FunctionReusable orbital launcher
ManufacturerRocket Lab
Country of originUnited States
Cost per launch$50 million[1]
  • 42.8 m
  • 140.4 ft
  • 7 m
  • 5 m
  • 480,000 kg
  • 1,060,000 lb
Associated rockets
ComparableFalcon 9
Launch history
StatusIn development
Launch sitesMARS, LC-3
First flight2025 (planned)[2]
Payload to low Earth orbit
  • 13,000 kg
  • 28,660 lb
  • 15,000 kg
  • 33,000 lb
Payload to Moon
Payload to Venus
  • 1,500 kg
  • 3,300 lb
Payload to Mars
  • 1,500 kg
  • 3,300 lb
Stages information
First stage
  • 7 m
  • 23 ft
Powered by
Maximum thrust
  • 7,300 kN
  • 1,640,000 lbf
Specific impulse
  • 320 s
Second stage
  • 11.5 m
  • 5 m
  • 16 ft
Powered by
Maximum thrust
  • 1,110 kN
  • 200,000 lbf

Neutron is a medium-lift two-stage launch vehicle under development by Rocket Lab. Announced on 1 March 2021, the vehicle is designed to be capable of delivering a payload of 13,000 kg (28,700 lb) to low Earth orbit in a partially reusable configuration,[3] and will focus on the growing megaconstellation satellite delivery market.[4] The vehicle is expected to be operational sometime in 2025.[3][5] It uses LOX and liquid methane propellant on both stages of the vehicle.[4]


An earlier design of Neutron, featured at the initial unveil in March 2021, featured a rocket 40 m (130 ft) tall with a 4.5 m (15 ft)-diameter payload fairing. Rocket Lab stated that they intended for the first stage of the vehicle to be reusable, with landings planned on a floating landing platform downrange in the Atlantic Ocean.[4][6]

On 2 December 2021, Rocket Lab unveiled a revised design for Neutron, featuring a tapered shape with a maximum diameter of 7 m (23 ft).[3] Rocket Lab abandoned plans for landing Neutron on a floating platform, instead opting for a return-to-launch-site reusability profile. Instead of a conventional payload fairing that is jettisoned and recovered at sea, the fairing is integrated into the vehicle, and opens during stage separation to release the second stage and payload, and then closes before the first stage lands back on earth. The rocket features a unique interstage design where the second stage is "hung" from the first stage structure.[7]

On the 22nd of September 2022, another revised design was unveiled at an investor day, with the first stage engine count increased from seven to nine, and the engine architecture changed from gas-generator to oxygen rich staged combustion. This was done primarily to allow for a lower turbine temperature, while maintaining the same specific impulse. The engine will run with a significantly lower chamber pressure than other similar engines, at the cost of some performance. They have also reduced the number of fairing segments from four to two.[8]

On the 27th of July 2023, new concept art on the Rocket Lab website showed a further revised design, with a reduction in the number of payload fairing sections from 4 to 2, redesigned landing legs, and small changes to the overall shape of the rocket. The number of payload fairing sections was reduced in order to allow for simpler fairing opening mechanisms while the landing legs were redesigned in order to be optimized for landings on floating platforms, allowing for an increase in launch availability. The redesigned legs feature a folding mechanism similar to the SpaceX Falcon 9 landing legs.[9][10]


On 28 February 2022, Rocket Lab announced that Neutron will launch from the Mid-Atlantic Regional Spaceport (MARS) within NASA's Wallops Flight Facility on the eastern coast of Virginia.[7][11][12] It was also announced that the company will build a 250,000 square feet manufacturing and operations facility adjacent to the Wallops Flight Facility.[12] Ground was broken for this facility on 11 April 2022.[13] As of December 2021, Rocket Lab is planning for the first launch to take place no earlier than 2024.[7] Test firing of Neutron's Archimedes occurred at NASA's Stennis Space Center in Hancock County, Mississippi.[14]

Development timeline

Past and future development timeline of Neutron.[15]

Date Milestone Status
Q2 2022 Moulds and tooling for Neutron completed Completed[16]
Q3 2022 Full-scale prototype hardware for Archimedes and Neutron being made Completed[17]
4 Nov 2022 Opening Archimedes test complex at NASA Stennis Space Center Completed[18]
Q4 2022 Hot firing Archimedes hardware for the first time Completed[19]
10 Jan 2023 Testing engine ignition on development hardware Completed[20]
Q1 2023 Test stand infrastructure completed for Neutron Stage 2 tank Completed[21]
8 Aug 2023 First Stage 2 build Completed[22]
4 Oct 2023 Stage two structural and cryogenic testing Completed[23]
6 May 2024 First Archimedes development engine built Completed[24]
NET 2023 Flight mechanisms test program In Progress
2024 Testing of all avionics and communications devices with critical onboard software and GNC algorithms Completed[25]
Unknown First Archimedes engine hot fire Not started[26]
NET 2024 Stage 1 build In progress
NET 2024 Stage 2 static fire Not started
NET 2024 Stage 1 static fire Not started
NET 2024 Launch complex 3 complete In progress
NET 2024 Final integration Not started
NET 2024 Wet dress rehearsal Not started
NET 2025 Launch Not started


Neutron can lift up to 15,000 kg (33,100 lb) while expended, 13,000 kg (28,700 lb) while landing the booster downrange and up to 8,000 kg (17,600 lb) with the first stage returning to the launch site. Rocket Lab forecasts Neutron will be able to launch 98% of all payloads launched through 2029. Rocket Lab also intends the design to be able to support constellation deployment, deep space missions, and eventually human spaceflight.[6]


  1. ^ "Rocket Lab targets $50 million launch price for Neutron rocket to challenge SpaceX's Falcon 9". CNBC. 24 March 2023.
  2. ^ "Rocket Lab Completes Archimedes Engine Build, Begins Engine Test Campaign" (Press release). 6 May 2024.
  3. ^ a b c "Neutron". Rocket Lab. 2 December 2021. Retrieved 2 December 2021.
  4. ^ a b c Foust, Jeff (1 March 2021). "Rocket Lab to go public through SPAC merger and develop medium-lift rocket". SpaceNews. Retrieved 1 March 2021.
  5. ^ "Rocket Lab Completes Archimedes Engine Build, Begins Engine Test Campaign". 6 May 2024. Retrieved 6 May 2024.
  6. ^ a b "Rocket Lab Unveils Plans for New 8-Ton Class Reusable Rocket for Mega-Constellation Deployment" (Press release). Business Wire. 1 March 2021. Retrieved 1 March 2021.
  7. ^ a b c Sheetz, Michael (2 December 2021). "Rocket Lab gives first look at plans for bigger, reusable Neutron rocket as it takes on SpaceX". CNBC. Retrieved 2 December 2021.
  8. ^ "Rocket Lab 2022 Investor Day & Neutron Update". YouTube. 22 September 2022.
  9. ^ Angle, Richard (27 July 2023). "Rocket Lab's Neutron undergoes design change". TESLARATI. Retrieved 23 October 2023.
  10. ^ Rocket Lab Q2 2023 presentation,, Retrieved 23 Oct 2023
  11. ^ Foust, Jeff (2 March 2021). "Rocket Lab says SPAC deal will accelerate development of Neutron rocket". SpaceNews. Retrieved 4 March 2021.
  12. ^ a b Rocket Lab selects Virginia's Eastern Shore for rocket launch site.
  13. ^ "Rocket Lab Breaks Ground on Neutron Production Complex in Wallops, Virginia". 11 April 2022. Retrieved 1 May 2022.
  14. ^ "Rocket Lab Plans Hancock County, Mississippi, Engine Test Complex". Area Development. 24 September 2022.
  15. ^ "Neutron". Rocket Lab. Retrieved 22 October 2023.
  16. ^ Rocket Lab Neutron update,, Retrieved 22 Oct 2023
  17. ^ Rocket Lab Q3 2022 presentation,, Retrieved 22 Oct 2023
  18. ^ "Rocket Lab Opens Archimedes Engine Test Stand at Stennis Space Center in Mississippi". Rocket Lab. Retrieved 22 October 2023.
  19. ^ Rocket Lab Q4 2022 Earnings, Retrieved 22 October 2023
  20. ^ Rocket Lab on Retrieved 22 Oct 2023
  21. ^ Rocket Lab Q1 2023 presentation ,, Retrieved 22 October 2023
  22. ^ "Rocket Lab - Events & Presentations - Presentations". Retrieved 22 October 2023.
  23. ^ Rocket Lab on,, Retrieved 23 October 2023
  24. ^ Archimedes is here,, Retrieved 6 May 2024
  25. ^ "Neutron". Rocket Lab. Retrieved 2 July 2024.
  26. ^ "Rocket Lab Completes Archimedes Engine Build, Begins Engine Test Campaign". Retrieved 11 June 2024.