❱ ❱ Extreme drop testing involves the use of a Chinook helicopter to hoist the launcher to a height of 5km before releasing it to fall into the ocean


❱ ❱ Thermal Vacuum testing exposed parts of the Solar

❱ ❱ Vibration testing takes place in the launch configuration with antennas, solar panels and other appendages in their stowed positions

suspended parts, while simulating the weightlessness of space. To enable each off-load rig to protect the deployable hardware, the spacecraft had to be orientated during each test so that the plane of the deployment was parallel to the ground. Once the tests were completed, all of the deployed items were re-stowed and small hold-down-and-release devices were attached to them, ready to be fired after completion of the vibration test campaign.

VIBRATION TESTING The two-part mechanical vibration test phase has started and will continue during the summer of 2019. It is designed to verify the suitability of the spacecraft to survive the lift-off and journey to reach its operational orbits around the Sun. The first part involves a sine vibration

test on an electro-mechanical shaker, replicating the powerful thrust of the Atlas V launcher, sudden engine cut-offs and lateral wind shear events throughout the launch and ascent. The sine vibrations are applied

separately up to a frequency of 100 Hz

Orbiter to the intense levels of radiated heat expected to be encountered when orbiting the sun

Extreme solar and vibration testing are not the only environmental ordeals that space vehicles are subjected to. Re-usable equipment also needs to be tested to ensure its re-usability once it has plummeted back down to earth. One such test was recently

in three axes with a series of low-level signature runs to determine whether the structural integrity changes. This stage has been successfully completed and was followed by acoustic tests, which covered the frequency spectrum from just below 100 Hz to 8 kHz. The largest excitations in the acoustic chamber existed in the approximate range of 100 to 500 Hz. A number of tests were undertaken as the acoustic noise pressure was steadily increased toward the final required qualification levels. Now, all the deployable appendages on the spacecraft are being deployed again, using the off-load rigs. This time, however, the various hold-down devices are all being fired to simulate post-launch deployment of both antennas, the solar arrays and the instrument boom. The boom has two phases of deployment, but only the first can be effectively deployed on the ground. These deployed structures will then be

returned to their stowed configuration and the hold-down release mechanisms will be re-commissioned, ready for flight.

carried out by the El Arenosillo Experimentation Centre in Spain on the Miura 5 orbital microlauncher. Miura 5 is designed to launch small satellites of up to 300kg to low Earth orbit and weighs 14 tonnes at liftoff. For the test, a Chinook CH-47

helicopter lifted the 15m long Miura 5 demonstration first stage section to an altitude of 5km then dropped it over a controlled area of the Atlantic Ocean, 6km off the coast of Huelva in southern Spain. During the descent, electronic

systems inside the demonstrator controlled a carefully timed release of three parachutes to slow it down until its splashdown at a speed of about 10 m/s. A team of divers recovered the demonstrator and hoisted it onto a tugboat, which returned to the port of Mazagón. The demonstrator appeared intact and is now at PLD Space in Elche, where it is undergoing inspection and further analysis. PLD Space is also using its

experience of such testing on the ESA’s Future Launchers Preparatory Programme.

Climatic & Vibration Testing Vol 2 No. 1 /// 3

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