SpaceX launched Qatar’s Es’hail-2 spacecraft Thursday, using a Falcon 9 rocket to place the communications satellite into orbit. Falcon lifted off from Florida’s Kennedy Space Center at the start of a 101-minute window that opened at 15:46 Eastern Time (20:46 UTC). Thursday’s mission used a flight-proven Falcon 9 booster, making its second mission.
Thursday’s launch marked SpaceX’s first mission for the State of Qatar. The Japanese-built Es’hail-2 satellite will be operated by the state-owned Qatar Satellite Company, also known as Es’hailSat. Falcon 9 placed the Es’hail-2 into a geosynchronous transfer orbit, with the satellite expected to then reach its final slot in geostationary orbit under its own power.
Es’hail-2 is the first dedicated Qatari satellite from launch. The Middle-Eastern state’s existing Es’hail-1 satellite was launched as a joint-venture between Es’hailSat and French telecommunications operator Eutelsat, with the Qataris buying-out their partners earlier this year. Es’hail-1, which was formerly also known as Eutelsat 25B, was deployed by a European Ariane 5ECA rocket in August 2013. Stationed at 25 degrees East, the Es’hail-1 satellite was expected to operate for at least fifteen years from launch.
The Es’hail-2 satellite will be located close to Es’hail-1, taking up station at 26 degrees East. Carrying a payload of Ka and Ku-band transponders, the spacecraft will be used for broadcasting and secure communications to Very Small Aperture Terminal (VSAT) devices. Es’hail-2’s footprint gives it coverage of the Middle East and northern Africa.
As well as its commercial transponders, Es’hail-2 carries an amateur radio payload, AMSAT Phase 4A (AMSAT-P4A), which is being flown as a result of a partnership between Es’hailSat, the Qatar Amateur Radio Society (QARS) and Germany’s AMSAT-DL – part of the global amateur satellite radio community.
AMSAT-P4A consists of two transponders: a narrowband transponder for conventional analog communications and a second wideband transponder which will be used for digital communications including the first spaceborne Digital Amateur Television (DATV) beacon. Es’hail-2 will be the first geostationary satellite to carry an amateur radio relay.
Es’hail-2 was constructed by Japan’s Mitsubishi Electric Corporation (MELCO) and is based around the DS-2000 platform. The satellite has a mass of around 3,000 kilograms (6,600 lb) and is designed to operate for at least fifteen years. Twin solar arrays, which will be deployed on orbit, provide power to the spacecraft’s systems and transponders.
Es’hailSat selected American commercial launch provider SpaceX to place Es’hail-2 into orbit. Thursday’s launch took place from the Kennedy Space Center in Florida, using a Falcon 9 rocket. Falcon 9 first flew in 2010, and will be making its sixty-third launch on Thursday.
As well as serving the commercial launch market, Falcon 9 has been used to carry payloads for the US military and NASA – for the latter it has deployed both scientific satellites and cargo resupply missions to the International Space Station. From next year, Falcon 9 will begin launching astronauts to the space station aboard the crew version of SpaceX’s Dragon spacecraft.
The Falcon 9 rocket is designed to be, at least in part, reusable. While most rockets discard stages and other components after they have served their purpose for a single launch – typically by allowing them to fall into designated areas of the ocean or on land – Falcon’s first stage can fly back to Earth to be refurbished for future missions.
Depending on mission requirements, the first stage can either return to a landing pad at its launch site, or if it does not have enough fuel to return a landing platform – designated an Autonomous Spaceport Drone Ship (ASDS) can be positioned along its path to receive the booster.
Thursday’s launch made use of a booster that has already flown one mission: Core 1047 was the first stage of a rocket that deployed the Telstar 19V satellite in July, making a successful touchdown aboard the ASDS, named Of Course I Still Love You, after separating from that vehicle.
Following Thursday’s launch Core 1047 landed on Of Course I Still Love You, which departed Port Canaveral on Monday to be towed into position for the launch.
The Block 5 version of Falcon 9, which was introduced in May and is now being used for all launches, is the first that is capable of making more than two launches. Earlier boosters could only fly twice before either being retired, or simply not recovered after their second launch. However, Core 1047 can be expected to fly again with another payload in the future.
The Es’hail-2 launch was not expected to see an attempt by SpaceX to recover the rocket’s payload fairing. While recovery and re-use of the protective fairing, which encloses satellites during the early stages of launch through Earth’s atmosphere, is SpaceX’s next objective for reusability, the ships that have been supporting their testing are stationed on the West Coast so are not available for Thursday’s launch.
Es’hail-2 launched from Launch Complex 39A (LC-39A) at the Kennedy Space Center. This is the same launch pad from which many of the Apollo missions – including the first manned missions to orbit and land on the Moon – began.
Built in the 1960s, the first launch from LC-39A came in November 1967 with the maiden flight of the Saturn V rocket that would carry astronauts to the Moon. Twelve of the thirteen Saturn V launches took place from LC-39A – with only Apollo 10 flying from the backup launch pad at nearby LC-39B.
The Saturn V’s final launch in May 1973 used a modified two-stage version of the rocket to place Skylab, America’s first space station, into orbit.
With the end of the Apollo program, Launch Complex 39 became home to the Space Shuttle. LC-39A was the first pad to become operational, hosting the program’s first launch – Columbia’s STS-1 mission – in April 1981.
This was the first of eighty-two Shuttle launches from LC-39A, ending with the final Space Shuttle launch, Atlantis’ STS-135, which flew in June 2011. The rest of the Shuttle’s 135 missions were flown from LC-39B.
SpaceX and NASA agreed a twenty-year lease for the launch pad in 2014, under which SpaceX has modified the facility to accommodate their Falcon 9 and Falcon Heavy rockets.
Unlike Saturn and the Space Shuttle, which were assembled vertically atop a mobile launch platform and then moved to the launch pad, Falcon 9 uses horizontal integration in a new hangar that SpaceX has constructed at the base of the pad’s launch ramp.
In the hours leading up to launch, Falcon is rolled out to the launch pad and raised to the vertical with the aid or a transporter-erector-launcher (TEL) or Strongback – now officially cited as the “T/E” by SpaceX.
Thursday’s launch was the fifteenth that SpaceX has conducted from LC-39A – following thirteen previous Falcon 9 launches and February’s maiden flight of the Falcon Heavy. The pad was last used in May for the launch of Bangabandhu 1, with the downtime between launches being used to prepare the complex for future crewed Dragon missions.
Among other work completed this year, SpaceX has finished removing the Shuttle-era Rotating Service Structure (RSS) from the pad and installed a new crew access arm on its Fixed Service Structure (FSS).
LC-39A is one of two launch pads that SpaceX operates on Florida’s Space Coast, alongside Space Launch Complex 40 (SLC-40) at the nearby Cape Canaveral Air Force Station. A third Falcon 9 launch pad is located at Space Launch Complex 4E of California’s Vandenberg Air Force Base, serving missions to higher-inclination orbits.
Falcon 9 is a two-stage rocket which burns RP-1 kerosene propellant oxidized by liquid oxygen. SpaceX began fuelling the rocket about 35 minutes before its planned liftoff, a few minutes after the Launch Director had verified that all necessary conditions are met to proceed with the operation.
RP-1 was loaded into both stages of the rocket, and the first stage oxidizer tanks were filled with liquid oxygen. Loading of oxidizer onto the second stage did not begin for another nineteen minutes. About seven minutes before liftoff, liquid oxygen was pumped through the first stage engines, chilling them in preparation for startup.
The arms that secure Falcon 9 to its T/E opened about four and a quarter minutes before launch. Around thirty seconds later the strongback moved slightly away from the rocket – although it only moved to its fully-retracted position as Falcon lifted off.
In the final minute of the countdown, Falcon’s propellant tanks were pressurized for flight and the rocket’s onboard computers conducted their final checks. The Launch Director gave a final “go” for launch with about forty-five seconds to go, and the first stage’s nine Merlin-1D engines roared to life at the three-second mark in the count. Lifting-off at T-0, Falcon took 32 minutes and 29 seconds to deploy Es’hail-2 into geosynchronous transfer orbit.
The first major flight event came about sixty-six seconds after liftoff, when Falcon reached the area of maximum dynamic pressure, or Max-Q. This is the point at which the rocket experiences the greatest mechanical stress due to aerodynamic forces, which increase with the vehicle’s speed, but diminish as it climbs out of the denser lower regions of Earth’s atmosphere.
Falcon’s first stage – Core 1047 – powered the rocket for the first two minutes and 35 seconds of Thursday’s launch. Four seconds after cutoff the first and second stages separated. The second stage’s Merlin Vacuum (MVac) engine, a version of the Merlin-1D optimized to operate in the vacuum of space, ignited seven seconds later to continue the journey towards orbit. Sixty-one seconds into the second stage’s burn, the payload fairing separated from the nose of the rocket.
While Falcon’s second stage carried on towards orbit with Es’hail-2, Core 1047 reoriented itself for its return to Earth. Deploying grid fins to guide its descent, the stage coasted to the apogee, or highest point, of its trajectory and fall back towards Earth.
Three minutes and 36 seconds after separating, the stage briefly restarted a subset of its engines to slow itself as it reenters the atmosphere, limiting heating which could cause damage. Just over a minute and a half later the booster fired again to make its landing aboard Of Course I Still Love You. Touchdown occurred eight minutes and 16 seconds after liftoff.
About nine seconds before the first stage landed, the second stage ended its first burn and entered a coast phase. Second Stage Engine Cutoff 1 (SECO-1) came at eight minutes and seven seconds mission elapsed time, with Falcon in an initial low Earth parking orbit. The subsequent coast phase lasted for eighteen minutes and twenty-seven seconds. A second burn lasting fifty-five seconds raised Es’hail-2 into geosynchronous transfer orbit, with the satellite separating five minutes after the end of the second burn.
Thursday’s launch was the first for SpaceX in over a month – the company’s last launch carried Argentina’s SAOCOM-1A satellite to orbit from Vandenberg Air Force Base in early October. SpaceX has four further launches scheduled for 2018, with the next expected on Monday out of Vandenberg. This will carry the multi-satellite SSO-A payload.
East Coast launches planned for December will deploy Dragon’s CRS-16 resupply mission to the International Space Station and the first third-generation GPS navigation satellite for the US Air Force. Another West Coast launch will close the year, carrying ten Iridium-NEXT satellites to complete the initial deployment of the new Iridium constellation.