Small carrier manufacturer Astra has identified the cause of a failed launch in August and said it will make its next attempt as early as the end of this month. On October 12th, the company announced that the launch of the "3.3 version rocket" LV0006 on August 28th failed because propellant leaked from a supply system and caught fire, causing one of the five first stage engines to fail less than 1 second after takeoff.

In a blog post about the accident investigation, Vice President and Chief Engineer Leon said that this is a problem that the company has never encountered before. A quick disconnect system designed to seal the pipeline for delivering RP-1 fuel and liquid oxygen to the rocket upon takeoff actually resulted in propellant leakage into a closed space between the rocket and the launch platform. He wrote, 'Those propellants were ignited by rocket exhaust, causing an overpressure event that cut off the connection to the fuel pump control electronics, resulting in the engine shutting down less than 1 second after takeoff.'.

Due to only four engines remaining in operation, the rocket hovered above the ground and floated away from the launch tower until it burned enough propellant to begin ascending with reduced thrust due to its lightness. The rocket reached its maximum dynamic pressure point, but the launch mission was terminated shortly thereafter.

Qunxing stated that it has made several modifications to correct that issue in subsequent launches. It has made improvements to the propellant delivery connection to reduce the risk of leakage and adjusted the position of the propellant interface so that even if there is a leak, the fuel and oxidizer will not meet. The company has also updated its verification procedures. Leon wrote, 'We believe that by taking these comprehensive improvement measures, the likelihood of similar incidents happening again in the future will be greatly reduced.'.

With the implementation of those changes, Qunxing stated that it is ready to launch the next rocket with the number LV0007. That launch had two launch windows: the first was from October 27th to 31st, and the second was from November 5th to 12th. Like the company's first three stage orbital launch attempts, the launch will take place on Kodiak Island in Alaska. That launch will also be the second launch under a contract with the US Aerospace Forces, with the mission code STP-27AD2.

Recently, it has been speculated that Qunxing Corporation is preparing for a new launch attempt based on a temporary flight restriction (TFR) announcement issued by the Federal Aviation Administration (FAA) on October 7th. That announcement restricted flying into the airspace near the Kodiak launch site due to "space activities". However, the start date of the no fly policy is October 19th and the end date is October 29th, and the relevant configuration is different from the TFR announcement of Qunxing's previous launch there.

The upcoming launch will be the fourth orbital launch attempt of the constellation. The first three attempts failed to achieve orbit insertion, but the second launch in December last year was only a little short of orbit insertion. Leon said that the August launch validated the improvements made after the second launch, including the use of a closed-loop propellant control system to better manage the propellant and avoid premature engine shutdown during the second launch.

The launch in August also validated the improved Guidance Navigation and Control (GNC) software. Leon wrote that the modified software program was fully demonstrated during this launch, allowing the rocket to correct its heading after tilting, and we were all satisfied with our GNC.

Qunxing did not disclose the launch schedule after the next launch. However, at an online meeting held by the Small Payload Splicing Association on October 5th, Star officials Williams stated that the company will launch from another location later this year. He did not specify the location, but said 'we are expected to announce it soon'. The main candidate location for the second launch site is Kennedy Space Center Launch Facility 48. That multi-user launch pad is intended for small carriers with low infrastructure requirements from companies such as Qunxing.

Source: Hang Xiaoyu