7 months, 10 launches: SpaceX racks up another win with Intelsat 35e flight
KENNEDY SPACE CENTER, Fla. — Hawthorne, California-based Space Exploration Technologies (SpaceX) successfully launched the Intelsat 35e communications satellite on its way to orbit. Liftoff took place at 7:38 p.m. EDT (23:38 GMT) on July 5, 2017, from Launch Complex 39A.
This was SpaceX’s third attempt to get Intelsat 35e off the ground and into a geostationary transfer orbit. On July 2, the Falcon 9’s computer automatically aborted the launch countdown within 10 seconds from liftoff. The same thing happened on the July 3 attempt. At least for the first abort, it was due to an out of criteria reading in the guidance, navigation, and control system.
The reason for the second abort wasn’t immediately clear. As such, the company founder and CEO Elon Musk tweeted out the launch teams would stand down for a potential July 4 attempt in order to do a review of rocket and pad systems.
“Only one chance to get it right,” Musk said.
SpaceX solved the problem by adjusting the acceptable margins for the launch.
For the third attempt, the launch had a 90 percent chance of favorable weather conditions. As the countdown reached zero, the expendable Falcon 9’s nine first stage Merlin-1D engines roared to life to send Intelsat 35e into space.
Intelsat 35e is the fourth of Intelsat’s EpicNG next-generation high-throughput satellites. It was lofted to provide high-performance services in both the C- and Ku-bands.
The Luxembourg-based company describes its latest satellite and which regions of the planet it will provide its services to as follows:
Its unique payload of C-band wide- and spot-beams enables higher efficiency and improved throughput for demanding applications including wireless backhaul, enterprise and mobility services in regions where weather patterns necessitate use of highly reliable C-band spectrum. The Intelsat 35e Ku-band services include a customized high power wide beam for DTH service delivery in the Caribbean, as well as services for mobility and government applications in the Caribbean, trans-Europe to Africa and the African continent.
“The primary challenge with this mission has been one of schedule,” Ken Lee Intelsat’s senior vice president of Space Systems told SpaceFlight Insider. “Intelsat 35e arrived here in the first quarter [of 2017], upon completion of manufacturing by Boeing.”
Lee said that SpaceX’s nimble nature and how the NewSpace company recovers when things go “off nominal”, including the most recent accident, which saw the loss of the $195 million Amos-6 satellite, when coupled with the decades of experience the spacecraft’s manufacturer, Boeing, brought to bear, made for a dynamic flow in terms of the lead up to tonight’s launch.
“Once SpaceX recovered from the delays of the most recent Space Coast launch, our mission started coming together at an accelerated pace by necessity,” Lee said. “In this situation, all of the collaborators on the mission – Intelsat, Boeing, and SpaceX – have to bring the right resources to maintain mission assurance.”
Lee said that Intelsat has worked on the launch of over 150 satellites in its corporate lifetime.
“There are three attributes needed to be a successful commercial launcher: reliability, schedule certainty, and competitive pricing,” Lee said. “It is good to see SpaceX developing as it strives to attain these three goals.”
Indeed, a recent report by Inverse stated SpaceX has redefined the launch service provider market by its strategy of reusability. Simply put, the other providers can’t currently compete with the prices SpaceX has to offer as they still operate under the single-use concept, with the rockets’ various stages and payload fairings being discarded after ferrying cargo to orbit.
Meanwhile, while the Intelsat 35e mission involved an expendable Falcon 9 first stage, SpaceX has recovered 11 first stages on previous missions, re-flying – and re-landing – two of them. The company has also started tackling the challenge of recovering and reusing the launch vehicle’s payload fairings. To date, the only part of the Falcon 9 that has proven not to be reusable is the second stage. However, Musk and company hope to change that in the future.
Powered by a mix of rocket-grade kerosene, more commonly known as RP-1, and liquid oxygen, the Falcon 9 carried out its static test fire on June 29. For the July 5 launch, SpaceX provided the following details in terms of the launch sequence:
COUNTDOWN Hour/Min/Sec Events
– 01:03:00 Launch Conductor takes launch readiness poll
– 01:00:00 RP-1 (rocket grade kerosene) loading underway
– 00:35:00 LOX (liquid oxygen) loading underway
– 00:07:00 Falcon 9 begins engine chill prior to launch
– 00:01:00 Flight computer commanded to begin final prelaunch checks
– 00:01:00 Propellant tank pressurization to flight pressure begins
– 00:00:45 SpaceX Launch Director verifies go for launch
– 00:00:03 Engine controller commands engine ignition sequence to start
– 00:00:00 Falcon 9 liftoff
LAUNCH AND SATELLITE DEPLOYMENT Hour/Min/Sec Events
00:01:18 Max Q (moment of peak mechanical stress on the rocket)
00:02:42 1st stage main engine cutoff (MECO)
00:02:46 1st and 2nd stages separate
00:02:53 Second stage engine starts
00:03:39 Fairing deployment
00:08:37 2nd stage engine cutoff (SECO-1)
00:26:18 2nd stage engine restarts
00:27:10 2nd stage engine cutoff (SECO-2)
00:32:01 Intelsat 35e satellite deployment
This was the 38th flight of a Falcon 9 rocket since the vehicle debuted in 2010. It was the 34th SpaceX launch from Cape Canaveral – the eighth from LC-39A.
2017 has become the year of SpaceX, with 10 launches successfully completed so far. With six months left in the year, that launch tempo shows no sign of abating as the company hopes to loft as many as 10 more Falcon 9’s spaceward.
While SpaceX has launched an impressive six Falcon 9 rockets in just over nine weeks, the company is not expected to fly its next mission, CRS-12, until Aug. 10, 2017. That flight will see a Dragon capsule sent to the International Space Station with crew supplies and experiments for Expedition 52.
Video courtesy of SpaceX
Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology, Space.com, The Mars Society and Universe Today.