‘Flight-proven’ Falcon 9 set to launch SES-10 satellite
CAPE CANAVERAL, Fla. — SpaceX is about to fly a milestone mission with the first launch of a “flight-proven” Falcon 9 rocket. After a successful static fire test, the company is targeting a liftoff at the opening of a 2.5-hour window at 6:27 p.m. EDT (22:27 GMT) Thursday, March 30, 2017.
This flight will send the SES-10 communications satellite into a geostationary transfer orbit (GTO) from Kennedy Space Center’s Launch Complex 39A. It will be the third time SES, a Luxembourg-based company, has entrusted SpaceX to send one of its spacecraft to orbit. In fact, the SES-8 mission in December 2013 was the first commercial satellite launched by a Falcon 9.
For the SES-10 mission, the 45th Weather Squadron has predicted the weather will only have a 30 percent chance of violating launch constraints with the primary concern being cumulus and thick clouds. However, if the launch is delayed by a day, conditions will worsen. For Friday, there will be a 60 percent chance of cumulus or thick clouds causing a weather-related scrub.
Whenever the 230-foot (70-meter) tall, two-stage Falcon 9 launches, this will be the first time the company has re-launched one of its recovered first stages.
“Let me be clear, we are prepared to stand in front of this rocket with great confidence,” said Martin Halliwell, SES’s chief technology officer, in a March 28 press briefing. “We have had unprecedented access to review the efforts to prepare [the rocket] for a second flight and we are confident in its readiness.”
To date, eight Falcon 9 first stages been recovered either on land or an ocean-going platform. At least two of those will not be re-flown: the stage from the Orbcomm-2 flight in December 2015, and the one from JCSAT-14 in May 2016.
The stage being flown for this mission is core 1021, which was used during the CRS-8 mission in April 2016. That flight sent a Dragon capsule toward the International Space Station. After stage separation, the first stage performed a series of burns that placed it on a trajectory to land on SpaceX’s Automated Spaceport Drone Ship “Of Course I Still Love You.” This was the first successful landing on an ocean-going platform.
While it was recovered nearly a year ago, it only took about four months to refurbish, according to SpaceX. For the SES-10 mission, however, it won’t be powering toward a low-Earth orbit as it did for CRS-8. It is going on a higher-energy GTO. Combine that with the 11,700-pound (5,300-kilogram) satellite, this means the first stage will only have enough fuel leftover to land on SpaceX’s drone ship downrange in the Atlantic Ocean.
Doing so will mark the second time this particular stage has landed on that platform and the first booster to be recovered twice – if the landing is successful. During the SES-9 mission in March 2016, the first stage used for that flight “landed hard” and damaged the drone ship. A visible hole was seen on the deck when it returned to port.
Since that flight, however, the company has recovered boosters after sending payload to GTO, but none as heavy as SES-10.
“We’re right at the limit from a mass point of view,” Halliwell said. “It’s going to be a pretty hot mission to try and bring this thing back.”
Built by Airbus Defence and Space, SES-10 is a geostationary orbit (GEO) communications satellite. After it is deposited into a GTO with a low point of 135 miles (218 kilometers) and a high point of 22,000 miles (35,410 kilometers) and an inclination of 26.2 degrees, it will use its onboard thrusters to circularize its orbit and position itself at the 67 degrees West longitude over South America. SES estimates the spacecraft will be in service by mid-May 2017.
It is a Ku-band satellite with 60 transponders. It will provide coverage to the Gulf of Mexico and South America, replacing the capacity currently being provided by AMC-3 and AMC-4.
SES-10 is built on the Eurostar-3000 satellite bus, which is the most commonly used for spacecraft built by Airbus Defence and Space.
To get to GEO, the spacecraft will use bi-propellant thrusters. Once in its designated orbital slot, it will use electric propulsion for station keeping. SES-10 is expected to have a 15-year orbital lifespan.
SES announced in August 2016 that it was going to fly atop a previously-flown Falcon 9 first stage. Neither SpaceX or SES have disclosed what kind of discount, if any, SES was getting. However, Gwynne Shotwell said during the APSCC 2016 conference that customers flying on reused boosters would get a 10 percent discount. SpaceX’s website lists a standard Falcon 9 launch for $62 million.
“[SES has] a long history of trying to pioneer stuff, trying to push things forward, trying to push the envelope,” Halliwell said.
Halliwell said the company first did this with the Russian Proton rocket in the mid-1990s and again by becoming the first commercial payload to fly on Falcon 9. Regarding the first re-flown booster, he said he has the confidence in the level of expertise that SpaceX has to make flying reused boosters the norm.
“But someone has to go first,” Halliwell said. “We internally say ‘OK, lets look at a risk assessment associated with this, and if we’re comfortable with that, let’s go first.’ We’ll take that step.”
Video courtesy of SES
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a blog about the International Space Station, called Orbital Velocity.