Europe’s Automated Transfer Vehicle (ATV-5, the Georges Lemaître) departed from the International Space Station (ISS) on Saturday morning, ahead of a destructive re-entry that was conduted on Sunday. The End Of Mission (EOM) events concluded the final ISS mission for the European cargo ship, although its spirit will live on with NASA’s Orion spacecraft program.
The ATV-5 was launched on July 29, 2014 – atop an Ariane ES booster from the Kourou spaceport in French Guiana. ATV-5 proved to be the heaviest passenger ever to ride on the Ariane rocket.
Ahead of its arrival, it flew under the Station to demonstrate new laser and infrared imaging technology that will help future spacecraft to rendezvous with uncontrolled objects.
After 14 days on orbit, ATV-5 docked with the ISS, delivering a large load of both internal (dry) and propellant (wet) cargo.
(ATV Docking Animation created from 70 hi res images acquired by L2 – LINK).
The pressurized Integrated Cargo Carrier (ICC) section lofted 2,600kg of cargo – including food, crew provisions, and scientific hardware – uphill to the orbital outpost.
The Service Module (SM) manifest included 570kg of water, 100kg of gas (air and oxygen), 2,230kg of propellants available for ISS reboosts, and 860kg of propellants for transfer to the Russian Segment (RS).
The European vehicle enjoyed a successful stay at ISS, which included shoving the Station out of the path of a piece of space debris.
The Pre-Determined Debris Avoidance Maneuver (PDAM), conducted in November, was required after a tracked object – possibly a lens cap/cover – from the Chinese spy satellite, Yaogan 12, became a “repeating conjunction concern” for the orbital outpost.
All integrated operations with the Station proceeded to plan, including the final task of re-loading trash into the ATV, which will be burnt up along with the vehicle during its destructive re-entry.
ESA astronaut Samantha Cristoforetti, working with Russian cosmonaut Sasha Samokutyaev, were the last humans to see the inside of the vehicle, as they completed their operations with the closing of the hatches between the two spacecraft on Friday.
Following its undocking, at 13:42 UTC on Saturday, ATV-5 conducted its pre-planned departure burn, ahead the plunge into Earth’s atmosphere.
The re-entry occurred on Sunday, which was a change to the previous plan.
ATV-5 was set to enter the atmosphere at the end of February, via what is known as a “shallow dive”. This would have allowed NASA and ESA teams to learn more about how the vehicle eventually succumbs to the destructive forces of diving through Earth’s atmosphere.
The decision to cancel the shallow entry option was taken due to the loss of one of the four power chains on the vehicle, resulting in the vehicle’s death plunge being moved up to Sunday.
“The ATV team has worked tirelessly for five missions in a row,” ATV-5 mission manager Massimo Cislaghi noted.
“While teams are sincerely disappointed not to conduct the planned shallow reentry, the revised plan doesn’t alter the program’s overall success.”
Because of this, the ReEntry Breakup Recorder (REBR) – a spacecraft “black box” designed to gather data on vehicle disintegration during re-entry in order to improve future spacecraft re-entry models, was removed from the ATV-5 and stored on the Station.
NASA is to utilize the saved REBR-W for use in a future re-entry, potentially on a Cygnus vehicle.
ESA note two entry monitoring experiments remained on board and were expected to send some information of the demise back to controllers in Toulouse, France.
In preparation for ATV’s impending demise, the first de-orbit maneuver, called DEO-1, lasted nearly 14 minutes.
Following initiation of a tumble, ATV-5 then gradually began to feel the increasing effects of Earth’s atmosphere.
As temperatures rise and stresses increase, the four X-shaped solar arrays will be ripped off, before the forces eventually rupture the pressure vessel and propellant tanks, leading to vehicle disintegration – ultimately marking the conclusion to the ATV-5 mission.
Any surviving debris from re-entry will fall harmlessly into the Pacific Ocean.
Although the ATV missions to the ISS are now coming to a close, key design elements will be re-purposed, becoming the bulk of the Service Module for NASA’s new crewed spacecraft, the Orion.
Debuting with the Exploration Mission -1 (EM-1) flight in 2018, the use of ATV hardware as part of the Service Module is expected to become a long-term deal between ESA and NASA.
Officials on both sides of the Atlantic have noted the arrangement is expected to become permanent throughout NASA’s Orion roadmap.
“It is with a feeling of pride that we look back at our accomplishments on the ATV program,” noted Thomas Reiter, Director of Human Spaceflight and Operations .
“We look forward to applying the experience and knowledge we gained from designing, building and operating five ATV spacecraft with excellent results to future exploration missions using the successor European Service Module of the Orion vehicle.”
(Images: L2’s ISS and ATV sections, plus ESA and NASA).
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