What's New

• De-integration of COLLIDE-2 took place on January 18, 2002. De-integration activities consist of removing the experiment from its flight container, removing the videotapes from the cameras, removing the data loggers, and installing the experiment in its shipping container.
• Visual inspection of the experiment when it came out of the flight container indicated that significant amounts of target material had come out of the target chambers. This is consistent with the target doors opening. The target doors were all almost entirely closed. This is also consistent with nominal door functioning.
• Visual inspection also confirmed that all 6 launchers had fired.
• The data logger data showed that the temperature of the experiment was well above freezing when the experiment ran. The light sensor data logger also indicated that the LEDs on IBS 3 functioned.
• Both camera tapes were inspected at KSC. They showed that all 6 IBS's functioned nominally. When each IBS door opened, particles from the target surface sprayed into the impact chamber. This appears to be due to the electric force acting on charges on the surfaces of the particles generated either during launch or by the friction of the opening door itself. These particles present some interference in the view of the impact, but it appears to be still straightforward to determine impact coefficient of restitution and some measure of ejecta mass and velocity from the impact itself. From an initial viewing of the video it appears that 2 of the projectile velocities deviated significantly from their design velocities.
• The following types of impacts are seen in COLLIDE-2 data: (1) impact with no rebound and no ejecta; (2) impact with no rebound, but some ejecta; (3) impact with rebound and ejecta.
• Bottom line: the experiment performed excellently and science return is high.

December 13, 2001:

• STS-108 is scheduled to land at KSC on December 17. De-integration for COLLIDE-2 is now scheduled for Friday, January 18, 2002, at KSC. There will be no information on the functioning of the experiment prior to de-integration.

December 7, 2001:

• COLLIDE-2 launched aboard orbiter Endeavour and STS-108 on December 5, 2001, at 5:19:27 p.m. Eastern Time. Landing is scheduled for December 16, 2001.
• The experiment was scheduled to run 14 hours after launch after being started on launch by a NASA baroswitch at approximately 50,000 feet altitude. Astronauts verified that the baroswitch turned on and activated a back-up trigger in case the 14 hour timer malfunctioned late on December 6, 2001.
• Data will be returned with the experiment and will be available for analysis after de-integration sometime in January 2002.

September 24, 2001:

• COLLIDE-2 was successfully integrated into its Hitchhiker canister on September 18, 2001, at the Kennedy Space Center RTG facility.
• Next steps for COLLIDE-2 are for its canister to be evacuated by KSC personnel, integrated on the MACH-1 bridge, and then the MACH-1 bridge installed in the payload bay of orbiter Endeavour.

• COLLIDE-2 has come out of storage and is undergoing final pre-flight testing.  All tests conducted to date indicate nominal performance of the experiment.
• The Project Safety Review Panel meeting for MACH-1 (and COLLIDE-2) is August 28-29.
• The Pre-Ship Review is August 31.
• Integration at KSC is scheduled for September 17-19.

• November 29, 2001 has been set as the launch date for STS-108.  If that date holds, COLLIDE-2 will come out of storage in mid-July, 2001.
• Work continues on both flight and ground safety data packages.

April 10, 2001:

• Launch of STS-108 is now set for no earlier than November 2001.
• COLLIDE-2 has been in storage for several months following a successful pre-storage review last Fall.
• An eye-catching new logo has been created for COLLIDE-2 by Gayle DiBiasio at NASA Glenn Research Center.  You can see this logo at the top of the COLLIDE home page.  Thanks Gayle!
• Behind the scenes work continues toward getting all the COLLIDE-2 safety paperwork in order.

October 2, 2000:

• COLLIDE-2 is now part of the MACH-1 Hitchhiker bridge payload on STS-108 (ISS UF-1) mission currently slated for early October 2001.  Of course, that launch date may change.
• Following a summer of testing, COLLIDE-2 is now waiting to go into storage.  A Pre-Storage review will take place October 20 (2000) at LASP.  Pending successful passage of that review, the experiment will go into hiding at LASP until about June 2001, or launch minus 4 months.  At that time there will be a series of tests to verify launch readiness, and the experiment will ship to KSC for integration at about launch minus two months, or early August under the current schedule.
• The experiment is working fine, so there's not much else to report.  Look for another update following the Pre-Storage Review, and then the next event will be next year when we come out of storage for pre-ship activities.

• It has been a while since the last update, but not due to any lack of activity.  Things have been moving so quickly on so many fronts that the Web Site got left in the dust.
• The launchers were retested on the KC-135 at NASA Glenn Research Center.  Not only the launchers but also the PI's stomach behaved very well.  The data from these tests have been reduced and combined with the data from the October tests and final settings for the launchers have been made for flight.  The set screws have been potted in place and the launchers are ready to go.
• A series of vibe tests have been conducted on individual IBS's following minor design modifications to eliminate dust leaking.  These procedures appear to have been successful.
• A full vibe test was conducted on June 13, 2000, and the experiment performed nominally following vibe.
• Two data loggers from Onset Computer Corp. have been added to COLLIDE-2 to provide engineering data on internal temperature and on the activation of the internal LEDs.
• The Safety Data Package and Structural Verification Document updates have been completed.
• COLLIDE-2 is currently undergoing a steady stream of functional tests to verify reliable performance of every experiment component.
• The launch scenario looked like we might get on board the LONESTAR payload on STS-107 in May 2001.  LONESTAR is overweight, however, and COLLIDE-2 may fall off to reduce the payload mass.  A final decision has been deferred until September 2000.
• New team members Jeffrey Gonder and Darren Curtis have been helping out in this final phase of testing and assembly of COLLIDE-2 before moving full time to the new PRIME (Physics of Regolith Impacts in Microgravity Experiment) project.  Look for a new web site devoted to PRIME on the LASP web page soon.

• The camera containers have been vibration tested.  They appear to have survived the vibration test with no problems.  Long term leak tests are underway.
• The IBS door redesign has been completed and vibration tested with dust.  This test revealed large amounts of dust leaking which resulted in the door jamming.  This problem is being addressed and the IBS's will be retested.  Images from the vibe test are here.
• Retests of the launchers for final calibration will take place on the KC-135 next week at NASA Glenn Research Center.

• Prototype tests of the new IBS door assembly have been conducted with excellent performance for the new door mechanism.
• Pictures from a test of a new lighting configuration inside the IBS are available here.

• A verification review was held by video conference on January 24, 2000 between CU-LASP and NASA GRC.  The review was successful, with some minor modifications to the test plan resulting from the review.
• COLLIDE-2 is no longer a GAS payload and is no longer G-788.  We are now officially designated COLLIDE-2, which is now classified as a Complex Autonomous Payload (CAP).
• David Wilcox at the NASA Shuttle Small Payloads Program Office is the mission manager for COLLIDE-2.

January 21, 2000:

• New design drawings of IBS's and launchers are available from the COLLIDE-2 main page.

• New pictures are online, and more will be added soon, and more regularly as COLLIDE-2 enters the year 2000.  Check out the main page of COLLIDE-2 and the Images page for links to new pictures.
• The first of the two new camera container tops has been undergoing a leak test since December 2, 1999.  At that time it was pumped up to a pressure of approximately 22.0 psi, thus exceeding the pressure difference it will see when it is placed in the evacuated GAS canister by 7 psi.  Today the pressure reading is 21.6 psi, with no discernible change in the reading for the last two weeks.  Our requirement of a leak rate of 1 psi/month (chosen to insure that there will be at least 1/2 atmosphere in the container when the experiment runs, perhaps as late as 6 months after integration) has been met by the new camera design.  This test will continue, and the other container will be tested in parallel as soon as new gauge fittings arrive.
• A design review meeting was held December 17, 1999, to consider the details of the door redesign.  Prototyping is currently underway.

• All 57 shots from the KC-135 test video have been converted to position and time data.  These data are being analyzed to give a precise measure of launcher velocity for each launcher at each different spring setting used.  So far, launcher #7, the low-velocity launcher with a design speed of 1 cm/s has been studied.  At spring setting 3, projectile velocities were 1.5 cm/s.  Lower settings were tried, but the velocities were too low to get an accurate measurement in the KC-135 environment.
• A test fitting has been ordered which will enable pressure testing of the new camera containers.

• A KC-135 test page has been set-up on site, including some still frames from the test video.
• There are 57 shots of the 7 launchers tested that are currently undergoing frame-by-frame analysis by Josh and Dave to get a speed calibration for each launcher.

• A lot has happened since July, including the PI learning how to use his new computer to update this web site.  Watch this space for more timely updates through the remainder of the COLLIDE-2 project.
• A new link to a page discussing all COLLIDE-2 activity has been created on this site.
• The KC-135 test of the redesigned launchers occurred the week of October 18 from NASA's Glenn Research Center.  Initial analysis of the video data indicates that the new launchers performed well.  A more detailed analysis is underway to quantify the launcher performance and provide a calibration so that the launchers can be set at the desired values for the COLLIDE-2 flight.  These final values will be verified on the KC-135 in a final test currently targeted for the week of March 20, 2000.  Josh performed additional experiments on the KC-135 on the behavior of vomitus at 0g, 1g, and 2g.
• The new camera container lids have been machined and will be pressure tested as soon as the correct O-rings arrive.
• The COLLIDE-2 PAR has been baselined, making COLLIDE-2 eligible for manifesting on a future shuttle flight.  Work on remaining safety paperwork is underway.

• Work progresses toward a test of the new COLLIDE-2 launchers on the NASA KC-135 reduced gravity aircraft for the week of September 20: a safety data package for the airplane equipment is in preparation; two launcher designs have been approved for testing and are in the machine shop; NASA Glenn Research Center is fabricating one part of the KC-135 experiment (a clear lexan box); the rest of the KC-135 mounting equipment has been designed and will start fabrication next week.
• One of the new launcher designs is for projectile velocities below 10 cm/s and adds a lever to the basic COLLIDE launcher design.  The higher speed launcher (for speeds of 10 to 100 cm/s) is a variation on the original launcher.
• 3/4-inch diameter quartz spheres have been obtained for testing as COLLIDE-2 projectiles.  Ground-based tests will determine whether or not to roughen the surfaces of the spheres.
• Glass viewports for the new camera containers have arrived and are being polished.  Next week the new camera covers and viewports will also go to the machine shop.

• Andrew Diaz joined the COLLIDE-2 team last month and has been working on a redesign of the camera container cover to prevent a repeat of the anomaly on STS-90 which resulted in loss of camera ambient pressure.  Andrew's got a neat design for the camera container.  We'll start getting new design drawings up soon.
• Ground-based tests are under way in Mike Mellon's lab.  Results of these tests so far have led to the selection of 3/4 inch diameter quartz or feldspar spheres for projectiles.  There are some interesting results with different target size distributions, however, and more experiments need to be done in order to select the target parameters for the flight of COLLIDE-2.  Fortunately, that decision has no bearing on any design or fabrication of new parts, so that work can continue in parallel with the hardware upgrades.
• Two new launcher designs have been approved for testing aboard NASA's KC-135 reduced gravity aircraft.  We will test prototypes of these launchers the week of September 20, 1999, at NASA's Glenn Research Center at Lewis Field, Cleveland, Ohio.
• Several minor modifications to the IBS assembly are under way to improve target tray door performance.  These include dust shields for the stepper motor lead screws, redesigned stepper motor lead screws, and a redesigned pressure relief system for the target tray.
• A draft Payload Accomodation Requirements (PAR) document has been submitted to NASA.
• Experiment parts are almost completely rendered in SolidWorks, providing a new, consistent, and accurate CAD model of the experiment.

• David Crotser has started work, focusing on improving the launchers of COLLIDE so that the desired impact velocities can be achieved with a higher precision than on the first flight.
• COLLIDE-2 has been assigned a GAS reservation number: G-788.
• Our GAS Program Technical Manager is Charles Williams.  We look forward to working with the SSPP (Shuttle Small Payloads Project) on COLLIDE-2 and anticipate getting our PAR and SDP into the system quickly.

• Work began in earnest yesterday on COLLIDE-2.  New COLLIDE-2 team member Thomas Calihan continued inspection, cleaning, and disassembly of the experiment in LSTB Room 116 where COLLIDE-2 is currently located.
• Adrian Sikorski was on hand to help Tom become familiar with LASP and the experiment.  We're looking forward to getting Adrian back in the Fall after he completes a summer internship in Wisconsin.
• One IBS was transported to the LASP campus facility for some of the ground-based testing as part of the COLLIDE-2 project.  We'll be using Mike Mellon's planetary soils laboratory for COLLIDE-2 ground-based tests.  We'll get photos and information on Mike and Tom on the COLLIDE-2 team page as quickly as possible.

• The COLLIDE-2 review process was completed today with authority to proceed granted by NASA.  Work will begin immediately on correcting the anomalies in COLLIDE and on ground-based testing in preparation for COLLIDE-2.  Thanks from the Colorado COLLIDE team to everyone in NASA's microgravity research program who helped get COLLIDE-2 out of the starting gate.  Expect more frequent updates as COLLIDE-2 gets underway in the next few weeks.

• The paper on the results of the first flight of COLLIDE has been accepted for publication at Icarus.  The text of the paper is available now from the Projects Documents page.  Figures will be posted shortly.
• An Investigation Continuation Review was held at LASP on December 10, 1998 to review plans for a reflight of COLLIDE with improvements to the hardware to address the anomalies encountered on the first flight.  Work is currently underway to address the issues raised at the ICR.

September 2, 1998:

• Results of the first flight of COLLIDE have been written up for publication and submitted to Icarus.
• The Safety Data Package has been reformatted so that it resides in a single electronic file for easy dissemination to other interested GAS experimenters.  This is available in three file formats from our Project Documents page.

• The COLLIDE structure has been completely disassembled, and it is being cleaned.  No structural problems have been uncovered.
• Launch and rebound velocities have been computed for all IBSs (except IBS 5, which did not launch).  These have been converted to normal coefficients of restitution, and a paper is in preparation describing the results of COLLIDE for submission next month to a peer-reviewed journal.
• The remaining scientific analysis is a determination of tangential coefficients of restitution.  Some spin information can be extracted from the COLLIDE videos.

• All IBS's and the electronics box have been removed from the COLLIDE support structure.  No additional anomalies have been uncovered.
• The electronics was run through the entire experiment sequence and the lighting commands functioned properly for all boxes.  Both cameras were run through their sequences as well from the flight electronics.  Unlike the camera performance in flight, the results from this laboratory test showed perfect camera operation.  This suggests that environmental differences at the time of execution of the experiment, not damage to the camera or electronics on launch, resulted in the cameras' uneven performance in flight.  Subsequent tests will emulate the flight conditions as closely as possible to determine if low ambient pressure, low temperatures, and/or elevated voltage regulator temperatures were responsible for the camera problems.

• A new section has been added to the COLLIDE web site: Results.  This page kicks off today with a few stills from the flight cameras.  In the future, this page will include reduced data and interpretation and scientific impact.

• COLLIDE has been moved to a new room at the LASP Space Technology Building.  This now clears the way for extensive post-flight analysis of the experiment to fully assess its condition.
• A complete electronic version of the COLLIDE Safety Data Package is undergoing final editing and assembly for delivery to GSFC to serve as the new standard in GASCAN SDPs.
• A piece of polycarbonate has been obtained as a possible replacement for the glass covers of the camera containers which broke on flight.  The camera containers will be tested with the polycarbonate to determine if that is a possible fix for that anomaly.
• Watch this space this week for images from COLLIDE's flight!

• A preliminary analysis of the door jamming in two of the IBS's revealed that IBS 2 and IBS 3 doors failed to open, apparently due to jamming or misalignment of the pins in their tracks, not due to dust on the motor lead screws.
• A re-examination of the videotape of one of the experiments that was badly blurred and apparently without any usable data suggests that good data may be retrievable from this impact experiment.  Although the image is very blurred, it is clear that the door opened and closed properly.  We also know that the launcher fired, and at the correct time in the experiment sequence, the tape shows a blur moving that is consistent with the projectile.  Frame by frame analysis of this sequence should enable us to extract high quality data on the coefficient of restitution of the projectile from the dust layer.  Although it is impossible to see any dust ejecta in this video data, the other impacts which have clear video show little or no dust ejecta from the impact.  It thus looks as though we will have a set of three measurements of the energy dissipation in low velocity collisions into dust.

• Martin Taylor and Josh Colwell de-integrated COLLIDE from its flight GAS container at KSC on Monday, May 18.  De-integration was smooth.  Here are the highlights and preliminary results from COLLIDE's flight on STS-90:
• The first piece of information we got was that the pressure inside the container was much higher than it should have been, based on the pressure it was pumped down to prior to launch.  We believe the pre-launch pressure to be 4*10^-5 bar (there is some confusion about this number: the report from KSC stated 4*10^-5 torr, which we believe to be impossibly low).  A rough measurement at de-integration only provided a lower limit of about 20 torr, or 0.026 bar.  Such a large increase in pressure could be due either to leakage of the canister seal, or leakage of our camera sealed containers.
• The Relay End Plate was removed first and provided the first good news: the end plate had a modest amount of JSC-1 dust on it, mostly collected near the O-ring on the end plate.
• The canister was then lifted off COLLIDE, revealing more dust scattered throughout the experiment.
• Preliminary inspection showed: (1) the glass cover plate on camera 2's sealed container was cracked.  (2) All six IBS launchers had fired (launcher doors were in the open position).  (3)  All six IBS doors were completely closed and contained virtually all of the dust that was originally loaded in them.  (4)  The no-load battery voltage on each battery string was 12.7 V.  (5) All connectors and external wiring appeared to be intact.
• We removed camera 2 from its container.  The pattern of cracking suggested excessive stress at the borders or corners of the glass plates.  A long crack arced from one corner to another.  All corners were badly shattered.  The rest was in a few large pieces.
• Camera 2 powered up normally.  Visual inspection of the videotape indicated that it had advanced from its prelaunch position.  All buttons on the camera were still in their pre-launch positions.
• Inspection of the camera 2 tape showed a completely blurred image for the first IBS.  It is possible to tell that the door opened and closed, but that is all.  The second IBS on the camera 2 tape operated perfectly.  The image is in focus and the camera orientation is excellent.  The projectile launched properly and hit the dust layer and there is a good view of the impact in the mirror.  The ball bounced off the dust layer at a greatly reduced speed, at an angle, and with some rotation.  The rotation probably originated with passage of the ball through the launcher.  No dust was released by the impact.  The final IBS on this tape was the low velocity (1 cm/s) projectile, and it did not make it out of the launcher.  All other aspects of this IBS functioned perfectly.
• We removed camera 1 from its container, and the glass was also cracked, in a nearly identical pattern, though not as extensively as for camera 2.
• Camera 1 powered up normally.  Visual inspection of the videotape indicated that it had advanced from its prelaunch position.  All buttons on the camera were still in their pre-launch positions.
• Inspection of the camera 1 tape showed a partially blurred and jumpy image for the first IBS.  It is possible to tell that the door opened about 1 inch, and that the projectile fired.  The second IBS on this tape functioned perfectly.  The projectile again bounced off the surface of the dust releasing virtually no ejecta.  The third IBS on this tape had a jammed door at about 1/4 inch open.  The projectile bounced off the door.
• The COLLIDE self-test functioned properly, and COLLIDE was installed in its shipping container for return to LASP where it should arrive by Monday, May 25, perhaps sooner.  At that time, a thorough examination should reveal the cause of the stuck doors.  Evaluation of the two cameras is also necessary to determine the source of their malfunctions, but the focus problem may have been simply due to poor illumination.
• The lack of dust ejecta is an exciting and completely unexpected result.  This suggests that accretion may be more efficient in collisions between regolith-covered objects, an important result for planetary accretion and planetary ring studies.  The dust packing density, kept constant in all six COLLIDE impacts, should now be varied to determine its effect on the amount or lack of dust ejecta produced.  Watch this space for video images and data from COLLIDE(STS-90).

• 1 day, 3 hours and 50 minutes into the mission, the crew got to the first activites for G-772, as scheduled.  At that time, they checked the PWR STATUS, and it was ON.  They then commanded the EXP ON, and the EXP STATUS went to ON.  This means that the baroswitch operated correctly on ascent, closing COLLIDE's power circuit.

• STS-90 launched from Kennedy Space Center on April 17 at 2:19 p.m. Eastern.  The launch was flawless into a clear blue Florida sky.  COLLIDE's power circuit was closed less than a minute into the mission by a switch in the payload bay sensitive to atmospheric pressure.  This initiated execution of COLLIDE's software which immediately began a 24 hour timer.  At approximately 2:15 p.m. April 18, the timer segment of the software completed and the execution of the experiment began.  No information on the performance our outcome of the experiment will be available until COLLIDE is removed from its flight container sometime after landing, expected to occur on May 4.

• A nice photo featuring the COLLIDE GASCAN is on the Kennedy Space Center web site.  The caption describes COLLIDE's location in the payload bay and summarizes its scientific goals.  The payload bay doors are now closed and Columbia is scheduled to be mated to the External Tank on March 16 and rolled out to the launch pad on March 23.
• New smaller versions of the images of COLLIDE prior to shipping to KSC have been put in our images section on this web site.

• A glimpse of the top of the COLLIDE GASCAN can be seen in the payload bay of Columbia in this picture from the Kennedy Space Center.  COLLIDE is in the aft can on the port side of Columbia.  The picture is looking toward the rear of the Payload bay, which means COLLIDE is the can on the far right of the picture, closest to Neurolab on the right hand side of the picture.  Unfortunately, there are no distinguishing characteristics visible.  The distinguishing characteristic of our can is that it is the only one in the payload bay without a payload patch on it.

• Launch of STS-90 has been postponed to April 16, 1998.  Details can be obtained from the STS-90 countdown page at the Kennedy Space Center

• COLLIDE is in the CAN!  We had a completely successful integration at KSC.  We are awaiting final word on the evacuation of the cannister at KSC before it is moved to the Orbiter Processing Facility tomorrow.
• We did have to overcome some relatively minor glitches, mostly involving omissions or inconsistencies in our Safety Data Package.  Thanks to the team at GSFC's Small Payloads Program for helping us over these hurdles, particularly Safety Officer Preston Wood, Technical Manager Charles Knapp, GAS Program Manager Susan Olden, and Field Operations Officer Russ Griffin.  One of these issues was relatively interesting: we neglected to include our desecant in our Materials List and could not track down the chemical composition of our desecant.  We needed to find a desecant that had its contents labeled so that we could add it to the Materials List and put in our camera containers to prevent condensation on the glass in front of the lens.  After contemplating flying rice, we discovered some packets of silica gel desecant in purses at the Titusville Florida Wal-Mart which the store generously donated to our cause.  Thanks Wal-Mart!
• Special thanks also to Russ Griffin who took COLLIDE team members Josh Colwell, Adrian Sikorski, Barry Arbetter, and Martin Taylor on a tour of KSC including a close-up tour of Columbia.

• Today at 2:54 MST COLLIDE departed on the first leg of its voyage to space.  It will arrive at the Kennedy Space Center tomorrow.  Team members Josh Colwell, Adrian Sikorski, and Barry Arbetter will follow COLLIDE this weekend and install it in the flight container at KSC next week.
• A final complete functional test was performed on January 14 with, apparently, 100% success.  We will see the tapes at KSC during integration to confirm that they operated correctly.
• Pictures of COLLIDE taken just prior to installation in the shipping container have been added to the images page.

• At this point it's easier to say what hasn't been done than what has been done, since we've done so much in the last month!
• The flight electronics have been built, assembled, tested, and are currently being potted (coated with protective plastic) for flight.
• A complete functional test of COLLIDE was performed on Sunday, January 4 following a series of successful interim tests.  This test was a complete success.  The experiment ran off one battery pack.  The only difference between the test configuration and the flight configuration was the duration of the Muscle Wire trigger signal for launching the projectiles.  For test purposes, only a 1 second signal was used.  This is marginally enough to fire the launchers, and indeed, only 2 of the 6 launchers fired.  This was not unexpected, and measurements of current showed that the Muscle Wire was being activated as planned.  For flight, the activation will be 4 seconds which will ensure that they will fire.  So far, the entire experiment has been run more than two times off just one of our two battery packs.  Fresh batteries will be installed at the Kennedy Space Center during integration.
• Flight dust has been sifted, and most of the IBS dust samples have been measured.
• The wire harness is complete with the exception of the power cable linking our batteries to the Space Shuttle.  These connections will be made next week when the experiment is built up for the final time prior to delivery to the Kennedy Space Center.  Integration remains scheduled to begin January 19, 1998.
• During a very busy month of December, we welcomed a new member to the COLLIDE team as Jack Loui built one of our flight electronics boards.  Jack did a super job.  Barry Arbetter and Adrian Sikorski did a terrific job of getting COLLIDE ready for delivery.
• So, at this point, all that remains is to weigh some dust, glue on a few more wire harness tie-downs, test the potted electronics, and put COLLIDE in its shipping container for shipment to KSC.  The current plan is to ship COLLIDE to KSC on Thursday, January 15.  Expect an update to this page that day.

December 9, 1997:

• The flight camera electonics boards have been built and tested.
• The microcontroller board has been prototyped.  A fully integrated test of the hardware in a standalone configuration with a combination of flight and prototype electronics will be conducted this week.
• Camera container 1 has passed initial pressure tests.  While we do not have enough time to certify the pressure containment for the full 2.5 months that will elapse between evacuation of the GASCAN and execution of the experiment, we can demonstrate that any leakage is occurring at a rate of less than 1 psi per week.  This should be sufficient to insure enough pressure in the container to allow the camera to operate normally.
• Connectors have been installed on both cameras.

December 1, 1997:

• After finishing playing musical space shuttles, COLLIDE is now slated to fly on STS-90, currently scheduled for an April 2, 1998 liftoff.  Integration of COLLIDE at the Kennedy Space Center begins January 19, 1998.
• The battery holders have been machined and assembled.
• The flight software has been completed.
• Camera containers are undergoing pressure tests at this time.
• Connectors have been installed on all IBS's.
• The DC/DC converter has been replaced with linear voltage regulators to insure greater reliability and an on-time delivery.
• The Phase III Safety Data Package has been delivered to JSC and KSC by GSFC for review and approval.

October 28, 1997:

• All three battery boxes have been successfully leak and proof pressure tested to pressures exceeding 22.5 psi, the nominal NASA requirement.  This experience provided some valuable information for the final assembly of the camera sealed containers which must be able to contain one atmosphere of pressure from integration through completion of the experiment - about 4 months.
• The electronics box parts have been machined.  The only remaining hardware items are wire harness tiedowns and some mounting brackets and standoffs for circuit boards.
• The switching board prototype, which controls the stepper motors, launchers, and lights, was successfully tested yesterday.  Prototypes for all electrical components have now been tested, except for the microcontroller board.
• The Muscle Wire has been installed on the launchers and these are now ready for connectors.

October 3, 1997:

• We discovered that the COLLIDE support structure didn't fit into the NASA shipping container!  This arose because we took the "available user volume" of a 19.75 inch diameter to its limit and made our end plates 19.75 inches.  This led to a press fit into the shipping container which is not possible with such large massive pieces of metal.  This was easily fixed by turning the plates down to 19.7 inch diameter.   Other modifications were made to the plates at this time, such as machining the hole for the interface cable to the space shuttle.
• The battery box interiors have been remachined and re-coated, and the flight diodes have been installed.  They are now awaiting coating of the wires and diodes so that we can conduct a proof pressure test.  All hardware for the proof pressure test is here.
• Yet one more iteration of the Safety Data Package has been completed, this time with fairly minor modifications.  The battery proof pressure test report is the only safety paperwork that remains to be delivered.  A materials list was delivered last week.  Minor updates to that list will go out this week.
• The second camera electronics have been modified, and the launcher plates will be ready for Muscle Wire installation by next week.  Josh is installing the connectors on the IBS motors.  Andrew is machining the final pieces of the electronics box.

September 10, 1997:

• Josh has started building the COLLIDE wire harness.  Approximately 120 wires will run from the central electronics box to the various IBS's and camera boxes.
• The shipping container for delivery of the experiment to the Kennedy Space Center was received from NASA's Goddard Space Flight Center.
• Adrian has finished the new polycarbonate mirror assemblies and is working on final build-up of the IBS's.
• Barry has nearly completed the prototype switching board for testing on the flight IBS's.  He has also found a way to mount the Intel surface mount microcontroller on the vector boards COLLIDE will use for its flight electronics.
• Josh has delivered the first iteration of the Energy Containment Analysis to GSFC.

September 3, 1997:

• On again, off again.  COLLIDE is once again off the STS-90 manifest and unofficially slated for the STS-91 Mir docking mission in late May, 1998.

August 27, 1997:

• COLLIDE has moved into the Rocket Lab, Room 179, of the Space Technology Building for final assembly, testing, and integration.
• The DC-DC converter is completely working, including the pulse generator portion of the circuit.
• The interiors of the battery boxes have been coated with fiberglass to protect the boxes from any leaking electrolyte and to insure against short circuits.
• The launchers are complete.  Most are designed for such low speeds that it is not possible to test them in a one-Earth-gravity environment, but the ones with the fastest launch speeds (1 m/s) will be tested.

August 20, 1997:

• The prototype DC-DC converter is working and requires only the addition of the pulse generator portion of the circuit.
• A final decision to reduce the number of batteries from 27 to 18 has been made. This will free up the volume inside one of the battery containers for circuit boards which would not otherwise fit in the logic box.  The extra string of 9 cells was for redundancy.
• The Phase III Safety Data Package was mailed today.
• Adrian and Andreas have completed the wire harness schematic.
• With the end of the summer term, COLLIDE bids farewell to these team members who have moved on to bigger and better things: Lance Lininger, Andreas Lemos, Damon Tohill. They will continue to participate via e-mail in COLLIDE developments, and Lance will continue to handle the structural verification safety document.  Thanks for all the great work!

August 5, 1997:

• A lot of new pictures have been added to the web site. Check out the links at the bottom of this page.
• Barry is building prototype logic boards which will enable us to test the electronics and hardware together for the first time and finalize the electronics design.

July 23, 1997:

• The structural verification document has been written by Lance Lininger and submitted to GSFC.
• All hardware except the battery boxes, the logic box, and some mounting devices and the bumpers have been machined. A new schematic and picture of the COLLIDE assembly can be seen here.
• Recent tests of the door mechanism with dust in flight IBS units in vacuum have exhibited pluming. Shaking during launch should help empty the pore spaces and bring them into pressure equilibrium with the can environment. We have enlarged the holes through which air can escape the target chamber, and we have added 4 additional holes.

July 15, 1997:

• All of the COLLIDE support structure has been machined and the experiment is partially assembled.
• As a result of the FSDP review, the glass mirrors are being replaced with more durable polycarbonate mirrors.

June 26, 1997:

• COLLIDE is back on STS-90, currently scheduled for launch April 2, 1998.
• All the IBS components have been machined. Damon is assembling them, and Damon and Adrian are painting the background grids on the bottom plates of each IBS.
• Five of the eight support struts have been machined. Two of the three support plates have been cut down and are getting screw holes.
• The two camera sealed containers have been machined.
• Wayne has successfully written control software and can interface with an LED mockup of the experiment control lines through the microcontroller.
• The LED boards have been fabricated and await soldering of components.
• The shipping Experiment Mounting Plate and associated connectors and hardware has been received from Goddard Space Flight Center.
• Review of the Final Safety Data Package with GSFC safety and technical personnel is scheduled for Monday, June 30, 1997.

May 23, 1997:

• The Final Safety Data Package was delivered May 19, 1997.
• Wayne is working on a test program for the microcontroller to set switches.
• Barry has begun procuring the remaining electrical hardware. He is working on final electrical schematics.
• Machining continues on schedule.
• Our launch opportunity is uncertain and may be slipped to STS-91, or later if there are no available GAS payload slots on that mission.

May 7, 1997:

• Lance is ahead of schedule in machining flight hardware.
• Damon has designed the LED circuit board. It is ready for production.
• The Final Safety Data Package is nearly complete. Delivery is now planned for May 15.
• Adrian has completed the battery box design.

April 25, 1997:

• COLLIDE has accepted an offer to fly on STS-90, the Neurolab mission currently scheduled for launch in April 1998. The experiment will be delivered to KSC in December 1997.
• The PSDP has been reviewed by GSFC, and work is proceeding on the Final Safety Data Package for submission in early May.

April 2, 1997:

• Machining of the flight IBS's is nearly complete.
• Andreas has completed the camera sealed container design, allowing for the most possible thermal and acoustic insulation.
• Damon has a design for the LED mounts and boards, and has tested the evacuation of the dust target tray to see if pluming due to trapped air pockets occurs when the door opens. In tests so far, no pluming was detected.
• Wayne has installed software on the PC for programming the microcontroller. He will map out the uses for the address lines of the microcontroller and begin writing code to run the motor.
• Lance is returning the stepper motors to EAD because there is a mismatch between their worm gears and bearing nut inside the motors. EAD is cooperating fully to fix the problem and we anticipate getting working replacement flight motors soon.

March 11, 1997:

• The preliminary Safety Data Package has been sent to NASA Goddard Space Flight Center for technical review. This is the first of many iterative steps to assure the safety of the COLLIDE payload.
• Lance and Adrian continue machining COLLIDE hardware. The sides for all six flight IBS's have been machined and work continues on the doors and door guides.
• Damon is working on a design for the LED lighting system, and Jeremy is testing the Muscle Wire launcher system, including testing of failure modes.
• Adrian has final specifications for the springs that will launch the projectiles. He is working on the battery box design. Andreas is finalizing the camera sealed container design and evaluating insulation for the cameras. Lance is doing a preliminary thermal analysis of the cameras to see how often and for how long they will need to be heated. Wayne has ordered software for the microcontroller programming effort.

February 19, 1997:

• Barry got the EAD stepper motor operating over the weekend and Damon and Jeremy have begun testing it. It is putting out more than twice the force of the airpax stepper motor and has been selected as the new stepper motor for the door assembly.
• Lance and Adrian have machined one of the eight flight struts for COLLIDE.
• Work continues on finalizing the launcher system. A new spring manufacturer has been identified. Concern about whether friction between the pusher and the walls of the launcher will stop the ball from launching have been raised. The nominal launching velocity at the low speeds may be increased to provide a margin of safety.
• Andreas has completed work on the sealed containers for the camcorders.

February 13, 1997:

• Concerns over the strength of the airpax stepper motor and the cost and difficulty of procuring worm gears long enough to open the IBS doors has prompted an evaluation of an alternative stepper motor by Eastern Air Devices. This motor has the advantages of greater force and arbitrary worm gear lengths. As soon as it is operational, we will switch to this stepper motor as the default motor for COLLIDE.
• JVC has informed us that we will be unable to command the cameras to record through their JLIP port. Instead, we will have to install the camera in the GASCAN already set to record, and start and stop recording simply by closing and opening the power circuit to the camera. This prevents us from exercising the tape prior to recording to reduce the risk of tape transport problems.
• The Intel microcontroller evaluation board is connected to the PC and ready for programming to begin.

February 5, 1997:

• Lance has begun machining the flight launchers.
• A new linear actuator by Eastern Air Devices has been ordered. This actuator is stronger than the Airpax actuator and may be used in its stead. Testing continues on the Airpax actuator.
• Work continues on preparation of the Safety Data Package.
• Illumination testing continues with satisfactory results obtained so far illuminating the dust and box with high intensity LEDs.

January 22, 1997:

• A breadboarded array of high intensity light emitting diodes was set up by Wayne Hooper and Damon Tohill for testing with the camera to determine the optimal number of LEDs for each box, and their configuration within the box.
• An evaluation board for the Intel microprocessor that will run the COLLIDE experiment was received as an academic gift donation from the Intel Corporation. This will allow Barry and Wayne to begin writing the software that will run the experiment.

January 14, 1997:

• The digital linear actuator that will be used to open and close the target tray doors on COLLIDE was successfully operated for the first time last week. This test clears the way for final validation of the Impactor Box System design with further testing of the motor under a vacuum and operation of the door with the motor with a full target tray.
• Manual tests of the door with a full target tray required vacuum grease to prevent the fine COLLIDE dust from jamming the door mechanism. With vacuum grease in place, the door opened and closed with a little more than a pound of force. Closing the door was more difficult, and remains a secondary requirement on the design.

December 4, 1996:

• The projectile launchers in each of the six COLLIDE Impactor Box Systems (IBS) are activated by a shape memory alloy ("Muscle Wire") circuit. The Muscle Wire contracts when heated by passing an electrical current through it. This pulls a spring-loaded pin which holds the projectile in place. The original Muscle Wire design was successfully tested through more than fifty cycles of pulling the pin. Following these tests, the design was modified to increase the radius of curvature of the support pins and to add backup and redundant Muscle Wires to the circuit. The new system has been successfully tested under a variety of conditions, including vacuum, and also with only half the system activated.
• Parameters have been defined for the springs which will launch the projectiles at the target tray.
• A controller chip for the Airpax stepper motor which will open the target tray door has been acquired for testing of the door opening mechanism.
• A primary structure design which satisfies the safety requirements by means of analysis has been achieved.

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