SpaceX launched the Starlink v1.0 L17 mission with a new group of Starlink satellites from the historic LC-39A at the Kennedy Space Center aboard a Falcon 9-boosted fly booster Thursday morning. The previous launch attempt on Sunday 28 February ended a scrub on T-1 minute 24 seconds.
Falcon 9 was launched at 03:24 EST (08:24 UTC) with the booster that landed successfully on the drone ship Of course I still like you.
The 20th Starlink mission to date, this launch has increased another 60 satellites for SpaceX’s ever-growing Starlink satellite internet constellation.
Due to technical, weather conditions, and droneship-related delays, Starlink v1.0 launched L17 after the L18 and L19 missions. It was the first time a Starlink mission had been launched ‘out of order’, but it was far from being a first for space travel in general; the Space Shuttle program was frequently filled with seemingly confusing mission numbers.
After many delays, the mission could finally be launched on February 17, but was postponed again after booster B1059 could not land after the Starlink v1.0 L19 mission.
During the 47th Space Summit on 23 February, SpaceX’s outgoing Vice President of Mission Insurance, Hans Koenigsmann, mentioned ‘heat damage’ as the cause of the unsuccessful recovery, but declined to disclose further details. It was later revealed that a hole in the trunk of one of the engines had a hole that caused an engine to shut down during the first flight and damage the heat, which in turn affected the entrance fire.
Preparations for the mission
On Jan. 31 at 2 p.m. local time, Falcon 9 successfully completed a static fire test, following an aborted static fire two days earlier.
After the failure of Starlink v1.0 L19, and after the almost month-long delay after the previous static fire, SpaceX decided to complete another static fire test on February 24 at 03:00 local time. A few hours later, the company confirmed that it was a success.
Static fire test completed – scheduled for Sunday 28 February at 20:37 EST for the launch of Starlink from LC-39A
– SpaceX (@SpaceX) 24 February 2021
Since the payload is already integrated – as standard with Starlink missions – Falcon 9 does not have to roll back to its hangar and receive its payload before it starts.
Countdown and start
Just 38 minutes before launch, SpaceX’s Launch Director confirmed that the Falcon 9 team was ‘go’ for propellant loading, which began three minutes later and continued until the last minutes of the countdown.
Initially, RP-1 kerosene began to flow in both stages of Falcon 9, while the liquid in liquid oxygen in phase 1 also began to flow. Stage 2 liquid oxygen loading begins at T-16 minutes.
The nine Merlin 1D engines on the first phase of Falcon 9 were thermally conditioned for ignition at T-7 minutes, a milestone known as engine cooling. Falcon 9 started at the T-1 minute, when the on-board computers put the propellant tanks to flight levels under pressure and performed the final flight checks.
After taking off from LC-39A, Falcon 9 began its pitch and roll maneuvers to direct a 53-degree oblique orbit flying northeast of Cape Canaveral.
After the separation at T + 2: 35, the first phase reoriented itself for landing, with a slow entrance firing at T + 6: 41.
At 8 minutes and 28 seconds after launch, the booster burned a final landing and hit the deck of Of course I Still Love You. It was the first Falcon 9 landing attempt after a failed recovery on the v1.0 L19 mission broke a streak of 24 successful landings straight.
Falcon 9 B1051 returns to Port Canaveral on board Just read the instructions for the Starlink v1.0 L16 mission – via Stephen Marr for NSF / L2
The second phase used two burns from the Merlin vacuum engine to reach the targeted feed path. After the first burn, the stage lasted about 40 minutes. It then performed a short, one second long burn to injure a roughly 250 by 290 kilometers orbit.
Deployment of all 60 Starlink satellites took place approximately 1 hour and 4 minutes after launch.
Once deployed, the satellites will take several weeks to reach their final orbits of 550 km using their Krypton-powered ion propellers.
Reuse of Booster and Fairing
SpaceX has chosen the veteran core B1049 for this launch: the oldest booster in the fleet. With a hundred-day turnaround from its last mission, this booster has set the fleet record for most flights at eight – a record previously held by B1051, which is likely to reach its ninth flight later this month.
| B1049 Flight History | Start date | Reversal time |
| Telstar 18V | 10 September 2018 | Nvt |
| Iridium-8 | 11 January 2019 | 123 days |
| Starlink v0.9 | 24 May 2019 | 133 days |
| Starlink v1.0 L2 | January 7, 2020 | 228 days |
| Starlink v1.0 L7 | 4 June 2020 | 149 days |
| Starlink v1.0 L10 | 18 August 2020 | 75 days |
| Starlink v1.0 L15 | 24 November 2020 | 98 days |
| Starlink v1.0 L17 | March 4, 2021 | 100 days |
This launch also featured reused fairs – both halves of previous Starlink missions. The active half – the side of Falcon 9’s tower for carrier erector – was making the first fourth flight of a crested half and probably had the Starlink v0.9, v1.0 L5 and v1.0 L12- missions supporting passive half probably flew on the Starlink v1.0 L3 and L10 missions.
About 45 minutes after launch, GO Searcher and GO Navigator both scooped up half of the water after their extravagance around 707 kilometers lower from the launch site.
The dedicated hood repair vessel, GO Ms Chief and GO Ms Tree, are engaged in maintenance work, including the removal of two of their arms. SpaceX has been successful in repairing screenshots after the splash, but a chip half has not been captured since the Starlink v1.0 L13 mission in October 2020.
SpaceX exercises shoulders out of the water @NASASpaceflight Fleetcam! Watch now: https://t.co/E1uidiatGl pic.twitter.com/3QZZdsXAu2
– colin (@ c_fletcher22) 25 February 2021
Starlink updates and future manifest
SpaceX plans to launch the Starlink v1.0 L20 mission from March 7 from SLC-40 at the Cape Canaveral Space Force Station. Further Starlink missions are likely to continue during March and April until the next scheduled launch for an external customer, the NASA Crew-2 mission on April 20 from LC-39A.
As SpaceX continues to deploy more satellites, the expanded beta program has enabled more users to start using Starlink for Internet access. Elon Musk tweeted that improvements to speed and deceleration are expected later this year.
The speed will double to ~ 300Mb / s and the delay will drop to ~ 20ms later this year
– Elon Musk (@elonmusk) 22 February 2021
Musk also mentioned that testing of these upgrades is underway and says users “Can sometimes see much higher download speeds on Starlink.”
The Starlink constellation is on course to offer connections most of the earth by the end of 2021 and global coverage in 2022, followed by densification of coverage to complete the initial constellation.
(Main photo via Stephen Marr for NSF)