Space Station Crew to Return to Earth Sunday

Three astronauts living on the International Space Station will return home to Earth Sunday (July 1) after spending more than six months in orbit.

NASA astronaut Don Pettit, Russian cosmonaut Oleg Kononenko and European Space Agency astronaut Andre Kuipers are scheduled to undock from the space station in their Russian-built Soyuz capsule at 12:48 a.m. EDT (0448 GMT) Sunday.

The trio is expected to land at 4:14 a.m. EDT (0814 GMT) Sunday on the Central Asian steppes of Kazakhstan.

"When a frontier feels like home, it is no longer a frontier; it has become "civilization." Those determined to wander must now pack their bags and move further into the cosmos," Pettit wrote in a blog post about his upcoming journey home. "Space station is very much on the frontier. It is only my temporary home, and now it is time for me to venture back to my real home."

Throughout their mission, Pettit and Kuipers have actively shared their orbital experiences with the public through Twitter, photos and blog posts. Pettit even penned a special poem, called "Last Day in Space," to commemorate his imminent return.

During their stint at the space station, Pettit, Kononenko and Kuipers also played host to the first ever visiting commercial spacecraft in May — SpaceX's Dragon capsule. The unmanned Dragon spacecraft was launched to the orbiting outpost as part of a crucial test flight to demonstrate its ability to haul cargo to and from the station.

As the robotic spacecraft approached the orbiting complex, Pettit and Kuipers used the space station's robotic arm to manually attach it to the outpost.

SpaceX holds a $1.6 billion contract with NASA for 12 robotic cargo delivery flights.

Pettit, Kononenko and Kuipers launched into space on Dec. 21, 2011, and arrived at the orbiting laboratory two days later. The spaceflyers began their stay as members of the station's Expedition 30 crew, but kicked off Expedition 31  with the departure of three previous station residents in April.

Kononenko served as commander of Expedition 31, but will pass the post on to fellow Russian cosmonaut Gennady Padalka in an official change-of-command ceremony Saturday (June 30), prior to his departure.

Padalka arrived at the space station in mid-May with NASA astronaut Joe Acaba and Russian cosmonaut Sergei Revin. The three will remain aboard the orbiting outpost until September. They will be joined by three more crewmembers later in July.

Follow Denise Chow on Twitter @denisechow or SPACE.com @Spacedotcom. We're also on Facebook and Google+.

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Boeing's Plan to Return to the Moon by 2022 (ContributorNetwork)

NASA Space Flight is reporting that Boeing made a presentation at the latest Global Exploration Workshop of a plan to return Americans to the moon by 2022, 50 years after the last astronauts walked on the moon.

The Boeing plan, which uses a "way station" located at the L1 point where the gravities of the Earth and moon cancel one another out as well as a reusable lunar lander is the first detailed approach to a return to the moon.

What would the way station look like?

The way station would be constructed at the International Space Station, using the remote manipulator arm. It would consist of a "Node4/DHS (Docking Hub System), an orbiter external air lock, a MPLM (Multi-Purpose Logistics Module) habitat module, and an international module." The various modules would be launched to the ISS with commercial rockets such as the Atlas V. Once assembled, a "space tug" would convey the way station to the L1 point.

How would the reusable lunar lander work?

A Space Launch System Heavy Lift launcher would deliver a fuel depot to the way station. Then a second SLS would deliver an Orion Multi Purpose Crew Vehicle and a reusable lunar lander. The lunar lander would take on fuel at the depot and then proceed on to the moon with the crew delivered by the Orion. The crew would conduct lunar surface operations, then return to the way station, transfer to the Orion, and return to Earth. Commercial launchers would top off the fuel depot as needed for subsequent lunar missions.

There is also a secondary plan that involves deploying the reusable lunar lander at the way station while it is built at the ISS. The SLS would launch an Orion MPCV and a Delta Cryogenic Second Stage (DCSS) to the way station. The DCSS would transfer fuel to the lander and then would boost it to the moon. As in the first scenario, the crew conducts lunar surface operations, then returns to the way station, transfers to the Orion, and returns to Earth.

The advantage of the second scenario over the first is that the long term storage of fuel is not necessary. The problem of preventing "boil off" of cryogenic fuel is one that would have to be solved before long term, space based depots become practicable.

What are the advantages of the Boeing plan?

Billions of dollars would be saved with a reusable lunar and one launch of an SLS per lunar mission. The way station could also be used as a base for running tele-operated robots on the lunar surface and deploying lunar surface infrastructure such as habitats.

What are some show stoppers?

The official plan, as articulated by President Obama, is still to bypass the moon and go to an Earth approaching asteroid. Also some analysts, such as Clark Lindsey, claim that there will be no money available for a way station and a reusable lunar lander and a heavy lift Space Launch System. But Lindsey's prediction of what the fiscal and political situation of 2018-2022 when this hardware would be developed and deployed remains idle conjecture, projecting the current situation into the future without changes that might be brought about by an election of a new administration.

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 LA Times, and The Weekly Standard.

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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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