RS1 (rocket). The RS1 is ABL Space Systems's main launch vehicle platform. Both stages are powered by ABL's E2 rocket engine, with nine to eleven in the first stage, and one in the second stage. They are powered by RP-1 or Jet-A kerosene as propellant and liquid oxygen (LOX) as the oxidizer. 

The containerized launch system and rocket can be deployed to and launched from a suitably flat site, the main requirements being access for trucks capable of carrying up to -long ISO containers (for the RS-1 first stage), and a flat concrete pad  x .

History
In 2020, ABL Space Systems was planning the first orbital launch of its RS1 rocket in 2022. The firm received contracts worth US$44.5 million from the United States Air Force, as well as private funding equaling US$49 million. According to Dan Piemont, the US$44.5 million Air Force contracts include a one-year deal from the tech incubator AFWERX to demonstrate launch technology and an agreement with Space and Missile Systems Center's Space Enterprise Consortium to conduct three demonstrations of a RS1 vehicle variant and deployable ground infrastructure in 2022.

The RS1 claims to be capable of carrying a payload of  to low Earth orbit. It is  tall. Launches where planned to be sold for US$12 million per flight. 
ABL had over 70 launch agreements.

The maiden flight on January 10, 2023, failed after a fire in the aft cavity damaged key harnessing, causing the engines to shut down 11 seconds into flight. RS1 crashed down near the launch pad, damaging infrastructure at the Pacific Spaceport Complex. The second attempt at launch failed on July 19, 2024 due to a static fire testing failure. After the second flight failure, ABL decided to terminate their commercial launch program, and instead focusing on turning RS1 into a missile defense launch vehicle.

ABL is also currently developing a modified RS1 with first stage engine replaced with an aerospike engine, as part of AFRL's ARISE program. In September 2022, AFRL designated X plane number X-63 to this modified RS1 configuration. A test launch was initially scheduled for 2023, but has now since been delayed to an unspecified time.

Previous design
In 2019, RS1 was planned to have three E1 engines, each producing  of thrust to power the rocket's first stage. A single E2 engine, with  of thrust, was planned for the rocket's second stage. Both engines would use liquid oxygen and RP-1 propellants. The first development build of the vehicle has been completed.

Testing
In 2019, ABL Space conducted testing of the E2 rocket engine at the company's test facilities at Spaceport America, New Mexico, which "provided the perfect location and support staff for us to test the E2 rocket engine". The test was considered a success.

In early 2020, the Air Force Research Laboratory (AFRL) joined with ABL Space Systems to test and develop rocket-propulsion components. In October 2020, the second stage with E2 engine was tested at Edwards Air Force Base.

On 19 January 2022, an anomaly during testing at Mojave Air and Space Port resulted in the destruction of the second stage of the RS1 rocket. On 27 January, the source of the anomaly was publicly identified by ABL's CEO Harry O'Hanley as being one of the second stage's E2 Vacuum engine's turbopumps suffering a hard start, which led to a "substantial fire on the aft end of the vehicle, resulting in a complete failure about 20 seconds later".

After three earlier attempts to launch their RS1 rocket in December 2022, ABL shifted the launch attempt to January 2023. The maiden flight on January 10, 2023 failed.

The second attempt at an orbital launch (DEMO-2 mission) was precluded as the rocket being prepared for that launch suffered irreparable damage in a fire at the launch pad following a static-fire test on 19 July 2024.

Launches sites

Pacific Spaceport Complex
The first RS1 flight was planned for 2022 from the Pacific Spaceport Complex on Kodiak Island, but the launch attempt was aborted. After two additional aborts, the first launch occurred on January 10, 2023. The maiden flight also failed and did not reach orbit.

Cape Canaveral
On 1 November 2021, Amazon announced that the first two prototype satellites of the Kuiper constellation, KuiperSat-1 and KuiperSat-2, would be launched using RS1 in the fourth quarter of 2022 from Launch Complex 48 at the Kennedy Space Center. Amazon subsequently shifted these satellites to Vulcan Centaur, subsequently moving them to an Atlas V launch on October 6, 2023. Meanwhile on March 7th, 2023, it was announced that the Space Force allocated ABL Space Space Launch Complex 15 (SLC-15).

SaxaVord Spaceport
On 7 February 2021, Lockheed Martin and the United Kingdom announced a contract with ABL to launch the UK Pathfinder mission (6 CubeSats) in 2022, from the Shetland Space Centre on the island of Unst, Scotland. The UK Pathfinder launch was scheduled to take place in late 2024.

Launches

See also
 Rocket Lab Electron
 Firefly Alpha

References

External links
 RS-1 rocket details
 launch system details 

Aerospace technologies
Rocket engines