Space Shuttle Endeavour unveiled for final blastoff set for May 16, 2011. Endeavour and her six man crew will deliver the $2 Billion Alpha Magnetic Spectrometer to the International Space Station which seeks to determine the origin and evolution of our Universe. Credit: Ken Kremer
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KENNEDY SPACE CENTER – A humongous crowd numbering perhaps half a million excited people is expected to witness the historic final blast off of Space Shuttle Endeavour.
Clocks are ticking down as the countdown enters the final phase before Monday morning’s liftoff (May 16) scheduled for 8:56 a.m. EDT from Pad 39 A at NASA’s Kennedy Space Center (KSC).
Endeavour was unveiled for blastoff earlier today as a protective cocoon like structure was pulled away from the shuttle stack. The Rotating Service Structure (RSS) was retracted from around the orbiter starting at 11:45 a.m. over about 45 minutes and under a gorgeous blue sky. See my photo album
Space Shuttle Endeavour awaits launch from Pad 39 A on May 16, 2011. Endeavour will deliver the $2 Billion Alpha Magnetic Spectrometer to the International Space Station. The AMS will search for dark matter, dark energy and antimatter to determine the birth of the Universe. Credit: Ken Kremer
In a lucky break, expected thunderstorms that could have delayed the retraction and launch preparations actually passed through the area overnight, much earlier than expected.
Shuttle managers will gather at 11 p.m. tonight for a critical meeting and decision to give the “Go-No Go” directive to load the External Fuel Tank with supercold liquid hydrogen and liquid oxygen fuel that powers the shuttle main engines for the eight and one half minute climb to orbit. The tanking process is scheduled to begin at 11:36 p.m.
There are no technical issues at this time that would prevent a launch. The weather outlook remains at “70 Percent GO”.
The goal of Endeavour and her all veteran six man crew is to deliver the Alpha Magnetic Spectrometer (AMS) to the International Space Station. The $2 Billion AMS is a state of the art particle physics detector that will search for dark matter, dark energy and antimatter and seek to determine how the Universe was born and evolved.
The 134 mission is set to last 16 days and will feature the final 4 spacewalks of the space shuttle program.
Close up of Endeavour at Pad 39A shows astronaut walkway to the White Room and crew cabin.
Credit: Ken Kremer
The crew will wake up at 12 a.m. Monday. They depart for the launch pad shortly after 5 a.m.
Launch coverage begins on NASA TV tonight at 11:30 P.M. shortly before fueling commences:
Close up of aft fuselage of Endeavour at Pad 39A. Credit: Ken KremerKen Kremer and Space Shuttle Endeavour at Launch Pad 39 A at the Kennedy Space Center.
Credit: Ken Kremer
Two access walkways leading to Endeavour. Astronaut walkway to White Room at center. Credit: Ken Kremer
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KENNEDY SPACE CENTER – Space Shuttle Endeavour is poised for launch as the countdown clock ticks down to a liftoff from Pad 39 A on Monday morning, May 16 at 8:56 a.m. EDT. The shuttle Mission Management Team (MMT) at the Kennedy Space Center (KSC) met today (May 14) and gave the green light to continue launch preparations for the STS-134 mission, which is the final flight of shuttle Endeavour.
The weather forecast remains at a 70 percent favorable chance of acceptable conditions on Monday, according to Shuttle Weather Officer Kathy Winters. The weather outlook drops to only 20 percent favorable on Tuesday in case of a one day delay. The weather rebounds to 80 percent favorable if the launch is postponed by 48 hours.
Side view of shutte Endeavour stack and access walkways. Astronaut walkway to White Room at top center. Credit: Ken Kremer
At a briefing for reporters at KSC today, shuttle launch managers were upbeat about preparations for the launch.
“We had a really good meeting today, unanimous consent from the Mission Management Team to press on with the launch countdown,” said Mike Moses, MMT chairman and manager of shuttle integration at KSC. “Everything’s in really great shape, really no issues at all.”
Moses added that no problems are expected with the heaters in the auxiliary power units (APU’s) that caused the launch scrub two weeks ago on April 29.
To the heavens with Endeavour. Credit: Ken Kremer
Shuttle Launch Director Mike Leinbach said, “The countdown is going extremely well and the team is ready to go. Tanking of the External Tank begins just prior to midnight. We are not working any issue at this time.”
Fueling of the External Tank with supercold liquid oxygen and liquid hydrogen starts at 11.36 p.m. Sunday night.
Leinbach said that local officials are expecting a crowd of about half a million people to descend on the Florida Space Coast area for the launch.
“You’ll recall for the first launch attempt on that Friday afternoon, the estimate was between 500,000 and 750,000,” he said. “So they’re not quite expecting that big surge, but it’ll still be a heck of a traffic jam after launch.”
Endeavour and her six man crew will deliver the $2 Billion Alpha Magnetic Spectrometer – a particle physics detector searching for dark matter, dark energy and antimatter – to the International Space Station during a 16 day mission that will include 4 spacewalks.
After Endeavour was rolled out to the pad, I had an awesome opportunity to photograph Endeavour at the pad from stunning vantage points all around the launch pad from top to bottom.
Herein is part 2 of my photo album focusing on my visit to the base of the shuttle stack on the mobile launch platform while looking to the heavens and standing directly beneath the External Tank and in between the Twin Solid Rocket Boosters. Part 1 of my photo album concentrated on the view from the upper levels and our visit to the White Room – where the astronauts board the shuttle orbiter to take their seats for the adventure of a lifetime.
Looking to the heavens from directly beneath Endeavour’s tail. Credit: Ken KremerSpace Shuttle Endeavour awaits launch from Pad 39 A
Endeavour will deliver the $2 Billion Alpha Magnetic Spectrometer to the International Space Station which seeks to unveil the Unknown and uncover the birth of the Universe. Credit: Ken Kremer View from directly below the External Tank and shuttle body flap between twin SRB’s. Credit: Ken KremerSpace Shuttle Endeavour atop Launch Pad 39 A is slated for liftoff on May 16. Endeavour and her six man crew will deliver the Alpha Magnetic Spectrometer to the International Space Station. Credit: Ken Kremer Shuttle belly with attach points to External Tank connected to loaded Solid Rocket Boosters
on top of pad 39 A. Credit: Ken KremerKen Kremer standing beside the Solid Rocket Booster and External Tank and on top of Launch Pad 39 A with Space Shuttle Endeavour. Credit: Ken Kremer
If you watch Endeavour’s launch, send me your launch and crowd photos to post in an STS-134 launch gallery here at Universe Today.
Space Shuttle Endeavour awaits launch sometime in May from Pad 39 A following launch scrub on April 29, 2011 at 3;47 p.m. Endeavour and her 6 man crew will deliver the $2 Billion Alpha Magnetic Spectrometer to the International Space Station which seeks to unveil the Unknown and uncover the birth of the Universe. Credit: Ken Kremer
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KENNEDY SPACE CENTER – The final launch of shuttle Endeavour will be further delayed, perhaps by a week or more – to May 6 or 11 time frame – as technicians working at the pad seek to determine the cause of the failure of multiple heaters in auxiliary power unit-1 (APU) which caused the scrub of Endeavour’s launch attempt on Friday, with just 4 hours remaining in the countdown. The six man crew of Endeavour had just departed for the launch pad inside the Astrovan and was forced to turn around soon thereafter. We saw them pass us by, heading back to crew quarters to await a resolution of the issues.
The launch delay came as a huge disappointment to NASA and the enormous crowd estimated at 750.000 people who came to Florida to watch the momentous liftoff in person for what many call a “life changing experience”. Even President Obama and the entire first family were on hand to witness Endeavour’s launch. But the top priority is to launch the shuttle safely and the launch team emphasized that they made absolutely no changes to the countdown procedures.
Repairs to Space Shuttle Endeavour are in progress at the launch pad. Arrow shows location of access door used by technicians to swap out the faulty Aft Load Control Assembly (ALCA-2) near the main engines. Credit: Ken Kremer On Saturday, technicians gained access to Endeavour’s aft fuselage which houses the components suspected to have malfunction and found that the cockpit control fuse panel is working. They also verified that thermostats associated with the failed APU heaters are still not working. This indicates that the root cause of the malfunction lies deeper inside the orbiter and it will take longer for technicians to access and fix whatever is causing the problem.
APU-1 is located on the left side of the orbiter in the aft section behind the end of the payload bay.
The heaters play a critical role in keeping the APU hydrazine fuel from freezing in orbit and remain in a fluid state. If the hydrazine were to freeze and then thaw back to a liquid, it would expand and potentially rupture the fuel lines with devastating consequences.
Diagram shows location of all 3 Shuttle APU's. Credit: NASA
The orbiter has three APU’s. Only one is required to fly safely. Three units provide redundancy and all must be in working order before launch. Otherwise the launch commit criteria would be violated, forcing a launch scrub. The APUs provide the hydraulics to maneuver the main engine nozzles, elevons, rudder, body flap, landing gear brakes and nose wheel steering system.
Technical teams got to work inside the orbiter on Saturday after the rotating service structure was rolled back around the orbiter to enable access. If the problem is deeper within the orbiter at the Load Control Assembly it will take several additional days to fix the problem. Retesting of any new components inside the LCA will take at least 48 hours. Furthermore if any ordnance needs to be disconnected, a further delay of multiple additional days is inevitable.
In order to launch Endeavour on Monday, May 2, at 2:34 p.m. EDT, NASA must resume the countdown on Sunday afternoon. NASA only has until May 4 to get Endeavour off the ground until they would be forced to stand down to make way for the May 6 blastoff of an Atlas V rocket carrying an Air Force early-warning missile detection satellite.
NASA officials are in touch with Air Force officials to determine if the Air Force could be flexible in changing their launch date in the event that Endeavour would be ready to launch on the blackout dates of May 5 to 7.
NASA will hold a news briefing at 2 p.m. on Sunday to update reporters on the situation.
A concept drawing of the Dragon spacecraft approaching the ISS. Credit: SpaceX
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While a test of SpaceX’s Dragon spacecraft docking capabilities with the International Space Station is tentatively scheduled for December, 2011, Russia has said it will not allow a SpaceX vehicle to dock with the ISS unless its safety is fully tested. “We will not issue docking permission unless the necessary level of reliability and safety is proven,” said Alexei Krasov, head of the human spaceflight department of Roscosmos. “So far we have no proof that those spacecraft duly comply with the accepted norms of spaceflight safety.”
NASA has not yet commented on the statement by Krasov, which was reported by the Russian media.
SpaceX has requested NASA to authorize the docking in December after another test flight of the Dragon sometime this summer. As it stands now, approximately twelve cargo resupply flights are planned by SpaceX through 2015, and SpaceX CEO has said he would like to start crewed flights by 2016.
Some critics are viewing Russia’s objections as having little to do with safety and more to do with the monopoly it will have for access to the ISS once the space shuttle program concludes later this summer. Russia has raised its going rates for ferrying US astronauts to the space station on the Soyuz space craft and for bringing cargo with the Progress craft resupply ship.
Launch sign at Kennedy Space Center counts down the days to the STS-134 launch of shuttle Endeavour. Photo credit: NASA/KSC › Larger Image
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The launch date for the long-awaited Alpha Magnetic Spectrometer-2 (AMS) to the International Space Station has been set for Friday, April 29, at 3:47 p.m. EDT on from NASA’s Kennedy Space Center in Florida. The 14-day STS-134 mission is shuttle Endeavour’s final scheduled flight. After a flight readiness review today, NASA and contractor managers determined the shuttle and station’s equipment, support systems and personnel are ready to go.
The other notable aspect of the mission is that Mark Kelly is commanding, and his wife, Representative Gabrielle Giffords is tentatively expected to attend the launch, just months after she was shot in the head. This certainly will bring a unique aspect to the launch, at least for the media coverage, drawing attention to the mission to those who might not normally take notice.
For those who always pay attention to shuttle missions, however, two aspects make this mission noteworthy: the AMS and Endeavour’s final mission. The mission will also feature the last four spacewalks by a shuttle crew.
The AMS is designed to measure cosmic rays to search for various types of unusual matter, such as dark matter and antimatter. The instrument’s experiments will help researchers study the formation of the universe.
Professor Sam Ting, AMS Principal Investigator, with the AMS in the background. Credit: Chase Clark.
Also during the flight, Endeavour also will deliver the Express Logistics Carrier 3, a platform that carries spare parts to sustain station operations after the shuttles are retired from service. During the scheduled spacewalks, astronauts will do maintenance work, install new components, and perform a complex series of tasks to top off the ammonia in one of the station’s photovoltaic thermal control system cooling loops.
The crew consists of Kelly, Pilot Greg H. Johnson, NASA Mission Specialists Michael Fincke, Andrew Feustel and Greg Chamitoff and European Space Agency Mission Specialist Roberto Vittori. They are scheduled to arrive at Kennedy on Tuesday, April 26, for final launch preparations.
STS-134 is the 134th shuttle mission, Endeavour’s 25th flight and the 36th shuttle mission to the station.
Universe Today will be on hand live to cover the launch from Kennedy Space Center, and provide updates as the mission progresses.
Canadarm2, the huge robotic arm on the International Space Station holds astronaut Stephen Robinson during the STS-114 mission. Credit: NASA
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On April 19, 2001, space shuttle Endeavour’s STS-100 mission launched to the space station, and in the payload bay was Canadarm2, a larger, more robust successor to the shuttle’s Canadarm. The Space Station Remote Manipulator System (SSRMS) is a sophisticated “construction crane,” and is responsible for much of the successful building of the ISS — module by module — in space.
“She is without a doubt one of the most critical components on board station having participated in the construction of the spacecraft that is on orbit today,” said Mike Suffredini, Program Manager of the International Space Station. “Twenty-nine missions have been supported by Canadarm2, two of them capturing and berthing the HTV vehicle, and in all that time with absolutely flawless performance. Without her we couldn’t have gotten to where we are today.”
See a gallery of images of Canadarm2’s 10 years in the space construction business.
April 22, 2001 – History is made. Canadian Space Agency Astronaut Chris Hadfield, attached to Canadarm, installs the next-generation Canadarm2 to the International Space Station during Shuttle Mission STS-100. Credit: NASA
Canadarm2 was installed on the ISS by astronaut Chris Hadfield during the first spacewalk by a Canadian. Canadarm2 has unloaded hundreds of tons of equipment and supplies ferried by the shuttle and assisted almost 100 spacewalks. Endeavour’s last flight later this month will mark Canadarm2’s 28th Shuttle mission.
July 15, 2001 – Canadarm2 performs its first official task, attaching the Quest Airlock to the Unity module of the International Space Station during Shuttle Mission STS-104. Credit: NASA
The Canadian Space Agency says that Canadarm2’s role on the ISS will expand as the orbital lab nears completion: in addition to performing routine maintenance, the robotic arm will make more frequent “cosmic catches,” where it will capture, dock and later release visiting spacecraft, as it has done with the HTV. When the space shuttle retires, reusable commercial spacecraft, like SpaceX’s Dragon and Orbital’s Cygnus, will be used to bring supplies and equipment to the ISS. Canadarm2 will capture each of these visiting vehicles. In late 2011 and early 2012, Canadarm2 will capture a series of 6 commercial spacecraft in just 7 months, beginning with the Dragon spacecraft, currently scheduled to arrive in October 2011.
How the ISS looked back in 2001, with Canadarm2 showing prominently. Credit: NASAJune 15, 2007 – Shuttle Mission STS-117 continued assembly operations that featured more work on the Station’s solar arrays. In this image, NASA astronaut Jim Reilly, attached to Canadarm2, and NASA colleague John “Danny” Olivas, are folding up an older solar panel so that it can be stowed and moved to another location on a future shuttle mission. Credit: NASANovember 3, 2007 – Canadarm2 played a big role in helping astronauts fix a torn solar array. The arm’s reach was extended by the Orbiter Boom Sensor System, and here, allowing astronaut Scott Parazynski analyses the solar panel while anchored to the boom. Credit: NASAFebruary 12, 2008 – Here, Canadarm2 has a firm grip on the European Space Agency’s Columbus module, which it grappled and attached to the station. Credit: NASA
More info on the SSRMS and how it was built:
The Expedition 27 crew on board the ISS pay tribute to 10 years of the SSRMS:
I’ve had this song in my head ever since Sunday when I first saw this video, so finally decided I had to post it. Astronaut (and flautist) Cady Coleman on board the International Space Station hooked up with Ian Anderson, founder of the rock band Jethro Tull, to collaborate for the first space-Earth duet. The song, “Bourree in E Minor,” was written by Johann Sebastian Bach, but Jethro Tull made the song famous (again) with their own arrangement of the tune back in 1969, the same year Neil Armstrong and Buzz Aldrin stepped on the moon. Coleman and Anderson played the song in recognition of 50 years of human spaceflight and the anniversary of the first launch of a human to space by cosmonaut Yuri Gagarin on April 12, 1961.
Coleman played her part from 220 miles above Earth late last week. Anderson played his part while on tour in Perm, Russia, during the weekend. The two parts were then joined.
Just see if you can keep this song out of your head for the rest of the day!
Celebrate Yuri’s Night on April 12, 2011 -- 50th Anniversary of Human Spaceflight
On April 12, 1961, Russian cosmonaut Yuri Gagarin (left, on the way to the launch pad) became the first human in space, making a 108-minute orbital flight in his Vostok 1 spacecraft.
Newspapers like The Huntsville Times (right) trumpeted Gagarin's accomplishment.
Credit: NASA
Send Ken your Yuri’s Night event reports and photos
Mark your calendars. April 12, 2011 marks the 50th Anniversary of Human Spaceflight and Cosmonaut Yuri Gagarin’s astonishing First Orbit of our precious planet Earth on April 12, 1961. Gagarin was the first human to enter outer space and see what no one else had ever witnessed – our commonly shared Earth as a planet and beautiful blue globe with no borders.
Space enthusiasts worldwide are celebrating this watershed moment in Human history at a network of over 400 “Yuri’s Night” parties taking place in more than 70 countries on 6 continents and 2 worlds, according to the official “Yuri’s Night” website.
Gagarin’s flight took place in the midst of the inflammatory Cold War rivalry between the Soviet Union and the United States and shocked the world into new realities. The Space Race led to the first lunar landing by the United States and Neil Armstrong’s first steps on the moons surface in 1969. Eventually, the world’s superpowers beat swords into plowshares and united their efforts to build the International Space Station.
Yuri Gagarin - first human in space. Credit: Russian ArchivesYuri Gagarin was the first person to boldly leave the bonds of Earth’s gravity and thus became the first “Spaceman”. Gagarin blasted off inside the bell-shaped Vostok 1 spaceship from the launch pad at Baikonur at 9:07 a.m, Moscow time (607 UTC) to begin the era of human spaceflight.
Gagarin flew around the Earth in a single orbit at an altitude of 302 kilometers (187 miles). The flight lasted 108 minutes and safely ended when he descended back and parachuted to the ground, just north of the Caspian Sea. At the age of 27, Gagarin was instantly transformed into a worldwide hero. After the momentous flight he soon embarked on an international tour.
20 years later on April 12, 1981, NASA’s first space shuttle blasted off on the STS-1 mission on a daring test flight with astronauts John Young and Bob Crippen strapped inside Space Shuttle Columbia.
Russian postcard featuring Yuri Gagarin
The first “Yuri’s Night – World Space Party” was held on April 12, 2001 to commemorate the 40th anniversary of Gagarin’s spaceflight. Over 10,000 people attended 64 events located worldwide. The goal was to inspire people, increase awareness and support for space exploration across the globe and foster the spread of new ideas to broaden our access to space.
“Yuri’s Night” has been growing in popularity every year. Events range in size from a few folks to numbers in the thousands. Attendees range from astronauts and cosmonauts, NASA and global space agency officials and reps, scientists and engineers, famous actors, playwrights, writers, artists, athletes and musicians to just everyday folks and kids of all ages and backgrounds. Everyone can get involved.
Yuri Gagarin in orbitIn honor of the 50th anniversary of Gagarin’s flight, documentary film maker Christopher Riley conceived and created a film titled “First Orbit” to try and show the approximate view of Earth that Gagarin actually saw. There is only scant footage of Gagarin’s actual flight and he himself took no pictures of the Earth from orbit.
“First Orbit” recreates much of the view of the Earth’s surface that Gagarin would have seen fifty years ago. Mostly he flew over the world oceans as well as the Soviet Union and Africa.
Riley collaborated with the astronauts aboard the International Space Station, chiefly Paolo Nespoli of ESA, who took film footage from the new 7 windowed Cupola as the station matched the actual flight path of Gagarin and Vostok 1 as closely as possible. The free film celebrates 50 years of human spaceflight.
“First Orbit” premiers worldwide on YouTube in a special global streaming event for Yuri’s Night on April 12 . Watch the short trailer below, with original and stirring music by Philip Sheppard.
Orbital flight path of Yuri Gagarin and Vostok 1 on April 12, 1961
Gagarin’s call sign was Cedar or Kder - which means Siberian Pine in Russian. Map courtesy of Sven Grahn
It’s easy and free to register your local party at the Yuri’s Night event website. There is still time to register your Yuri’s Night party – Indeed the list has grown as I typed out this story !
Send Ken your “Yuri’s Night” event photos/short report to post in a round up story at Universe Today about the global festivities celebrating the historic achievement of Yuri Gagarin. Email kremerken at yahoo dot com
First Orbit Trailer II
Russian built Mini Research Module MRM-1 launched aboard US Space Shuttle Atlantis in May 2010.
Shuttle Atlantis delivered MRM-1 (known as Rassvet) to the International Space Station.
MRM-1 undergoes final prelaunch processing inside clean room at Astrotech Space Operations Facility in Florida. Docking port to ISS is protected by red colored covering. Equipment airlock for experiments at top. Russian Flag mounted at left.
Rassvet underscores the cooperation that exists today, in stark contrast to their rivalry during the Cold War. Russia, the United States, Europe, Japan and Canada have now united their space exploration efforts to build the International Space Station. The worlds space powers cooperate in other space exploration projects today as well that venture to the Moon, Mars and beyond to Deep Space. Credit: Ken Kremer
A new opportunity is available to students to have their experiments flown to the ISS. Credit: NAS
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Just a bit of a traffic jam at the International Space Station has prompted a 10-day delay of the targeted launch for space shuttle Endeavour’s 25th and final mission, STS-134. Originally scheduled for April 19, the shuttle launch is now scheduled for 3:47 p.m. EDT on Friday, April 29. The delay removes a scheduling conflict with a Russian Progress supply vehicle scheduled to launch April 27 and arrive at the station April 29. Current restrictions do not allow a Progress to dock to the station while a shuttle is there.
Meanwhile, A Russian Soyuz spacecraft emblazoned with Yuri Gagarin’s face and name is scheduled to liftoff today (Monday, April 4, 2011) at 6:18:20 p.m. EDT (22:19 GMT) from the Baikonur Cosmodrome in Kazakhstan, bringing two cosmonauts and one astronaut to the ISS to round out the current Expedition 27 crew, returning the crew size to 6. On board will be Soyuz commander Alexander Samokutyaev, flight engineer Andrey Borisenko and NASA astronaut Ron Garan.
The Soyuz will launch from the same launch pad used by Yuri Gagarin when he became the first human in space 50 years ago on April 12, 1961. The Russian Space Agency is dedicating this launch of the Soyuz TMA-21 spacecraft to the anniversary. You can watch the launch on NASA TV.
NASA managers will hold a Flight Readiness Review on Tuesday, April 19 to make sure everything is go for the April 29 launch date for STS-134. The primary goals of Endeavour’s mission are to deliver critical supplies and equipment to the International Space Station, along with a $2 billion Alpha Magnetic Spectrometer, a particle physics experiment. Four spacewalks also are planned to carry out needed maintenance on the orbiting lab complex.
The shuttle launch is already generating a lot of interest – not only because it is Endeavour’s final flight, but also because Commander Mark Kelly’s wife, Congresswoman Gabriel Giffords, is hoping to be present at Kennedy Space Center for the liftoff. She was shot in the head in January of this year, but has recovered sufficiently to consider attending her husband’s final shuttle launch.
One other item of note: NASASpaceflight.com is reporting that a Soyuz flyaround is being considered again while the space shuttle is docked at the ISS. NASA had requested such a flyaround during the previous shuttle mission, STS-133, to be able to take images—both engineering and documentary – of the ISS with spacecraft from each of the partnering space agencies present. Japan’s HTV-2 has now departed, so if the flyaround is approved to take place during the STS-134 mission, that spacecraft would, of course, be missing from the family photo.
The ATV Johannes Kepler docked at the International Space Station. Credit: NASA
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ESA’s Automated Transfer Vehicle Johannes Kepler is more than just a cargo carrier for the International Space Station, it is also an on-orbit refueling station and orbit booster. On May 17-19, 2011 the Kepler ATV is scheduled to conduct its first refueling of the ISS, as it will transfer about 850.6 liters (225 gallons) of propellant for the station’s own thrusters for future boosts in orbit.
Preparations for the ISS refueling began on March 22 with a leak test of the propellant transfer lines, to ensure the connections between the ISS and ATV-2 were completely sealed; the test was a success, meaning that as of now, everything is go for the station’s refueling.
The Johannes Kepler ATV-2 approaches the International Space Station. Docking of the two spacecraft occurred on Feb. 24, 2011. Credit: NASA
In mid-March, the ATV increased the ISS’s orbit with a 882-second (14 and a half minutes) burn, giving the ISS an extra push of about 2.1 m/s. In all, Kepler brought nearly 10,000 pounds (4,500 kilograms) of propellant that has been used by its thrusters to boost the space station to a new altitude of 400 kilometers (248 miles) above the Earth. This will be the new “normal” for the station’s orbit. Previously, the ISS orbited about 350 km (220 miles) up.
The main benefit of raising the station’s altitude is to cut the amount of fuel needed to keep it there by more than half. This also means that visiting vehicles will not be able to carry as much cargo as they could if they were launching to the station at a lower altitude since they will need more fuel to reach the station, but it also means that not as much of that cargo needs to be propellant.
The orbit of the ISS degrades because Earth’s atmosphere — though tenuous at those altitudes – expands and contracts through the Sun’s influence, and there are enough molecules that contact the surfaces of its large solar array panels, the large truss structure, and pressurized modules to change its speed, or velocity, which is about 28,000 kilometers an hour (17,500 mph).
At the ISS’s old altitude, the space station uses about 19,000 pounds of propellant a year to maintain a consistent orbit. At the new, slightly higher altitude, the station is expected to expend about 8,000 pounds of propellant a year. And that will translate to a significant amount of food, water, clothing, research instruments and samples, and spare parts that can be flown on the cargo vehicles that will keep the station operational until 2020 and beyond.
Kepler also sent a breath of fresh air to the station by transferring about 8kg of oxygen to the ISS in March, which was the first re-pressurization of the ISS’s internal atmosphere conducted by Kepler.
A view the space station as Discovery approaches for docking. Credit: NASA
