NASA announces revised Space Shuttle launch dates

New Shuttle launch dates announced

17 April 2007
NASA has announced a revised launch schedule for the upcoming Space Shuttle missions. The revised schedule follows a review of repairs to the insulation on the Shuttle's external fuel tank, which was damaged during a sudden hail storm over NASA's Florida launch site in February.
 
Repairs to the external fuel tank are expected to be ready for the launch of Space Shuttle Atlantis on the STS-117 mission no earlier than 8 June 2007. The launch window for STS-117 extends to 18 July 2007.

The STS-118 mission - the second Space Shuttle flight of the year - is due to follow during a launch window that opens on 9 August 2007.

Originally scheduled for August, the STS-120 mission with ESA astronaut Paolo Nespoli, which will also carry the Italian-built Node 2 connecting module into orbit, is now targeted for 20 October 2007.

Flight STS-122, which will see the launch of the Columbus laboratory, one of Europe's major contributions to the International Space Station, is now due for launch from NASA's Kennedy Space Centre on 6 December 2007. The crew of the STS-122 mission includes ESA astronauts Hans Schlegel and Leopold Eyharts.  
 
Read the NASA release »»

Comet McNaught (C/2006 P1) has not only become the brightest comet SOHO has ever seen, but even the brightest comet observed in over forty years! The comet swung by the sun on Jan 12th - 15th, and is now emerging into the skies of the southern hemisphere. During its close encounter with our mother star, comet McNaught became a naked-eye object in broad daylight. It was discovered on August 7th, 2006 by the hugely successful comet discoverer Rob McNaught (Siding Spring Survey). At time of discovery, the comet was a very faint object, but the predicted perihelion distance (closest distance to the sun) of just 0.17 AU indicated already that the object had the potential to become very bright.

As you are probably aware, the LASCO instrument on-board SOHO has the ability to watch comets as they get extremely close to the Sun. Fortunately for us, comet McNaught has passed right through the LASCO C3 field of view! We do not know exactly the peak brightness of the comet yet, but it is definitely brighter than -3 mag! It is thus much brighter than comet NEAT or comet 96P/Machholz. In other words, comet McNaught is by far the brightest and most spectacular comet SOHO has ever seen!

Comet McNaught

Large JPEG Image / High-Res TIFF Image (4.8 MB)

Quicktime Movies: Large / Medium / Small MPEG Movies: Large / Medium / Small

False-color image of comet McNaught using a LASCO C3 blue filter image with a short exposure time of 4.8 sec. This image shows the structure of the comet in more detail. The head of the comet, however, was so bright that it still saturated the CCD chip (see below). (High-Res TIFF Image)

The comet appeared in the field of view of SOHO's coronagraph LASCO C3 at around 02:00 UT (05:00 EDT) on January 12th. It passed its perihelion around 19:00 UT on January 12th, and exited C3's field of view at roughly 03:00UT on January 16th.

Since LASCO was built to observe the faint solar corona, its exposure times are not tuned to handle objects as bright as this extraordinary comet. In fact, comet McNaught is so bright that it saturates the CCD camera so that "bleeding" occurs along pixel rows. There is a bright horizontal streak on either side of the comet's head, because the charge leaks easier along the direction in which the CCD image is read out by the associated electronics.

The lower the magnitude number, the brighter the object. The brightest stars in the sky are categorized as zero or first magnitude. Negative magnitudes are reserved for the most brilliant objects: the brightest star is Sirius (-1.4); the full Moon is -12.7; the Sun is -26.7.

        موضوع میکرو لنزیگ به نظر می رسد که مبحث جدیدی در علم ستاره شناسی باشد اما واقعیت امر این است که این روش عمری طولانی دارد. در سال 1936 آلبرت انیشتین  مباحثی را در رابط با میکرو لنزیک به چاپ رسانده بود. انیشتین در نظریه نسبيت عام خود که نور در اطراف یک میدان گرانشی انحنا پیدا می کند، اشاره دراد. در واقع او می دانست که جاذبه تنها مسئولیت نگه داشتن پاهای ما را بر روی زمین دارد بلکه همچنین به هندسه و دینامیک هستی در ارتباط است. او در نظریه نسبيت عام خود نشان داد هرجرمی که دارای میدان گرانشی باشد توانایی تغییرشکل دادن هندسه فضا – زمان اطراف خود را دارد.

بنابر نظریه نسبیت چنانچه جرم سنگینی مثل یک ستاره دقیقاً از میان زمین و یک ستاره پس زمینه عبور کند گرانش ستاره میانی مانند یک عدسی عمل می کند و ممکن است به طور تصادفی باعث همگرایی پرتوهای ستاره پشتی برای ما ناظران زمینی شود. که به طور موقت روشنایی ستاره پس زمینه را افزایش یابد. این افزایش روشنایی طبق الگویی اتفاق می افتد که ستاره شناسان را قادر می سازد بین ستاره هایی که نورشان به سبب همگرایی گرانشی تغییر می کند با ستاره های متغیر عادی تفاوت قایل شوند.

حال اگر در این حالت سیاره ای که به دور ستاره همگرا کننده می گردد، به مسیر نور نزدیک شود، تعبیری در این روشنایی ایجاد می شود که بسته به مسیر حرکت ممکن است باعث کم نور شدن یا پر نور شدن ستاره پس زمینه نسبت به الگوی شناخته شده باشد. اتفاقی که دراین نوع کشف سیارات خارجی روی میدهد ناشی از اختلالی است که جرم سیاره باعث آن می شود گرانش جزیی سیاره تغییر ناچیزی در مسیر نور ستاره پس زمینه ایجاد میکند، نوری که گرانش ستاره مادر آن را به سمت زمین همگرا می کند. این انحراف باعث می شود که نور ستاره کم تر از آنچه توسط الگو پیش بینی می شود به ما برسد.

میکرولنزیک یک دید عجیب و نادر نیست حتی می تواند در شناسایی سیارات فرا خورشید ی( سیاراتی که در خارج  از سیستم منظومه شمسی ما قرار دارند). همانطور که در بالا اشاره شد، ه ما کمک کند.

میکرولنزیگ حساسیت بیشتری 1 نسبت به دیگر روش ما دارد و می تواند سیارات هم جرم با مشتری را کشف کند. اما کشف سیارات فرا خورشیدی زمین مانند نیز دور از تصور نیست. اگز چه دانش ما در رابط ما ---- فرا خورشیدی محدود است اما سیارات زمین مانند می تواند نقطه شروعی برا ی تحقیق در مورد زندگی وحیات فرا زمینی باشد. پس همین روزها منتظر چنین خبرهایی باشید؟!!

به گفته پرفسور آندره گولد اگر سیاره ای فراخورشیدی همسان با جرم زمین وجود داشته باشد با این روش قابل کشف است میکرو لنزیگ گرانشی که سال پیش اولین کشف خود را انجام داده  بود با کشف امسال خود به جهانیان نشان داد که در آینده کشف فراخورشیدی یک کار عادی خواهد بود. لازم به ذکر است که آماتورها در کشف سیارات فراخورشیدی نقش بسزایی دارند. چنانکه چندی پیش دو آماتور از اهالی نیوزلند به نام های کریستی و مک کوریک نقش مهمی را در این اکتشاف داشتند پس منتظر کشف زمین فرا خورشیدی توسط آماتورهای پر تلاش باشیم؟!

منبع:www.iaas.org

Commander Fyodor Yurchikhin and cosmonaut Oleg Kotov of the 15th International Space Station crew docked with the orbiting laboratory at 3:10 p.m. EDT Monday to begin a six-month stay aboard.

Image to right: Expedition 15 crew launches from the Baikonur Cosmodrome in their Soyuz spacecraft. Photo credit: NASA TV

With them is Spaceflight Participant Charles Simonyi. He is an American flying under contract with the Russian Federal Space Agency.

He will return to Earth with Expedition 14 crew members, Commander Michael Lopez-Alegria and Flight Engineer Mikhail Tyurin, on April 20. Expedition 14 launched to the station last Sept. 18.

Expedition 15 crew members were welcomed by the Expedition 14 crew, including astronaut Sunita Williams, their third Expedition 15 crew member. She launched to the station aboard the STS-116 mission of Discovery on Dec. 9. She joined Expedition 14 in progress and will provide Expedition 15 with an experienced flight engineer for the early part of its increment.

Williams, 41, is a Naval Academy graduate and a Navy commander. She flew helicopters and was a helicopter test pilot before being selected as an astronaut in 1998.

Yurchikhin, 48, is making his second flight into space. He was a member of the STS-112 crew which launched to the station aboard Atlantis on Oct. 7, 2002, with the Starboard 1 Truss. He holds a Ph.D. in economics and was named a cosmonaut-candidate in 1997.

Kotov, 41, is making his first spaceflight. He graduated from the Moscow Medical Academy in 1988, and was named a cosmonaut-candidate in 1996.

Astronaut Clayton Anderson is scheduled to replace Williams as a flight engineer during Expedition 15. Anderson, 48, holds a master's degree in aerospace engineering from Iowa State University. He was selected as an astronaut in 1998 and will be making his first spaceflight.

Two Expedition 16 crew members are expected to arrive next fall to replace Yurchikhin and Kotov

International Space Station Commander Mike Lopez-Alegria and flight engineers Mikhail Tyurin and Sunita Williams moved their Soyuz TMA spacecraft from the Earth-facing port of the station's Zarya module to the aft port of the Zvezda module Thursday.

Image to right: The Soyuz TMA-9 spacecraft undocks from the station's Zarya module. Credit: NASA TV

The move, with Tyurin at the controls, was made to clear the Zarya port for the arrival of Expedition 15 Commander Fyodor Yurchikhin and Flight Engineer Oleg Kotov, along with spaceflight participant Charles Simonyi.

Docking their Soyuz to the now-vacant Zarya port after their scheduled April 7 launch will allow them to avoid a relocation move later in their expedition.

The Soyuz docked at the Zvezda docking port at about 6:54 p.m. EDT after a flight of almost 30 minutes. During that time they traveled about a third of the way around the world. On the station, the Soyuz is about 80 feet from where it started.