NASA's Curiosity Mars Rover Approaches 'Cooperstown'

NASA's Mars rover Curiosity completed its first two-day autonomous drive Monday, bringing the mobile laboratory to a good vantage point for pictures useful in selecting the next target the rover will reach out and touch.

When it drives autonomously, the rover chooses a safe route to designated waypoints by using its onboard computer to analyze stereo images that it takes during pauses in the drive. Prior to Monday, each day’s autonomous drive came after a segment earlier that day that was exactly charted by rover team members using images sent to Earth. The Sunday-Monday drive was the first time Curiosity ended an autonomous driving segment, then continued autonomously from that same point the next day.

The drives brought Curiosity to about 262 feet (about 80 meters) from "Cooperstown," an outcrop bearing candidate targets for examination with instruments on the rover's arm. The moniker, appropriate for baseball season, comes from a named rock deposit in New York. Curiosity has not used its arm-mounted instruments to examine a target since departing an outcrop called "Darwin" on Sept. 22. Researchers used the arm's camera and spectrometer for four days at Darwin; they plan to use them on just one day at Cooperstown.

Starting to use two-day autonomous driving and the shorter duration planned for examining Cooperstown serve to accelerate Curiosity's progress toward the mission's main destination: Mount Sharp.

In July, Curiosity began a trek of about 5.3 miles (8.6 kilometers), starting from the area where it worked for the first half of 2013, headed to an entry point to Mount Sharp. Cooperstown is about one-third of the way along the route. The team used images from NASA's Mars Reconnaissance Orbiter to plot the route and choose a few points of potential special interest along the way, including Darwin and Cooperstown. 

"What interests us about this site is an intriguing outcrop of layered material visible in the orbital images," said Kevin Lewis of Princeton University, Princeton, N.J., a participating scientist for the mission who has been a leader in planning the Cooperstown activities. "We want to see how the local layered outcrop at Cooperstown may help us relate the geology of Yellowknife Bay to the geology of Mount Sharp."

The team is using images taken from the vantage point reached on Monday to decide what part of the Cooperstown outcrop to investigate with the arm-mounted instruments.

The first day of the two-day drive began Sunday with about 180 feet (55 meters) on a southwestward path that rover drivers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., evaluated ahead of time as safe. The autonomous-driving portion began where that left off, with Curiosity evaluating the best way to reach designated waypoints ahead. The vehicle drove about 125 feet (38 meters) autonomously on Sunday.

"We needed to store some key variables in the rover's non-volatile memory for the next day," said JPL rover driver John Wright. Curiosity's volatile memory is cleared when the rover goes into energy-conserving sleep mode overnight.

The stored variables included what direction the rover was driving when it ended the first day's drive, and whether it had classified the next 10 feet (3 meters) in that direction as safe for driving. When it began its second day of driving, Curiosity resumed evaluating the terrain ahead for safe driving and drove 105 feet (32 meters), all autonomously.

This new capability enables driving extra days during multi-day activity plans that the rover team develops on Fridays and before holidays.

A key activity planned for the week of Nov. 4 is uploading a new version of onboard software -- the third such upgrade since landing.  These upgrades allow continued advances in the rover's capabilities. The version prepared for upload next week includes, for example, improvements in what information the rover can store overnight to resume autonomous driving the next day. It also expands capabilities for using the robotic arm while parked on slopes. The team expects that to be crucial for investigations on Mount Sharp.

JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Science Laboratory Project for NASA's Science Mission Directorate, Washington. JPL designed and built the project's Curiosity rover.

Juno Status Report

As of Oct. 17, Juno was approximately 4.4 million miles (7.1 million kilometers) from Earth. The one-way radio signal travel time between Earth and Juno is currently about 24 seconds. Juno is currently traveling at a velocity of about 23.6 miles (38 kilometers) per second relative to the sun. Velocity relative to Earth is about 6.5 miles (10.4 kilometers) per second. Juno has now traveled 1.01 billion miles (1.63 billion kilometers, or 10.9 AU) since launch.

Juno’s Earth flyby gravity assist was completed on Oct. 9. Several Juno science instruments made planned observations during the approach to Earth, including the Advanced Stellar Compass, JunoCam and Waves. These observations provided a useful opportunity to test the instruments during a close planetary encounter and ensure that they work as designed. The main goal of the flyby -- to give the spacecraft the boost it needed in order to reach Jupiter – was accomplished successfully, and the spacecraft is in good health and responding to ground controllers.

Soon after its closest approach to Earth, the spacecraft initiated the first of two "safe modes" that have occurred since the flyby.  Safe mode is a state that the spacecraft may enter if its onboard computer perceives conditions on the spacecraft are not as expected.  Onboard Juno, the safe mode turned off instruments and a few non-critical spacecraft components, and pointed the spacecraft toward the sun to ensure the solar arrays received power.  The likely cause of the safe mode was an incorrect setting for a fault protection trigger for the spacecraft's battery. During the eclipse, the solar cells, as expected, were not generating electricity, and the spacecraft was drawing on the battery supply. When the voltage dropped below this fault protection trigger, the spacecraft initiated the safe mode sequence. The spacecraft acted as expected during the transition into and while in safe mode. The spacecraft exited the safe mode on Oct. 12.

The spacecraft entered the safe mode configuration again on Sunday evening (10/13/13).  When the spacecraft's onboard computer transitioned from the Earth flyby sequence to the cruise sequence, a component called the stellar reference unit remained in the Earth flyby configuration.  When the spacecraft's computer saw the draw on electricity was slightly greater than expected, it did as it was programmed to do and initiated a safe mode event.

Navigation has confirmed that Juno's current trajectory is "near-perfect" vs. planned. The mission team is in two-way communications with the spacecraft and it is operating as expected, and designed for, in safe mode. They expect to exit safe mode sometime next week.

Juno will arrive at Jupiter on July 4, 2016, at 7:29 p.m. PDT (10:29 p.m. EDT).
Juno was launched on Aug. 5, 2011. Once in orbit around Jupiter, the spacecraft will circle the planet 33 times, from pole to pole, and use its collection of eight science instruments to probe beneath the gas giant's obscuring cloud cover. Juno's science team will learn about Jupiter's origins, structure, atmosphere and magnetosphere, and look for a potential solid planetary core.

Juno's name comes from Greek and Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief, and his wife, the goddess Juno, was able to peer through the clouds and reveal Jupiter's true nature.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems, Denver, built the spacecraft. JPL is a division of the California Institute of Technology in Pasadena.

A Giant Misalignment in a Multiple Planet System

A long-standing puzzle in the study of exoplanets is the formation of hot Jupiters, gas giant planets that snuggly orbit their host star. To explain their short orbital periods, theory suggests that hot Jupiters form in long orbits and then quiescently migrate through the protoplanetary disc, the flat ring of dust and debris that circles a newly fashioned star and coalesces to form the planets.

This theory was challenged when the orbital plane of hot Jupiters were discovered to be frequently misaligned with the equator of their host stars. Scientists interpreted this as evidence that hot Jupiters are the result of chaotic close encounters with other planets.

A decisive test between the two theories are systems with more than one planet: if misalignments are indeed caused by dynamical perturbations which lead to the creation of hot Jupiters, then multi-planet systems without hot Jupiters should be preferentially aligned. What new research reveals is quite different.

Using data from the NASA's Kepler space telescope, an international research team led by Daniel Huber, a NASA Postdoctoral Program fellow at NASA's Ames Research Center in Moffett Field, Calif., studied Kepler-56, a red giant star four times larger than the sun located at a distance of approximately 3,000 light years from Earth. By analyzing the fluctuations in brightness at different points on the surface of Kepler-56, Huber and his collaborators discovered that the star's rotation axis is tilted by about 45 degrees to our line of sight.

"This was a surprise because we already knew about the existence of two planets transiting in front of Kepler-56. This suggested that the host star must be misaligned with the orbits of both planets," explains Huber. "What we found is quite literally a giant misalignment in an exoplanet system."

The culprit for the misalignment is suspected to be a third, massive companion in a long period orbit, revealed by observations obtained with the Keck telescope on Mauna Kea, Hawaii.

"Computer calculations show the outer companion may have torqued the orbital planes of the transiting planets in concert, leaving them co-planar but periodically misaligning them with the equator of the host star," said Daniel Fabrycky, co-author and professor of astronomy at the University of Chicago.

Nearly 20 years after the discovery of the first hot Jupiter, the giant misalignment in the Kepler-56 system marks an important step towards a unified explanation for the formation of hot Jupiters.

"We now know that misalignments are not just confined to hot Jupiter systems," said Huber. "Further observations will reveal whether the tilting mechanism in Kepler-56 could also be responsible for misalignments observed in hot Jupiter systems."

Cassini Spacecraft Finds 'Plastic' in Space

A small amount of propylene was identified in Titan's lower atmosphere by Cassini's Composite Infrared Spectrometer (CIRS). This instrument measures the infrared light, or heat radiation, emitted from Saturn and its moons in much the same way our hands feel the warmth of a fire.
Propylene is the first molecule to be discovered on Titan using CIRS. By isolating the same signal at various altitudes within the lower atmosphere, researchers identified the chemical with a high degree of confidence. Details are presented in a paper in the Sept. 30 edition of the Astrophysical Journal Letters.
"This chemical is all around us in everyday life, strung together in long chains to form a plastic called polypropylene," said Conor Nixon, a planetary scientist at NASA's Goddard Space Flight Center in Greenbelt, Md., and lead author of the paper. "That plastic container at the grocery store with the recycling code 5 on the bottom -- that's polypropylene."
CIRS can identify a particular gas glowing in the lower layers of the atmosphere from its unique thermal fingerprint. The challenge is to isolate this one signature from the signals of all other gases around it.
The detection of the chemical fills in a mysterious gap in Titan observations that dates back to NASA's Voyager 1 spacecraft and the first-ever close flyby of this moon in 1980.
Voyager identified many of the gases in Titan's hazy brownish atmosphere as hydrocarbons, the chemicals that primarily make up petroleum and other fossil fuels on Earth.
On Titan, hydrocarbons form after sunlight breaks apart methane, the second-most plentiful gas in that atmosphere. The newly freed fragments can link up to form chains with two, three or more carbons. The family of chemicals with two carbons includes the flammable gas ethane. Propane, a common fuel for portable stoves, belongs to the three-carbon family.
Voyager detected all members of the one- and two-carbon families in Titan's atmosphere. From the three-carbon family, the spacecraft found propane, the heaviest member, and propyne, one of the lightest members. But the middle chemicals, one of which is propylene, were missing.
As researchers continued to discover more and more chemicals in Titan's atmosphere using ground- and space-based instruments, propylene was one that remained elusive. It was finally found as a result of more detailed analysis of the CIRS data.
"This measurement was very difficult to make because propylene's weak signature is crowded by related chemicals with much stronger signals," said Michael Flasar, Goddard scientist and principal investigator for CIRS. "This success boosts our confidence that we will find still more chemicals long hidden in Titan's atmosphere."
Cassini's mass spectrometer, a device that looks at the composition of Titan's atmosphere, had hinted earlier that propylene might be present in the upper atmosphere. However, a positive identification had not been made.
"I am always excited when scientists discover a molecule that has never been observed before in an atmosphere," said Scott Edgington, Cassini's deputy project scientist at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. "This new piece of the puzzle will provide an additional test of how well we understand the chemical zoo that makes up Titan's atmosphere."
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate in Washington. The CIRS team is based at Goddard.