Proto-flight Test Research Articles

Environmental Test Program for the Mars Exploration Rover Project

On June 10 and July 7, 2003, the National Aeronautics and Space Administration (NASA) launched two spacecraft from Cape Canaveral, Florida, for 6-month flights to the Red Planet, Mars. The two Mars Exploration Rover spacecraft landed safely on the planet on January 3 and 24, 2004. Prior to the successful launch, both of the spacecraft were involved in a comprehensive test campaign that included development, qualification, and protoflight test programs. Testing was performed to simulate the environments associated with launch, interplanetary cruise, landing on the planet, and Mars surface operations. Unique test requirements included operating the spacecraft while the chamber pressure was controlled to simulate the descent to the planet from deep space, high-impact landing loads, and rover operations on the surface of the planet at 8 Torr and -130 °C (-202 °F). This paper will present an overview of the test program that included vibration, pyroshock, landing loads, acoustic noise, thermal-vacuum, and solar simulation testing at the Jet Propulsion Laboratory (JPL) Environmental Test Laboratory facilities in Pasadena, California.

Reconfirmation of the optical performances of the laser communications terminal onboard the OICETS satellite

A flight model of the free-space laser communications terminal onboard the Optical Inter-orbit Communications Engineering Test Satellite (OICETS) was well developed by the National Space Development Agency of Japan, and the Proto-Flight Test was over in January 2001. At present, the flight model of the satellite is stored in the manufacturer and waiting for its launch. The system level test of the satellite is conducted every 6 months, and the movable devices are turned on every 3 months during this storage period. The optical pointing and tracking characteristics of a laser communications terminal called the Laser Utilizing Communications Equipment (LUCE) are tested again as the terminal level test in the thermal vacuum test. The pointing and tracking accuracy, the far-field pattern of the laser transmitter, the bit error rate, and so on are verified in this reconfirmation test. The acquisition time is also measured in the ambient and vacuum conditions. The LUCE terminal maintains the optical performances in order to establish the optical inter-satellite communication link between the OICETS and an European experimental data relay satellite.