3-D Sprags and Rollers
EVA Roller Wrench
Commercial Roller Wrench
Awards and Recognitions
Space Experiment Module Flight
This is the logo we designed for our experiment.
The NASA/Goddard Space Flight Center (GSFC)'s Shuttle Small Payloads Project has developed an educational opportunity to fly experiments aboard the Space Shuttle in their Space Experiment Module (SEM). We took advantage of this opportunity by flying a three-dimensional (3-D) roller mechanism on STS-95 in the fall of 1998.
The goal of the experiment is to study how the 3-D rollers behave in a period of extended micro-g and the experimental set-up is shown in Figure 1.
Figure 1 ¥ 3-D Roller SEM Experiment
The motor turns the 3-D roller mechanism in the free-spin direction for a few seconds and then for one second, it will reverse and apply 30 in-lbf of torque, reverse again and continue to apply torque in the free-spin direction. Backdrive and applied torque data is collected every two hours. Here is a sample data run:
T = 0 sec
Turn on the electronics
T = +1 sec
Turn on the motor
T = +2 min 40 sec
T = +2 min 50 sec
T = +2 min 51 sec
Reverse motor again (so that it is going in its original direction)
T = +3 min 01 sec
Stop collecting data
T = +3 min 02 sec
Turn off motor and electronics
Our SEM was then integrated in a Get Away Special (GAS) carrier as shown in Figure 2.
Figure 2 ¥ Integration of SEM into the GAS carrier
Photo courtsey NASA/GSFC Public Affairs
The GAS canister was then shipped to the Kennedy Space Center, arrived on the 31st of August 1998, and was installed on SPARTAN 201 Flight Support Structure (FSS).
Launch of STS-95 occurred on Thursday, 29 October 1998 at 2:19pm EST (1920 UT). A picture that NASA Public Affairs took is shown below in Figure 3.
Figure 3 ¥ Launch of STS-95
Photo from NASA/KSC Public Affairs web site
Figure 4 shows the GAS canister that our SEM is inside. We sat in Bay 10 of the Orbiter mounted on the SPARTAN FSS. One of the end caps of the GAS can appears inside the circle and the rest of the canister goes back into the picture towards the aft end of the Cargo Bay.
Figure 4 ¥ SEM-04 on-orbit
Photo captured from NASA TV by Dr. Ruthan Lewis
We received word that SEM-04 was activated at 6 hours, 25 minutes, and 40 seconds after launch (at 8:45pm EST). The timeline described above ran for 6 days, 6 hours, 45 minutes, and 5 seconds which means the experiment stopped running and data collection ceased on Thursday, 5 November 1998 at 3:30am EST. SEM-04 was deactivated on the 5th of November at 4:03pm EST (7 days, 1 hour, 43 minutes, and 50 seconds after launch). Here is a quick summary of the timeline:
|Mission Elapsed Time (MET)
||Eastern Standard Time (EST)
|0 day : 0 hr : 0 min : 0 sec
||29 Oct 98 14:19:34
||Launch of STS-95
|0 day : 6 hr : 25 minutes : 40 sec
||29 Oct 98 20:45:14
|6 day : 6 hr : 45 min : 5 sec
||5 Nov 98 03:30:19
||Timeline stopped running and data collection ended
|7 day : 1 hr : 43 min : 50 sec
||5 Nov 98 16:03:24
|8 day : 21 hr : 44 min : 56 sec
||7 November 12:04:29
||STS-95 landing (wheels stop)
Our experiment was delivered back to us on December 16, 1998. Take a look at the complete integration and deintegration timeline of the SPARTAN 201-05 experiment to find out when we were actually mounted in the Cargo Bay of the Orbiter.
On the 8th of January 1999, the STS-95 crew visited GSFC and we had the opportunity to meet them and show them our experiment.
Crew on stage discussing their mission
(from left to right: Payload Specialist John H. Glenn Jr., Payload Specialist Dr.
Chiaki Mukai, Mission Specialist Pedro Duque of Spain, Mission Specialist Dr. Scott E. Parazynski,
Mission Specialist Stephen K. Robinson, Pilot Steven W. Lindsey, and Commander Curt Brown)
SEM team showing the crew members the wrench
(from left to right: Kris Edwards, Brian
Roberts, Curt Brown, Stephen Robinson, Scott Parazynski, and Steven Lindsey)
John Glenn meeting the SEM team
(from left to right: John Glenn, Kris Edwards,
Brian Roberts, Glen Henshaw, and Laurie Shook)
John Glenn inspecting the "ratchetless" wrench
(from left to right: John Glenn, Mike Pang, Brian Roberts, Laurie Shook, Glen
Figure 5 ¥ STS-95 Crew's Visit to GSFC
Photos courtsey of NASA/GSFC Public Affairs
A good summary of our experiment set-up and results can be found in:
- Roberts, B., Shook, L., Hossaini, L., and R. Cohen, "Analysis of Three-Dimensional
Roller Performance in a Micro-g Environment," in 1999 Shuttle Small Payloads Project Symposium
Proceedings, NASA-CP-1999-209476, 13-15 September 1999 (also published as SSL Document Number 99-010).
For some cool pictures of our experiment and the SPARTAN 201, check out:
Here are some links related to our experiment inside the SEM:
Our experiment received plenty of media coverage.
- "Student's Space Wrench to Get Test on Glenn Shuttle" (22 October 1998 University of Maryland Press Release)
- "Historic John Glenn Flight To Feature Maryland And Goddard Science Experiments" (October 1998 edition of Goddard News, Volume 2, Number 42)
- Interview on Prince George's TV news (October 27, 1998)
- Interview on WMAL (October 27, 1998)
- Interview on DC News channel 9 news (October 27, 1998)
- Pieces of Upper St. Clair to hit space: Students'
projects to blast off with Glenn, Shuttle (October 28, 1998 article in the Pittsburgh Tribune Review)
- "Grad student designs Glenn's space wrench" (29 October 1998 article in the The Diamondback, Number 43)
- "Grad student walking on air as his wrench blasts off" (29 October 1998 article in the The Prince George's Journal)
- Story on Discovery News on the Discovery channel (October 30, 1998)
- "UM graduate student's project goes aloft with Glenn: Space socket wrench to undergo testing" (30 October 1998 article in the Baltimore Sun)
- "Student's Wrench Getting First Real Space Test on Discovery's Flight" (3 November 1998 article in the Outlook: The University of Maryland Faculty and Staff Weekly Newspaper)
- "Flight test area man's handiwork" (November 4, 1998 article in the Youngstown Vindicator)
- "A Wrench That is Out of This World" (5 November 1998 article in Prince George's Sentinel)
- "Wrenching experience" (12 November 1998 article in the Canfield Town Crier)
- "A Wrench from Space" (March 1999 article in the Home Technology Newsfront section of Popular Science)
- "Tools of the Trade" (Winter 1999 article in College Park Magazine)
- "Bringing Space Technologies Down to Earth" (NASA's Goddard Space Flight Center 1998 Technology Transfer Report)
We teamed with two school districts:
To learn more about the mission, check out the following:
Fortunately with Senator John Glenn flying on STS-95, there was plenty of coverage of his return to flight: