Chinese commercial rocket Hyperbola-1 fails in Return to Flight attempt

by Leo Bruce

iSpace, a private Chinese launch service provider, made an attempt to Return to Flight (RTF) with their Hyperbola-1 (SQX-1) vehicle on Tuesday August 3. This RTF mission was in response to Hyperbola-1’s second ever mission, which suffered a failure during ascent in February resulting in the loss of the payload and mission.

Tuesday’s flight attempt marked the vehicle’s third ever launch, and whilst it’s believed the flight progressed further than the previous anomaly, there is a growing consensus that the latter stages of the mission were not successful. 

The vehicle took off from Site 95B at the Jiuquan Satellite Launch Center in the Inner Mongolia region of China, with launch occurring at approximately 07:39 UTC. According to the Notice to Airmen (NOTAM) released prior to launch day, the vehicle pitched south from the launch center, strongly suggesting that this launch was to a polar Sun-Synchronous Orbit (SSO) like the rocket’s previous flights.

Witnesses captured the vehicle’s liftoff and ascent, both of which appeared to look nominal, with the vehicle soaring through the stage of flight where the last mission failed.

There are a multitude of reports regarding what happened to the mission during and after ascent. The most official of reports was from the state owned Xinhua news agency, who released a brief statement a number of hours after launch. They confirmed the launch occurred at 07:39 UTC, and corroborated with reports that it was an unsuccessful mission, notably outlining how the satellite “did not enter nominal orbit after separation” and that mission objectives were not achieved.

Before this statement was released, several reports claimed or alluded to the possibility that the payload fairing did not separate, resulting in the payload being unable to nominally detach from the upper stage. The spacecraft colliding into the two joined fairing halves would immediately result in the loss of payload operability in orbit.

Another report claimed the vehicle successfully burned through the solid propellant first and second stages, but that the third solid fueled stage underperformed. It’s unknown if this is linked to the above scenario, but the payload would not be able to offset this lack of performance with its own Reaction Control System (RCS) if fairing separation did not occur.

If fairing separation was successful, but the third stage underperformed, then it is also not known if the satellite’s onboard RCS would have enough performance to offset the below-nominal orbital parameters.

No official update from iSpace has been given.

There was no confirmed public information on the exact payload aboard Tuesday’s launch, but it’s believed to likely be a singular satellite designated Jilin-1 Mofang-01A. The Jilin-1 series of Earth observation satellites are operated by Chang Guang Satellite Technology Co.

Return to Flight

Tuesday’s launch was a “Return to Flight” mission for Hyperbola-1. The vehicle’s previous mission took place on February 1, 2021, also from Jiuquan Satellite Launch Center, and carried the Fangzhou-2 (‘Ark-2’) satellite.

Shortly after liftoff, during the period of maximum dynamic pressure (Max Q), the vehicle disintegrated, and iSpace officially confirmed loss of the vehicle. 

The second flight of Hyperbola-1 ends in failure during first stage flight in February 2021

After an almost month long investigation, the company determined the cause of failure to be a piece of foam insulation. This insulation was designed to be ejected from the vehicle’s exterior during ascent, however, it flew into one of the rocket’s four grid fins at the aft section of the rocket which are supposed to provide ascent guidance and stability. 

The foam would eventually break free from the control surface, but in doing so caused the IV (no. 4) grid fin to snap-back thirty degrees in an attempt to regain control. This dramatically changed the vehicle’s trajectory, resulting in excessive aerodynamic loads and vehicle breakup. 

In response to the investigation, it is understood that iSpace has mitigated any future risk of this failure mode repeating, and Tuesday’s launch verified this as witness video footage prove the vehicle progressed through first stage flight nominally. Even before this failure, significant design changes were seen between the first two Hyperbola-1 vehicles to fly, alluding to iSpace’s continued evolution and adaptation of the vehicle. 

Whilst Tuesday’s mission progressed further than previous, it was off-nominal with the presumption of payload loss, therefore another investigation will be launched into what exactly caused this mishap.

Rise of China’s commercial space

This private Chinese launch company, formally known as Beijing Interstellar Glory Space Technology Ltd. (“Interstellar Glory”), has achieved a milestone for the country, being the first commercial company to have achieved orbit and one of few private companies to do so in the world. Formed in 2016 and based in Beijing, iSpace’s current fleet consists of both suborbital and orbital rockets utilizing solid propellant. 

The company’s first flight was with the suborbital Hyperbola-1S rocket, which took off from Hainan Island in April 2018. The flight reached an altitude of 108 km, above the internationally-recognized boundary of space.

Five months later, in September, the Hyperbola-1Z debuted at Jiuquan Satellite Launch Center, also reaching an apogee of 108 km but with commercial payloads onboard, delivering three such payloads above the Karman Line. 

Hyperbola-1 is iSpace’s current and only orbital launch vehicle, taking the title of China’s first orbital commercial launcher. With four solid propellant stages, standing 24 meters tall, 1.4 meters in diameter, and with 770 kN of thrust, the launcher is specifically suited toward the small-satellite market. The vehicle is capable of delivering up to 300 kg into a 500 km Sun-Synchronous Orbit (SSO).

With the small-satellite market forecasted to grow internationally, iSpace hope to utilize Hyperbola-1 in capturing much of China’s commercial small-sat sector, something many of China’s medium and heavy-lift launchers operated by the government owned China Aerospace Science and Technology Corporation (CASC), do not cater for by nature. 

Render of the planned reusable Hyperbola-2 rocket – via iSpace

The most upcoming of iSpace’s developments is Hyperbola-2, notably moving away from the company’s dependence on solid propellant vehicles by using liquid methane and liquid oxygen fueled JD-1 engines, taking up to 1,900 kg to Low Earth Orbit (LEO). Also of note is the vehicle’s plan to be partially reusable, with the first of its two stages to be recovered via propulsive landing.

Along with JD-1 hotfires, the company was recently seen testing the vehicle’s aerodynamic guidance in the form of grid fins for Hyperbola-2. Vertical takeoff and vertical landing (VTVL) “hop” tests are also planned.

Further developments for the company include tapping into the suborbital tourism market with their own space plane, whilst also expanding their orbital payload capability by developing the reusable Hyperbola-3 (SQX-3) family of rockets.

The Hyperbola-3 (SQX-3) variants of vehicles will use the in-development JD-2 engines, also using liquid methane and liquid oxygen as their propellants. As seen by the landing legs and grid fins on the first stage and boosters, iSpace intends to recover these via propulsive landing. In this sense, Hyperbola-2’s development, testing, and flights will aid Hyperbola-3’s recovery efforts. 

While both Hyperbola-1 launches were unsuccessful, these have been the only Chinese launch failures this year. The CASC operated Long March series of rockets have successfully completed 24 orbital launches in 2021.

(Lead photo prior to Hyperbola-1’s maiden flight – via iSpace)

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