ABL Space Systems completes acceptance testing of RS1 upper stage

WASHINGTON — ABL Space Systems has completed testing of the second stage of its small launch vehicle, four months after a previous version of the stage was destroyed in a test accident.

In a video posted May 16, the company said it completed acceptance testing of the second stage of its RS1 vehicle at its Mojave, California, test site, including a static-fire test of the stage. The company has since shipped the stage to its launch site in Kodiak, Alaska.

The company was conducting similar tests of its second stage in Mojave Jan. 19 when the stage was destroyed in what the company called a “test anomaly.” The company later said the stage’s E2 engine suffered a hard start, when the flow of propellants and ignition fluid in an engine doesn’t allow for a gradual increase in energy, but instead an explosive rise. That created a fire at the base of the stage, leading to a complete failure about 20 seconds later.

Dan Piemont, president of ABL Space Systems, told SpaceNews the company used the incident as a “great opportunity” to demonstrate how quickly it can build and test a stage. The company built the stage itself in three weeks, followed by structural tests. The E2 engine went through its own tests before the integrated stage performed a four-week campaign of acceptance tests.

Before the January accident, the company had planned a first launch of the RS1 rocket, capable of placing up to 1,350 kilograms into low Earth orbit for a list price of $12 million, early in the year. Shortly after the accident, the company estimated a three-month delay in its plans. Piemont said after the recent acceptance tests that the company was now targeting “early summer” for its first launch, pending completion of acceptance tests of the first stage.