OneWeb 17 | Falcon 9 Block 5

Lift Off Time
March 09, 2023 – 19:13 UTC | 14:13 EST
Mission Name
OneWeb 17
Launch Provider
(What rocket company launched it?)
(Who paid for this?)
Falcon 9 Block 5 B1062-13; 25.59-day turnaround
Launch Location
Space Launch Complex 40 (SLC-40), Cape Canaveral Space Force Station, Florida, USA; 9 days, 19 hours, 59 minutes turnaround
Payload mass
~6,000 kg (~13,000 lbs) (40 x 147.7 kg plus deploy hardware)
Where did the satellites go?
Polar low-Earth orbit. Initial orbit 589 x 600 at 86.51º, final orbit of 1,200 km
Did they attempt to recover the first stage?
Where did the first stage land?
Landing Zone 1 (LZ-1), Cape Canaveral Space Force Station, Florida, USA
Did they attempt to recover the fairings?
Yes, the fairings were recovered by Bob
Were these fairings new?
No, both fairing halves were flight-proven and had flown five previous times
This was the:
– 209th Falcon 9 launch
– 143rd Falcon 9 flight with a flight-proven booster
– 149th re-flight of a booster
– 15th re-flight of a booster in 2023
– 177th booster landing
– 103rd consecutive landing (a record)
– 16th launch for SpaceX in 2023
– 116th SpaceX launch from 
– 32nd orbital launch attempt of 2023
Where to watch
Official Replay

How Did It Go?

SpaceX successfully launched 40 OneWeb internet communication satellites atop its Falcon 9 Block 5 rocket. Lifting off from Space Launch Complex 40, at the Cape Canaveral Space Force Station, in Florida, USA, the OneWeb 17 mission placed satellites into a polar orbit, which will be raised thereafter to a 1,200 km polar orbit. OneWeb 17 boosted the number of satellites launched to 584.

This mission was going to be the first mission of SpaceX’s upcoming second stage Merlin vacuum nozzle redesign, which will be used on lower-performance missions. This shorter, and therefore lower-performance, nozzle will decrease the number of return to launch site (RTLS) missions that SpaceX is able to launch; for this reason, it is likely that future missions in this payload class will land on one of SpaceX’s ASDSs.

What Is OneWeb?

OneWeb is a planned satellite internet constellation with the goal of providing internet coverage to the entire globe. Similar to SpaceX’s Starlink, the OneWeb constellation aims to deliver semi-low-latency internet to locations where ground-based internet is unreliable or unavailable.

OneWeb plans to have 648 satellites in its constellation, providing them with the 600 satellites needed for global coverage and an additional 48 on-orbit spares in case a satellite fails. These satellites are in a 1,200 km low-Earth polar orbit, which is significantly lower than the global internet services available today. The current satellite internet solutions orbit 35,786 km above the Earth, in geostationary orbit. However, the orbit of OneWeb’s satellites is still significantly higher than the ~550 km orbit that SpaceX’s Starlink satellites use. OneWeb is expecting the final 648 satellite constellation to provide download speeds of roughly 50 Mb/s.

OneWeb. orbits
Final orbits of the 648 satellite constellation (Credit: Airbus)

The constellation consists of 18 orbital planes, with 36 satellites in each plane. However, in May 2020, OneWeb submitted an application to the FCC, requesting to increase its constellation size to 48,000 satellites. OneWeb has also announced that the second generation of the OneWeb network will be a global navigation satellite system (GNSS), like GPS.

What Is A OneWeb Satellite?

Each OneWeb satellite has a compact design and a mass of 147.5 kg. The satellites are each equipped with a Ku-band antenna, operating between 12 and 18 GHz. One interesting note is that these satellites will use a slightly abnormal frequency, eliminating interference with satellites in geostationary orbit.

The OneWeb satellites were built by OneWeb Satellites, which is a joint venture between OneWeb and Airbus.

The satellites are designed to deorbit after 25 years safely. However, this leaves many concerned as this orbital region is already the most crowded with space debris.

OneWeb, satellite
Artist depiction of a OneWeb satellite (Credit: TechCrunch)

OneWeb’s Return

In March 2020, OneWeb filed for Chapter 11 bankruptcy and laid off most of its employees. However, OneWeb was able to maintain operations for the 74 satellites they currently had in orbit. In November 2020, the UK government and Bharti Enterprises invested over a billion US dollars into OneWeb with the goal of finishing the constellation.

As if these issues weren’t enough, in wake of new European sanctions at the start of the year OneWeb was unable to launch their satellites on the Soyuz vehicle–the rocket that launched the first 13 OneWeb missions. In lieu of this, on April 20, 2022, OneWeb announced launches atop the GSLV Mk III and Falcon 9.

What Is Falcon 9 Block 5?

The Falcon 9 Block 5 is SpaceX’s partially reusable two-stage medium-lift launch vehicle. The vehicle consists of a reusable first stage, an expendable second stage, and, when in payload configuration, a pair of reusable fairing halves.

First Stage

The Falcon 9 first stage contains 9 Merlin 1D+ sea-level engines. Each engine uses an open gas generator cycle and runs on RP-1 and liquid oxygen (LOx). Each engine produces 845 kN of thrust at sea level, with a specific impulse (ISP) of 285 seconds, and 934 kN in a vacuum with an ISP of 313 seconds. Due to the powerful nature of the engine, and the large amount of them, the Falcon 9 first stage is able to lose an engine right off the pad, or up to two later in flight, and be able to successfully place the payload into orbit.

The Merlin engines are ignited by triethylaluminum and triethylborane (TEA-TEB), which instantaneously burst into flames when mixed in the presence of oxygen. During static fire and launch the TEA-TEB is provided by the ground service equipment. However, as the Falcon 9 first stage is able to propulsively land, three of the Merlin engines (E1, E5, and E9) contain TEA-TEB canisters to relight for the boost back, reentry, and landing burns.

Second Stage

The Falcon 9 second stage is the only expendable part of the Falcon 9. It contains a singular MVacD engine that produces 992 kN of thrust and an ISP of 348 seconds. The second stage is capable of doing several burns, allowing the Falcon 9 to put payloads in several different orbits.

For missions with many burns and/or long coasts between burns, the second stage is able to be equipped with a mission extension package. When the second stage has this package it has a grey strip, which helps keep the RP-1 warm, an increased number of composite-overwrapped pressure vessels (COPVs) for pressurization control, and additional TEA-TEB.

falcon 9 block 5, launch
Falcon 9 Block 5 launching on the Starlink V1.0 L27 mission (Credit: SpaceX)

Falcon 9 Booster

The booster that supported the OneWeb 17 mission is B1062-13. As the name implies, the booster has supported 12 previous missions.

B1062’s missionsLaunch Date (UTC)Turnaround Time (Days)
GPS Block III SV04November 5, 2020 23:24N/A
GPS Block III SV05June 17, 2021 16:09223.70
Inspiration4September 16, 2021 0:0290.33
Starlink Group 4-5January 6, 2022 21:49112.91
Ax-1April 8, 2022 15:1791.73
Starlink Group 4-16April 29, 2022 21:2721.26
Nilesat-301June 8, 2022 21:0439.98
Starlink Group 4-25July 24, 2022 13:3845.69
Starlink Group 4-27August 19, 2022 19:2126.24
Starlink Group 4-36October 20, 2022 14:5061.81
Starlink Group 5-1December 28, 2022 09:3468.78
Starlink Group 5-4February 12, 2023 05:1045.82
OneWeb 17March 9, 2023 19:1325.59

Following launch, the Falcon 9 booster conducted three burns. These burns softly touched down the booster on Landing Zone 1 (LZ-1), at the Cape Canaveral Space Force Station.

falcon 9 booster, landing, drone ship
Falcon 9 landing on Of Course I Still Love You after launching Bob and Doug (Credit: SpaceX)

Falcon 9 Fairings

The Falcon 9’s fairing consists of two dissimilar reusable halves. The first half (the half that faces away from the transport erector) is called the active half, and houses the pneumatics for the separation system. The other fairing half is called the passive half. As the name implies, this half plays a purely passive role in the fairing separation process, as it relies on the pneumatics from the active half.

Both fairing halves are equipped with cold gas thrusters and a parafoil which are used to softly touch down the fairing half in the ocean. SpaceX used to attempt to catch the fairing halves, however, at the end of 2020 this program was canceled due to safety risks and a low success rate. On OneWeb 17, SpaceX recovered the fairing halves from the water with their recovery vessel Bob.

In 2021, SpaceX started flying a new version of the Falcon 9 fairing. The new “upgraded” version has vents only at the top of each fairing half, by the gap between the halves, whereas the old version had vents placed spread equidistantly around the base of the fairing. Moving the vents decreases the chance of water getting into the fairing, making the chance of a successful scoop significantly higher.

All times are approximate

00:38:00SpaceX Launch Director verifies go for propellant load
00:35:00RP-1 (rocket grade kerosene) loading underway
00:35:001st stage LOX (liquid oxygen) loading underway
00:16:002nd stage LOX loading underway
00:07:00Falcon 9 begins engine chill prior to launch
00:01:00Command flight computer to begin final prelaunch checks
00:01:00Propellant tank pressurization to flight pressure begins
00:00:45SpaceX Launch Director verifies go for launch
00:00:03Engine controller commands engine ignition sequence to start
00:00:00Falcon 9 liftoff

OneWeb 17 Launch, Landing, And Deployment

00:01:12Max Q (moment of peak mechanical stress on the rocket)
00:02:181st stage main engine cutoff (MECO)
00:02:211st and 2nd stages separate
00:02:282nd stage engine starts
00:02:341st stage boostback burn starts
00:03:211st stage boostback burn ends
00:03:34Fairing deployment
00:06:201st stage entry burn starts
00:06:361st stage entry burn ends
00:07:271st stage landing burn start
00:07:561st stage landing
00:08:322nd stage engine cutoff (SECO-1)
00:55:142nd stage engine starts (SES-2)
00:55:172nd stage engine cutoff (SECO-2)
00:58:49Deployment of first and second OneWeb satellites
00:59:12Deployment of third and fourth OneWeb satellites
01:00:13Deployment of fifth and sixth OneWeb satellites
01:00:34Deployment of seventh and eighth OneWeb satellites
01:01:05Deployment of ninth and 10th OneWeb satellites
01:02:40Deployment of 11th and 12th OneWeb satellites
01:04:27Deployment of 13th and 14th OneWeb satellites
01:14:21Deployment of 15th and 16th OneWeb satellites
01:14:37Deployment of 17th OneWeb satellite
01:15:40Deployment of 18th and 19th OneWeb satellites
01:17:29Deployment of 20th and 21st OneWeb satellites
01:18:00Deployment of 22nd and 23rd OneWeb satellites
01:19:13Deployment of 24th and 25th OneWeb satellites
01:19:52Deployment of 26th and 27th OneWeb satellites
01:29:39Deployment of 28th and 29th OneWeb satellites
01:30:41Deployment of 30th OneWeb satellite
01:31:05Deployment of 31st and 32nd OneWeb satellites
01:32:10Deployment of 33rd OneWeb satellite
01:32:18Deployment of 34th OneWeb satellite
01:33:13Deployment of 35th and 36th OneWeb satellite
01:34:38Deployment of 37th and 38th OneWeb satellite
01:35:17Deplyoment of 39th and 40th OneWeb satellite

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