Troubles Surface for Webb Telescope

Troubles Surface for Webb Telescope
In the blur of astro-news from last week — the deaths of two prominent astronomers, fabulous Comet Hartley 2 results, asteroid dust inside Hayabusa, and a planet from another galaxy — we couldn't quite get to an important story involving Hubble's eventual replacement: the James Webb Space Telescope.

The JWST effort has been under way in earnest since 2002, when NASA managers selected TRW as the project's prime contractor and renamed the spacecraft (formerly the Next Generation Space Telescope) to honor James E. Webb, the agency's second administrator. The plan was, and is, to place a giant space observatory far from Earth (to minimize interference) and give it a primary mirror 21 feet (6.5 m) across — more than seven times Hubble's light grasp — to probe the visible and (especially) infrared universe as never before.

Back then, rosy announcements predicted a total cost of around $1 billion and a launch sometime this year.

If only! Along the way, reality set in. By 2005 the construction cost-to-launch estimate had ballooned to $2.4 billion, and the debut had slipped to 2014. That's where things stood until this year, when an Independent Comprehensive Review Panel took a hard look at the numbers. The bottom line is that JWST's total cost to launch and operate is likely about $6½ billion, $1½ billion more than NASA budgeted. Moreover, the earliest possible launch date is September 2015.

Given that construction is so far along, you've got to wonder why NASA misjudged things so badly. You would think that the agency had learned its lesson building the Hubble Space Telescope, which was supposed to take just four years to assemble when construction began in 1979 but ended up taking 11 years to reach space. The loss of the Space Shuttle Challenger in 1986 didn't help, but the HST project had numerous problems of its own making.

So what went wrong with JWST?

According to the review panel's final report, NASA officials made two "fundamental mistakes" when the project underwent a major Confirmation Review in July 2008. First, the panel found, "the Project Budget presented for Confirmation was not based upon a current, bottom-up estimate of projected costs." Second, project managers failed to factor in — and provide funds for — development problems that were likely to occur.



Hubble and Webb mirrors compared
Measuring more than 21 feet (6.5 m) across, the primary mirror for the James Webb Space Telescope will have a diameter some 2½ times that of the Hubble Space Telescope.

Even to meet a 2015 launch date, NASA will need to pump an additional $250 million into the project's budget in fiscal 2011 and 2012 — funds that the agency isn't likely to get from Congress. If forced to find that money internally, the agency will likely have to cancel or defer other space-science programs already under way.

Perhaps more urgently, the panel recommended that NASA administrator Charles Bolden yank project management from its Goddard Space Flight Center and instead run the effort from a dedicated office at the agency's Washington headquarters. Bolden, in response, supported the panel's findings and is appointing a new JWST program director.

The news isn't all bad. The review panel found the technical state of the project to be sound and its scientific goals intact. Money spent to date hasn't been wasted, it noted in an Afterword, and "no technical constraints to successful completion have been identified." Once in orbit, the Webb telescope is expected to have the ability to look back 13½ billion years, to when the universe was just 2% of its current age and the first galaxies were forming.

Silica on a Mars Volcano Tells of Wet and Cozy Past

PASADENA, Calif. -- Light-colored mounds of a mineral deposited on a volcanic cone more than three billion years ago may preserve evidence of one of the most recent habitable microenvironments on Mars.

Observations by NASA's Mars Reconnaissance Orbiter enabled researchers to identify the mineral as hydrated silica and to see its volcanic context. The mounds' composition and their location on the flanks of a volcanic cone provide the best evidence yet found on Mars for an intact deposit from a hydrothermal environment -- a steam fumarole, or hot spring. Such environments may have provided habitats for some of Earth's earliest life forms.

"The heat and water required to create this deposit probably made this a habitable zone," said J.R. Skok of Brown University, Providence, R.I., lead author of a paper about these findings published online today by Nature Geoscience. "If life did exist there, this would be a promising type of deposit to entomb evidence of it -- a microbial mortuary."

No studies have yet determined whether Mars has ever supported life. The new results add to accumulating evidence that, at some times and in some places, Mars has had favorable environments for microbial life. This specific place would have been habitable when most of Mars was already dry and cold. Concentrations of hydrated silica have been identified on Mars previously, including a nearly pure patch found by NASA's Mars Exploration Rover Spirit in 2007. However, none of those earlier findings were in such an intact setting as this one, and the setting adds evidence about the origin.

Skok said, "You have spectacular context for this deposit. It's right on the flank of a volcano. The setting remains essentially the same as it was when the silica was deposited."

The small cone rises about 100 meters (100 yards) from the floor of a shallow bowl named Nili Patera. The patera, which is the floor of a volcanic caldera, spans about 50 kilometers (30 miles) in the Syrtis Major volcanic region of equatorial Mars. Before the cone formed, free-flowing lava blanketed nearby plains. The collapse of an underground magma chamber from which lava had emanated created the bowl. Subsequent lava flows, still with a runny texture, coated the floor of Nili Patera. The cone grew from even later flows, apparently after evolution of the underground magma had thickened its texture so that the erupted lava would mound up.

"We can read a series of chapters in this history book and know that the cone grew from the last gasp of a giant volcanic system," said John Mustard, Skok's thesis advisor at Brown and a co-author of the paper. "The cooling and solidification of most of the magma concentrated its silica and water content."

Observations by cameras on the Mars Reconnaissance Orbiter revealed patches of bright deposits near the summit of the cone, fanning down its flank, and on flatter ground in the vicinity. The Brown researchers partnered with Scott Murchie of Johns Hopkins University Applied Physics Laboratory, Laurel, Md., to analyze the bright exposures with the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument on the orbiter.

Silica can be dissolved, transported and concentrated by hot water or steam. Hydrated silica identified by the spectrometer in uphill locations -- confirmed by stereo imaging -- indicates that hot springs or fumaroles fed by underground heating created these deposits. Silica deposits around hydrothermal vents in Iceland are among the best parallels on Earth.

Murchie said, "The habitable zone would have been within and alongside the conduits carrying the heated water." The volcanic activity that built the cone in Nili Patera appears to have happened more recently than the 3.7-billion-year or greater age of Mars' potentially habitable early wet environments recorded in clay minerals identified from orbit

Mr. Hartley's Amazing Comet

Today the Deep Impact spacecraft zipped past Comet 103P/Hartley 2 at a distance of about 435 miles (700 km) at 6:59:47 a.m. PDT (13:59:47 Universal Time). After confirming that the spacecraft had survived its 27,000-mile-per-hour brush with this icy interloper, the scientists and engineers who'd gathered at the Jet Propulsion Laboratory in California held their collective breath for about 20 minutes while waiting for the first images to be radioed to the ground.

Any apprehension quickly turned to joy, as the views revealed the craft's pinpoint targeting and crisp images of an elongated, irregularly shaped body spewing gas and dust from a plethora of jets.

Spacecraft have now photographed five comets at close range, and with a length of just 1¼ miles (2 km), Hartley 2 is the smallest. However, as investigator Jessica Sunshine (University of Maryland) noted today during a press briefing, "It's the most interesting and, for its size, the most active."

Radar images acquired by Arecibo Observatory last week had prepared the mission scientists to expect an elongated body. But no one was anticipating such an unusual visage: the comet's two ends, both roughly textured, are the sources of perhaps dozens of individual jets, while the midsection looks completely smooth, as if covered deeply by a blanket of fine dust. "We have a lot of work to do to try to understand what's going on here," Sunshine admitted.

Project scientist Michael A'Hearn (University of Maryland) noted that images of the comet taken continuously since October 1st had shown periodic surges of carbon dioxide (CO2) emanating from the nucleus. Judging from the close-ups, he says it's now clear that "one area on the comet is incredibly rich in dry ice, and that's what drags out the grains and produces all the phenomena that we see."

Unlike spacecraft that veritably drip with instrumentation, Deep Impact carries a minimalist payload: medium- and high-resolution cameras, along with an infrared spectrometer.

Today's views were not the most detailed frames — those will be radioed back to Earth in the coming days. According to project manager Tim Larson, the spacecraft will continue to photograph the comet's nucleus for three more weeks as it recedes into the distance.

The rendezvous was the second cometary encounter for this spacecraft, which previously looked on as a large copper bullet slammed into Comet 9P/Tempel on January 4, 2005. After that eventful encounter, NASA managers recommissioned the still-viable craft as the EPOXI mission, a combination of its two extended mission components: Extrasolar Planet Observations and Characterization (EPOCh), and the second cometary flyby, called the Deep Impact Extended Investigation (DIXI).

On hand for today's festivities at JPL were Malcolm Hartley and his wife. Hartley discovered this object in March 1986 on glass plates taken with the Siding Spring Observatory's UK Schmidt telescope in New South Wales, Australia. Its high eccentric path carries the comet from a perihelion near Earth's orbit out to beyond Jupiter and back every 6½ years. In fact, right now this periodic visitor is quite close to Earth and putting on a decent showing in the predawn sky.

Finally, here's something for you space-trivia buffs: There's actually been a sixth close flyby of a comet — in fact, it was a fly-through. Do you know which spacecraft it was? Offer your guess in the comments section below; I'll congratulate the first person to post the correct answer in a future story about the Comet Hartley 2 results!