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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 Collect data
T = +2 min 50 sec Reverse motor
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) Event
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 SEM-04 activated
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 SEM-04 deactivated
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 Henshaw)

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). [ paper (1.1 MB PDF) | presentation ]

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.

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: