1.2163231-1900622061
The Ariane 5 rocket blasts off from the spaceport in Kourou, French Guiana early on Friday, carrying Al Yah 3 satellite. Image Credit: Twitter

Arianespace has confirmed early on Friday that the two satellites -- European-owned SES-14 and UAE's Al Yah-3 -- launched on an Arian 5 rocket are now on orbit and continuing their missions following an initial loss of contact with the heavy-lift launch vehicle.

The rocket's liftoff took place on January 25, 2018, at 7.20 pm from French Guiana (2.20am UAE time on Friday, January 26, 2018).

The loss of contact was reported at about the 9th minute into the flight.

"A few seconds after ignition of the upper stage, the second tracking station located in Natal, Brazil, did not acquire the launcher telemetry. This lack of telemetry lasted throughout the rest of powered flight," Arianespace said in a statement early on Friday. 

Satellite on orbit

"Subsequently, both satellites were confirmed separated, acquired and they are on orbit. SES-14 and Al Yah 3 are communicating with their respective control centers. Both missions are continuing." 

Arianespace's chief executive reported that contact was lost with the Ariane 5 rocket. The "anomaly" was detected a few seconds after ignition of the rocket's upper stage.

Ariane 5, one of the world's most reliable satellite launchers, hasn't recorded a failure since 2002.

Stephane Israel, chief executive of Arianespace, the European consortium behind the Ariane launchers, reported the 'anomaly' during the mission designated Flight VA241. 

'Anomaly'

"Ladies and gentlemen, I come to give you some information because we have had an anomaly on this launch. Indeed, we lost contact with the launcher a few seconds after ignition of the upper stage."

"But as I said, we lost contact. Up to now, our customers do not have contact with the satellite. We need now some time to know if they have been separated, and where they are exactly, to better analyze the consequences of this anomaly."

"I want to present my deepest excuses to our customers, who have entrusted us one more time. We know that there is no launch with no risk. We know that launch is always difficult, and tonight Ariane 5 has had an anomaly, so let's take time now to better understand the situation of the satellites."

"Arianespace, in full transparency, will come back to you to provide you with some more information as soon as we have them. I apologize on behalf of Arianespace."

The website spaceflightnow.com, covering the event from the Guiana Space Centre and quoting updates from the Arianespace mission status, reported that despite the telemetry loss, the European rocket delivered the two payloads to orbit after an unexpected radio blackout raised worries. 

The two satellites are now reported to be on their Geostationary Transfer Orbit (GTO), a transfer orbit used to reach geosynchronous or geostationary orbit using high-thrust chemical engines.

The Ariane 5 rocket was launched from the European Space Centre in Kourou, French Guiana at 2.20am UAE time on Friday.

Here's an illustration of the sequence of double launch following what initially was a "flawless" flight early Friday. 

Ariane 5 is one of the world's best-performing satellite launchers. Between April 2003 and December 2017, it has flown 82 consecutive missions without failure. 

Part of a joint venture between Yahsat (owned by Mubadala Investment Company) and Orbital ATK, Al Yah 3 was launched from French Guiana, on the north-east of South America.

The satellite will provide broadband services to 60 per cent of Africa’s population and to more than 95 per cent of Brazil’s population, highlighting the significance of Al Yah 3.

First hybrid propulsion satellite

UAE's Al Yah 3 is a special spacecraft.

The manufacture of Al Yah 3, the first hybrid electric propulsion GEOStar-3 satellite completed by Orbital ATK, involved a project management team comprising Emirati engineers who have been based at Orbital ATK’s satellite manufacturing facility in Virginia, US.

Yahsat has already launched two satellites — Al Yah 1 in 2011 and Al Yah 2 in 2012 — with both satellites providing broadband and communication services to 140 countries in the Middle East, Africa, and Europe, among others.

Using Orbital’s powerful GEOStar-3 satellite platform, Al Yah 3 will deliver over 53 high-power Ka-Band user beams to provide high-speed data services for end-user applications as well as IP backhaul for telecommunications service providers.

Tracking, telemetry 

Three hours after liftoff, Arianespace issued a statement to announce both of the mission’s payloads achieved orbit. 

Question, however, lingered early Friday about the accuracy of the satellite deployments and officials did not confirm whether the satellites were located in their targeted elliptical “supersynchronous” orbits.

According the European space launcher, it turned out that none of the "downrange" tracking stations primed to receive telemetry from the Ariane 5 established contact with the rocket.

“A few seconds after ignition of the upper stage, the second tracking station located in Natal, Brazil, did not acquire the launcher telemetry,” the company said. “This lack of telemetry lasted throughout the rest of powered flight.

“Subsequently, both satellites were confirmed separated, acquired and they are on orbit. SES 14 and Al Yah 3 are communicating with their respective control centers. Both missions are continuing.”

The Ariane 5’s computer aimed to deploy SES 14 and Al Yah 3 in a “supersynchronous” transfer orbit.

The far point of the Ariane 5’s intended drop-off orbit was more than 9,000 kilometers above the altitude typically targeted on an Ariane 5 launch carrying a commercial geostationary satellite.

The choice of “supersynchronous” transfer orbit, officials explained, is aimed to reduce the time and fuel burn for the satellites to reach their designated "parking" slots in space.

 

GLOSSARY:

Geostationary Earth Orbit  

A geostationary equatorial orbit (GEO) is a circular geosynchronous orbit in the plane of the Earth's equator with a radius of approximately 42,164 km (measured from the center of the Earth). A satellite in such an orbit is at an altitude of approximately 35,786 km (22,236 mi) above mean sea level. Satellites are parked near the equator. Due to the delicate balance between the distance and gravity, they stay at the same position relative to the earth for a long time. When they go off course, the satellites' on-board thrusters are fired to correct their position. 

Geosynchronous / geostationary transfer orbit (GTO) 

A geosynchronous / geostationary transfer orbit (GTO) is an elliptical orbit, with an apogee (high point) of 35,784 kilometers, a perigee (low point) of a few hundred kilometres, and an inclination roughly equal to the latitude of the launch site, into which a spacecraft is initially placed before being moved to a geosynchronous or geostationary orbit.

1.2163231-254822621
Yahsat’s Al Yah 3 satellite being prepared for launch in Kourou, French Guiana. It is part of a joint venture between Yahsat — owned by Mubadala Investment Company — and Orbital ATK. Image Credit: Supplied
View gallery as list