Space Launch Complex 4 (SLC-4) is a launch and landing site at Vandenberg Space Force Base, California, U.S. It has two pads, both of which are used by SpaceX for Falcon 9, one for launch operations, and the other as Landing Zone 4 (LZ-4) for SpaceX landings.

Space Launch Complex 4
SLC-4 with Falcon 9 on launch pad at SLC-4E in January 2017
Map
Launch siteVandenberg Space Force Base
Location34°37′59″N 120°36′47″W / 34.633°N 120.613°W / 34.633; -120.613
Time zoneUTC−08:00 (PST)
• Summer (DST)
UTC−07:00 (PDT)
Short nameSLC-4
Operator
Total launches261
Launch pad(s)2 (1 became a landing zone for Falcon 9)
Orbital inclination
range
55–145°[1]
SLC-4 (PALC-2-4 / SLC-4E) launch history
StatusActive
Launches167
First launch14 August 1964
Atlas-Agena D (KH-7 Gambit 4010)
Last launch24 November 2024
Falcon 9 Block 5 (Starlink G9-13)
Associated
rockets
LZ-4 (PALC-2-3 / SLC-4W) landing history
StatusActive
Landings21 (21 successful, 0 failure)
First landing7 October 2018 (SAOCOM 1A)
Last landing20 October 2024 (OneWeb #20)
Associated
rockets
Falcon 9
SLC-4W (PALC-2-3) launch history
StatusRepurposed
Launches94
First launch12 July 1963
Atlas-Agena D (KH-7 Gambit 4001)
Last launch18 October 2003
Titan 23G (USA-172 / DMSP)
Associated
rockets
Atlas-Agena, Atlas SLV-3, Titan IIID, Titan 23G

The complex was previously used by Atlas and Titan rockets between 1963 and 2005. It consisted of two launch pads, SLC-4W and SLC-4E, which were formerly designated PALC-2-3 and PALC-2-4 respectively. Both pads were built for use by Atlas-Agena rockets, but were later rebuilt to handle Titan rockets. The designation SLC-4 was applied at the time of the conversion to launch Titan launch vehicles.[2]

Both pads at Space Launch Complex 4 are currently leased by SpaceX. SLC-4E is leased as a launch site for the Falcon 9 rocket, which first flew from Vandenberg on 29 September 2013, following a 24-month refurbishment program which had started in early 2011.[3][4] SpaceX began a five-year lease of Launch Complex 4 West in February 2015 in order to use that area as a landing pad to bring back VTVL return-to-launch-site (RTLS) first-stage boosters of the reusable Falcon 9 launch vehicle. That pad was later named by SpaceX as Landing Zone 4 and first used operationally for a Falcon 9 booster landing in 2018.

SLC-4E

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Atlas-Agena

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The first launch from PALC2-4 occurred on 14 August 1964, when a KH-7 satellite was launched by an Atlas-Agena D. After 27 Atlas-Agena launches, the last of which was on 4 June 1967, the complex was deactivated.[5]

 
Titan IIID launch from SLC-4E

Titan IIID

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During 1971 the complex was reactivated and refurbished for use by the Martin Marietta Titan III launch vehicles. The Titan IIID made its maiden flight from SLC-4E on 15 June 1971, launching the first KH-9 Hexagon satellite.[6] The first KH-11 Kennan satellite was launched from the complex on 19 December 1976.[7] All 22 Titan IIIDs were launched from SLC-4E, with the last occurring on 17 November 1982.

Titan 34D

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The complex was then refurbished to accommodate the Martin Marietta Titan 34D. Seven Titan 34Ds were launched between 20 June 1983, and 6 November 1988.[8] SLC-4E hosted one of the most dramatic launch accidents in US history when a Titan 34D-9 carrying a KH-9 photoreconnaissance satellite exploded a few hundred feet above the pad on 18 April 1986. The enormous blast showered the launch complex with debris and toxic propellant (hydrazine and dinitrogen tetroxide), resulting in extensive damage. 16 months after the accident, the pad was back in commission when it hosted a successful launch of a KH-11 satellite.[9][10]

 
Final Titan IV launch from SLC-4E in 2005

Titan IV

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The last Titan variant to use the complex was the Titan IV, starting on 8 March 1991, with the launch of Lacrosse 2. On 19 October 2005, the last flight of a Titan rocket occurred, when a Titan IVB was launched from SLC-4E, with an Improved Crystal satellite. Following this launch, the complex was deactivated, having been used for 68 launches.[11] [12]

 
Inaugural mission of the Falcon 9 v1.1 from SLC-4E in September 2013

Falcon 9

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SpaceX refurbished SLC–4E for Falcon 9 launches in a 24-month process that began in early 2011.[3] The draft environmental impact assessment with a finding of "no significant impact" was published in February 2011.[3] Demolition began on the pad's fixed and mobile service towers in summer 2011.[4]

By late 2012, SpaceX anticipated that the initial launch from the Vandenberg pad would be in 2013, with the larger variant Falcon 9 v1.1.[13] As the pad was nearing completion in February 2013, the first launch was scheduled for summer 2013,[14] but was delayed until September 2013.

Launch history

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Statistics

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8
16
24
32
40
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
2020

Atlas (1964–1967)

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Titan IIID / 34D (1971–1988)

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Titan IV (1991–2005)

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Falcon 9 (since 2013)

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Upcoming launches

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Planned date (UTC) Launch vehicle Trajectory Payload Remarks
November 2024 F9 B5 LEO Starlink × ~23 (Group 11-2)
Net 2024 F9 B5 SSO NAOS (LUXEOSys)
April 2025[30] F9 B5 Geocentric SPHEREx & PUNCH
November 2025 F9 B5 SSO Sentinel-6B

SLC-4W

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SLC-4W started operations in 1963 as Space Launch Complex 4W, and continued as an operational launch site through 2003. In 2015, SpaceX started conversion of the launch site into Landing Zone LZ-4. Landing operations commenced in 2018 at LZ-4.

SLC-4W launch history

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Statistics

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1
2
3
4
5
6
7
8
'63
1965
1970
1975
1980
1985
1990
1995
2000

By rocket type

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Atlas-Agena
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The first launch to use what is now SLC-4 occurred on 12 July 1963, when an Atlas LV-3 Agena-D launched the first KH-7 Gambit reconnaissance satellite, from PALC-2-3. Twelve Atlas-Agenas launches were conducted from PALC-2-3, with the last occurring on 12 March 1965.

Titan IIIB
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Following this, it was rebuilt as SLC-4W, a Titan launch complex. The first Titan launch from SLC-4W was a Titan IIIB, on 29 July 1966. All 68 Titan IIIB launches occurred from SLC-4W, with the last on 12 February 1987.

 
A Titan 23G on SLC-4W
Titan 23G
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After the retirement of the Titan IIIB, it became a Titan 23G launch site, and twelve Titan II launches, using the 23G orbital configuration, were conducted between 5 September 1988 and 18 October 2003. Following the retirement of the Titan 23G, SLC-4W was deactivated. 93 rockets were launched from SLC-4W.

SLC-4W was the site of the launch of Clementine, the only spacecraft to be launched from Vandenberg to the Moon, which was launched by a Titan 23G on 25 January 1994.

Launch timeline 1963–2003

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LZ-4

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Development history

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SpaceX signed a five-year lease of Launch Complex 4W in February 2015, in order to use the area to land reusable launch vehicles at the pad. The location is being used for vertical landing of Return-To-Launch-Site (RTLS) first-stage boosters of the Falcon 9 rockets that are launched from the adjacent SLC-4E launch pad.[32][33] This novel use of SLC-4W had initially surfaced in July 2014 when NASASpaceFlight.com published that SpaceX was considering leasing SLC-4W for use as a RTLS vertical-landing facility for reusable first-stage boosters.[34]

Principal structures on the pad were demolished in September 2014 as construction of the landing pad began and was completed sometime around 2017.[35]

Landing statistics

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Landing outcomes (Falcon 9)

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1
2
3
4
5
6
7
2018
2019
2020
2021
2022
2023
2024
  •   Falcon 9 Success
  •   Falcon 9 Failure

Detailed landing history

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The landing of SAOCOM 1A, the first landing at LZ-4

After performing return-to-launch-site (RTLS) landings at its two Cape Canaveral Space Force Station landing pads, Landing Zones 1 and 2,[33][36] the company initially planned to attempt the first West Coast booster landing at Vandenberg AFB with the fourth Iridium NEXT satellite launch in December 2017, but ultimately opted for an expendable mission.[20][37]

In July 2018, SpaceX filed an FCC permit to communicate with a Falcon 9 first stage post-landing at SLC-4W, hinting at a potential RTLS landing, for the SAOCOM 1A mission.[38] This launch was later rescheduled to October 8, 2018.[32] Publicly announced through FCC permits and sonic boom warnings, SpaceX renamed SLC-4W as Landing Zone 4 ahead of the first landing attempt. The landing of a Falcon 9 first stage booster successfully occurred at Landing Zone 4 in October 2018, following the launch of the Argentinian SAOCOM 1A satellite.[32]

Notes

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  1. ^ a b Falcon 9 first-stage boosters have a four-digit serial number. A decimal point followed by a number indicates the flight count. For example, B1021.1 and B1021.2 represent the first and second flights of booster B1021. Boosters without a decimal point were expended on their first flight.

References

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  1. ^ "Falcon User's Guide" (PDF). SpaceX. September 2021. p. 11.
  2. ^ "NROL-85 Launch". National Reconnaissance Office. Retrieved 2 April 2023.
  3. ^ a b c Scully, Janene (5 February 2011). "Report: Falcon plan OK for environment". Santa Maria Times. Retrieved 7 February 2011.
  4. ^ a b "SpaceX". SpaceX. 15 August 2011. Archived from the original on 17 August 2011. Retrieved 15 August 2011.
  5. ^ Ben Evans. "SpaceX Launch Success Trials New Rocket, New Engine, New-Look Falcon 9". americaspace.com. Retrieved 2 April 2023.
  6. ^ Wade, Mark. "Titan". Encyclopedia Astronautica. Archived from the original on 5 August 2008. Retrieved 25 January 2009.
  7. ^ "Titan 3D". Gunther's Space Page. Retrieved 17 October 2013.
  8. ^ "Space Launch Complex 4 East". Cape Canaveral Space Force Museum. Retrieved 23 December 2023.
  9. ^ "The Space Review: Death of a monster". thespacereview.com. Retrieved 3 September 2015.
  10. ^ Broad, William J. (19 April 1986). "The New York Times: TITAN ROCKET EXPLODES OVER CALIFORNIA AIR BASE". The New York Times. Retrieved 21 September 2019.
  11. ^ "SpaceX Primed for Final Falcon 9 v1.1 Launch on Sunday". AmericaSpace. Retrieved 23 December 2023.
  12. ^ "Vandenberg: Space Launch Complex PALC2-4 (4E)". collectSPACE. Retrieved 23 December 2023.
  13. ^ "SpaceX Gears Up for Launches at Vandenberg Air Force Base". Space News. 12 November 2012. Retrieved 9 February 2013.
  14. ^ "First look/SpaceX Launch Complex/Vandenberg AFB". dailybreeze.com. 11 February 2013. Retrieved 1 April 2013.
  15. ^ Lindsey, Clark (4 January 2013). "NewSpace flights in 2013". NewSpace Watch. Archived from the original on 26 May 2013. Retrieved 3 January 2013.
  16. ^ "Dragon Mission Report | Q&A with SpaceX founder and chief designer Elon Musk". Spaceflight Now. 18 May 2012. Retrieved 25 May 2012.
  17. ^ "Launch Schedule | Spaceflight Now". spaceflightnow.com. Retrieved 23 January 2016.
  18. ^ "SpaceX: Jason-3 Mission" (PDF). spacex.com. SpaceX. Retrieved 23 January 2016.
  19. ^ "Formosat5 program description". NSPO. Retrieved 10 May 2014.
  20. ^ a b Gebhardt, Chris (16 October 2017). "SpaceX adds mystery "Zuma" mission, Iridium-4 aims for Vandenberg landing". NASASpaceFlight.com. Retrieved 17 October 2017.
  21. ^ @ChrisG_NSF (2017). "Chris G - NSF Tweet". Twitter.
  22. ^ "Used SpaceX Rocket Launches 10 Communications Satellites Once Again". Space.com. 22 December 2017. Retrieved 23 December 2017.
  23. ^ Graham, William (22 February 2018). "SpaceX launches Falcon 9 with PAZ, Starlink demo and new fairing – NASASpaceFlight.com". NASASpaceFlight.com.
  24. ^ "SpaceX lanzará el satélite Paz de Hisdesat a finales de año" [SpaceX will launch the Paz satellite of Hisdesat at the end of the year]. Infoespacial.com (in Spanish). 7 March 2017. Retrieved 9 March 2017.
  25. ^ Tariq Malik (30 March 2018). "Liftoff! Used SpaceX Rocket Launches 10 Iridium Satellites into Orbit". space.com. Retrieved 2 April 2023.
  26. ^ "Double Asteroid Redirection Test (DART)". Retrieved 17 July 2021.   This article incorporates text from this source, which is in the public domain.
  27. ^ Krebs, Gunter. "SARah 2/3". Gunter's Space Page. Retrieved 22 November 2020.
  28. ^ "BTW it looks all but certain 2 out of 22 Starlink satellites on just-launched Group 7-16 are actually "Starshield" sats of the US military: * Mysterious drop outs in live cam feeds from the 2nd stage during ascent * No forward looking camera views seen as per usual practices". X (Formerly Twitter).
  29. ^ "BTW it looks all but certain 2 out of 22 Starlink satellites on just-launched Group 7-16 are actually "Starshield" sats of the US military:* Mysterious drop outs in live cam feeds from the 2nd stage during ascent* No forward looking camera views seen as per usual practices". X (Formerly Twitter).
  30. ^ "SPHEREx". jpl.nasa.gov. Retrieved 28 October 2022.
  31. ^ McDowell, Jonathan. "Satellite Catalogue". Jonathan's Space Page. Retrieved 7 February 2009.
  32. ^ a b c "SpaceX Falcon 9 launches with SAOCOM 1A and nails first West Coast landing". NASASpaceFlight.com. 7 October 2018. Retrieved 8 October 2018.
  33. ^ a b Clark, Stephen (17 February 2015). "SpaceX leases property for landing pads at Cape Canaveral, Vandenberg". Spaceflight Now. Retrieved 19 February 2015.
  34. ^ Bergin, Chris (28 July 2014). "SpaceX Roadmap building on its rocket business revolution". NASASpaceFlight.com. Retrieved 28 July 2014. At this point, we are highly confident of being able to land successfully on a floating launch pad or back at the launch site and refly the rocket with no required refurbishment
  35. ^ SpaceX Demolishes SLC-4W Titan Pad. YouTube. 18 September 2014. Archived from the original on 21 December 2021. Retrieved 3 September 2015.
  36. ^ Gebhardt, Chris (6 February 2018). "SpaceX successfully debuts Falcon Heavy in demonstration launch from KSC". NASASpaceFlight.com. Retrieved 27 February 2018.
  37. ^ Gebhardt, Chris (22 December 2017). "SpaceX close out 2017 campaign with Iridium-4 launch". NASASpaceFlight.com. Retrieved 27 February 2018.
  38. ^ Gebhardt, Chris (6 July 2018). "SpaceX, ULA near-term manifests take shape, SpaceX aims for 1st RTLS at Vandenberg". NASASpaceFlight.com. Retrieved 9 July 2018.
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