Following the launch of South Korea’s first homegrown space rocket Nuri, another challenge for space will be made on Jeju Island.Jeju’s provincial government said Tuesday that the Korea Advanced Institute of Science and Technology (KAIST) will test the launch of a science observation rocket in Hangyeong-myeon township on the island to commemorate its 50th anniversary by the end of this year.The test is aimed at tracing the trajectory flight of a small liquid-propelled rocket with a length of 3 meters and a diameter of 20 centimeters.Hankyeong-myeon is an ideal site for rocket launches since it is located outside the airspace of private airports and military bases.
As the Korean launch vehicle Nuri (KSLV-II), made with pure domestic technology, achieved 'half success', while foreign media are paying attention to our rapid development of space science and technology, the Korea Advanced Institute of Science and Technology (KAIST), together with Perigee Aerospace (hereinafter referred to as Perigee), a rocket-making startup created by undergraduate students, is planning to launch a rocket from Jeju in December to mark the 50th anniversary of the school's opening this year.<snip>Dowa and KAIST selected Yongsu-ri, Hangyeong-myeon, Jeju-si as the launch site, and completed discussions with residents.Researchers from the Department of Aerospace Engineering at KAIST are stationed in Yongsu-ri Village to prepare for launch. The final launch test is expected in early December.Perigee is a start-up company that aims to develop an ultra-small space launch vehicle. CEO Shin Dong-yoon is a 24-year-old fourth-year undergraduate, but he has already been in business for 6 years.This launch is an experiment in ballistic flight of a small liquid-propelled rocket 3m in length and 20cm in diameter. Ultimately, the first liquid methane-based test projectile will be launched into space at an altitude of 100 km or higher.
2021.12.29. Blue Whale 0.1 launch @ Jeju IslandPerigee Aerospace Inc.Rocket failed to follow an intented flight trajectory due to strong wind, and an on-board AFTS terminated the flight.It was an unsuccessful attempt but the team was able to test important hardware to be used on our upcoming orbital launch vehicle (engine, cryo valves, flight computer, telemetry, ground software… etc.)
In a remote coastal area on the southern resort island of Jeju on December 29, Perigee Aerospace launched a test rocket with a length of 3.2 meters, a diameter of 19 centimeters, and a weight of 51 kilograms, using ethanol and liquid oxygen as fuel. It was aimed at building experience and checking the combustion of a liquid propulsion engine and the performance of pre-set flight and trajectory, communication, and navigation devices.After flying for several seconds, the suborbital rocket called "Blue Whale 0.1" came down drawing a trajectory like a shell and fell into the sea with its parachute open. After the rocket was recovered by a civilian fishing boat, Perigee Aerospace CEO Shin Dong-yoon admitted failure, saying the rocket lost its track due to a gust of wind that activated the rocket's automatic flight suspension system. "At the moment the rocket took off, there was a much stronger gust than expected," Shin told reporters. "The wind sent it flying off course and the automatic flight suspension system stopped its engine." However, Shin was not totally disappointed, saying the failed launch conducted in collaboration with the Korea Advanced Institute of Science & Technology (KAIST provided a good experience.
Perigee LOX-LNG upper stage engine prototypes being test fired at rocket development facility in Daejeon, Republic of Korea.ㅤHere, two different test configurations are shown:First one is a copper calorimeteric chamber to characterize injector and propellant supply performance.The second one is a flight-like ablative chamber to characterize long duration performance and temperature variations.ㅤNote the plume shapes are different between the two, as the ablative version has a larger nozzle exit angle to connect a nozzle extension.
With static fire completed, we're now preparing for the 3rd and the last flight of the BW-0.1.
Additionally, this BW0.1v3 vehicle is run by an upgraded flight software with an improved aerodynamic model.
I counted only one launch so far, when was the second?
Second flight of the Blue Whale 0.1 🚀— December 29, 2021.Rocket failed to follow an intented flight trajectory due to strong wind, and an on-board AFTS terminated the flight. It was an unsuccessful attempt, but the team was able to test some important hardware for our next test vehicle.
First flight of the sounding rocket — Dec. 05, 2021.Jeju launch center, Jeju, Korea
The perfect propellant tank doesn't exi-⠀Perigee structure team is testing the propellant tank for the BW-1 upper stage at cryogenic temperature and a maximum expected operating pressure (MEOP).⠀The upper stage engine is pressure-fed for a simple and robust design. So, the tanks should supply propellants to the engine inlets at about 20 bar (290 psi).⠀Normally, this kind of high pressure can only be dealt with by a thick-walled pressure vessel. Not to mention they are soooooooooo heavy for launch vehicles.⠀To reduce the mass, the BW-1 propellant tanks are made of carbon fiber composites. And as the result, the upper stage propellant tank weighs just 20 kg.⠀There are, however, some technical problems when using CFRP for rocket fuel tanks.⠀Firstly, the cryogenic temperature of rocket propellants makes most materials brittle and easy to break at a relatively weak shock and vibration. Therefore, it is essential to keep the resin system somewhat “ductile” even at cryogenic temperature.⠀Secondly, the CFRP (Carbon Fiber Reinforced Plastic) sounds cool but is literally a plastic and even a small shock can trigger fierce combustion in an oxygen-rich environment. To prevent the propellant tanks from becoming a hybrid rocket grain during the flight, special additives were added to increase the activation energy of the wall matrix.⠀Lastly, joining metallic parts was extremely difficult due to CTE difference between CFRP and metals. A special bonding agent that remains elastic over a wide range of temperature (and should also be LOX-compatible) was developed to attach upper and lower bosses, a common dome, and a LOX transfer tube submerged inside the LNG tank.
Their numbers in the table seem to be a bit confused, I don't understand how the rocket could carry 170kg to SSO but only 150kg to unspecified "LEO." Since elsewhere on the site it's said that the rocket carries 150kg to LEO, I'm going to assume the numbers were just swapped in the table and it should be 170kg to "LEO."Also, while IANARS and I sometimes have gotten in trouble for looking too closely at numbers, I don't understand how the upper-stage engine has just 4.3kN of thrust. For comparison, Electron's vacuum Rutherford has 25.8kN, six times as much. Sure, that's the uprated Electron which carries 33% more payload to SSO, but unless the first stage is doing significantly more of the work, I don't see how the second stage gets the job done.And if the first stage is doing significantly more of the work...then that's an interesting design decision and I'd be curious what the community thinks about it.