For the fifth time in 2014, Arianespace is readying one of its mammoth Ariane 5 boosters to deliver a heavyweight payload into orbit. Mission VA-220—the 76th flight by an Ariane 5 and the 220th overall flight by a member of Arianespace’s rocket family—is scheduled to roar aloft from the ELA-3 (Ensemble de Lancement Ariane) launch complex at the Guiana Space Centre in Kourou, French Guiana, on the evening of Thursday, 16 October. The launch “window” extends from 6:00 p.m. until 7:51 p.m. GFT (5:00 p.m. until 6:51 p.m. EDT), and VA-220 will deliver the Intelsat-30 (also known as “DLA-1,” for “DirecTV Latin America”) and ARSAT-1 communications satellites into geostationary orbit, at an altitude of approximately 22,000 miles (35,000 km). The latter will represent Argentina’s first geostationary communications satellite. Counting one Vega and three Soyuz launches, Thursday’s mission will represent the ninth overall flight by Arianespace in 2014.
Steps to prepare for VA-220 got underway earlier this year and were performed in tandem with the campaigns to launch the VA-219 Automated Transfer Vehicle (ATV)-5 and VA-218 Measat-3B and Optus-10 missions in July and September, respectively. In May 2014, the first hardware for the VA-220 launch vehicle arrived in French Guiana, aboard the MN Colibri seagoing vessel, and were unloaded at the Paricabo port for transportation by road to the Guiana Space Centre. The 100-foot-tall (30-meter) “cryotechnic main stage” of the Ariane 5 was removed from its protective shipping container and installed onto the operational launch table in the Launcher Integration Building (BIL). This was followed by the attachment of Ariane 5’s twin solid-fueled boosters, the cryogenic upper stage and the Vehicle Equipment Bay (VEB), which contains its computerized “brain.”
Early in September, the ARSAT-1 satellite was delivered by a charted An-124 cargo jetliner, touching down at Félix Eboué International Airport, near the French Guianese capital of Cayenne. This was followed by the Intelsat-30 (DLA-1) satellite, which arrived a week later, also via a chartered An-124. By the end of September, as fueling of the two satellites with attitude-control propellants concluded, the two-stage Ariane 5 vehicle was transferred from the BIL into the Final Assembly Building (BAF). As well as being a physical transfer, this operation marked the transfer of responsibility for the vehicle from prime contractor Airbus Defence & Space to Arianespace.
Both satellite cargoes were integrated with the booster last week, with Intelsat-30 riding the upper “deck” of the two-tiered Système de Lancement Double Ariane (SYLDA) payload dispenser and ARSAT-1 occupying the lower deck. The ogive-shaped payload fairing was then installed over the two satellites, ahead of the Launch Readiness Review on Tuesday, 14 October, and the scheduled rollout of the 171-foot-tall (52-meter) stack to the ELA-3 launch zone on Wednesday. Upon arrival at the pad, Arianespace engineers will set to work establishing electrical, fluid, and other connections with ground facilities.
The process of loading 260,000 pounds (118,000 kg) of liquid oxygen and 50,000 pounds (22,700 kg) of liquid hydrogen to power the French-built Vulcain-2 engine of the first stage are expected to get underway at T-4 hours and 50 minutes. The propellant tanks will be pressurized at T-4 minutes and the vehicle will transition to internal power. In the final seconds, systems aboard Ariane 5 will assume primary command of all critical functions and the guidance system will be unlocked to Flight Mode. The Vulcain-2 engine will roar to life at T-0, generating 300,000 pounds (136,000 kg) of thrust, although liftoff will not occur for another 7.5 seconds, as a series of computer-controlled health checks are undertaken. When all is verified to be well, the twin solid-fueled boosters—each punching out 1.4 million pounds (635,000 kg) of propulsive yield and together generating 92 percent of the thrust needed to get Ariane 5 off the pad—will ignite and VA-220 will be committed to its mission.
The vehicle will rise vertically for about five seconds, after which the VEB computers will initiate a combined pitch and roll program maneuver, actively rotating the stack onto a north-easterly trajectory and placing it onto the correct flight azimuth to insert its primary payloads into their required orbits. “It maintains an attitude that ensures the axis of the launcher remains parallel to its velocity vector,” noted Arianespace in its VA-220 launch kit, “in order to minimize aerodynamic loads throughout the entire atmospheric phase, until the solid boosters are jettisoned.” One minute after launch, the Ariane 5 will go supersonic and pass “Max Q,” the period of maximum aerodynamic stress on the airframe. The twin boosters will burn out and be jettisoned at T+143 seconds, parachuting into the Atlantic Ocean about 300 miles (480 km) east of Kourou. By this point, the vehicle will have attained a velocity in excess of 1,200 mph (1,900 km/h) and will continue to climb under the impulse of its Vulcain-2 engine.
Three and a half minutes into the flight, the payload shroud will be detached, exposing the Intelsat-30 and ARSAT-1 satellites to the space environment for the first time. Shutdown of the Vulcain-2 is expected about eight minutes and 56 seconds after liftoff, whereupon the cryotechnic main stage will be jettisoned and descend to a splashdown off the coast of Portugal. Meanwhile, the second stage—powered by a restartable, 6,100-pound-thrust (2,770 kg) Aestus engine—will ignite to pick up the baton for the final push into orbit. By now, the rocket will be over 105 miles (170 km) in altitude and traveling at more than 4,300 mph (6,900 km/h). Its progress during this period will be monitored by tracking stations at Ascension Island in the mid-Atlantic, Libreville in Gabon, and Malindi on the Indian Ocean coast of Kenya.
Fueled by unsymmetrical dimethyl hydrazine and nitrogen tetroxide, the Aestus will burn for about 15 minutes and 40 seconds, shutting down a little under 25 minutes after leaving the Guiana Space Centre. Upon orbital injection, the VA-220 stack will be achieved a velocity of about 20,926 mph (33,678 km/h) and an altitude of about 406.8 miles (654.7 km). With Intelsat-30 mounted in the upper deck of the SYLDA payload dispenser, it will be released first into space, at T+27 minutes and 52 seconds. The SYLDA will then separate about four minutes later, and ARSAT-1 will itself be released from the lower deck at T+33 minutes and 43 seconds. Following standard collision avoidance maneuvers, the VA-220 mission will end at T+44 minutes and 38 seconds.
Built by Space Systems/Loral (SS/L) of Palo Alto, Calif., and based upon its 1300 spacecraft “bus,” the 13,900-pound (6,300-kg) Intelsat-30 is the first of two satellites intended to provide high-power hybrid C-band and Ku-band services for direct-to-home television access across Latin America. The two satellites—also known as DLA-1 and DLA-2, for DirecTV Latin America—will be co-located with Intelsat’s Galaxy 3C satellite at 95 degrees West longitude, which has been operational since 2002. With 10 C-band transponders and 72 Ku-band transponders, Intelsat-30 will receive electrical power from two deployable solar arrays and is expected to remain functional for about 15 years. It represents the latest in a multi-generational line of communications satellites which stretch back to Intelsat-1, the world’s first commercial geostationary satellite, launched in April 1965.
Meanwhile, ARSAT-1 will provide Argentina with its own space-based telecommunications system for the first time. Home-built by the INVAP high-technology company, headquartered in San Carlos de Bariloche, with its communications payload fabricated by Thales Alenia Space, it was developed under the direction of the ARSAT national telecommunications organization. This will be the first occasion that a mission of this type has been controlled from a Latin American country. Equipped with 24 Ku-band transponders, ARSAT-1 will offer coverage of Argentina and its neighbors—including Chile, Bolivia, Uruguay, and Paraguay—with direct-to-home television, Internet access, data transmission, and IP telephony. The 6,400-pound (2,900-kg) satellite will operate from 72 degrees West longitude for up to 15 years.
Mission VA-220 marks the 76th flight by an Ariane 5, which first flew in June 1996, and the 220th overall flight by a member of Arianespace’s rocket family, since the maiden voyage of the Ariane 1 in December 1979. To date, it has proven an exceptionally reliable vehicle, having enjoyed 71 wholly successful missions. Only two have failed outright and two others have been classified as partial failures. On its very first launch, it succumbed to a control software malfunction, which caused it to veer from its intended trajectory and the Flight Termination System (FTS) remotely destroyed the rocket. Its second launch in October 1997 fared little better, suffering a premature shutdown of its core stage and failing to achieve orbit. Two others, in July 2001 and December 2002, also underperformed, but the Ariane 5 has since maintained an unblemished record.
Thursday’s launch of Intelsat-30 and ARSAT-1 will be the fifth Ariane 5 mission of 2014, coming on the heels of VA-217 in February, which delivered the Athena-Fidus and ABS-2 satellites; VA-216 in March, which lofted Astra 5B and Amazonas 4A; VA-219 in July, which delivered the fifth and final Automated Transfer Vehicle (ATV-5) toward the International Space Station (ISS); and VA-218 in September, which boosted Measat-3B and Optus-10 into orbit. Putting this into context, the maximum number of Ariane 5 vehicles launched in a single calendar year has been seven, achieved in 2009 and 2012, with most other years averaging between four and six. However, when one counts Arianespace’s two other operational rocket families, the Soyuz has completed three missions—including the delivery of Europe’s Sentinel-1A radar-imaging satellite in April and the ill-fated Galileo Full Operational Capability (FOC)-1 satellite in August—and the Vega has completed one. This will give Arianespace a tally of nine launches to date in 2014 at the conclusion of VA-220.