Spaceflight Insider

Smallest orbital-class rocket launch ends in failure

The SS-520-4 rocket zips off the launch pad at the Uchinoura Space Center in Japan to send a 6-pound (3-kilogram) CubeSat into orbit. Photo Credit: NVS Live

The SS-520-4 rocket zips off the launch pad at the Uchinoura Space Center in Japan to send a 6-pound (3-kilogram) CubeSat into orbit. The vehicle stopped sending telemetry some 31 seconds later. Photo Credit: NVS Live

Launching out of Japan’s Uchinoura Space Center at 8:33 a.m. Japan Standard Time on Jan. 15 (23:33 GMT on Jan. 14), 2017, was a rocket poised to be the smallest and lightest to ever send a payload into orbit. However, telemetry for the fin-stabilized sounding rocket, called SS-520-4, was lost after the first stage finished its 31-second burn.

According to SpaceFlight101, all telemetry from the vehicle was lost after the first stage finished firing and tracking data showed debris from the rocket falling into the Pacific Ocean.


The TRICOM-1 CubeSat. Photo Credit: JAXA

The SS-520-4 was a modified sounding rocket originally designed to send a payload into sub-orbital trajectories. Its base design was a two-stage solid-propellant rocket, the SS-520 (which is itself an evolution of the single-stage S-520). This flight added a solid-fueled third stage.

The Japan Aerospace Exploration Agency (JAXA) hoped this one-off experiment, with a budget of $3.5 million provided by Japan’s Ministry of Economy, Trade and Industry, will show an inexpensive launch concept using already available technology is possible. The goal of the flight was to collect data for a future dedicated CubeSat launcher. It is unclear if this failure will impact any future launch vehicle design.

The S-520 first stage design has flown 29 times as a dedicated sounding rocket since 1980. The two-stage SS-520 has launched twice with a payload capacity to send some 300 pounds (140 kilograms) of payload on trajectories peaking between 430 miles (700 kilometers) and 620 miles (1,000 kilometers).

With a third stage added, the SS-520-4 was expected to be able to send a small CubeSat to an orbital velocity of more than 17,000 mph (27,000 km/h).

Together, the whole stack was about 31 feet (9.5 meters) tall and 20 inches (52 centimeters) wide. Its liftoff mass was only 5,732 (2,600 kilograms). The first stage itself weighed about 2 metric tons and had an average thrust of 31,500 pounds (140 kilonewtons).

At launch time, the S-520 first stage fired for about 31.7 seconds and accelerated the whole stack to a speed of about 1.2 miles (2 kilometers) per second.

Had everything continued as planned, a coast phase lasting about 30 seconds would have come next. Then the payload fairing would have separated at about 78 kilometers in altitude. The first stage would have detached one second after payload fairing jettison.

Next, at two minutes and 50 seconds, the 5.6-foot (1.7-meter) long second stage was supposed to begin spin stabilization using onboard nitrogen tanks before firing its engine for about 24.4 seconds.

This would have accelerated the stack to about 2.2 miles (3.6 kilometers) per second some 3 minutes and 45 seconds before it too would have separated, leaving the small third stage in control of the flight.

The third stage, which was about 31 inches (80 centimeters) long, would have then fired for three seconds after stage separation and burned for 25.6 seconds to reach its intended orbit of about 180 kilometers by 1,500 kilometers at a 31-degree inclination relative to Earth’s equator.

Payload separation would have come next and taken place some 7 minutes, 30 seconds after leaving Japan at an altitude of some 124 miles (200 kilometers) and 1,120 miles (1,800 kilometers) downrange.

Unlike traditional CubeSats, which are deployed using an injection system, this satellite was to feature a base-mounted separation system connected to the third stage of the rocket.

The payload, TRICOM-1, was designed and built by students at the University of Tokyo. It was to be an educational communications and Earth observation CubeSat measuring 4.6 by 4.6 by 13.6 inches (11.6 by 11.6 by 34.6 centimeters). It weighed 6 pounds (3 kilograms).

It had five small cameras, store-and-forward communication equipment, and would have been powered by solar cells and batteries. TRICOM-1 would have had an operational life between one and three months before atmospheric drag would have caused the CubeSat to re-enter Earth’s atmosphere.

Video courtesy of NVS



Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity.

Reader Comments

Maybe the wiring in the image explains the failure? 😉
ULA has promised to launch a cubesat for free each year, so the Japanese could’ve saved their $3½ millions for nothing.

Richard Sommery-Gade

Nothing is ever easy. Try try again.

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