Featured Image Credit: SpaceX
Lift Off Time | March 09, 2023 – 19:13 UTC | 14:13 EST |
|---|---|
Mission Name | OneWeb 17 |
Launch Provider | SpaceX |
Customer | OneWeb |
Rocket | 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 |
Payload mass | ~6,000 kg (~13,000 lbs) (40 x 147.7 kg plus deploy hardware) |
Where are the satellites going? | Polar low-Earth orbit. Initial orbit TBD, final orbit of 1,200 km |
Will they be attempting to recover the first stage? | Yes |
Where will the first stage land? | Landing Zone 1 (LZ-1), Cape Canaveral Space Force Station, Florida, USA |
Will they be attempting to recover the fairings? | Yes, the fairings will be recovered by Bob |
Are these fairings new? | TBD |
How’s the weather? | The weather is currently 95% GO for launch (as of March 08, 2023 – 13:30 UTC) |
This will be 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 SLC-40 – 33rd orbital launch attempt of 2023 |
Where to watch | The official livestream will be listed here once available |
What’s All This Mean?
SpaceX is set to launch 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 will place satellites into a polar orbit, which will be raised thereafter to a 1,200 km polar orbit. OneWeb 17 will boost 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.
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’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 Booster
The booster supporting the OneWeb 17 mission is B1062-13. As the name implies, the booster has supported six previous missions.
| B1062’s missions | Launch Date (UTC) | Turnaround Time (Days) |
| GPS Block III SV04 | November 5, 2020 23:24 | N/A |
| GPS Block III SV05 | June 17, 2021 16:09 | 223.70 |
| Inspiration4 | September 16, 2021 0:02 | 90.33 |
| Starlink Group 4-5 | January 6, 2022 21:49 | 112.91 |
| Ax-1 | April 8, 2022 15:17 | 91.73 |
| Starlink Group 4-16 | April 29, 2022 21:27 | 21.26 |
| Nilesat-301 | June 8, 2022 21:04 | 39.98 |
| Starlink Group 4-25 | July 24, 2022 13:38 | 45.69 |
| Starlink Group 4-27 | August 19, 2022 19:21 | 26.24 |
| Starlink Group 4-36 | October 20, 2022 14:50 | 61.81 |
| Starlink Group 5-1 | December 28, 2022 09:34 | 68.78 |
| Starlink Group 5-4 | February 12, 2023 05:10 | 45.82 |
| OneWeb 17 | March 9, 2023 19:13 | 25.59 |
Following launch, the Falcon 9 booster will conduct three burns. These burns aim to softly touch down the booster on Landing Zone 1 (LZ-1), at the Cape Canaveral Space Force Station.
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 will attempt to recover 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.
OneWeb 17 Countdown
All times are approximate
| 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 |
OneWeb 17 Launch, Landing, and Deployment
| HR/MIN/SEC | EVENT |
|---|---|
| 00:01:12 | Max Q (moment of peak mechanical stress on the rocket) |
| 00:02:18 | 1st stage main engine cutoff (MECO) |
| 00:02:21 | 1st and 2nd stages separate |
| 00:02:28 | 2nd stage engine starts |
| 00:02:34 | 1st stage boostback burn starts |
| 00:03:21 | 1st stage boostback burn ends |
| 00:03:34 | Fairing deployment |
| 00:06:20 | 1st stage entry burn starts |
| 00:06:36 | 1st stage entry burn ends |
| 00:07:27 | 1st stage landing burn start |
| 00:07:56 | 1st stage landing |
| 00:08:32 | 2nd stage engine cutoff (SECO-1) |
| 00:55:14 | 2nd stage engine starts (SES-2) |
| 00:55:17 | 2nd stage engine cutoff (SECO-2) |
| 00:58:49 | Deployment of first and second OneWeb satellites |
| 00:59:12 | Deployment of third and fourth OneWeb satellites |
| 01:00:13 | Deployment of fifth and sixth OneWeb satellites |
| 01:00:34 | Deployment of seventh and eighth OneWeb satellites |
| 01:01:05 | Deployment of ninth and 10th OneWeb satellites |
| 01:02:40 | Deployment of 11th and 12th OneWeb satellites |
| 01:04:27 | Deployment of 13th and 14th OneWeb satellites |
| 01:14:21 | Deployment of 15th and 16th OneWeb satellites |
| 01:14:37 | Deployment of 17th OneWeb satellite |
| 01:15:40 | Deployment of 18th and 19th OneWeb satellites |
| 01:17:29 | Deployment of 20th and 21st OneWeb satellites |
| 01:18:00 | Deployment of 22nd and 23rd OneWeb satellites |
| 01:19:13 | Deployment of 24th and 25th OneWeb satellites |
| 01:19:52 | Deployment of 26th and 27th OneWeb satellites |
| 01:29:39 | Deployment of 28th and 29th OneWeb satellites |
| 01:30:41 | Deployment of 30th OneWeb satellite |
| 01:31:05 | Deployment of 31st and 32nd OneWeb satellites |
| 01:32:10 | Deployment of 33rd OneWeb satellite |
| 01:32:18 | Deployment of 34th OneWeb satellite |
| 01:33:13 | Deployment of 35th and 36th OneWeb satellite |
| 01:34:38 | Deployment of 37th and 38th OneWeb satellite |
| 01:35:17 | Deplyoment of 39th and 40th OneWeb satellite |
