Arianespace Launches First Pair of Fully Operational Galileo Satellites—ANOMALY UPDATE

Derived from a vehicle which has accomplished more than 1,800 launches since the mid-1960s, the Soyuz vehicle is one of the world's most reliable rockets. Photo Credit: Arianespace
Derived from a vehicle which has accomplished more than 1,800 launches since the mid-1960s, the Soyuz vehicle is one of the world’s most reliable rockets. Photo Credit: Arianespace

Following a 24-hour postponement, caused by poor weather conditions in the vicinity of the Guiana Space Centre in Kourou, French Guiana, Arianespace has launched its ninth Soyuz vehicle on a historic mission to deliver the first pair of Galileo Full Operational Capability (FOC-1) navigational satellites into orbit. Liftoff took place at 9:27:11 a.m. GFT (8:27:11 a.m. EDT) Friday, 22 August, from the Ensemble de Lancement Soyouz (ELS) zone, close to the French Guianese coastal town and commune of Sinnamary. All aspects of the ascent phase ran smoothly and the Galileo twins—named “Doresa” and “Milena,” in honor of German and Estonian children, who won a 2011 European Commission art competition—were deployed into orbit a little under four hours later. However, it subsequently became clear that “complementary observations” made after the separation of the satellites highlighted “a discrepancy between targeted and reached orbit.” Based upon U.S. Space Surveillance tracking data, Spaceflight101 described the discrepancy as “significant.” Investigations are currently underway as to the impact this anomaly will have on the long-awaited mission.

As described in AmericaSpace’s Galileo FOC-1 preview article, the launch was originally scheduled to take place yesterday morning (Thursday, 21 August), with backup opportunities on Friday and Saturday. In anticipation of the opening attempt at 9:31:14 a.m. GFT (8:31:14 a.m. EDT), the three-stage Soyuz rocket and its Fregat upper stage were transferred in a horizontal configuration from the assembly building to the ELS launch zone on Monday, 18 August, and raised to the vertical. The payload fairing—known as the “upper composite,” housing the satellites on opposite faces of a two-sided dispenser—was installed atop the stack the next day.

Whilst engineers, technicians, and managers geared up for the launch, Arianespace and the European Space Agency (ESA)—acting on behalf of the European Commission, which has funded the Galileo program—convened at the Guiana Space Centre on Wednesday, 20 August, to sign a contract for three launch services with the Ariane 5 heavy-lift booster to continue the delivery of what will eventually be a 30-satellite Galileo constellation by 2019. Under the language of this contract, a total of 12 Galileo FOC satellites will be lofted by the Ariane 5 alone from 2015 onward. “With its Ariane 5 ES heavy-lift launch vehicle, Arianespace is able to provide the most appropriate solution for stepping up the deployment of the entire Galileo constellation,” said Arianespace Chairman and CEO Stéphane Israël. “Ariane has once again demonstrated its excellence as it lends its expertise to Europe’s ambitions in space. With the three Ariane, Vega and Soyuz launch vehicles operated from the Guiana Space Centre, European spaceport, Arianespace is giving Europe guaranteed access to space and suitable solutions to meet its wide-ranging needs.”

Attached to their Swedish-built payload dispenser, the Galileo FOC-1 twins are prepared for launch. Photo Credit: Arianespace
Attached to their Swedish-built payload dispenser, the Galileo FOC-1 twins are prepared for launch. Photo Credit: Arianespace

At length, weather conditions proved unacceptable to fly Thursday, 21 August, and a 24-hour scrub was called at about 5 a.m. GFT (4 a.m. EDT), some three hours ahead of the planned launch time. Shortly afterwards, Arianespace announced that a second attempt would be made at 9:27:11 a.m. GFT (8:27:11 a.m. EDT) Friday, 22 August.

About an hour before the opening of Friday’s launch window, the Soyuz-Fregat booster was fully fueled and the mobile gantry was retracted to a distance of about 330 feet (100 meters) to expose the stack to the elements. Similar in design to the vehicles which, four times yearly, rocket crews of astronauts and cosmonauts toward the International Space Station (ISS), the Soyuz boasted three main stages. Its central “core,” fed by a single RD-108A engine, was surrounded by four tapering boosters, themselves powered by RD-107A engines. All three were fueled by a mixture of liquid oxygen and a highly refined form of rocket-grade kerosene, known as “RP-1.” Meanwhile, the second stage was linked to its lower counterpart by means of a lattice-like framework. Its single RD-0110 engine was timed to ignite a couple of seconds after the separation of the first stage. Finally, the Fregat upper stage—capable of restarting up to 20 times in flight, but slated for just two discrete “burns” on the Galileo FOC-1 mission—was powered by the storable propellants unsymmetrical dimethyl hydrazine and nitrogen tetroxide.

At 9:22 a.m. GFT (8:22 a.m. EDT), with five minutes remaining before liftoff, the Launch Key—an actual, physical key, needed to transfer control to the Soyuz systems, activate ground and vehicle telemetry and allow the final stages of the countdown to proceed—was inserted. Nitrogen purging to remove contaminants from the fuel lines and engine combustion chambers followed, and at 9:24 a.m. GFT (8:24 a.m. EDT), as planned, umbilical connections were severed between the payload and the ground control system. All fuel tanks were verified at Flight Pressure and the final topping-off of cryogens was terminated. Sixty seconds later, the Soyuz-Fregat transitioned to internal power and the autosequencer was initiated, commanding all vehicle critical functions through liftoff.

Ignition of the first stage commenced at T-17 seconds, building up to full power by T-3 seconds. After final umbilical disconnections and confirmation that turbopumps were running at full speed and all engines—including those of the tapering boosters—were functioning normally, the vehicle was released from the ELS and committed to flight at 9:27:11 a.m. GFT (8:27:11 a.m. EDT). Shortly after clearing the tower, the Soyuz-Fregat executed a combined pitch, roll, and yaw program maneuver to establish itself onto the proper flight azimuth for the injection of the two Galileo FOC-1 satellites into orbit.

Rising rapidly, it passed 1,100 mph (1,770 km/h) within a minute of leaving Kourou. At T+118 seconds, at an altitude of about 28 miles (45 km), the four tapering boosters exhausted their supply of propellant and were jettisoned, leaving the central core and its single engine to continue second-stage flight. By two minutes into the ascent, the rocket was traveling in excess of 3,350 mph (5,390 km/h). The bulbous payload fairing was discarded at three minutes and 29 seconds, and, by five minutes, the central core was exhausted and jettisoned. At this point, the vehicle was 105 miles (170 km) high and the time came for the ignition of the third stage’s RD-0110 engine. This served to boost the stack to a velocity of more than 13,420 mph (21,600 km/h), and by the time the third stage separated, about nine minutes and 23 seconds after launch, the Galileo FOC-1 payload was in space and primed for its two orbit-insertion Fregat burns.

The Soyuz-Fregat booster delivered the first pair of Galileo Full Operational Capability (FOC-1) satellites into a medium Earth orbit. Photo Credit: Arianespace
The Soyuz-Fregat booster delivered the first pair of Galileo Full Operational Capability (FOC-1) satellites into a medium Earth orbit. Photo Credit: Arianespace

Sixty seconds after the third stage was discarded, the Fregat was lit for the first time, burning for 13 minutes and eight seconds. It then fell silent for a lengthy ballistic “coasting” phase of about 3.5 hours, ahead of a second burn, which commenced at 1:06 p.m. GFT (12:06 p.m. EDT), some three hours and 39 minutes after launch. This firing lasted a little less than five minutes, preparatory to the release of the two Galileo FOC-1 satellites from their opposing sides of the Swedish-built payload dispenser. “It will deploy the spacecraft … by firing a pyrotechnic separation system,” explained Arianespace, “to release them in opposite directions at the orbital insertion point.” Deployment into an orbit inclined 55.040 degrees to the equator occurred at T+3 hours, 47 minutes, and 57 seconds. The target orbit was about 14,600 miles (23,520 km) circular. However, according to Spaceflight101, the actual values for the insertion orbit were around 8,500 miles (13,700 km) x 16,100 miles (25,900 km), at an inclination of 49.7 degrees. It remains unclear what impact this will have on the unfolding mission.

Assuming the orbit-insertion anomaly can be resolved, the deployment sets the stage for an extensive period of orbital checkout of the twins, which represent the fifth and sixth members of the Galileo constellation, following the launch of four In-Orbit Validation (IOV) satellites in October 2011 and October 2012. “On completion of the initial checks, run jointly by ESA and the French space agency, CNES, the two satellites will be handed over to the Galileo Control Centre in Oberpfaffenhofen, Germany, and the Galileo In-Orbit Testing Facility in Redu, Belgium, for testing, before they are commissioned for operational service in the autumn,” noted Arianespace in the aftermath of the mission.

Labeled “Europe’s answer to GPS,” the Galileo FOC constellation is anticipated to be completed by Soyuz-Fregat and Ariane 5 boosters by 2019. Preparations for the delivery of the constellation got underway in December 2005, when the first Galileo In-Orbit Validation Element (GIOVE-A) was launched into a 14,600-mile (23,520-km) orbit atop a Soyuz-Fregat from the Baikonur Cosmodrome in Kazakhstan. It was joined by a second satellite, GIOVE-B, lofted atop a Soyuz-Fregat from Baikonur in April 2008. “Giove” is the Italian word for Jupiter and recognizes the great Italian scientist Galileo Galilei (1564-1642), who telescopically discovered the giant planet’s four major satellites and for whom the Galileo network is named. Both GIOVE satellites were designed to ensure that the eventual Galileo FOC constellation could meet the frequency-filling allocation and reservation requirements of the International Telecommunications Union (ITU).

Successful operations with the GIOVE twins was followed by two Soyuz-Fregat missions from Kourou in October 2011 and October 2012 to launch two pairs of Galileo In-Orbit Validation (IOV) satellites. The establishment of these four satellites allowed for a full, end-to-end evaluation of their capabilities and for the first three-dimensional positioning “fixes” to be made. On 12 March 2013, it was announced by the European Commission that the first ground-based position relying only upon Galileo signals had been determined at ESA’s Navigation Laboratory, within the European Space Research and Technology Centre (ESTEC) at Noordwijk, The Netherlands. With only four satellites, of course, this early part of the constellation is visible at the same time for a maximum of only 2-3 hours per day. However, this frequency will significantly expand as members of the Galileo FOC network are delivered into orbit. Following today’s launch of the FOC-1 satellites, a second pair (FOC-2) will be lofted atop a Soyuz-Fregat from Kourou in November 2014.

Crated in separate containers, the Galileo FOC-1 twins arrive in French Guiana on 7 May 2014. Photo Credit: Arianespace
Crated in separate containers, the Galileo FOC-1 twins arrive in French Guiana on 7 May 2014. Photo Credit: Arianespace

When fully deployed, the Galileo FOC network—commanded from ground stations near Munich, Germany, and Fucino, Italy—will comprise 27 active satellites and three on-orbit “spares,” distributed along three circular medium Earth orbit planes at an altitude of 14,600 miles (23,520 km), inclined at about 56 degrees to the equator. These will eventually enable a wide range of pan-European applications, including in-car navigation, high-precision farming, transportation, emergency intervention, and civil protection, with far higher-precision signals than previously attainable. In fact, Galileo is expected to provide horizontal and vertical position measurements within 3.3 feet (1 meter) and far better geolocation and positioning services at high latitudes than other systems, such as the United States’ GPS and Russia’s GLONASS. Early in 2014, GPS Daily reported that Galileo’s search and rescue functionality carried the potential to pinpoint 77 percent of simulated distress locations within 1.2 miles (2 km) and 95 percent within 3.1 miles (5 km).

Built by OHB System in Germany, and with their navigational payloads supplied by Surrey Satellite Technology, Ltd., in the United Kingdom, the Doresa and Milena Galileo FOC-1 satellites each weigh about 1,600 pounds (730 kg). They measure 8.2 feet (2.5 meters) long by 4 feet (1.2 meters) wide and boast a total wingspan of 48.2 feet (14.7 meters) across the breadth of their electricity-generating solar arrays. The latter are capable of generating 1.4 kilowatts of power to keep the satellites operational for up to 12 years.

Each of the Galileo satellites is named for a child winner of a 2011 European Commission painting competition. Under the rules of this competition, the applicants had to have been born at some point during 2000-2002, when the Galileo program was inaugurated, and were required to submit a drawing related to space or aeronautics. The order in which the names of the children were assigned to each satellite were determined by the alphabetical order of the European member-states, written in their national languages, beginning with Belgium and concluding with the United Kingdom. The four IOV missions, launched in 2011 and 2012, honored children from Belgium, Bulgaria, the Czech Republic, and Denmark, whilst Doresa and Milena are from Germany and Estonia. The FOC-2 pair of satellites, to be lofted in November 2014, are named “Adam” and “Anastasia,” for children from the Republic of Ireland (Eire) and Greece.

Designated Soyuz Flight VS09, Friday’s launch was the ninth Arianespace mission with the Russian-built rocket from French Guiana since its debut—which carried the first pair of Galileo IOV satellites—back in October 2011. Since then, the rocket has also transported two European Pléiades civil/military Earth imaging satellites, two more Galileo IOV satellites, Chile’s Sistema Satelital para Observación de la Tierra (SSOT) remote-sensing satellite, four members of France’s Electronic Intelligence by Satellite (ELISA) spacecraft, eight O3B communications satellites, the Sentinel-1A Earth imaging satellite in April 2014, and last December’s long-awaited Gaia space observatory.


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One Comment

  1. Apparently something went wrong – the two satellites now appear to be stranded in an orbit that has a much lower perigee than what was intended. They may be write-offs.

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