SpaceX launches Transporter-4, first of six missions for Falcon 9 in April

by Lee Kanayama

SpaceX has launched Transporter-4, the fourth dedicated smallsat rideshare mission under their rideshare program. Transporter-4 – with its batch of 40 payloads – launched on a flight-proven Falcon 9 from Space Launch Complex-40 (SLC-40) from Cape Canaveral Space Force Station (CCSFS) on April 1 at 12:24:16 pm EDT (16:24:16 UTC).

Transporter-4 was SpaceX’s 12th overall flight, second Transporter mission, and the fifth launch from SLC-40 of the year.

Rocket and program overview:

On Transporter-4, SpaceX once again used a flight-proven Falcon 9 first stage booster. The booster used on this mission was B1061-7, the fifth time a booster supported seven flights. B1061 previously supported the SpaceX Crew-1, Crew-2, SiriusXM-8, SpaceX CRS-23, NASA’s IXPE, and the Starlink Group 4-7 missions.

For Transporter-4, B1061 had a turnaround time of 57 days.

Following B1061’s sixth flight on the Starlink Group 4-7 mission, it was taken off of the droneship A Shortfall of Gravitas (ASOG) and transported to SpaceX’s Hangar X facility at Roberts Road.

From there, it underwent refurbishment and inspections. On March 26, with its second stage attached, it was transported to the Horizontal Integration Facility (HIF) at SLC-40.

At the HIF, the 40 encapsulated payloads were attached to the second stage. From there, the rocket – which was already placed on the Transporter Erector (T/E) – was rolled out ahead of its launch.

Now becoming a normal occurrence, the static fire was skipped for this mission.

The Crew-1 mission with booster 1061 lifts off from LC-39A in November 2020. (Credit: Brady Kenniston for NSF)

Since the introduction of the smallsat rideshare program in 2019, SpaceX launched 376 satellites on their Transporter missions – including Transporter 4.

The first dedicated mission was Transporter-1 in January 2021 where Falcon 9 (B1058-5) launched a record 143 satellites – including 10 Starlinks – to orbit.

In June 2021, Transporter-2 took 88 satellites – including three Starlinks – to orbit. The most recent Transporter mission was Transporter-3 in January 2022. On this mission, B1058-10 successfully launched 105 satellites, this time with no Starlink satellites.

Transporter-1 was not the first time SpaceX launched a dedicated rideshare mission. In December 2018, Falcon 9 launched the Spaceflight SSO-A mission with 64 satellites on board.

The rideshare program allows customers frequent, low-cost access to space. SpaceX currently offers a base cost of $1.1 million for a satellite up to 200 kg.

With these missions, SpaceX can deliver multiple payloads to the popular Sun-Synchronous Orbit (SSO) in one launch.


For future missions, Transporter-5 is scheduled for June 2022 and Transporter-6 in October 2022.


Final launch preparations began at T-38 minutes with the Launch Director (LD) conducting the Go/No-Go poll to begin propellant loading.

Once the Go was given, at T-35 minutes the auto-launch sequence began and propellant loading started with RP-1 and Liquid Oxygen (LOX) flowing into first stage while the second stage was only loaded with RP-1.

Stage two completed RP-1 loading at T-22 minutes, and LOX load began at T-16 minutes.

At T-7 minutes, the Falcon 9 first stage began to chill its engines with liquid oxygen to ensure there were no thermal shocks to the engines at ignition.

At T-1 minute, the Falcon 9 entered “startup,” when the flight computers took control of the countdown. At the same time, the propellant tanks on both stages pressurized for flight.

At T-3 seconds, the nine first-stage Merlin 1D engines were commanded to ignite. Once the engines were verified to be healthy and producing full thrust, the hydraulic hold-clamps released the rocket, allowing liftoff.

A few seconds later, Falcon 9 began a pitch maneuver to an azimuth that will reach a 97.95-degree inclination.

SpaceX used the “Polar Corridor” for this mission that allows launches from CCSFS to reach polar orbits. With populated islands to the south, rockets have to complete a “dogleg” maneuver to avoid them – essentially flying around them.

Stage one shut down its nine engines at T+2 minutes and 30 seconds. Four seconds later, the second stage separated from the first stage and the MVac engine ignited for the first of three burns.

At T+3 minutes 1 second, the payload fairing separated, exposing the 40 payloads to space. The fairings then splashed down and be recovered by support ship Doug.

After a short coast, the first stage began its entry burn. The roughly 29-second burn slowed the stage to protect itself from the stresses of atmospheric reentry. The first stage then landed on the dronshipe Just Read The Instructions ~532 km downrange. It was the 112th landing overall and the 38th consecutive successful landing of a Falcon rocket.

Falcon 9 (B1062-2) lands on JRTI following the GPS-III SV05 mission. (Credit: SpaceX).

At T+9 minutes 59 seconds, the MVac engine shut down as it reached its initial orbit. This orbit measured 640 km x 655 km.  Falcon 9 then deployed three of its payloads. Once they were deployed, Stage 2 coasted for 11 minutes before Second Engine Start (SES)-2.

This burn lasted two seconds. After another 40 minute coast, Stage 2 burned its engine for the third time for just one second to place itself into its final orbit of 490 x 510 km at an inclination of 97.4 degrees.

Starting at T+1 hour and 14 minutes, the rest of the payloads began deploying. The deployment sequence lasted for 12 minutes.


The largest satellite onboard is the Environmental Mapping and Analysis Program (EnMAP) German hyperspectral satellite. With a mass of 980 kg, EnMAP will be used to monitor and characterize Earth’s environment on a global scale. Once in operation, it will be used to provide unique data that will be used to address environmental changes.

EnMAP in final processing before its delivery to Florida (Credit: OHB/H)

EnMAP was originally supposed to launch on the Indian PSLV rocket but was moved to the Falcon 9. It will operate for five years in a 650 km orbit.

Also onboard, Satellogic Inc. will launch four updated ÑuSat Mark IV satellites and their new Mark V satellite. These Earth-imaging satellites will see in both visible and infrared light will increase ÑuSat’s constellation size to 27 satellites.

The flight will also carry a transfer stage – the D-Orbit ION Satellite Carrier Vehicle (SCV) 005 Almighty Alexius. Almighty Alexius is a free-flying, self-propelled CubeSat deployer to carry hosted or deployable payloads. It is the fifth ION-SCV, having been used previously on the Vega VV16 in September 2020 and all previous Transporter missions.

An example of payload configurations on a Transporter mission. Several 15-inch and 24-inch diameter ports are available, as well as a custom-fit top adapter. Credit: SpaceX

Almighty Alexius will carry eight total payloads – four Kleos Space CubeSats, three CubeSats from the University of Chile, and a passive payload for Spacelust called Upmosphere.

As another one of many multi-launch partners for the smallsat rideshare program, Exolauch once again has ports for their customers. Exolaunch is a German-based launch service and separation system provider for smallsat payloads.

On the CarboNIX separation ring, the NanoAvionics microsatellite bus MP42 will be launched for their customer OQ Technology. The EXOpod CubeSat deployer will carry the ARCSAT satellite for the Norwegian Defence Research Establishment. Another EXOpod will also carry a single 12U CubeSat for Omnispace.

Spaceflight, Inc. has several ports on Transporter-4. One such payload is Lynk 05 for Lynk Global Inc. to test communications with mobile phones. Three more payloads are the HawkEye 360 Hawk-4A, 4B, and 4C transportation-monitoring satellites.

Other customers to be launched on Transporter-4 come from a wide range of companies and countries. These include GNSS Navigation and Occlusion Measurement Satellites (GNOMES)-3, Albania-1, BDSat, RROCI, Pixxel, 12 Swarm Spacebees, and more.

April schedule

April will be a busy month for SpaceX. Following this mission is Axiom-1 – currently targeting liftoff on April 6 at 12:05 pm EDT. Axiom-1 will utilize B1062-5 with Crew Dragon Endeavour on a 10-day mission to the International Space Station. It will be the first all-private mission to the station.

The classified NROL-85 mission will follow and will use B1071-2 and SLC-4E at Vandenberg Space Force Base.

On April 20, the SpaceX Crew-4 mission will launch using B1067-4 and the brand-new Crew Dragon Freedom. With a launch time of 6:37 am EDT, it will carry a crew of four to the ISS for SpaceX’s fourth operational mission to the orbiting lab. With both Axiom-1 and Crew-4, SpaceX will launch two crew missions in just two weeks.

The fifth mission planned for SpaceX is the Starlink Group 4-14 mission. Using B1058-12, it will launch from SLC-40. SpaceX’s sixth and final planned mission in April is the Nilesat 301 mission. Targeting April 30th, it will launch from SLC-40 on an unknown booster.

Lead image: Falcon 9 lifts off from SLC-40. Credit: SpaceX)

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