Dryden Drop

Overview...DDT@PSU

The Dryden Drop Tower (DDT) is a laboratory facility at PSU with which to conduct fundamental and applied research in a near weightless environment. The experiments conducted are valuable for the development of mathematical and computer models for predicting the behavior of unearthly phenomena that occur aboard spacecraft. Much of the specific projects support collaborative research activities with NASA. Important DDT characteristics,features, acknowledgements and list of major  donors are provided below. (DDT@PSU FAQ)
 
At the university level, the DDT is a suitable tool to introduce students to 'micro-gravity' phenomena common aboard orbiting spacecraft. The brief time afforded by our tower (2.13 seconds) provides ample time for many fluids, combustion, and materials science investigations. Graduate research as well as undergraduate student projects gives students exposure to and experience in designing equipment and experiments to meet the unique requirements of such an environment. These experiences are essential to the successful design and analysis of robust systems for actual spacecraft. Terrestrial applications of low-gravity drop tower studies are common.
 
At the k-12 level, the DDT is a perfect tool with which to introduce students to concepts such as gravity, displacement, velocity, acceleration, and aerodynamic drag as well as a wide range of gravity-masked phenomena. Curiosity-driven studies are fun, strange, and always educational, providing STEM activities at all levels.
 
The general public, industry, and other institutions are welcome to inquire about the tower capabilities and availability.
 
DDT Characteristics:
Tower height: 31.1m (102ft)
Free fall distance: 22.2m (73ft)
Low-g time: 2.13 sec.
g-level:  < 10-3go
Deceleration distance: ~ 3.5m
Drag Shield mass: 115kg
Experiment mass: < 50kg
Peak deceleration: 15go
Average deceleration: 8.5go
Automated Retrieval: 3 min.
 
Cable-Guided Drag Shield Approach
Open Enclosure
Magnetic Field/Eddy Current Deceleration
Air Collet Release Mechanism
Single Floor, Single Person Operation
Aesthetic, Public Space
 
 
Concept
The overarching concept for the DDT design stems from the collective drop tower design and research experience of the DDT Board (Y. Chen, T. Snyder, and M. Weislogel). That said, it is clear that the DDT draws significant inspiration from the2.2s Drop Tower at NASA’s Glenn Research Center in Cleveland Ohio. The 2.2s NASA tower is one of the most user friendly and productive facilities in the world and has conducted over 26,725 drops since its creation in the early 1960s. The 2.2s NASA tower also served as an inspiration for the later approach of Snyder (WSU-to-UFL) whose developments and innovations fed back design improvements to the NASA tower and others as well, including the DDT (i.e. Spain, Australia and other small towers in the USA, seelinks). (General information for drop towers may be found here, with the largest facilities operating now in China, Germany, Japan, and the U.S.)
 
Detailed Design and Build
The DDT project was initiated to celebrate the lasting contributions of outgoing Dean, Robert Dryden, to the Maseeh College of Engineering and Computer Science at Portland State University (Spring 2008). The resources for the work, including significant in-kind donations, were made available through a nearly spontaneous chain of events by generous MCECS Board members, Portland area industry leads, alumni, and friends of the university. The monies were matched in part by the state of Oregon. The drop tower was viewed as not just a means to conduct micro-gravity research, but more broadly to support under/graduate coursework and expand STEM-related outreach to our community. The work was managed by Howard S. Wright Constructors and split into PSU and Contractor components. The PSU component included the design requirements, drag shield, deceleration system, experiment platform, release and recovery stage, controls and control programming. These tasks were taken on by individual graduate students and graduate and undergraduate student teams. The contractor components concerned the tower architecture, structure, materials selection, electrical, controls, assembly, and management. The DDT differs from other university drop tower projects because of the significant influence of the professional team. A steady stream of ideas from these folks and the skills to complete them on time and within budget made this a most unique and enjoyable project.
 
 
Blue lights at nightDavid Evans and Associates, Inc.:  www.deainc.com/
EC Company:  www.e-c-co.com/
FocusMicro:  www.focusmicro.com/

Ray and Betty Guenther
Howard S. Wright Constructors:  www.howardswright.com/default.aspx
IBM Corporation:  www.ibm.com/us/en/
KPFF Consulting Engineers:  www.kpff.com/index.asp
NECA/ IBEW 48:  www.necaibew48.com/
Opto 22:  www.opto22.com/

Philips Color Kinetics:  colorkinetics.com/
Platt Electric Supply:  www.platt.com/
The Massiah Foundation: www.massiah.com/
Morgan and Constance Pope
Bill and Julie Reiersgaard
Schnitzer Steel:  www.schnitzersteel.com/

Henry and Janice Schuette
Solus, Inc.:  www.solusinc.org/

Scott and Judy South
TriQuint Semiconductor, Inc.:  www.triquint.com/
ZGF Architects LLP:  www.zgf.com/
 
 
Further Thanks...
 
We are also grateful for the creative technical input of Bassam Bazzi, Craig Briscoe, Jon Orrell, Blake Patsy, Dan Pelissier, Hal Pietrobono, John Raglione, Bill Reiersgaard, Dave Salisbury, and John Thompson, ... and to PSU personnel Jennifer Chambers, Danielle Cox, Bob Dryden, Debbie Hutchins, Francis McBride, Gerry Recktenwald, and Renjeng Su, ... A special thank you to Morgan Pope for teeing us off.
 
PSU Students: Donald Bell, Jenna Bell, Shubham Chopra, Cam Long, Corey Monk, Daniel Mullen, Xincheng Ren, Josh Stratton, Phu Tran, Beenish Zia, Zdenek Zumr, ... 
 
Alumni: Ben Semerjian, Matt Thomas, James Kubli
 
DDT Board: Yongkang Chen (PSU), Trevor Snyder (Xerox), Mark Weislogel (PSU)
 
Special Product Providers
 
DDT Structure: Timblin Group
Latches: Hartwell
Falling parts fabrication: BBC Steel