This week has seen the worldwide launch cadence slow, with only four launches taking place. SpaceX’s Falcon 9 has launched just twice, with a mission for the U.S. National Reconnaissance Office and a Commercial Resupply Services mission to the International Space Station.
Moreover, a Minotaur rocket has launched another classified reconnaissance payload from Vandenberg, and China has launched a raft of satellites from Taiyuan.
Firefly’s Alpha rocket was also set to make another attempt at launching a Lockheed Martin test satellite following delays from launch attempts in March, but this launch has now been postponed until the end of April.
On Wednesday, April 16, at 12:33 PM PDT (19:33 UTC), a Minotaur IV lifted off from Space Launch Complex 8 (SLC-8) at Vandenberg Space Force Base (VSFB) in California carrying a classified payload for the National Reconnaissance Office (NRO). The vehicle followed a southeasterly trajectory to place the payload into a low-Earth orbit (LEO).
This was the first Minotaur launch from Vandenberg since 2011.
Yesterday, NRO & @northropgrumman launched NROL-174.
Fun fact: the Minotaur IV rocket was once a Peacekeeper ICBM that sat watch 24/7 in support of our nation’s nuclear deterrent. Now it has completed its final mission of placing a national security payload on orbit. 🚀🛰️ pic.twitter.com/GwViyDCgBh
— NRO (@NatReconOfc) April 17, 2025
Chang Zheng 4B | Unknown Payload
China launched a Chang Zheng 6A (CZ-6A) rocket from LC-9 at Taiyuan Satellite Launch Center. Liftoff took place on Friday, April 18, at 22:51 UTC, during a window lasting until 23:10 UTC.
LM-6A carried six satellites – Shiyan-27A through F.
The Chang Zheng (CZ) 6A rocket consists of two stages with four additional strap-on engines. A 4.2 m diameter, 57m high fairing sits atop the second stage, giving the vehicle a 50 m height.
LAUNCH! SpaceX Falcon 9 B1082-12 launches NROL-145 from SLC-4E, Vandenberg.
Overview: https://t.co/w0oBdM6x7G
Live: https://t.co/v9Srr7FD5T pic.twitter.com/bHEBa0UCKt
— NSF – NASASpaceflight.com (@NASASpaceflight) April 20, 2025
A Falcon 9 launched on Sunday, April 20, at 5:29 AM PDT (12:29 UTC) from Space Launch Complex 4 East (SLC-4E) at VSFB in California.
The classified payload is believed to be the tenth batch of Starshield satellites for a reconnaissance satellite constellation built by SpaceX and Northrop Grumman for the NRO. The constellation will allow the NRO to provide the U.S. government with imaging and other reconnaissance capabilities.
The booster supporting this flight was B1082 flying for the twelfth time. The booster successfully landed on Of Course I Still Love You, one of SpaceX’s autonomous droneships, stationed at approximately 640 km downrange in the Pacific Ocean.
B1082 has previous flown 11 missions – all from VSFB – namely Starlink Group 7-9, Starlink Group 7-14, USSF-62/WSF-M1, Starlink Group 8-2, Starlink Group 9-1, Starlink Group 11-1, OneWeb #20, Starlink Group 9-11, Starlink Group 11-2, Starlink Group 11-8, and Starlink Group 15-1. The booster’s first flight took place on January 3, 2024.
This was the 44th Falcon 9 mission of 2025, and the 80th orbital launch attempt Worldwide.
Falcon 9 is a 3.9-meter-diameter, 70-meter-high two stage rocket. Nine Merlin 1D engines power the first stage booster, while the second utilizes a single vacuum-optimized Merlin engine. Falcon 9 and Falcon Heavy are the first and only reusable orbital rockets in service today, with one Falcon booster having recently flown its 27 mission. The two payload fairings are also recovered and reused after flight.
A cargo resupply mission to the International Space Station (ISS) launched on Monday, April 21, at 4:15 AM EDT (08:15 UTC) from Launch Complex 39A (LC-39A) at Kennedy Space Center in Florida. SpaceX Cargo Dragon C209 launched atop a Falcon 9 on a northeasterly trajectory to intercept the Station.
Dragon C209 was flying for the fifth time, having previously flown CRS-22, CRS-24, CRS-27, and CRS-30. The Dragon’s first flight was on June 3, 2021.
LAUNCH! SpaceX Falcon 9 B1092-3 launches CRS-32 Dragon to the ISS.
LIVE:https://t.co/jkyfaqqhzb pic.twitter.com/rqtqYYqG4d
— NSF – NASASpaceflight.com (@NASASpaceflight) April 21, 2025
This mission was awarded to SpaceX as part of a six-mission contract extension to the Cargo Resupply Services 2 (CRS2) contract in March 2022, covering missions through CRS-35 in 2026. The Cargo Dragon will carry a payload of food, water, and other essentials to the Station, as well as an array of science experiments and spare parts. The booster supporting this mission was B1092, which landed successfully at Landing Zone 1 (LZ-1) at the Cape Canaveral Space Force Station following launch.
Booster B1092 was making its third flight, having previously flown Starlink Group 12-13 and NROL-69. The booster’s first flight was on February 27 of this year.
Included in the science payload for this mission is a French atomic clock that will form part of the Atomic Clock Ensemble in Space (ACES) experiment — a European facility that will test fundamental physics outside of the Columbus module on the ISS. By creating a “network of clocks,” ACES will link its highly precise timepieces with the most accurate clocks on Earth and compare them to measure the flow of time.
According to Einstein’s theory of general relativity, gravity affects the passing of time. Experiments on Earth have shown that time flies faster at higher altitudes, such as at the tops of mountains or in orbit. ACES will take this experiment to the next level, making precise measurements on the ISS as it flies 400 km above Earth. The data gathered by ACES will offer scientists new insights into the relationship between gravity and time, advancing our understanding of fundamental laws of physics.
⏱️ One second in 300 million years – that's how accurate ACES will be 💪@esa's Atomic Clock Ensemble in Space will use its two ultra-precise atomic clocks to revolutionise timekeeping from orbit 💫. Learn more in our blog 👉https://t.co/OgiHDWPfdw pic.twitter.com/hdMYBTW5Bb
— Human Spaceflight (@esaspaceflight) April 10, 2025
Another experiment, “Aerosol Monitors,” will compare three different monitors to determine the best methods to detect and categorize different particles within the ISS. One of these monitors will be able to differentiate between dust and smoke, which will be important for ensuring the safety and good health of crew members onboard the ISS.
Dragon will also carry a robotic spacecraft guidance demonstration, a pharmaceutical manufacturing experiment, and a plant growth experiment, among others. Autonomous docking with the Station is scheduled for April 22, at 12:20 UTC.
(Lead image: Falcon 9 launches from Florida. Credit: Julia Bergeron for NSF)
