GPS Block III SV04 | Falcon 9

Lift Off Time (Subject to change)
November 5th, 2020 23:24 UTC | 18:24 EST
Mission Name and what it is
GPS Block III SV04: The fourth Third Generation Global Positioning System (GPS) satellite, named Sacagawea
Launch Provider (What rocket company is launching it?)
SpaceX
Customer (who’s paying for this?)
United States Space Force
Rocket
Falcon 9 Block 5 B1062.1
Launch Location
Space Launch Complex 40 (SLC-40), Cape Canaveral Air Force Station, Florida, USA
Payload mass
3,880 kg (8,550 pounds)
Where’s the satellite going?
Medium Earth Orbit – 20,200 km (12,500 miles), 55° inclination
How’s the weather?
The weather is currently 80% go for launch (As of November 5, 22:00 UTC)
Will they be attempting to recover the first stage?
Yes
Where will the first stage land?
The booster will land 635 km downrange on SpaceX’s autonomous spaceport drone ship (ASDS) Of Course I Still Love You
Will they be attempting to recover the fairing?
Fairing recovery from water is expected, Go Ms. Chief is deployed (Go Ms. Tree is still being repaired in port)
This will be the:
  • 1st launch with minor changes to the Merlin engine after the GPS abort in October
  • 97th launch of a Falcon 9
  • 64th booster landing
  • 20th mission for SpaceX in 2020
  • 4th GPS Block III satellite to launch
  • 39th landing attempt on Of Course I Still Love You
  • 59th SpaceX launch from SLC-40
  • 14th consecutive landing
Where to watch
SpaceX official Stream

What’s all this mean?

SpaceX’s Falcon 9 rocket will launch the GPS Block III SV04 satellite for the US Space Force. SV04 is part of the United States Space Force’s next generation GPS constellation. It is launching from Space Launch Complex-40 (SLC-40) at the Cape Canaveral Air Force Station (CCAFS). This launch will mark the fourth GPS Block III launch to date.

What is the GPS constellation?

GPS, or Global Positioning System, is a medium-Earth orbit satellite constellation which is operated by the United States Space Force. It is America’s global navigation satellite system, providing worldwide coverage for geolocation and time. Currently, there are 31 active GPS satellites in orbit, with an additional 24 planned.
SpaceX launching GPS Block III on Falcon 9
GPS Block III SV01 launching on Falcon 9 B1054 (Credit: SpaceX)
Out of those 31 active satellites, there are four different models, and two different blocks. From newest to oldest there are two operational GPS Block IIIs, which were launched in 2018 and 2019. There is another Block III satellite that is not yet in its operational orbit. There are also 12 operational GPS Block IIFs, which launched from 2010-2016. Next,  7 operational GPS Block IIR-Ms; they launched from 2005-2009. Finally, there are 10 operational Block IIRs, launched between 1997 and 2004. Learn more about the block versions here. The GPS constellation brings impressively accurate readings to the civilian population, with even more accuracy for the branches of the military. For the civilian population, GPS provides an impressive 500-30 cm of accuracy. This is especially impressive as each satellite is a circular orbit with an orbital height of 20,180 km.  GPS Block III plans to improve on this even further.

What is GPS Block III?

GPS Block III is the third major iteration of the GPS satellite. Each satellite was designed and manufactured by Lockheed Martin. Each satellite is designed to have a 15 year lifespan, but based on previous blocks lasting over twice as long as their lifespan, each satellite will likely last longer. The goal of GPS Block III was to provide enhanced signal reliability, accuracy and integrity. The satellites will build upon, or improve, features included on the Block IIR-M and IIF satellites including: The first satellite was supposed to launch in 2014, but experienced many delays that pushed the first launch back to December 2018. The 10th, and final, GPS Block III satellite is expected to launch NET Q2 2023.
Artist rendering of a GPS III satellite (Credit: Lockheed Martin)
Artist rendering of a GPS Block III satellite (Credit: Lockheed Martin)

What is Falcon 9 Block 5?

The Falcon 9 Block 5 is SpaceX’s partially reusable two-stage medium-lift launch vehicle. Block 5 is the final iteration of the Falcon 9; the goal is to apply all the lessons learned from 56 previous Falcon 9 pre-Block 5 flights into a human-rated reusable rocket. The Falcon 9 contains 3 main components: a reusable first stage, an expendable second stage, and a reusable fairing.

falcon 9
Falcon 9 Block 5 launching on the GPS Block III SV03 mission (Credit: SpaceX)

Block 5 updates:

SpaceX introduced a lot of changes on Block 5, allowing it to become the crewed-launching reusable rocket that we know today. To start, the Composite Overwrapped Pressure Vessel (COPV) had to undergo a complete redesign. NASA mandated the COPV redesign, as it had been the cause of both of the Falcon 9 failures: AMOS-6 and CRS-7.

Alongside with certification for human spaceflight, Block 5 came with a number of other major changes. To increase the amount of flight each booster could handle, and decrease the turnaround time, SpaceX reinforced the landing legs, upgraded the grid fins, and added a carbon fiber interstage. They also added heat resistant external paint and upgraded the engines. For more information about the changes in Block 5, and the other Blocks of the Falcon 9, check out this video by the Everyday Astronaut:

Tim Dodd explains the differences between the Falcon 9 versions. (Click image to watch) (Credit: Andrew Taylor)

Falcon 9 Booster B1062

The booster supporting this mission is B1062. This is the booster’s first flight, which will change its designation to B1062.1.

Following stage separation, the Falcon 9 will conduct 3 burns. These burns will softly touch down the booster on Of Course I Still Love You.

Falcon 9 entering port
Falcon 9 B1051.5 entering port after launching Starlink 9. (Credit: Lupi)

Fairing Reuse

SpaceX is the first entity ever that recovers and reflies its fairings. The recovery vessels, Go Ms. Tree and Go Ms. Chief, will most likely attempt to recover the fairing halves. After being jettisoned, the two fairing halves will use cold gas thrusters to orientate themselves as they descend through the atmosphere. Once at a lower altitude, they will deploy parafoils to help them glide down to a soft landing for recovery.

GPS Block III SV04 Full Mission Profile

Countdown

Hr/Min/Sec              Event
– 00:38:00                 SpaceX Launch Director verifies go for propellant load. – 00:35:00                 RP-1 (rocket grade kerosene) loading underway. – 00:35:00                 1st stage LOX (liquid oxygen) loading underway – 00:16:00                 2nd stage LOX loading underway – 00:07:00                 Falcon 9 begins engine chill prior to launch – 00:01:00                 Command flight computer 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, Landing, and Satellite Deployment*

Hr/Min/Sec              Event
00:01:11                    Max Q (moment of peak mechanical stress on the rocket) 00:02:31                   1st stage main engine cutoff (MECO) 00:02:35                   1st and 2nd stages separate 00:02:42                   2nd stage engine start (SES-1) 00:03:27                   Fairing deployment 00:06:47                   1st stage entry burn complete 00:08:07                   2nd stage engine cutoff (SECO-1) 00:08:35                   1st stage landing 01:03:32                    2nd stage engine start (SES-2) 01:04:17                    2nd stage engine cutoff (SECO-2) 01:29:18                    GPS Block III SV04 deployment * All times are approximate
7 comments
  1. It will launch October 03, 2020 01:43 UTC, but a month ago EDT? Wow.. the East Coast is having some serious time distortion this time year.

  2. NROL-44 (The first time I watch a live coverage of rocket launch).
    Starlink 13 (The second).
    GPS III SV 4 (The third).
    Maybe it was because me? Don’t know.

  3. Hey mate. Love the show and I learn a lot. I have a suggestion for one of your longer videos. Could you do one on plume interactions in particular focus on the centre engine. I love the way they expand in the upper atmosphere and I wonder how this expansion interferes with the power they put out. Thanks mate

    1. He actually has done a video about that! If you watch his video on aerospikes, pay close attention to the section about how bell nozzles work.

  4. Great work, always nice to read prelaunch previews.

    One clarification you need to give, will the booster land on OISLY as stated in “WHERE WILL THE FIRST STAGE LAND?” or JRTI stated in section “FALCON 9 BOOSTER B1062”

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