Reusable Vehicle Testing

RVT
Function Technology demonstrator for liquid propulsion based VTOL rocket flight
Manufacturer ISAS/JAXA
Country of origin Japan

The Reusable Vehicle Testing (RVT) project was conducted by the Japanese Space Agency (JAXA) from 1998 until 2003. The project involved a series of experimental vehicles to test repeated flights of a reusable rocket. Four complete vehicles were developed during the project. The design of the experimental vehicles addressed various technical challenges for future Reusable Launch Vehicles (RLV) such as flight on demand, quick turnaround, higher performance, lightweight structures and materials.

The project involved ground and flights tests with the flight testing conducted at the Institute of Space and Astronautical Science (ISAS) Noshiro Rocket Testing Center in the northern part of Japan's main island.[1]

Naming Conventions

The four vehicles developed during the project were assigned the designations RVT #1 to RVT #4.

Each of the ground and flight test experiments was assigned a name from RVT-1 to RVT-11.

RVT # 1

The first aircraft was developed with the following features:

  • Liquid hydrogen and liquid oxygen propellants stored in spherical metal tanks
  • Engines in a group, have been simplified as a gas is pressurized. The thrust of the functions needed for vertical takeoff and landing, the thrust is not biased.
  • Attitude control by high-pressure nitrogen gas.
  • Complete airframe consisting of engine frame at the base, internal fuel and oxidizer tanks (oxidizer above the fuel), nitrogen gas tanks and attitude control system mounted at the top of the airframe. The frame around the bottom of the tanks is attached to helium pressurant. The aeroshell (a moulded cover to reduce air resistance) was not installed.
RVT Vehicle #1 Tests
Dates Test Designation Remarks
August 24 to September 5, 1998 RVT-1 During the period August 24 to September 5, 1998, tests of the engine thrust characteristics were conducted with the majority of the airframe fixed to a test stand. Data was obtained to verify the effective control of the thrust level.
October 23 to November 8, 1998 RVT-2 During the period October 23 to November 8, 1998, ground tests were conducted with the vehicle in a state almost the same as flight. Tests were conducted to measure the engine thrust and control characteristics under the environmental conditions expected during flight and to verify the operation of the navigation guidance and control system.
March 13 to March 26, 1999 RVT-3 During the experiments of period March 13 to March 26, 1999 the vehicle was flown for the first time. In the first of two flights the vehicle reached an altitude of 0.7m and translated horizontally a distance of 0.5m. The second flight achieved 4m altitude and 3.5m horizontal translation. The duration of the second flight was 11.5 seconds.

RVT # 2

This vehicle was used for experiments intended to test improvements that increased the flight range.

  • Design engine durability
  • Navigation by GPS
  • Aeroshell
RVT Vehicle #2 Tests
Dates Test Designation Remarks
March 6 to March 23, 2000 RVT-4 The majority of the airframe was fixed to a test stand and tests confirmed the thrust characteristics of the new engine.
July 17 to August 4, 2000 RVT-5 Assembled and tested in the form of a plane flight. From the second half of the aeroshell attached experiments, the influence of takeoff and landing (the heat of the engine bouncing off the ground) and hydrogen leakage (in the aeroshell) and detection was confirmed.
June 9 to June 26, 2001 RVT-6 Included a total of six flights. In the first flight the altitude was increased to 10m. The second flight reached 20m altitude, tested the GPS and had an error of the landing site of just 5 cm. The third flight reached 22m altitude. Four flights of the period's six, took place in three and a half days.

RVT # 3

This test vehicle was developed to accumulate the necessary technology needed to reach an altitude of 100 km.

  • Composite tank for liquid hydrogen
  • High-performance engine and injector
  • Refinement of the operational factors for re-usability
  • Expanded range of flight
RVT Vehicle #3 Tests
Dates Test Designation Remarks
December 2001 RVT-7 A stand-alone firing test of the engine. The rocket testing center at Ishikawazimaharima Heavy industries (in Aioi City in Hyogo Prefecture) was used to verify the performance of a new injector for the RVT engine.
March 14 to 3 March 30, 2003 RVT-8 Included five engine firing tests experiments and featured a new lighter vehicle with composite propellant tanks.
October 14 to November 1, 2003 RVT-9 Three flights reaching a maximum altitude of 42m.

RVT # 4

This vehicle was built as a practical reusable rocket, demonstrating a number technologies.

  • Engine pressurization was by a gas turbo pump including capability to change the formula
  • Liquid oxygen tank made from composite materials
  • SURASUTA oxygen gas by using hydrogen gas attitude control, propellant engine integration
RVT Vehicle #4 Tests
Dates Test Designation Remarks
November 12 to November 16, 2006 RVT-10 Included eleven ground firing tests. The turbo pump engine design was tested for re-usability, controllability and life-time.
September 3 to October 6, 2007 RVT-11 Included three turbopumps tests. Testing was conducted at the ramjet engine test facility at the JAXA Kakuda Space Center. The tests characterised the new design's liquid hydrogen turbopump, in particular the improved reliability and thrust response.
11 October to mid-December, 2007 RVT-12 The second turbo pump engine ground firing tests. JAXA Multi-Purpose Experiment at Noshiro 4 in the ground firing tests, thrust control functions and high-response, the data obtained engine start-up and looked fixedly at the lower fuel consumption in-flight re-ignition in the future.
December 2008 RVT-13 The turbo pump engine firing tests. JAXA Multi-Purpose Experiment at Noshiro thrust in an 8 kN firing test using the expander 9 turbopump. Check the suitability of such systems and aircraft characteristics and limitations of the engine test of the step response and frequency response of the quasi-static and dynamic thrust control, the examined the limits of deep throttling.
2009 RVT-14 Formula 3 engine turbopump ground firing tests. JAXA ground firing tests in the multi-purpose test-bed at Noshiro. The thrust characteristics of 70% over the promotion of high-thrust zone, to assess the suitability of the system to obtain data about the aircraft thrust control characteristics.

Future Developments

JAXA proposes to develop a reusable high altitude rocket based on the technologies demonstrated in the RVT project. The rocket would take a payload of about 100 kg to an altitude of 100 km. RVT-derived equipment such as engines and attitude control will be used. The development and flight testing is expected to take 5 years and the cost is estimated at 50 billion yen. The rocket, capable of five flights in a day. The cost per flight, based on 2500 flights, is expected to be 10,000 yen, reducing the per flight cost compared to current day expendable rocket systems, which cost between 2 and 6 billion yen. The experimental payloads will be recovered after the flight, which will also minimize costs for the payload developer. Moreover, it will be possible to stop and hover the vehicle at any altitude, which is impossible with conventional sounding rockets.

See also

References

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