Spaceflight Insider

Falcon 9 for Intelsat 35e tested; flown boosters return to ports

SpaceX performs a static fire test on the Falcon 9 rocket that will send Intelsat 35e into orbit. Photo Credit: SpaceX

SpaceX performs a static fire test on the Falcon 9 rocket that will send Intelsat 35e into orbit. Photo Credit: SpaceX

KENNEDY SPACE CENTER, Fla. — Hot off the heels of its weekend launch doubleheader, SpaceX performed a static fire test for another Falcon 9 rocket. Just three days from now, the rocket will deliver the Intelsat 35e telecommunications satellite into space.

The static fire test took place at 8:30 p.m. EDT on June 29 (00:30 GMT June 30) at the historic Launch Complex 39A (LC-39A) in advance of a scheduled flight at the beginning of a 58-minute window opening at 7:36 p.m. EDT (22:36 GMT) on July 2. It has been six days since the company last launched from that pad and only four days since it launched a Falcon 9 from Vandenberg Air Force Base in California.

SpaceX performs static fire tests on each of its rockets in the days before their planned launches. The company does this to ensure all is working properly with the vehicle and ground support equipment.

Static fire tests involve fueling both stages of the Falcon 9 with rocket grade kerosene, also called RP-1, and liquid oxygen. Once a simulated countdown reaches zero, the nine first stage Merlin-1D engines are ignited for about three seconds before cutting off.

With the static fire test for the Intelsat 35e mission done, engineers will now work to verify all was indeed well with the system. It will then be lowered back to the horizontal position on top of its Transporter Erector and rolled back into the hangar just outside the perimeter of LC-39A to install the payload and fairing to the top of the rocket.

In the hours before the planned liftoff, the 229-foot (70-meter) tall rocket will be rolled back up the launch ramp at LC-39A.

Weather for the July 2 launch is iffy at best. The 45th Weather Squadron released its first official forecast for the flight and is predicting a 60 percent chance of inclement weather during the launch window.

“Typical summertime storms are expected in Central Florida each afternoon for the next several days,” the report reads. “Winds in the low and mid-levels are southwesterly, which will hinder the inland progression of the sea breeze and its associated storms. The same winds will also guide any storms and [anvil clouds] that develop to the west, back toward the Space Coast.”

An artist's rendering of Intelsat 35e. Image Credit: Boeing

An artist’s rendering of Intelsat 35e. Image Credit: Boeing

The report goes on to state that the main concerns for launch time will be anvil and cumulus clouds.

In the event of a 24-hour scrub to July 3, the outlook improves slightly to only a 50 percent chance of inclement weather with the same cloud concerns.

The intel on Intelsat 35e

Intelsat 35e is a high-throughput geostationary communications satellite. The Falcon 9 will be delivering the 13,000-pound (6,000-kilogram) satellite into a geostationary transfer orbit (GTO). The spacecraft’s onboard propulsion system will finish the job of circularizing itself at a geostationary orbit some 22,300 miles (35,900 kilometers) in altitude at the 34.5 West longitude orbital slot. It will service parts of the Americas, Europe, and Africa.

The satellite is designed and manufactured by Boeing on its 702MP bus. It will have C- and Ku-band transmitters and will be powered via two solar wings that generate between 6 kilowatt and 12 kilowatts of electricity. It is expected to operate for at least 15 years.

Ordered in 2014, it is the ninth spacecraft to be built on the Boeing 702MP platform and will be the fourth high-throughput EpicNG satellite for the Intelsat company. It will replace Intelsat 903, which was launched in 2002 and is currently residing in the 34.5 West longitude orbital slot.

It was announced in August 2016 that the satellite would fly atop a Falcon 9 Full Thrust rocket. The various improvements of the variant allowed for satellites of up to 18,300 pounds (8,300 kilograms) to be sent to GTO. This meant the company could contract with SpaceX without having to wait for the long-delayed Falcon Heavy rocket.

SpaceX rockets and spacecraft coming and going

This mission will be the third launch in just over nine days if it takes off on schedule. However, unlike the previous two flights, it will not involve a first stage recovery attempt. As such, there will be no landing legs or grid fins attached. The reason for that is the weight of the satellite payload and required velocity requires all of the available thrust the Falcon 9 has to offer.

Moreover, the drone ship that would catch any returning booster on the East Coast is currently busy offloading the first stage from the previous Florida launch.

The Of Course I Still Love You Autonomous Spaceport Drone Ship returned to Port Canaveral on June 29 with the twice-flown core 1029. It was used not only to help power the BulgariaSat-1 mission spaceward last week but also the Iridium-1 mission in January 2017.

Of note is another first for the NewSpace company: According to NASA Spaceflight, instead of “welding” the rocket’s feet to the deck of the drone ship, a large flat battle-bot-like robot that some have dubbed the “Roomba” was used to drive under the stage to “grab” onto the rocket to better secure the booster.

It is unclear if core 1029 will be refurbished for a third launch in the future. According to Space News, SpaceX President Gwynne Shotwell said that the current version of the Falcon 9 can only be re-flown two or three times, but the future Block 5 version, which will debut later this year, will be able to relaunch “a dozen or so times.”

On the other side of the continent, the booster recovered in the Pacific from the June 25 Iridium-2 launch was returned to the port of Los Angeles. The Just Read The Instructions drone ship arrived with core 1036 late in the morning of June 28.

After the Intelsat 35e mission, SpaceX will have launched six Falcon 9 rockets in just nine weeks. To date, the company has launched nine of these boosters in 2017 – Sunday’s launch would make 10.

With as many as 10 more scheduled flights on the manifest for 2017, SpaceX’s record year is on pace to surpass the United Launch Alliances record of 16 missions in a single calendar year. In 2009, ULA launched one Delta IV Heavy, eight Delta II, two Delta IV Medium, and five Atlas V rockets.

However, under the current manifest, after Intelsat 35e launches, the next mission for SpaceX will be more than a month later. On Aug. 10, 2017, the company will launch the CRS-12 Dragon capsule toward the International Space Station. CRS-11 is currently still berthed to the Earth-facing port of the station’s Harmony module, but it is scheduled to land on July 2.


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 website about human spaceflight called Orbital Velocity. You can find him on twitter @TheSpaceWriter.

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