November 1, 2013
November 5 update: India has launched the Mars Orbiter Mission. The spacecraft is now in its planned Earth orbit, and will depart for Mars on December 1.
In more than half a century of trying, only two space agencies — from the United States and Europe — have managed to pull off entirely successful Mars missions. Attempts by Russia, Japan, England, and China to send spacecraft to the Red Planet have all ended in total or near-total failure.
Now India’s space agency, ISRO, hopes to succeed where others have stumbled. Next Tuesday, an Indian PSLV rocket is scheduled to lift off from the Satish Dhawan Space Centre near the country’s southern tip, carrying the Mars Orbiter Mission spacecraft, also known unofficially as Mangalyaan — Hindi for “Mars craft.”
It’s a bold step for India, but then so was its Chandrayaan-1 lunar orbiter, which mapped the moon’s surface in 2008. By designing the $70 million (cheap for a Mars orbiter) MOM mission as a technology demonstrator, the Indian Space Research Organization (ISRO) has taken the cautious route, and may have improved its odds. Rather than load up a big spacecraft with lots of expensive instruments (which would have required a bigger but more failure-prone rocket called the GSLV), ISRO went with the smaller, more reliable PSLV, and a modest payload.
Mangalyaan carries just five small instruments: a color camera, an infrared spectrometer for mapping minerals on the Martian surface, a photometer for measuring hydrogen and deuterium in the atmosphere, another spectrometer focused on the upper atmosphere, and an instrument for measuring methane. The last is of special interest to scientists trying to solve the mystery of methane on Mars. Telescopes on Earth and Europe’s Mars Express spacecraft in Martian orbit have detected enough of the gas in the atmosphere to suggest that it’s being produced currently by Martian organisms. But the Curiosity rover came up empty when it sniffed for methane near the surface. The Methane Sensor for Mars on Mangalyaan is designed to detect atmospheric methane down to several parts per billion. “That would be a valuable contribution,” says Michael Mumma of NASA’s Goddard Space Flight Center, one of the leaders in studying Martian methane. “However, the technical difficulties [of achieving that sensitivity] should not be overlooked.”
We’ll keep our fingers crossed on that one.
If the spacecraft just arrives safely in Mars orbit and operates there for six to ten months as anticipated, that alone could qualify the mission as a triumph. Chandrayaan-1 was rightly seen as a success, but the mission was cut short by component failures, and operating at Mars is more difficult than orbiting the moon. The rocket engine designed to brake Mangalyaan into Mars orbit when it arrives next September will have to start flawlessly after a 300-day cruise through cold space. Communications, power, and thermal control will all be more complicated than they were with Chandrayaan.
The graveyard of lost Mars missions includes 19 from Russia alone (although, to be fair, half of those were early in the space age). Japan’s Nozomi spacecraft suffered a fuel valve problem in 1998, and never recovered enough to reach Mars orbit. China’s small Yinghuo-1 Mars orbiter had hoped to piggyback on the Russian Fobos-Grunt Mars mission in 2011, but both spacecraft were stranded in Earth orbit when a rocket misfired. England’s Beagle 2 lander, launched in 2003, crashed on the Martian surface. NASA has had its failures, too, including the Mars Climate Orbiter lost in 1999 due to a mixup over metric vs. imperial measurements.
So wish the team at ISRO luck. Launch is scheduled for 4:08 a.m. Eastern (U.S.) time on November 5.
Here K. Radhakrishnan, head of the ISRO, gives a lengthy guided tour of the spacecraft for New Delhi Television:
October 30, 2013
Scientists following up on data from the Kepler planet-hunting telescope have identified Earth’s closest twin yet—at least in terms of size and mass. Measuring only 1.2 times the radius of Earth, Kepler -78b is now the smallest planet for which we also know the mass: about 1.7 times Earth’s. The two planets have roughly the same density, which means Kepler-78b is probably made of rock and iron too.
That’s pretty much where the similarity ends, though. Kepler-78b orbits perilously close to its host star—so close, in fact, that its year lasts only 8.5 hours, and surface temperatures are several thousand degrees on the side facing the star. No water, no life, and no good explanation—at least not yet—for how such a small planet ended up so close to its star. According to current theory, the star would have been two to three times bigger than it is today when the planet formed. But if -78b started off in its current location, “the planet’s orbit would be inside the star itself,” which is clearly not possible, says Dimitar Sasselov of the Harvard-Smithsonian Center for Astrophysics in Boston, speaking at a press conference today. One possible explanation is that the planet is the dead core of a gas giant planet that migrated inward from farther away, but that theory is problematic too, says Sasselov. He called -78b “a poster child for a totally new class of planets” that has recently emerged from the Kepler data.
The discovery sets a new standard for observing small, rocky worlds. Kepler found the planet and measured its radius last spring, but it wasn’t until the summer that two independent groups—one working with the HIRES spectrograph at the Keck Telescope in Hawaii and the other with the HARPS-N spectrograph at Italy’s Telescopio Nazionale Galileo in the Canary Islands—were able to make the exquisitely sensitive measurements that allowed them to calculate the mass of Kepler-78b, based on the spectral signature of the tiny planet tugging on the much bigger star.
The two teams reported their results in Nature magazine today.
October 18, 2013
A “rogue” exoplanet with the preliminary name PSO J318.5-22 has been detected by a group of astronomers led by Michael Liu from the University of Hawaii at Manoa. By “rogue planet,” astronomers mean one that has no host star – it wanders alone through galactic space.
This particular world is a Jupiter-type gas giant, located about 80 light years from Earth in a collection of young (less than 50 million years old) stars in the Beta Pictoris moving group. With only about six times the mass of Jupiter, PSO J318.5-22 is one of the least massive rogue planets detected so far. It’s a sub-brown dwarf, even less massive than a brown dwarf (a gas giant that failed to become a star).
Radiation levels within this type of planet are very high, with a seamless transition from gas to liquid in the deep atmosphere. Convection would move any organic compounds at the surface down into the interior, where they would encounter extreme temperatures and pressures. Thus, life within a gas giant like PSO J318.5-22 has to be considered extremely unlikely. But the rogue planet could be accompanied by a large moon, whose subsurface could be a potential abode of life.
The discovery gives credence to the notion that rogue planets might be very common. By some estimates, there could be as many as 100,000 of these nomads for each star in our galaxy!
According to current theories about solar system formation, small, rocky planets sometimes come close to very large planets in the chaotic early stages before their orbits stabilize. Such close encounters could potentially hurl the smaller planets out of the solar system entirely, leaving them to wander the galaxy as nomads. In fact, the Mars-size object that collided or had a near-collision with the early Earth (resulting in our unusually large Moon) is thought to have become a rogue planet.
Any planet bumped in this way from its original solar system might be very Earthlike, and life could already have taken hold. Once ejected, the atmosphere would freeze to the surface. However, heat from radioactivity in the core could provide enough energy to keep an ocean of water beneath the icy surface. And it’s distinctly possible that unicellular life and even subsurface life at hydrothermal vents could develop on this kind of “Steppenwolf planet.”
Under certain conditions, an ice layer might not even be necessary. A thick atmosphere of molecular hydrogen could provide enough pressure and insulation to keep liquid water on the surface, if the atmosphere had 100 to 10,000 times the pressure of Earth’s and the planet was ejected quickly. In that case, once again, the planet might retain primitive forms of life.
Thus, even if a planet loses its star, it doesn’t mean necessarily that it loses its inhabitants. Life can find many ways to persist.
January 2, 2013
On this day in 1959, the Soviet Union launched a 4-foot-diameter metal ball — a close copy of the Sputnik satellite that had kicked off the space age two years earlier — in the direction of the moon. On January 4 Luna 1, also known as “Mechta” or Dream, passed within 6,000 kilometers of the lunar surface. The Soviets had meant for it to hit the moon, and had loaded commemorative “pennants” on board that were supposed to scatter in every direction at the moment of impact. But a faulty rocket burn caused the probe to miss its target. Fifty-three years later, Luna 1, the first object to escape Earth’s gravity, is still in orbit around the sun.
In 1959, such a demonstration of Soviet rocket power didn’t sit well with American notions of technological superiority, and there was much fretting in the Western press. LIFE magazine editorialized about “The Warning of Mechta,” and pointed fingers at the politicians and bureaucrats. One writer named Lloyd Mallan took it a step further, claiming, in an article titled “The Big Red Lie,” published in the April 11, 1959 issue of True magazine, that the Soviets had made up the whole story about Luna 1.
After a long fact-finding trip (“14,000 miles behind the Iron Curtain”), Mallan concluded not only that “Lunik [the somewhat derisive nickname used in some American reports] does not exist and never did” but that “the Russians do not have any ICBMs,” and that the striking power of the Red Air Force had been greatly exaggerated. Mallan based his conclusions partly on the mistaken idea that no Westerners had heard signals from the Russian moon probe.
In August of that year, a Congressional fact-finding committee alarmed by Mallan’s claims heard different from people who actually knew what they were talking about. William Pickering, head of the Jet Propulsion Laboratory in California, told the committee that the Goldstone tracking antenna had detected signals from a spacecraft moving away from the moon on January 4. According to the committee report, “Dr. Pickering said there was no doubt in his mind that the object being tracked was the Soviet Moon rocket.” None of the expert witnesses doubted it, in fact.
During the hearings Mallan’s patriotism even came into question, based on his past involvement with communist-sympathizing groups during the Spanish Civil War. Although the hearings put to rest any serious possibility of Luna 1 being a hoax, Mallan went on to a dubious career debunking (usually erroneously) other Russian space achievements.
As for the Russians, they scored again later that year with Luna 3, the first spacecraft to photograph the far side of the moon. Boris Chertok, a veteran of the cold war space race, wrote in his multi-volume memoir about those early days when his country was briefly ahead of the United States:
You can criticize the utopian plans for building communism, the trampling of human rights, and the Communist Party’s dictatorship in a totalitarian state all you want. But it is impossible to erase from the history of the Khrushchev era the favorable conditions created for developing cosmonautics and its related sciences. Cosmonautics did not arise simply from militarization, and its aims were more than purely propagandistic. During the first post-Sputnik years, the foundations were laid for truly scientific research in space, serving the interest of all humankind. All Soviet people, not just those of us who were directly involved in the missile and space programs, felt proud and were thrilled to be citizens of the country that was blazing the trail for the human race into the cosmos.
December 14, 2012
Fifty years ago today, we became interplanetary explorers. NASA’s 447-pound Mariner 2 probe zipped past Venus at a distance of 21,564 miles, sending back data on temperature and magnetic fields — the first successful visit to another planet.
In December 1962 that was quite an engineering triumph, and the spacecraft — modeled after the then-disaster-prone Ranger lunar probes — barely survived its ordeal at Venus. In fact, it’s still amazing that a small team at the Jet Propulsion Laboratory in Pasadena, who had never done any of this stuff before, was able to design, build, launch, and execute a successful planetary flyby, almost from scratch, in just a few months.
The project manager for Mariner 2 was Jack James, a Texas-born electrical engineer who had previously worked on missile programs at JPL. James wrote a memoir before he died in 2001; the following anecdotes from the Mariner 2 chapter are used here by permission of his son, Jack James.
In the rush to carry out the crash effort, errors were made. An error I actually enjoyed had to do with the quick rewriting of the Air Force contracts with [its launch contractors]. The young Air Force lieutenant who rewrote, negotiated, and had the contracts signed had been given verbal instructions. He apparently wasn’t too clear on the ultimate destination of this new mission. He had listed in the objectives of the contracts that they were to carry out a mission to Venice.
The flyby depended on the spacecraft’s ability to refine its course on the way to Venus, and one of James’ team doubted that the midcourse correction system could be ready in time to hit the summer 1962 launch window for Venus.
I consulted Dr. Homer Joe Stewart, who was serving in two posts: he was a key senior advisor to JPL, and at the same time a professor of aeronautics at Caltech. He was a man I thought a great deal of. I asked if we would be able to conduct a meaningful mission if we had no mid course correction system. In typical Homer Joe fashion—with a cigarette dangling from his lips and wearing a seersucker suit and tennis shoes—he went to a blackboard and started scribbling a lot of computations and drawings, most of which I did not follow. He concluded that the Atlas Agena injection accuracy alone would result in little chance of the spacecraft getting close enough to Venus to measure the magnetic fields or to make temperature measurements. He estimated that the mission would be primarily for national prestige by being the first spacecraft to go into the vicinity of a planet, but would not produce much in the way of scientific data.
James and another JPL manager, Bob Parks, then went to Washington and got NASA Headquarters’ permission — and the funding — to attempt the first American planetary mission.
Bob and I were staying in some old hotel I am certain was one that Lincoln had slept in. It had no air conditioning, but in those days hotel windows could be opened. To cool off a bit and celebrate, Bob and I, in our undershirts, took a bottle of Vodka, a bucket of ice, and some glasses, and walked up the staircase out onto the roof of the building. We gazed out at that great D.C. skyline and celebrated what we had accomplished and the uncertainties of what was about to begin.
In a 1987 interview to mark the 25th anniversary of Mariner 2, James recalled how the team worked long hours during the four months that their probe operated in interplanetary space.
I’d get called at all times of the night, you know, or I might be on travel. I was continually being called and given a report on things. My nerves had become so taut by this time, that I instructed everyone that would call me to start out with one of two sentences: “There is no problem,” or, “There is a problem.” I mean, just get it over with….Quite often, I got calls, “There is a serious problem.”
Mariner 2 survived, though, and returned data proving that Venus was oven-hot, and devoid of life (just as a young, not-yet-famous postdoc named Carl Sagan had predicted). The United States had beaten the Soviets (who had tried and failed to make a similar flyby) to Venus, and JPL had established itself as the world leader in planetary exploration, a position it still holds today.
As James wrote years later:
The science community was happy.
The NASA people were happy.
The newspaper people were happy.
The Campus was happy.
We were all happy.
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