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

The 2.2 Second Drop Tower is one of two drop towers located at NASA’s Glenn Research Center in Cleveland. The tower, which began life as a 100-foot-high fuel distillation tower, dangles over a bluff at Glenn. The tower has been used for over 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.

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 in both time and money required to conduct space experiments.

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 that is enclosed in an aerodynamically designed drag shield that 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 onboard 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 7.5 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

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: 1,075 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: Ernest Williams
216-433-3554
Ernest.T.Williamsii@nasa.gov

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

Using Our Facilities

NASA’s Glenn Research Center in Cleveland provides ground test facilities to industry, government, and academia. If you are considering testing in one of our facilities or would like further information about a specific facility or capability, please let us know.

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