Astra successfully makes orbit on fourth attempt

by Thomas Burghardt

Smallsat launch startup Astra Space has now joined the short list of companies with a successful orbital rocket. The launch window for the mission, number LV0007, opened on November 18 (November 19 UTC), but a first launch attempt was scrubbed. LV0007 finally lifted off at 10:16 PM PST on November 19 (06:16 UTC on November 20). The launch was conducted from LP-3B at the Pacific Spaceport Complex in Kodiak, Alaska.

Similar to the last attempt, the only payload onboard was a test payload for the United States Space Force’s (USSF) Space Test Program which was intentionally not deployed. The USSF designation for the mission is STP-27AD2.

LV0007 was the fourth Rocket 3 vehicle to make an orbital launch attempt, and the first to end in success. The first-ever Rocket 3 vehicle, more specifically designated Rocket 3.0, was intended to launch on the “1 of 3” mission in pursuit of the DARPA Launch Challenge. Of three companies that entered the challenge – Astra, Virgin Orbit, and Vector Space Systems – Astra was the only company to reach launch day.

On the last launch opportunity to progress in the challenge – March 2, 2020 – the mission was scrubbed, and the challenge went unclaimed. Later that month, while Astra pivoted towards completing a test flight, the vehicle was lost before it could make its launch attempt due to a fire during a pre-launch countdown rehearsal. No payloads or personnel were harmed.

The next vehicle, Rocket 3.1, was the first to fly. In September 2020, the rocket successfully lifted off from Kodiak, but the flight was terminated by range safety due to a guidance issue early in flight.

The next iteration, Rocket 3.2, was successfully able to reach space in December 2020. First stage flight, payload fairing and stage separation, and upper stage ignition all occurred nominally, and the upper stage reached its targeted altitude of 390 kilometers. However, a fuel mixture issue resulted in insufficient horizontal velocity to achieve a stable orbit, and the upper stage destructively reentered Earth’s atmosphere.

This was followed in August 2021 by the first Rocket 3.3 vehicle, designated LV0006. The STP-27AD1 mission, carrying a test payload for the USSF, suffered an engine failure less than a second after liftoff, resulting in insufficient thrust to follow a nominal flight path. While the flight continued for approximately two and a half minutes, the rocket’s trajectory eventually deviated enough to require flight termination. The cause of the failure was identified as a propellant leak from the ground support equipment (GSE).

With fixes implemented, the second Rocket 3.3 vehicle, designated LV0007, was intended to do what LV0006 could not. The launch was preceded by a static fire test, which acted as a countdown and fueling rehearsal and a test of the engines on the first stage. This approximately nine-second-long engine test was successfully completed on November 17.

The test flight itself, again aiming to demonstrate the capability to reach orbit, began with ignition of the five first stage engines. The Delphin engines are electrically pumped and fueled by kerosene and liquid oxygen. When propellant depletion occurred on the first stage approximately two minutes and 50 seconds after launch, the five Delphin engines shut down, followed shortly after by fairing separation at T+2 minutes 55 seconds.

The payload fairing encapsulates both the upper stage and the payload during the atmospheric phase of flight. The vehicle flew south from Kodiak toward an 86-degree inclination orbit, targeting an orbital altitude of 500 kilometers.

Following fairing separation, the upper stage separated at T+3 minutes, and the single Aether engine ignited three minutes and five seconds after liftoff. Aether is a vacuum optimized engine also fueled by kerosene and liquid oxygen.

The upper stage burned until about eight and a half minutes after launch, when second engine cutoff, or SECO, occurred, shutting down the Aether engine.

Once orbit was achieved, a signal simulating payload deployment was received by the upper stage at T+8 minutes 40 seconds. No payload was physically separated from the rocket. This concluded the test flight.

Astra’s future launch manifest includes missions for NASA, the US Space Force, Planet Labs, and Spire Global. However, proceeding into these missions was contingent on a successful orbital test flight – a task now completed by LV0007.

Lead photo via NASASpaceflight/Astra

NASASpaceflight and Astra are partnering to broadcast the LV0007 test flight. As part of the partnership, Astra is covering some expenses associated with producing the broadcast.

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