Earth to Lend Helping Hand to Comet Craft

Earth is a great place to pick up orbital velocity," said Tim Larson, the EPOXI project manager from NASA's Jet Propulsion Laboratory in Pasadena, Calif. "This flyby will give our spacecraft a 1.5-kilometer-per-second [3,470 mph] boost, setting us up to get up close and personal with comet Hartley 2."

EPOXI is an extended mission of the Deep Impact spacecraft. Its name is derived from its two tasked science investigations -- the Deep Impact Extended Investigation (DIXI) and the Extrasolar Planet Observation and Characterization (EPOCh). On Nov. 4, 2010, the mission will conduct an extended flyby of Hartley 2 using all three of the spacecraft's instruments (two telescopes with digital color cameras and an infrared spectrometer).

The University of Maryland is the Principal Investigator institution. JPL manages EPOXI for NASA's Science Mission Directorate, Washington. The spacecraft was built for NASA by Ball Aerospace & Technologies Corp., Boulder, Colo.

the Orbiting Carbon Observatory.

NASA has selected Orbital Sciences Corp. of Dulles, Va., to launch the Orbiting Carbon Observatory-2 (OCO-2) mission. The spacecraft will fly in February 2013 aboard a Taurus XL 3110 rocket launched from Vandenberg Air Force Base in California.

The total cost of the OCO-2 launch services is approximately $70 million. The estimated cost includes the task ordered launch service for a Taurus XL 3110 rocket, plus additional services under other contracts for payload processing, OCO-2 mission-unique support, launch vehicle integration, and tracking, data and telemetry support.

OCO-2 is NASA's first mission dedicated to studying atmospheric carbon dioxide. Carbon dioxide is the leading human-produced greenhouse gas driving changes in Earth's climate. OCO-2 will provide the first complete picture of human and natural carbon dioxide sources and "sinks," the places where the gas is pulled out of the atmosphere and stored. It will map the global geographic distribution of these sources and sinks and study their changes over time. The OCO-2 spacecraft will replace OCO-1, lost during a launch vehicle failure in 2009.

Crew Sets Up Hardware, Prepares for Soyuz Move

With Expedition 24 recently expanded to its full crew complement of six, the International Space Station’s residents tackled a variety of science and maintenance tasks Tuesday.

Flight Engineers Doug Wheelock, Shannon Walker and Fyodor Yurchikhin, who arrived at the station on the Soyuz TMA-19 spacecraft Thursday, participated in familiarization briefings with the crew members who welcomed them aboard -- Commander Alexander Skvortsov and Flight Engineers Mikhail Kornienko and Tracy Caldwell Dyson. The three new flight engineers also had an hour of free time set aside to study the layout of their orbital home for the next five-and-a-half months and learn to move about in its large habitable space.

Working in the Destiny laboratory, Wheelock and Walker began installing and outfitting the Window Observation Research Facility, a rack surrounding the lab’s 20-inch window. This rack will serve as an attachment point for cameras and scanners to be mounted in the window and provides power and data transfer capabilities for those instruments.

Caldwell Dyson performed her third session with an experiment that studies changes in the astronauts’ aerobic capacity during long-duration spaceflight. NASA is interested in tracking these changes because a reduction in maximum oxygen uptake directly impacts a crew member’s ability to perform strenuous activities such as spacewalks or emergency operations.

New Crew Members Prepare for Docking

Three new Expedition 24 crew members continued their voyage aboard the Soyuz TMA-19 spacecraft to the International Space Station after launching from the Baikonur Cosmodrome in Kazakhstan at 5:35 p.m. EDT Tuesday.

Flight Engineers Doug Wheelock, Shannon Walker and Fyodor Yurchikhin executed another rendezvous burn and tested the docking systems of the Soyuz TMA-19 Wednesday to prepare for docking to the aft port of the station’s Zvezda service module at 6:25 p.m. Thursday.

Fellow Expedition 24 crewmates, Commander Alexander Skvortsov and Flight Engineers Mikhail Kornienko and Tracy Caldwell Dyson, will welcome them aboard the orbiting complex when the hatches open around 9:25 p.m.

Our Powerful Sun

Eight planets and their moons, tens of thousands of asteroids, and trillions of comets revolve around the sun. One of these is our Earth, orbiting the sun at an average distance of about 92,960,000 miles (149,600,000 kilometers). The sun is a huge, glowing ball that provides light, heat, and other energy to our Earth. But our beneficial space neighbor is also capable of some stellar "temper tantrums."

On Thursday, June 17, Dr. David Hathaway, a solar scientist at NASA's Marshall Space Flight Center, will answer your questions about how our sun works and produces phenomena such as sunspots, solar flares, and solar storms -- "hot' topics that have communication and health implications for everyone on Earth.

Joining the chat is easy. Simply visit this page on Thursday, June 17 from 3-4 p.m. EDT. The chat window will open at the bottom of this page starting at 2:30 p.m. EDT. You can log in and be ready to ask questions at 3:00. See you in chat!

Mars Exploration Rover Spirit

Rocks examined by NASA's Spirit Mars Rover hold evidence of a wet, non-acidic ancient environment that may have been favorable for life. Confirming this mineral clue took four years of analysis by several scientists.

An outcrop that Spirit examined in late 2005 revealed high concentrations of carbonate, which originates in wet, near-neutral conditions, but dissolves in acid. The ancient water indicated by this find was not acidic.

NASA's rovers have found other evidence of formerly wet Martian environments. However the data for those environments indicate conditions that may have been acidic. In other cases, the conditions were definitely acidic, and therefore less favorable as habitats for life.

Laboratory tests helped confirm the carbonate identification. The findings were published online Thursday, June 3 by the journal Science.

"This is one of the most significant findings by the rovers," said Steve Squyres of Cornell University in Ithaca, N.Y. Squyres is principal investigator for the Mars twin rovers, Spirit and Opportunity, and a co-author of the new report. "A substantial carbonate deposit in a Mars outcrop tells us that conditions that could have been quite favorable for life were present at one time in that place. "