Rocket failure exposes space station vulnerability

The International Space Station is seen through the docking port of the U.S. space shuttle Atlantis as it departs the station in this still image taken from NASA TV on July 19, 2011.

Credit: Reuters/NASA/Handout

By Irene Klotz

CAPE CANAVERAL, Florida | Thu Sep 8, 2011 12:44pm EDT

CAPE CANAVERAL, Florida (Reuters) - When a Russian rocket failed on its way to orbit last month, it exposed a vulnerability in the International Space Station program that a former NASA astronaut thinks China could help address.

The August 24 failure of the Russian Progress rocket prompted NASA and its partners in the $100 billion space station project to delay launch of the next crew until the cause of the failure is found, fixed and tested.

The cause of the accident is under investigation after the unmanned rocket burned up in the atmosphere and debris fell onto parts of Siberia. The Progress rocket, which was carrying a cargo capsule of food and fuel, and the Soyuz booster that carries crew use nearly identical upper-stage motors.

Half of the station's six live-aboard crew members are due home next week and their colleagues will follow by November 19. The dates were determined by the design lifetimes of the Soyuz capsules already in orbit -- which do not use rockets to return to Earth -- and other technical factors.

If a new crew is not launched by mid-November, the station could be left untended for the first time in 11 years.

Former U.S. astronaut Leroy Chiao, a four-time flyer who served as commander of the space station from October 2004 to April 2005, says leaving the station unmanned raises the odds it could tumble from orbit.

"There are a number of relatively small mistakes or glitches that could cause you to loose attitude control," Chiao told Reuters, referring to how engineers maintain the space station's position in orbit.

UNLIKELY SCENARIO

Without good pointing, the station's antennas might not be able to lock on to satellites and ground stations needed to communicate with mission control centers.

NASA says that scenario is highly unlikely and the station would be safe even if it had to be left unmanned for a short time.

"You're talking about multiple, multiple failures," station program manager Mike Suffredini told Reuters. "You'd have to lose a lot of equipment and even then (the station) doesn't start spinning wildly. It drifts."

Eventually, ground control teams could regain control of the station by switching to omni-directional antennas or waiting until the outpost flies over Russian ground stations, Suffredini said.

With the retirement of the U.S. space shuttles this summer, crews can reach the station only aboard Russian rockets. China, the only other country able to fly people into orbit, is not a partner in the space station.

Chiao said it was time for that to change to ensure the integrity of the recently completed project of 16 nations that is designed to operate at least through 2020 as a unique gravity-free scientific research outpost.

"I think (China) is the fastest route to a backup vehicle for the space station," he said.

The current U.S. plan is to pay Russia to fly NASA astronauts, at a cost of more than $50 million per person, until U.S. companies are able to do so.

Several firms -- including Boeing Co, Space Exploration Technologies, Sierra Nevada Corp and Blue Origin -- are designing commercial passenger spaceships, helped in part by NASA contracts worth a total of $92 million.

Suffredini said Chiao was underestimating the amount of time and complexity needed to bring China into the space station partnership, even if political winds shifted and the proposal gained momentum.

"Just because they built a system that's like the Soyuz doesn't mean you can dock it with the space station," he said.

NASA administrator Charlie Bolden said he thinks Russia will be able to resume Soyuz flights before the last of the current crew departs in November.

"The possibility of de-manning station is always something you think about but it's not something that's high on my list of concerns right now," Bolden said.

(Editing by Tom Brown and John O'Callaghan)

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Dead NASA Satellite Falling From Space, But When & Where? (SPACE.com)

This story was updated at 2:05 p.m. EDT.

An out-of-control NASA satellite that is dead in space will plunge back to Earth in the next few weeks, but exactly when and where the spacecraft will fall are still a mystery, space agency and military officials said today.

The spacecraft, called the Upper Atmosphere Research Satellite, is about the size of a school bus and is expected to re-enter Earth's atmosphere sometime between late September and early October, NASA officials said. The nearly 12,500-pound (5,668-kilogram) satellite will fall over a stretch of land more than 500 miles (804 kilometers) long somewhere between northern Canada and southern South America.

But NASA and U.S. military officials tracking the defunct UARS satellite won't have a better idea of where the spacecraft will fall until around two hours before it happens. [Photos: Space Debris & Cleanup Concepts]

"We continue to say late September is the best estimate that we can give right now," Air Force Maj. Michael  Duncan, deputy chief of the U.S. Strategic Command's space situational awareness division, told reporters today (Sept. 9).  " There are so many factors that will affect it between now and that point in time — the atmosphere changes on a daily basis —  that it's impossible to say how that's going to impact this re-entry."

Even two hours before re-entry, the military will only be able to pinpoint the area of impact to within about 6,000 miles (10,000 kilometers), Duncan said.

There is a 1-in-3,200 chance that a person somewhere on Earth could be hit by falling satellite debris, but the odds of the UARS spacecraft re-entering over a populated area are extremely remote, NASA officials said.

"So those are actually very, very low odds that anyone is going to be struck by a piece of debris," said Nick Johnson, the chief scientist of NASA's Orbital Debris Program at the agency's Johnson Space Center in Houston.

Johnson said 26 large pieces of the UARS satellite are expected to survive the re-entry and reach the Earth's surface. Altogether, about 1,170 pounds (532 kg) of material from the UARS satellite are expected to reach Earth. The largest piece of debris could weigh nearly 300 pounds (150 kg).

"Throughout the entire 54 years of the Space Age there has been no report of anyone being injured or impacted by any re-entering debris," Johnson said.

Dead satellite in space

The $750 million UARS satellite has been dead in orbit since 2005, when it was decommissioned after a 14-year Earth-observation mission.

The spacecraft is the largest NASA satellite to make an uncontrolled fall back to Earth in years, agency officials said. It is about 35 feet (10.7 meters) long and 15 feet (4.5 m) wide.

Johnson said that, on average, a spacecraft as large as UARS falls back to Earth about once a year. In 2010, a total of 400 pieces of satellites or spent rockets fell back to Earth, though most pieces either burned up during re-entry, fell into the ocean or fell over unpopulated areas, he added.

"Satellites re-entering is actually very commonplace," Johnson said.

NASA is encouraging any member of the public who finds a piece of the UARS satellite to not touch the object and notify local law enforcement authorities. The satellite's remains are still owned by the United States government and cannot be sold to space memorabilia hunters NASA officials said.

NASA launched the UARS satellite in 1991 aboard the space shuttle Discovery on a mission to study Earth's upper atmosphere. In particular, the spacecraft examined Earth's ozone layer to help scientists better understand ozone layer depletion. The satellite was also able to track atmospheric effects from the Mt. Pinatubo volcano eruption in the Philippines at the time, said Paul Hertz, chief scientist for NASA's science missions.

Hertz said that the UARS satellite was shut down because the observations it was collecting were being performed by newer, better satellites.

In 2005, NASA commanded the spacecraft to use all of its remaining propellant to move into a lower orbit, one that would send it on a funeral dive back through Earth's atmosphere in about five or six years, Johnson said.

"The current orbit is about 245 kilometers by 275 kilometers," he added. "And obviously decreasing every day."

Eyes on the sky

NASA and the military's space tracking division are keeping a close watch on the UARS satellite for any changes in its descent over the next few weeks.

The space agency is posting weekly updates on the falling spacecraft on a special UARS mission website. The updates are coming from the Joint Space Operations Center at the U.S. Strategic Command at Vandenberg Air Force Base, Calif., which is tracking the satellite.

"The reason for the updates on NASA's part is to keep you and the public informed," said NASA spokeswoman Beth Dickey. "We know we will get a lot of questions about it, so we want to be up front about it."

Space debris is one of the most challenging hurdles facing space agencies and satellite operators today. According to NASA, there are about 22,000 pieces of space junk larger than 4 inches (10 cm) currently being tracked by the U.S. Space Surveillance Network. Only 1,000 of those objects are actually working spacecraft, the agency states.

Last week, a report by the National Research Council found that the amount of space junk around Earth has reached a tipping point in which, even if no new debris were added, objects would continue to create more debris through collisions. That report states that the need to limit or clean up space debris is more important than ever.

Skywatchers on alert

Keeping a skywatching eye on the comings and goings of UARS as it nears re-entry is a global network of satellite surveillance amateurs.

According to satellite sleuth Harro Zimmer of Berlin, Germany, his current analysis — based on couple of different methods — shows a possible decay window between Sept. 29 and Oct. 5.

"The last word will be coming from the solar activity over the next two weeks," Zimmer told SPACE.com.

Zimmer also advised that Belgian observer, Bram Dorreman, has reported that UARS looks to be slowly rotating with a period of 17 seconds. Its magnitude changes from 1.2 to 3.5 on the scale astronomers use to measure the brightness of objects in space. On that scale, the brighter an object is, the lower the number of its magnitude.

Johnson said that if the UARS satellite does re-enter over a populated region, it should be a magnificent sight to skywatchers on the ground. But even that is a long shot.

"This would be quite a nice show. It is a relatively large vehicle, it would be visible in daylight, Johnson said. "Odds are it's going to happen over an ocean, unlikely to be seen unless it's, you know, an airliner. We've had reports like that before. "

SPACE.com's Space Insider Columnist Leonard David contributed to this report from Colorado.You can follow SPACE.com Managing Editor Tariq Malik on Twitter @tariqjmalik. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

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Sens. Nelson, Hutchison Accuse Administration of Sabotaging NASA Rocket Project (ContributorNetwork)

Sen. Bill Nelson, D-Fla., and Sen. Kay Bailey Hutchison, R-Texas, have issued a statement accusing the Obama administration of deliberately attempting to undermine the development of a rocket crucial for NASA's plans for future space exploration.

The accusation comes in the wake of a story in the Wall Street Journal speculating, possibly based on a White House leak, that NASA's plans for space exploration would cost as much as $62 billion and that the White House was experiencing "sticker shock." A NASA document was subsequently released with more information concerning various scenarios for space exploration through 2025 with cost estimates.

The two senators, the chairman and ranking member of the Science and Space Subcommittee of the Senate Commerce Committee, are essentially accusing the White House and NASA of cooking the books and making up inflated budget numbers in an effort to kill a heavy lift rocket known as the Space Launch System. Development of the SLS was mandated by Congress in a 2010 NASA bill that was signed by President Barack Obama.

The accusation of bad faith and even legal malfeasance by Nelson and Hutchison represents an escalation of the toxic relations between the White House and NASA and Congress that have developed since Obama ordered the cancellation of the Constellation space exploration program. Nelson and Hutchison seem to have concluded that the White House and NASA are not interested in following the law or of seriously pursuing space exploration beyond low Earth orbit.

The accusation fits the known facts. For most of this year, NASA has been pursuing delaying tactics to stop the commencement of the SLS program. This has resulted in mass layoffs of NASA and contractor personnel due to the end of the space shuttle program who might have instead transitioned to the SLS development program. Hiring back these people may prove to be difficult after a long delay.

The suspicion is that the numbers quoted in the Wall Street Journal article and the NASA document will be used to cancel the SLS program outright as part of a deficit reduction deal, pushing off the commencement of space exploration beyond low Earth orbit indefinitely. With budget deficits in excess of a trillion dollars and President Obama demanding $450 billion for a jobs program, cancellation of the SLS would seem to be almost inevitable.

It is unclear what Nelson and Hutchison can do about their accusation. If the White House and NASA are not disposed to follow Congressional direction concerning space policy, enacting new directions would seem to be pointless. The commencement of a formal Senate investigation, including subpoenas, would now seem to be indicated. But that will take time and, in the meantime, hopes for the recommencement of space exploration by astronauts for the first time in decades are, once again, placed on hold.

Mark R. Whittington is the author of Children of Apollo and The Last Moonwalker. He has written on space subjects for a variety of periodicals, including The Houston Chronicle, The Washington Post, USA Today, the L.A. Times, and The Weekly.

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New Look at Exploding Stars Provides Cosmic Yardstick (SPACE.com)

Nola Taylor Redd, SPACE.com Contributor
Space.com Nola Taylor Redd, Space.com Contributor
space.com – Thu Aug 11, 2:14 pm ET

In universe spanning more than a billion light-years, distance can't be measured with a ruler. To judge how far away objects are, astronomers must rely on other objects whose properties are already known — such as certain kinds of exploding stars called supernova.  

New research is shedding light on the identity of one of these "standard candles," so-called because their brightness is standard enough that their true distance can be deduced from it.

Astronomers are hoping that analyzing one specific type of supernova explosion will give them a better understanding of how frequently it differs from another type. That, in turn, should allow for even more precise measurements of distance in the universe.

One dwarf or two

When a compact, dying star known as a white dwarf orbits another star closely enough, its strong gravitational pull can ultimately rip its partner apart. But the massive survivor can pack only so much material onto its surface. When its critical point is reached, it explodes as a Type 1a supernova.  

These events can be divided into two categories. One involves only the single white dwarf and its victim. The other involves two white dwarfs, with one destroying the other.  New research, published in the Aug. 12 issue of the journal Science, takes a look at just how commonplace the single-white-dwarf version of a Type 1a supernova may be. [Video: Supernovas – Destroyers and Creators]

When two white dwarfs are orbiting one another and the smaller one moves too close, it is almost instantly torn apart, creating a disk to orbit its destructive companion.

Almost immediately, the disk falls onto the remaining star, pushing it over the critical mass threshold and causing an explosion.

But when the second star in a pair isn't a white dwarf, things move slower. The stars don't get as close, and tidal forces manage to pull away only some of the gas from the near side of the second star. The white dwarf feeds on the material until it eventually reaches the critical mass, exploding as a supernova.

"Both models agree that the explosion is an accreting white dwarf," the lead author of the study, Assaf Sternberg at the Weizmann Institute of Science in Israel, told SPACE.com via email. "The disagreement is on the origin of the accreted material."

It is this material that interested Sternberg and his team. When the destroyed star is a white dwarf, the material is quickly consumed, but when it is not, traces of the gas linger even after the explosion.

The international team of astronomers used the Keck telescope in Hawaii  and the Magellan telescope in Chile to study the sodium in gas clouds around 41 Type 1a supernovas. Sodium is an element found in most stars but not in white dwarfs.

From the sample taken, the team determined that at least 24 percent of the explosions did not involve white dwarfs as the companion.

This number was a lower limit: Half or even all of the pairings could involve only one white dwarf star. The researchers couldn't specifically target which explosions contain white dwarfs and which do not. Instead, they looked for a distribution. They found more systems with sodium than would be found if there were an equal number of double-white-dwarf and single-white-dwarf systems.

Judging distances

Josh Simon, of the Carnegie Institute, explained how this event helps determine distances in the universe.

"If you know that the light bulb is 60 watts, then you can figure out how far away the light is from you by measuring how bright it looks," he told SPACE.com by email.

But the second star in the set could be a number of things. Simon likened the different pairings to light bulbs of varying wattage.

"You can't tell the difference between a 50-watt bulb nearby, a 60-watt bulb a bit further away, or a 100-watt bulb even farther away than that," Simon said.

Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

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'Dog Days' of Summer End With Dog Star's Sky Return (SPACE.com)

The so-called "Dog Days" of summer in the Northern Hemisphere officially came to an end this week, when the Sirius, the bright Dog Star, returned the night sky.

Everyone talks about "Dog Days" but few may know what the expression actually means. Some might suggest it signifies hot, sultry days "not fit for a dog." (If during you live in Dallas or Oklahoma City this summer, you may probably more than agree with this particular definition.) Others, meanwhile, may say it's the weather in which dogs go mad.

But the actual Dog Days, or "Canicular" days as they're known, are defined as the period from July 3 through Aug. 11 when the Dog Star, Sirius, rises in conjunction (or nearly so) with the sun. As a result, the classical Greek and Roman belief was that the combination of the brightest luminary of the day (the sun) and the brightest star of night (Sirius) were responsible for the extreme heat that is experienced during the middle of the northern summer. Other effects, according to the ancients, were droughts, plagues and madness.

A more sensible view was put forward by the astronomer Geminus around 70 B.C. He wrote: "It is generally believed that Sirius produces the heat of the Dog Days, but this is an error, for the star merely marks a season of the year when the sun’s heat is the greatest." [The 9 Hottest Places on Earth]

The sky map of for the star Sirius here shows where it currently appears in the predawn sky.

Dog star's night sky legacy

In ancient Egypt, the New Year began with the return of Sirius. It was, in fact, the "Nile Star" or the "Star of Isis" of the early Egyptians. Interestingly, some 5,000 years ago, this star's "heliacal rising" (appearing to rise just prior to the sun) occurred not in August, as is the case today, but rather on or around June 25. 

When the ancient Egyptians saw Sirius rising just before the sun, they knew that the "Nile Days" were at hand. Its annual reappearance was a warning to people who lived along the Nile River. The star always returned just before the river rose, and so announced the coming of floodwaters, which would add to the fertility of their lands. People then opened the gates of canals that irrigated their fields. 

Priests, who were the calendar keepers, sighted the first rising of the Dog Star from their temples. At the temple of Isis-Hathor at Denderah is a statue of Isis, which is located at the end of an aisle lined by tall columns. A jewel was placed in the goddess’ forehead. [Skywatching Events for August 2011]

The statue was oriented to the rising of Sirius, so that the light from the returning Dog Star would fall upon the gem. When the priests saw the light of the star shining upon the gem for the first time, they would march from the temple and announce the New Year.  In the temple appears the inscription: "Her majesty Isis shines into the temple on New Year’s Day, and she mingles her light with that of her father Ra on the horizon."

The Dog Star returns this week

This week, just before sunrise, Sirius can again be glimpsed rising just above the southeast horizon for those living in mid-northern latitudes. At more southerly latitudes, Sirius is already conspicuous, twinkling above the horizon at dawn. 

Sirius is the brightest star of the constellation Canis Major, the "Greater Dog" in Latin. According to Burnham's Celestial Handbook other names for it include "The Sparkling One" or "The Scorching One."

The star appears a brilliant white with a tinge of blue, but when the air is unsteady, or when it is low to the horizon as it is now, it seems to flicker and splinter with all the colors of the rainbow. At a distance of just 8.7 light-years, Sirius is the fifth-nearest known star. Among the naked-eye stars, it is the nearest of all, with the sole exception of Alpha Centauri. 

So regardless of how hot your local weather is, or has been, this appearance of Sirius — a star we most associate with the winter season — now rising just ahead of the sun, is a subtle reminder that the hottest part of the year is now behind us and a promise that a change toward cooler weather is only weeks away. 

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.

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NASA Sun-Watching Satellite Spots Comet Elenin in Deep Space (SPACE.com)

A NASA spacecraft  aimed at the sun shifted its unblinking gaze to an approaching comet last week to snap a new photo of the icy object as it flew by.

The image shows the comet Elenin as it passed within 4.3 million miles (7 million kilometers) of one of NASA's twin Stereo sun-watching spacecraft during a series of deep space photo sessions that began on Aug. 1. NASA rolled the Stereo-B satellite to give its instruments a view of the comet flyby, officials said.

From Stereo's observations, the fuzzy comet Elenin can be seen streaking across a small portion of the sky. The comet was seen by Stereo's HI-2 telescope between Aug. 1 to 5, and by the higher resolution HI-1 telescope between Aug. 6 to 12, NASA officials said. Stereo mission scientists planned to take photos for one-hour every day through Aug. 12. [See the Stereo probe's new comet Elenin photo]

"From August 15 onward, the comet enters the HI-1 telescope's nominal field of view, at which time we should enjoy continuous viewing of the comet," NASA researchers explained in an update posted to the Stereo mission website.

Comet Elenin is expected to become brighter over the next few days, and could be detectable using Stereo's coronagraph instrument between Aug. 20 and Sept. 1, NASA officials said. Mission managers are then expecting the comet to become visible to another sun-watching spacecraft – NASA's Solar and Heliospheric Observatory (SOHO) – for six days, beginning on Sept. 23.

Comet Elenin was discovered in December by Russian astronomer Leonid Elenin, who spotted the icy wanderer using the International Scientific Optical Network's robotic observatory near Mayhill, New Mexico. 

Viewed from Earth, comet Elenin presently appears as a faint smudge of light in deep sky exposures. By late August the comet could be visible to the naked eye as a dim "fuzzy star" with a tail. [Best Close Encounters with Comets]

Comet Elenin will fly through the inner solar system in October 2011 and be 22 million miles (35 million kilometers) away at its closest approach to our planet, NASA scientists have said. The comet is not expected to be particularly dazzling, but the flyby may be a good chance to study a relatively young comet from the outer solar system.

Some doomsday theorists have pinned the Nibiru rogue planet hypothesis on the small comet.

Conspiracy theorists say a planet, known as Nibiru, will swing in from the outskirts of our solar system and collide with Earth and wipe out humanity in 2012. Since no rogue planet has been found in the outer solar system, some people have argued that comet Elenin will be the true culprit in the Nibiru-Earth collision.

NASA has dismissed the notion that comet Elenin is anything other than a dim, wimpy comet. It poses no threat to Earth, making its closest pass at a distance roughly 100 times farther than the distance from Earth to the moon.

NASA's identical twin Stereo spacecraft were launched in October 2006. They are offset from one another, one flying ahead of the Earth and the other behind. The name "Stereo" is short for Solar Terrestrial Relations Observatory.

Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

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Fund Raising Effort Reopens SETI Institute's Allen Telescope Array (ContributorNetwork)

The Allen Telescope Array, a dedicated cluster of radio telescopes dedicated to the Search for Extraterrestrial Intelligence, is back in business thanks to a fund raising effort conducted by the SETI Institute.

The ATA, which was built thanks to private funding from Microsoft executive Paul Allen, was forced to shut down through lack of funding. The fund raising effort, according to Space.Com, has raised the $200,000 necessary from about 2,000 donors to reopen the facility and to recommence the search for ET's radio signals. One of the donors, coincidentally, was actress Jodi Foster, who played an astronomer who finds signals from aliens in the film "Contact," based on the novel by Carl Sagan.

SETI or the Search for Extraterrestrial Intelligence has had a long a storied history, ever since Project Ozma in 1960. SETI has been primarily a privately funded effort since NASA's effort was defunded by the Congress in the mid 1990s. The defunding of NASA's SETI was part of a wave of political attacks on big science projects in the early to mid 1990s that also terminated the Super Conducting Super Collider and almost ended the space station project.

The Allen Telescope Array consists of a 42 small dishes spread out over an area near the Hat Creek Radio Observatory, 290 miles northeast of San Francisco, California. Each dish is 20 feet or 6 meters in diameter, making them relatively small. However the ATA tracks areas of the sky simultaneously to conduct radio astronomy, especially of other galaxies, as well as conducting SETI operations. It is hoped that ATA will eventually consist of 350 dishes, making it one of the most powerful radio astronomy facilities on the planet. In this way the detecting power of the small dishes, when the ATA is eventually completed, would be combined as a "phased array" to make it the equivalent of a single dish 114 meters in diameter and the angular resolution of a dish 700 meters across. The plummeting price of electronics and the relatively small size of the dishes make the ATA a nimble observatory that can track targets in the sky relatively quickly. As technology improves, the dishes, because of their relatively small size, can be more easily upgraded or replaced than a single, large dish.

Besides SETI, ATA is "--being used for radio astronomy observations of our galaxy and other galaxies, gamma ray bursts and transient radio sources, and SETI." The ATA has been in operation since 2007 and has already garnered a great deal of radio astronomy science, including radio images of a number of galaxies.

Mark R. Whittington is the author of Children of Apollo and The Last Moonwalker. He has written on space subjects for a variety of periodicals, including The Houston Chronicle, The Washington Post, USA Today, the L.A. Times, and The Weekly Standard .

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