SpaceX launched its fifth batch of Starlink internet satellites on Monday, Feb. 17 at 10:05 Eastern (15:05 UTC) from SLC-40 at Cape Canaveral Air Force Station. The mission featured the fastest turnaround time to-date of a Falcon first stage booster. However, while a secondary objective, the booster missed its landing spot on the drone ship during its return.



(Lead Image by Thomas Burghardt for NSF)

The first stage booster for this weekend’s Starlink mission was serial number B1056. The flight was the core’s fourth mission.

The booster’s most recent launch was JCSAT-18/Kacific1, occurring on Dec. 16 at 19:10 Eastern. Thus, less than 63 days elapsed between the third and fourth flights of B1056.

This is a new first stage turnaround record for SpaceX.

The company’s previous record was a 72-day turnaround of Block 4 booster B1045 between the TESS and CRS-15 missions for NASA in 2018.

A 63-day turnaround moves SpaceX closer to the current all-time record for an orbital-class launch vehicle. Space Shuttle Atlantis is the current record holder, with only 54 days between the launches of STS-51J and STS-61B.

With SpaceX getting increasingly better at reusing rockets, it is seemingly only a matter of time before the company beats Atlantis’ record.

SpaceX launched B1056 for the first time with the CRS-17 launch on May 4, 2019. The booster’s second flight was then the CRS-18 mission on July 25. Following CRS-18, the booster went on a several months long break, until it flew again on Dec. 16 with the JCSAT-18/Kacific 1 mission.

The break in the action was due to SpaceX’s light launch manifest in the second half of 2019.

SpaceX is quickly ramping up the deployment of the Starlink constellation in 2020 – leading to a much higher launch cadence over the coming months. Fast turnaround times between flights are a key for the company’s ability to execute its busy manifest.

SpaceX is hoping to launch approximately two Starlink missions per month over the course of the year. It successfully achieved that cadence in January, but weather-related delays with the most recent flight on Jan. 29 have caused a domino effect, which will see only one Starlink launch in February.

Monday’s launch occurred from Space Launch Complex 40 (SLC-40) at the yet to be renamed Cape Canaveral Air Force Station. With the recent creation of the Space Force, Cape Canaveral Air Force Station will soon become Cape Canaveral Space Force Station. This change is expected to occur within the next 30 days.

While SLC-40 has been used to launch all of SpaceX’s Starlink missions thus far, the company will soon begin flying Starlink missions from Pad 39A at Kennedy Space Center as well.

The first Starlink launch to utilize Pad 39A is currently set for early March.

Mondays’ mission was known as the “fifth launch of Starlink satellites,” according to SpaceX in their public communications. The company does not use a “Starlink-5” or similar terminology to distinguish between the Starlink launches.

Internally, the Feb. 17 mission is known as “Starlink V1.0-L4,” representing that the launch was the fourth launch of version one satellites.

The first launch of Starlink satellites was known internally as “Starlink V0.9,” as that mission’s satellites differed slightly from the full production version.

With 60 satellites flying on each Starlink mission, the total number of spacecraft in SpaceX’s internet constellation will rise to 300 with the launch on Feb. 17.

There was a low risk that recovery weather would be unacceptable for a launch on Monday, according to an official forecast published by the 45th Space Wing – as proved to be the case. Recovery weather conditions caused the launch to slip to Feb. 16, after originally being scheduled for Feb. 15.

An issue with a second stage valve then caused the launch to be rescheduled for Feb. 17.

The primary concern for a launch on Monday was upper-level wind shear. There was a moderate risk that it would not be acceptable for launch, according to the weather forecast. However, this proved to be within acceptable limits for lift-off.

Recovery weather conditions – which have been problematic for previous Starlink launch attempts – were not expected to be a problem on Feb. 17.

Launch vehicle fueling for the Starlink launch commenced at T-35 minutes. At T-45 seconds, the launch director verified that teams were go for launch. Stage separation occurred at two minutes and 36 seconds into the mission.

The payload fairing then separated three minutes and 10 seconds into flight. Fairing recovery vessels Ms. Tree and Ms. Chief attempted to recover the fairing halves from in their nets. The catch attempts were expected to occur approximately 45 minutes into the launch. They were deemed to be unsuccessful.

Falcon 9 first stage B1056 was also making a recovery attempt. It was to perform a propulsive landing on the droneship Of Course I Still Love You approximately eight minutes and 24 seconds after launch.

Falcon 9 B1056.4 has missed the drone ship. pic.twitter.com/259Yh545uy — Chris B – NSF (@NASASpaceflight) February 17, 2020

However, this failed, with the booster ‘soft landing’ in the ocean next to the drone ship.

Seconds later, the second stage shutdown its single MVac engine after completing its burn.

Deployment of the 60 Starlink satellites into a 212 by 386-kilometer orbit at a 53 degree inclination occurred around 15 minutes into the mission.

Each satellite weighs approximately 260 kilograms for a total payload mass of 15,600 kilograms.

Shortly after separation, the first 20 satellites will begin raising their orbits to the operational altitude of 550 kilometers. The 20 spacecraft will occupy one of three orbital planes being filled with Monday’s launch.

The remaining 40 satellites will move into two additional planes of 20 satellites each in the coming weeks.

SpaceX is filling as many orbital planes as possible per launch so that they can quickly provide reliable internet coverage. The company hopes to begin service to initial customers within a few months.

With the constellation, SpaceX hopes to greatly increase access to high speed internet worldwide. Customers will be able to purchase a pizza-sized dish to receive high-speed internet from the satellites nearly anywhere on Earth.