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Audit: Mars mission faces hurdles before launch

LOS ANGELES (AP) — NASA's next-generation rover to the surface of Mars, which is already overbudget and behind schedule, faces significant hurdles as it races to the launch pad for a November liftoff, an internal audit released Wednesday found.

The space agency insisted the remaining work to be done will not result in yet another launch slip.

"At this point in time, we are fully on schedule," said Dave Lavery, the project's program executive at NASA headquarters.

The mobile Mars Science Laboratory is intended to be the most sophisticated rover sent to the Martian surface. From the outset, the mission managed by NASA's Jet Propulsion Laboratory has been plagued by development woes that have put it behind schedule and driven up costs. The total cost of the mission has ballooned to $2.5 billion from $1.6 billion.

NASA's inspector general faulted project managers for routinely underestimating costs and calculated that an extra $44 million to the development budget may be needed to avoid another delay or cancellation.

The latest price tag "may be insufficient to ensure timely completion of the project in light of the historical pattern of cost increases and the amount of work that remains to be completed," the report said.

The size of a Mini Cooper and nicknamed Curiosity, the rover is a souped-up version of the golf cart-size twin rovers Spirit and Opportunity. Essentially a science laboratory on wheels, Curiosity carries a suite of tools to analyze Martian rocks and soil to determine whether environmental conditions were ever favorable to support primitive life.

Curiosity was supposed to fly in 2009, but problems during construction forced NASA to push back launch by two years to 2011 when the orbits of Mars and Earth are again closely aligned. It will reach the Martian surface in August 2012.

Engineers had to redesign the heat shield after it failed safety tests. There were delays in shipping instruments to NASA. It took longer than expected to build and test the gear boxes that enable the mega-rover to drive and flick its robotic wrist.

Auditors found 1,200 reports of problems and failures that have not been resolved as of February. Since then, only about 1,000 issues remained. Though the number was a bit on the high side, it was not out of the character for such a complicated mission, Lavery said.

While engineers have fixed most of the problems that delayed the launch, some key issues lingered, including potential contamination of rock and soil samples by the spacecraft's robotic arm. NASA has since found a solution to minimize contamination, but auditors said they remained concerned that the fix would not be completed in time for Curiosity's departure later this month from California to Florida to be prepped for launch.

DART Project » Blog Archive » Probe Installation (phase 1) at ...

Of June work was undertaken in a pasture field at Diddington, Cambridgeshire. The main focus of this work was the installation of Time Domain Reflectometry probes, temperature sensors and the removal of bulk soil and other samples in a trench containing an archaeological feature. Additional work included coring, SPAD and spectroradiometry transects.

The field team consisted of:

Machining was undertaken by Mark from Lattenbury Services. Many thanks to Tim and Vicky Dickens from Thornhill Estates for all their help. Quinton Carroll, the Cambridgeshire County Archaeologist, visited the excavation prior to backfilling on the 8

The trench was located over a feature detected by magnetometry survey and characterised by coring. The cores contained pottery fragments and charcoal. Topsoil was removed by a JCB with a 1.2m wide toothless ditching bucket. The trench was excavated to a length of 7m. A sealing layer with a depth of 30cm was under the topsoil and also removed by machine. This layer looks like a high energy waterborne deposit laid as part of an aggrading phase of the floodplain. Further research will be undertaken on the nature and extent of this deposition event.  The ditch was in the expected location at 60cm depth. It was a 60cm deep feature with a flattened V shaped profile that contained three fills. The upper fill (context 3) contained bone, slag, daub and pottery. The fill was sandy silt with frequent gravel inclusions and occasional flecks of charcoal. Context 4 contained pottery, stone and slag. The fill was dark sandy silt with frequent charcoal and occasional gravel inclusions. The basal fill, context 5, contained flint and a single sherd of pottery. The fill was largely sandy gravel with rare charcoal flecking. After the sediments were excavated and recorded the surrounding ‘natural’ matrix was removed by machine using a toothed bucket to a depth of c. 1.2m. Bulk samples of the ‘natural’ soil were taken by machine and emptied into cubic metre soil sacks. The section was cleaned and recorded and each context was recorded.

The machine excavated a 30cm deep platform for the solar panels and box which contains the batteries and sensor array. The frame for the solar panels and sensor box was placed on the platform and levelled. The solar panel and box were installed and the frame partially backfilled to stabilise the base. 50 cm long metal bars, for Ground Penetrating Radar (GPR) calibration, were installed in the trench sections.

Australian soil and land survey handbook, guidelines for conducting surveys

Soil sampling and methods of analysis

In situ treatment of hazardous waste-contaminated soils

Abstracts of recent published material on soil and water conservation

Transactions of the ASAE.