2.2 Second Drop Tower

The 2.2 Second Drop Tower has been used for nearly 50 years by researchers from around the world to study the effects of microgravity on physical phenomena such as combustion and fluid dynamics and to develop technology for future space missions.

Facility Overview

Dropping in Microgravity Environment event — Students participate in the Dropping in Microgravity Environment (DIME) event.

The NASA Glenn 2.2 Second Drop Tower is one of two drop towers located at the NASA site in Brook Park, Ohio. The tower, which began life as a 100-foot high fuel distillation tower, dangles over a bluff at the Glenn Research Center. The tower has been used forover 50 years by researchers from around the world to study the effects of microgravity on physical phenomena such as combustion and fluid dynamics, and to develop new technology for future space missions.

Microgravity, which is the condition of apparent (near) weightlessness, can only be achieved on or near Earth by putting an object in a state of free fall. In this way, NASA conducts microgravity experiments on Earth using drop towers and aircraft flying parabolic maneuvers, and in space using unmanned rockets, and the International Space Station.

Multiphase flow experiment hardware integrated into a 2.2 second drop tower frame.

The 2.2 Second Drop Tower is “a gateway to space” for many of the microgravity experiments conducted on the International Space Station because these experiments often begin on Earth with exploratory testing in the drop tower. This may be followed by further drop testing to verify or optimize the design of the space hardware and to identify the best test conditions for the space experiment. As such, the drop tower is used to maximize the scientific return from experiments conducted in space. This is an important role, given the significant investment required to conduct space experiments in both time and money.

The drop tower’s 2.2 second microgravity test time is created by allowing the experiment package to free fall a distance of 79 feet (24 m). The Drop Tower uses an experiment/drag shield system to minimize the aerodynamic drag on the free falling experiment. Experiments are assembled in a rectangular aluminum frame which is enclosed in an aerodynamically designed drag shield (which weighs 725 pounds, 330 kg). This package is hoisted to the top of the tower (the eighth floor), where it is connected to monitoring equipment (e.g., high-speed video cameras and on-board computers) before being dropped. A low gravity environment is created as the package freefalls from the eighth floor to the first floor, a distance of 79 feet 1 inch (24 m). The experiment is isolated from aerodynamic drag because it is not attached to the drag shield. The experiment itself falls seven and one half inches (19 cm) within the drag shield while the entire package is falling. The drop ends when the drag shield and experiment are stopped by an airbag, located at the bottom of the tower.

Quick Facts

2.2 Second Drop Tower
Operational Parameters
Microgravity Duration	2.2 seconds
Free Fall Distance	79 feet, 1 inch (24 m)
Gravitational Acceleration	0.001 g
Mean Deceleration	15 g
Peak Deceleration	30 g
Experimental Drop Packages
Gross Drop Package Weight	1075 lbs. (487 kg) (drag shield and equipment)
Experimental Payload Weight	up to 350 lbs. (159 kg)
Experimental Payload Diameter	38 inches wide, 33 inches high, 16 inches deep (96cm x 84cm x 40cm)

Microgravity experiments are often tested in the drop tower before use on the International Space Station.
A low gravity environment is created as the package freefalls from the eighth floor to the first floor. The drop ends when the drag shield and experiment are stopped by an airbag, located at the bottom of the tower.
The drop tower’s 2.2 seconds microgravity test time is created by allowing the experiment package to free fall a distance of 79 feet (24m).

Capabilities

Operational Parameters

Microgravity Duration: 2.2 seconds
Free Fall Distance: 79 feet (24 m)
Gravitational Acceleration: <0.001 g
Mean Deceleration: 15 g
Peak Deceleration: 30 g

Experimental Drop Package

Payload Width: 38 in. (96 cm)
Payload Height: 33 in. (84 cm)
Payload Depth: 16 in. (40 cm)
Payload weight: up to 350 lbs (159 kg)
Gross vehicle weight: 1075 lbs. (487 kg)

Instrumentation/Data Acquisition

Digital and Analog Video Cameras
Analog-Digital Data Acquisition, 32 channels
24 VDC Battery Power
Programmable Logic Controller
Pressure Transducers
Flow Meters
Thermocouples
Radiometers
Lasers

Mode of Operation

Provides microgravity test environment for a fraction of the cost of conducting an experiment in space, lowest cost of all NASA ground based microgravity facilities
Can accommodate NASA, government, and private industry research programs
Twelve drops per day
Engineering staff to perform or consult on payload design
Experimenter can integrate experiment hardware into NASA provided experiment frame or facility technical staff can perform electrical and mechanical integration of payloads
Third party safety review of experiments is required

Contact

2.2 Second Drop Tower
Facility Manager: Thomas Hoffman
216-433-5637
thomas.r.hoffman@nasa.gov

Test Facility Management Branch
Branch Chief: Michael S. McVetta
216-433-2832
michael.s.mcvetta@nasa.gov

Using Our Facilities

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