SpaceX is targeting Monday, July 20 for the launch of a South Korean military communications satellite, ANASIS-II. Liftoff of the Falcon 9 Block 5 rocket is scheduled within a window from 5:00 PM to 8:55 PM EDT (21:00 to 00:55 UTC). The launch will take place from SLC-40 at the Cape Canaveral Air Force Station in Florida.
(Lead image via Mike Deep for NSF)
The United States Space Force’s 45th Weather Squadron predicts a 70% chance of acceptable weather for launch on Monday. If weather or a technical issue should cause a scrub, a backup opportunity exists on Tuesday, with a 50% chance of acceptable weather.
Army/Navy/Air Force Satellite Information System 2 (ANASIS-II), previously named KMitSatCom-1, is a secure communications satellite for the South Korean Agency for Defense Development. The spacecraft is the first dedicated South Korean military communications satellite. It will supplement the Koreasat-5/ANASIS-I satellite, a combined civilian and military communications satellite launched in 2006.
South Korea’s Defense Acquisition Program Administration contracted with Lockheed Martin for the satellite, as part of a package for Lockheed Martin’s F-35A combat aircraft. Lockheed Martin then subcontracted the construction of the satellite to Airbus Defence and Space. The satellite was shipped from the Airbus satellite factory in Toulouse, France to Cape Canaveral on June 8th.
The ANASIS-II spacecraft is based on Airbus’s Eurostar E3000 satellite bus, over 80 of which have been ordered for various communications missions. While the mass of ANASIS-II is classified due to its military mission, other E3000 satellites range from 4500 to 6500 kilograms at launch.
ANASIS-II will be deployed into a geostationary transfer orbit (GTO) by its Falcon 9 launcher. The satellite will then utilize its own propulsion to maneuver into its operational geostationary orbit. In the past, geostationary communications satellites made up the bulk of SpaceX’s commercial launch manifest, but ANASIS-II will be SpaceX’s first GTO mission of 2020.
The Falcon 9 first stage that will launch ANASIS-II is B1058.2, the second flight of the booster which launched Bob Behnken and Doug Hurley on the Demo-2 mission from LC-39A. The stage successfully completed a static fire test at SLC-40 on Saturday, July 11 at 6:00 PM EDT.
Initially planned to launch on July 14, SpaceX teams stood down in order to evaluate a potential hardware swap on the second stage. The technical issue was addressed, and the new launch date of July 20 was established.
When the ANASIS-II mission lifts off, the B1058 booster will break multiple turnaround records. SpaceX’s booster turnaround record was previously held by B1056, which launched the 5th Starlink mission just 62 days, 14 hours, and 55 minutes after launching the JCSat-18/Kacific-1 mission. The time between Demo-2 and ANASIS-II, if launched on Monday, will be just 51 days.
This also breaks the overall turnaround record for an orbital rocket, previously held by Space Shuttle Atlantis. Atlantis launched on her first two missions, STS-51-J and STS-61-B, within just 54 days, 9 hours, and 14 minutes. If launched on Monday, B1058 will hold the record for shortest turnaround of a rocket between two orbital launches, ever.
On launch day, the countdown begins 38 minutes before liftoff, when the SpaceX launch director gives the go for propellant load. If all conditions are clear to proceed, fueling begins three minutes later and 35 minutes before launch, when RP-1 fuel begins flowing into Falcon 9’s first and second stages, and liquid oxygen begins loading into the first stage. At T- 16 minutes, liquid oxygen also begins flowing into the second stage.
Seven minutes prior to launch, the nine Merlin 1D engines on the first stage begin thermal conditioning in order to prevent thermal shock from the super cold propellants. One minute before liftoff, Falcon 9’s onboard computers startup, taking control of the countdown and beginning to pressurize propellant tanks to flight pressures.
At T- 45 seconds, the launch director verifies that all systems are go for launch. Main engine start is commanded three seconds before the vehicle lifts off from the pad.
After clearing the towers at SLC-40, Falcon 9 begins to pitch downrange, gaining the horizontal velocity needed to achieve orbit. The vehicle reaches the point of maximum dynamic pressure at T+ 1 minute and 12 seconds, and the nine first stage engines throttle to maintain acceptable loads on the vehicle. The first stage continues powering the flight until T+ 2 minutes and 32 seconds, when main engine cutoff occurs. The stages separate, and the Merlin Vacuum engine on the second stage begins its first burn, which lasts until T+ 8 minutes and 6 seconds. The payload fairing is deployed at T+ 3 minutes, 34 seconds.
After liftoff, B1058.2 will attempt to land on Just Read the Instructions, one of SpaceX’s Autonomous Spaceport Drone Ships. Just Read the Instructions is stationed 628 kilometers downrange, due east of Cape Canaveral. B1058 will have then visited both drone ships, having touched down on Of Course I Still Love You after the Demo-2 launch.
The first stage completes an entry burn at T+ 6 minutes, 46 seconds, in order to protect the stage from the intense heat and forces of reentry. The booster touches down aboard Just Read the Instructions at T+ 8 minutes, 31 seconds.
SpaceX will also make another fairing recovery attempt, utilizing parafoils on the fairing halves to attempt catches aboard the GO Ms. Chief and GO Ms. Tree recovery ships. SpaceX has not successfully caught a fairing half since the 4th Starlink mission in January 2020, but fairings have been recovered after soft splashdowns in good enough condition to be reflown. The recovery attempt will occur approximately 45 minutes after launch, and 782 kilometers downrange.
After a coast phase until T+ 26 minutes, 32 seconds, the Merlin Vacuum engine on Falcon 9’s second stage reignites for 56 seconds. The ANASIS-II satellite is then deployed at T+ 32 minutes, 29 seconds, completing the 11th orbital Falcon 9 launch of 2020.
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