Japan planning to upgrade HTV cargo spacecraft
The Japan Aerospace Exploration Agency, or “JAXA”, wants to upgrade its homegrown H-II Transfer Vehicle (HTV ), also known as Kounotori, an automated cargo spacecraft used to resupply the International Space Station (ISS). On Wednesday, May 20, 2015, the country’s Education, Culture, Sports, Science and Technology Ministry unveiled the plan to improve the HTV craft at a meeting of a panel of space development experts.
The ministry is looking to include relevant expenses in its budget estimate for the next fiscal year if the plan is approved by the government’s Committee on the National Space Policy.
The HTV spacecraft is 13 feet (4 meters) across and about 33 feet (10 meters) in length and an estimated mass of 10.5 tons. Manufacturing and maintenance costs will be halved from about $165 million by reducing the spacecraft’s mass by about 30 percent while maintaining its transport capacity of some 6 tons.
The development period is still unknown.
HTV is designed to deliver supplies including food, clothes, and experiment devices to the ISS in orbit at an altitude of about 400 kilometers and return with spent equipment, used clothing, and other waste material. The spacecraft with waste material is incinerated when it makes a re-entry into the atmosphere.
The spacecraft consists primarily of three parts: a propulsion module installed at the rear and composed of main engines for orbit change, Reaction Control System (RCS) thrusters for position control, fuel and oxidizing reagent tanks, and high-pressure air tanks; an avionics module installed in the center part, with electronic equipment for guidance control, power supply, and telecommunications data processing; and a logistics carrier that stores supplies.
The development of the HTV is aimed at the practical use of a low-cost and highly reliable means of transport to the ISS. It is expected that the practical operation of the spacecraft will allow Japan to accumulate know-how that can serve as basic technology for its future projects on the Space Flyer Unit and on manned transportation.
Four HTV spaceships have been launched to space so far. The first craft was launched on Sept. 10, 2009. Five subsequent missions are planned—one each year for 2015–2019.
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