in Earth orbit. As it stands, there are three possible outcomes. First, the engines can be fired and the mission proceeds with a slight delay. Second, the engines don't fire. If this happens, the probe will lose 1.25 miles (2 km) of altitude a day until it burns up in the Earth's atmosphere with a month. Third, the engines fire, but the probe misses the two-week launch window, in which case it will never reach Mars.
As things stand, an uncontrolled re-entry seems the most likely outcome. According to the Russian news service Interfax (article in Russian), the chances of success are "negligible," with the Russian armed forces' former chief space adviser Vladimir Uvarov stating "Based on my experience, you cannot make the upper-stage work on a second attempt." He went on to say more bluntly, "I think we have lost the Phobos-Grunt."
Space program at stake
Despite this, the Russians continue to try. Part of the reason is that the past year in space has been a disastrous for them. With the loss of three satellites on launch in December 2010, another in February 2011, a third in August, and the crash of a Progress cargo ship en route to the International Space Station less than a week later, morale among Russian space scientists and confidence of Russia's launch customers was on the floor. Phobos-Grunt was their chance for a comeback, and if it fails, Russian sources are already talking about mass resignations, sackings and restructuring.
Worse, the "Mars Curse" has been revived. Mars missions have a terrible reputation for failure, with over half of them ending in disaster. Half of those failures over the past fifty years have been Russian, with the only real success dating back to 1973. Their last attempt was in 1996, and that ended up in the Pacific Ocean. Therefore, a lot is riding on the success of this mission and, however slim the odds, the Russians are determined to play their hand until the end.
Please keep comments to less than 150 words. No abusive material or spam will be published.
The propellant is harmless because it will burn and disperse in the upper atmosphere no one on earth will be exposed to so much as One part per billion of the stuff.
The cobalt-57 that vaporizes into the atmosphere is again harmless do to the low concentrations, but do to its high melting point of 1768 K,1495 C, 2723 F and higher Boiling point 3200 K 2927 C, 5301 F a significant lump stands a good chance of getting to the ground. It is a gamma ray emitter and should not be touched, but in seven years it will have fully decayed away.
Oh yeah - they did a GREAT job with the UARS satellite, didn\'t they?
What is the worst case scenario? It is reported the spacecraft weighs 13 tons with 8.3 tones of I believe liquid fuel. Because the fuel is said to be highly toxic, very likely the oxidizer is nitrogen tetroxide. I personally have seen nitrogen tetroxide released to the atmospheres both at Cape Kennedy from a launch complex and at high altitude when a Titan 4 exploded after launch from Vandenberg Air Force Base in California. I was not a part of either program and happened to be a few miles away when they happened. It makes a very spectacular orange brown transparent cloud and is deadly when concentrated. It is possible that fuel system parts surviving reentry could be contaminated with trace amounts of the propellants but unlikely to be a real hazard.
It is unclear if the lander portions of the mission have any fuel and if they do what type of fuel. All the fuel would certainly be released in the upper atmosphere where it is not a problem, leaving 4.7 tons, 9400 lb. of solid materials to be accounted for. Normally, it will break up into small peaces but this depends on the details of the design. It is nearly inconceivable that the spacecraft would remain in one large peace, but if it did, this is the size of two SUV\'s and would hit the ground at between 500 and 1200 mph. If it hit a building it could cause the collapse of a large multi story building, but this is highly unlikely. There could be a few large peaces weighing a few hundred pounds that would survive reentry and hit the ground at less then the speed of sound. If it hits something or someone, It would not be a good thing. Hitting an airliner in flight would be the worst mechanical problem.
The spacecraft will break up. The deployable items like the solar arrays will be the first things to come apart. The Cobalt 57 is in what is called a RTG, Radiological Thermal Generator. These are deployed on a boom away from the spacecraft to limit the radiation exposure of the rest of the spacecraft and for cooling so the \"Thermal\" part of the electric generator will work. If the RTG is deployed, a big if because it is probably a part of the lander or the independent orbiter, the RTG would separate from the rest of the spacecraft. The normal practice is to design RTG\'s to completely burn up on reentry. If it is not deployed, it could be shielded from reentry by the body of the spacecraft and reach the ground nearly intact. Depending on the details of the design, small particles of the Cobalt 57 could be spread over a large populated area. This is the worst case. It would be impossible to clean up. Depending on the particle size, it may or may not represent a problem to people.
The spacecraft was launched from the Baikonur Cosmodrome at 45.95 degree north latitude. This makes it the most likely reentry above 40 N or below 40 S latitude, but it could come down anyplace between 45.95 N and S latitude. The majority of the earth is covered with water and much of the land is sparsely populated so it is unlikely any persons will be effected. But it is possible and the effects could be substantial. The only thing that \"they are not telling\" is that the reentry location will be fairly well known 48 hours before reentry, meaning where the debris foot print will be known to within a few hundred miles. Because the debris foot print will be several hundred miles long and a few hundred miles wide, it is possible for parts to come down anyplace within 10s of thousands of square miles. It is not possible to give a reasonable warning or evacuation of 10,000 square miles in 48 hours.
Charge the cost of the Shuttle launch to the Russian Federation and it\'s all good. But nooo, had to quit flying the only ships that enabled in space repairs on very expensive satellites.
Even when there is not fuel on board, spacecraft can be dangerous things, the deployables are released by pyrotechnic devices. These are basically small shotgun shells contained in a steel enclosure, sometimes stuff comes flying out to them and they can be set off by static electricity.
Even if a shuttle was ready and available for use, it takes months to plan a repair mission and train the crew. It is a complicated thing to pull off. The Solar Max repair was nearly a complete failure because a button on the thermal blanket was in the way. The Phobos spacecraft can\'t wait months, it will reenter in about one month. It has only about a week before Mars moves out of position for the transfer orbit to intersect the planet.