Europe's last cargo freighter blasts off from Kourou
BY STEPHEN CLARK
Posted: July 29, 2014
KOUROU, French Guiana -- The last of Europe's automated cargo freighters blasted off from a South American spaceport Tuesday, soaring into orbit in pursuit of the International Space Station with 7.3 tons of fuel, food and supplies.
As the countdown clock reached zero, the Ariane 5's Vulcain 2 core engine ignited. Following a computer-controlled health check, the rocket's twin strap-on boosters lit and the Ariane 5 moved skyward.
The 16-story launcher raced into the night over French Guiana, lighting up the space center in an orange glow as the rumble of the rocket reached spectators and villagers miles away.
The Ariane 5 surpassed the speed of sound in 48 seconds, then let go of two large solid-fueled boosters about 2 minutes, 24 seconds into the flight. The hydrogen-fueled Vulcain 2 engine continued firing for 9 minutes before emptying its propellant tanks.
A nearly cloud-free sky afforded dazzling views of the launch as the rocket dimmed before finally disappearing as it flew hundreds of miles northeast of the space base.
The Ariane 5's main engine gave way to an upper stage Aestus engine for two burns to put the ATV into a circular orbit approximately 161 miles above Earth.
The launcher released the supply ship at 0051 GMT (8:51 p.m. EDT), and the craft extended four solar array wings to begin generating power. A communications antenna boom also deployed as planned, according to the European Space Agency.
Arianespace, the Ariane 5's commercial operator, declared the launch a success.
The ATV cargo carrier, named for the Belgian priest and physicist Georges Lemaitre behind the Big Bang theory, is set for docking to the International Space Station's Zvezda service module Aug. 12.
"Sixty consecutive successful launches for Ariane 5," said Stephane Israel, chairman and CEO of Arianespace. "Georges Lemaitre is on its way to the ISS."
The spacecraft weighed more than 20 tons at launch, making it the largest in the fleet of international resupply vehicles servicing the space station.
But Tuesday's launch marked the last flight of the ATV, which is being phased out in favor of U.S.-built commercial cargo craft and Japan's resupply freighter -- called the H-2 Transfer Vehicle.
"The last of the litter is now in orbit," said Jean-Jacques Dordain, ESA's director general.
"Georges Lemaitre is the last ATV, six years after the launch of the first, which was in March 2008," Dordain said. "Six years have gone by in the meantime, but the ATV is, and will remain for a long time to come, a unique space vehicle. It's the most complex vehicle that ESA and European industry have ever developed and produced. It's both a launcher and a satellite. It's both automatic and man-rated. It's capable of unparalleled accuracy and controlled atmospheric re-entry."
The U.S. and Japanese vehicles can carry up larger experiments than the ATV, which attaches to the Russian segment of the space station with a smaller passageway than NASA's modules.
Russia's Progress spacecraft delivers propellant, but in smaller quantities than the ATV.
But the ATV is the only cargo craft to do it all.
With the arrival of the Georges Lemaitre spacecraft, Europe's five ATVs will have delivered 31,446 kilograms, or 69,327 pounds, of cargo, fuel, water and air to the space station, according to Thomas Reiter, head of ESA's human exploration and operations directorate.
"The first studies started in the 1980s, so we are 25-to-30 years down the road, and there is a lot of energy, motivation, and competencies in ATV," said Bart Reijnen, head of orbital systems and space exploration at Airbus Defence and Space, lead contractor for the cargo spacecraft. "For all the teams that have been working over such a long time period, it's not easy to say farewell to ATV. You can be sure about that."
The cargo complement includes 1,896 pounds of propellant to be pumped inside the Russian Zvezda service module, 1,858 of fresh water, 220 pounds of air and pure oxygen, and about 5,941 pounds of dry cargo.
Cargo items include coffee, soy sauce and supplies for a Japanese experiment on fish.
The complexity of the ATV was unmatched in the European space industry when ESA started the program. Cargo deliveries by the European supply ships help pay ESA's share of the space station's common operating costs through a barter arrangement with NASA.
"It's one million lines of code, just to give you idea, because it's very complex to have an automatic docking," said Eric Beranger, head of space programs at Airbus Defence and Space. "You need to anticipate all possible mishaps using sensors, and yet be able not to lose track of your target and be able to dock. This software onboard ATV is able to dock with a precision within 6 centimeters (2.4 inches). It gives you an idea at 28,000 kilometers per hour (17,400 mph). On top of that, this ATV will be the heaviest ever launched -- more than 20 [metric] tons."
The fluids and air will be transferred into tanks on the space station's Russian segment, while astronauts and cosmonauts aboard the research lab will unpack the dry cargo, which includes experimental hardware for European, Japanese and U.S. investigations ongoing inside the outpost.
The European cargo craft can also boost the space station's orbit and maneuver the huge complex out of the way of space junk during its mission.
The largest piece of hardware aboard ATV 5 is an electromagnetic levitator for ESA's Material Science Laboratory inside the Columbus module. The device will melt down metallic samples for research in material thermodynamics, according to ESA.
Officials decided to stop building ATVs, opting to focus on a new development using the spacecraft's technologies to keep European engineering teams sharp.
After considering a cargo return vehicle and an orbital cleanup spaceship to clear space debris from orbit, ESA member states agreed in November 2012 to build a service module for NASA's Orion crew capsule, a U.S.-led program to send astronauts on missions to deep space destinations, such as asteroids, the moon and Mars.
The agreement covers the construction of a service module for an unmanned test flight of the Orion spacecraft around the moon set for launch no earlier than late 2017. Based on technologies and components developed for the ATV, the service module supplies propulsion and power for the Orion capsule.
"I think in this way we can nicely demonstrate that all the effort we have taken to build such a fantastic vehicle to do this fantastic cargo transfer and automated docking ... is not lost, but it's built upon for future activities," said Thomas Reiter, a former astronaut and director of ESA's space exploration programs.
Negotiations have not started for European construction of service modules for later Orion missions, including crewed flights.
Beranger called the final ATV mission "both an au revoir and the beginning of a new adventure."
If all goes according to plan, the ATV will reach the vicinity of the space station Aug. 8 for a mock rendezvous. The cargo freighter will pass about 5 miles underneath the space station to test the capabilities of a new infrared navigation camera that could guide future missions in space.
The ATV's primary rendezvous sensors, a suite of telegoniometers and videometers, have guided the supply ships to four dockings with the space station with help from a GPS navigation system for long-range tracking.
The optical guidance system fires lasers on final approach to the space station, bouncing the light off of specially-located reflectors mounted on the aft end of the outpost's Zvezda service module.
The Laser Infrared Imaging Sensors, or LIRIS, carried on the ATV do not require the reflectors, enabling future missions to rendezvous with nearly any object in orbit.
ESA's ATV contractor Airbus Defence and Space, along with Sodern and Jena-Optronik, proposed flying the new laser and infrared sensors on the ATV 5 mission. The infrared camera was provided by French company Sodern, with German-based Jena-Optronik supplying the laser lidar, according to ESA.
"The purpose is to validate, in a real operational environment, these partially new technologies that might be used in the future," said Massimo Cislaghi, ESA's ATV 5 mission manager. "We don't have a real application yet, but they might be used in the future for rendezvous and docking with non-cooperative targets. It's a little bit like science fiction, but the typical example is the retrieval of a spacecraft out of control before it becomes a danger for re-entry or debris."
The "fly-under" maneuver to test the infrared camera is set for Aug. 8, and the laser lidar sensor will be tested during the ATV's final approach on docking day.
At the end of the mission, currently scheduled for January or February, the ATV will undock from the space station's Zvezda service module with trash and waste. Like the previous European cargo ships, the ATV 5 mission will plunge back into the atmosphere, destroying itself and the garbage inside, clearing precious room on the space station for fresh experiments and cargo.
But NASA and ESA officials have devised a plan to change the re-entry trajectory to collect data on how the ATV responds when it falls into the atmosphere, helping engineers validate computer models to predict how the space station will re-enter at the end of its mission as a crewed orbiting research laboratory.
Pending final approval from safety officials, the shallow re-entry profile would occur over the uninhabited South Pacific Ocean.
The ATV also carries an internal camera to record and transmit imagery of the re-entry from inside the spaceship's pressurized module.
Follow Stephen Clark on Twitter: @StephenClark1.