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Technical constraints

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ESA / Education / Drop Your Thesis!

While defining their projects, applicants should read the ZARM Drop Tower User Manual list of documents carefully. Additionally they should keep in mind the following constraints that apply to the experiments: 

Dimensions of the experiment

  • The overall height of the experiment shall not exceed 953 mm (short capsule) or 1,718 mm (long capsule). Warning: Only the drop mode is available for the long capsule.
  • Experiments are mounted on platforms of 700 mm diameter. Platforms are fixed by four stingers which restrict the free space to a diameter of 600 mm.
ZARM drop tower capsules
ZARM drop tower capsules

Mass in the capsule

  • The distribution of mass should be even.
  • [Drop mode, Long capsule] The maximum experiment mass is 221.2 kg.
  • [Drop mode, Short capsule] The maximum experiment mass is 264.4 kg
  • [Catapult mode] The maximum experiment mass is 161.5 kg.

For catapult experiments, the deviation of the centre of gravity shall be smaller than 1 mm with respect to the vertical axis. The catapult capsule will be finally tarred by engineers of ZARM FAB mbH as part of the capsule integration process.


Mass on the platform

  • The overall weight of a platform (including 15.5 kg for the platform itself) shall not exceed 100 kg. The mass eccentricity should be as low as possible. If mass eccentricity is too high, additional counterbalance masses (accumulated to the payload) will be mounted to the rig at ZARM.
  • Point load of a platform shall not exceed 50 kg.


Accelerations and decelerations

  • The experiment shall be able to withstand the maximum deceleration of 50 g for 200 ms. The deceleration can be regarded as a steady load rather than as an impulse. This means that holders of any item must be designed to cope with at least 50 times their normal load. A safety factor of two (100 times normal load) however is strongly recommended.
  • Catapult experiments shall be able to withstand a peak acceleration of 30 g at the beginning of the experiment.


Interfaces and setup

  • Experiments are remotely controlled via the capsule computer system.
  • The power supply is provided by rechargeable a battery pack with a nominal voltage of 24 V DC (max. 40 Amp). Experimental hardware directly connected to the power supply needs to match the operation voltage limitation with a range of 22.6 V to 30 V DC.
  • The mechanical set up should be prepared by a professional workshop technician.