NASA Sounding Rocket 36.185
PI: Dr. Joseph M. Davila, NASA Goddard Space Flight Center
26 July, 2000, 12:00pm MDT (2:00pm EDT, 1800UT)
White Sands Missile Range, NM
Mission Description:
A NASA 2-stage Terrier-Black Brant sounding rocket (36.185) is scheduled to be launched on July 26, 2000 at 12:00pm MDT (2:00pm EDT, 1800UT) from White Sands Missile Range (WSMR). It will propel the Solar Extreme ultraviolet Research Telescope and Spectrograph (SERTS) experiment to a predicted altitude of nearly 200 miles on a sub-orbital flight. The Principle Investigator is Dr. Joseph M. Davila of NASA Goddard Space Flight Center, in collaboration with the Naval Research Laboratory and the University of Southern California.
Payload Description:
The payload consists of an experiment which is intended to study the Sun's outermost atmosphere, called the solar corona. It was designed and built by the NASA Goddard Space Flight Center, under the guidance of Principle Investigator Dr. Joseph Davila and co-investigator Dr. Roger Thomas. The experiment contains a spectrometer which will allow scientists to examine radiation in the Extreme Ultraviolet (EUV) regime. These wavelengths are emitted by the Sun's hot corona at temperatures typically in the range of 1 to 3 million degrees. By making measurements at a large number of wavelengths between 300 and 355 Angstroms, information about the density, temperature, and plasma flows within individual coronal structures can be derived. The light is focussed onto the spectrometer by a telescope, which has been specially designed to transmit EUV wavelengths. The spectrometer also contains two windows or "lobes" which are used to take images of the Sun. The information from the spectrometer will be combined with the images.
The scientific objectives of this mission are:
Scientific observations of solar active regions, continuing the buildup of the SERTS "Spectral Atlas".
Radiometric cross-calibration with the Solar and Heliospheric Observatory (SOHO) Spacecraft.
Wavelength cross-calibration with the Coronal Diagnostic Spectrometer (CDS) on SOHO. Because SERTS is a recoverable payload, it can be used to provide information on the performance of CDS and other SOHO instruments, which are in their fifth year of operation orbiting the Sun roughly 1 million miles from Earth.
Resolution of spectral lines which are simultaneously imaged by telescopes such as the Extreme Ultraviolet Imaging Telescope (EIT) on SOHO and the Transition Region and Coronal Explorer (TRACE) Spacecraft.
Determine the resistance of thermophilic microorganisms to space conditions and EUV radiation. Two types of bacteria, mounted on cell-holders specifically design for this application, will be exposed to space environment. One of the microorganisms to be tested has been isolated from a hot spring of Yellowstone National Park.
Launch Vehicle Description:
The SERTS experiment is scheduled to be flown on a 2-stage expendable rocket vehicle. A Terrier Black Brant Mod 2 sounding rocket will lift the SERTS payload to a predicted altitude of nearly 200 miles on a sub-orbital flight. While in flight the SERTS experiment will be operated and pointed by service modules specifically designed to provide unique support. Key among these systems are the Solar Pointing Attitude Rocket Control System (SPARCS) which provides for the pointing of the payload towards the area of interest on the Sun. This flight will also use a command uplink to allow for scanning of the target area. A 3-link telemetry system will be used to relay the data to the ground and for recording and evaluation after the flight. It is expected that the SERTS instrument will gather up to 6 minutes of solar data. The entire payload and service module assembly will be recovered by parachute on White Sands Missile Range and returned to the Goddard Space Flight Center. The sub-orbital Rocket Program is managed by the Wallops Flight Facility located at Wallops Island, Virginia. Support for the assembly and pre-flight checks of the vehicle and payload are performed by the NASA Sounding Rocket Contract, NSROC.
Timeline:
The launch of the SERTS experiment is scheduled for 12:00pm MDT (2:00pm EDT) on July 26, 2000, from the WSMR LC-36 Athena Launch-Rail. Total flight time will be approximately 15 minutes.
Major Flight Events Are as Follows:
FLIGHT TIME (seconds) |
ALTITUDE (km) |
EVENT |
|---|---|---|
6.2 |
3.1 |
Terrier (First Stage) Burnout |
12.0 |
6.2 |
BBVC (Second Stage) Ignition |
44.4 |
46.2 |
BBVC Burnout |
50.0 |
58.2 |
Video Camera On |
59.0 |
77.0 |
Vehicle despin from 3.5 to 0.5 Hz |
63.0 |
85.1 |
Payload Separation from Motor |
64.0 |
87.1 |
Attitude Control Enable |
66.0 |
91.1 |
Experiment Door Open |
74.0 |
106.6 |
Nose Tip Eject |
99.8 |
152.5 |
Begin First Exposure |
217.4 |
283.9 |
Change Pointing |
282.8 |
303.0 |
Apogee (Highest Altitude) |
342.0 |
287.4 |
Change Pointing |
465.6 |
152.8 |
End Last Exposure |
485.0 |
118.9 |
Experiment Door Close |
515.0 |
59.5 |
Spin-up for Re-entry |
632.0 |
4.9 |
Parachute Deploy (16K Ft) |
901.1 |
0 (!) |
Payload Touchdown |
Thur. August 10 (T + 15)
The decision was made that an immediate re-flight of SERTS is not needed, since we are now satisfied that the solid observations already in hand are adequate to support SOHO calibrations. We can verify that there is in fact overlap of our actual SERTS-00 data with CDS measurements made several hours earlier. The intensity of the co-observed solar area was constant to better than 10% between times of CDS and SERTS coverage, and the signal quality from both instruments is sufficient to provide useful cross-comparisons. Therefore, we will next ship the payload to the Rutherford-Appleton Laboratory in England for its calibration there as had been originally planned and on the original schedule.
In addition to providing calibrations for SOHO, the SERTS data include a full set of EUV spectra of several quiet regions near the sun's south pole, as well as some remarkable EUV spectra extending well above the polar limb. The EUV monitor supplied by USC also worked well and got all the measurements that were expected. And analysis of the first biological sample carried by SERTS-00 in our collaboration with UMBI has shown very positive results. So we can now safely declare the 2000 flight as yet another extremely successful mission in the ongoing SERTS series.
Wed. August 02 (T + 7)
The truck with our SERTS instrument and equipment arrived back at GSFC today, and everything appears to be in excellent condition. We have now had a chance to look at the observations made with SERTS-00 last week. Our instrument worked beautifully, and we got a full data set from three different areas on the sun. The EUV wavelength range was just right, as was the spatial and spectral focus. Sadly, the attitude control system provided for us did not go to our requested roll angle, so that none of the SERTS measurements hit our intended target, a 4x4 arcmin area around the solar active region AR 9097. This was particularly unfortunate since that region was undergoing a class C5 flare at the time, and was very well covered by a world-wide consortium of ground and space based observatories specially coordinated for our flight. In particular, the mis-pointing jeopardizes one of our main goals, cross-calibrating with the CDS instrument onboard the SOHO spacecraft. On the other hand, we found that there is some overlap of our SERTS data with CDS scans made for another program several hours before the SERTS flight. It will take a while to determine if these other observations are adequate to support a reasonable cross-calibration. There is also some possibility that we might be allowed to send our instrument back to WSMR for another launch within a month or so, in order to ensure proper cross-calibration with CDS/SOHO.
In any case, we did get a complete set of quiet sun EUV spectra near the solar south pole, as well as above the limb there. And the UMBI biological samples got their full dose of EUV exposure, leading to a nice CNN article. Therefore, even with the disappointment of missing our desired targets, much of the project went extremely well.
Thur. July 27 (T + 1)
The SERTS crew at the launch site is busy packing up the instrument and ground equipment to ship back to Goddard. Once they get back, a fuller account of the launch should be available. In the meantime, we have an initial image of one of the exposures taken during the flight. Images of the Sun from the two lobes can be seen in the relatively cool helium line at far left, and two much hotter iron lines overlapping each other to the right of center, plus some other fainter lines. The narrow slit section runs down the middle, between the two lobes.
Wed. July 26 (after launch)
SERTS was successfully launched today on schedule at 18:00 UT! Preliminary examination of the stored telemetry data from the electronic detector shows that the instrument worked correctly. The instrument landed safely in the desert, and has been recovered! More news later.
Wed. July 26 (T - 1 hour)
Three more visitors arrived yesterday: Thomas's wife, Jan, the UMBI principal investigator for the biological experiment, Dr. Jocelyne DiRuggiero, and long-time SERTS Mission Manager from Wallops, Frank Lau. We passed the pre-launch 'T-3hr' tests, the rocket motors are armed, and the launch rail is being raised. Final targeting has been transmitted to all collaborating observatories, many of which have already started their supporting measurements. Everything is now ready for flight!
Tue. July 25 (T - 1)
Dr. Leon Ofman arrived last night to round out the SERTS team from GSFC attending the launch. The final complete mission simulation, called the 'vertical', was held this morning, and all support systems are now ready for flight. The instrument went through its full observing sequence for the first time with the detector cooled to its flight temperature of -30C. All nine of the compressed dark images were recorded and successfully decompressed, providing another set that can be used in the scientific analysis of the actual flight data. Yesterday's tests showed that direct sunlight on the cooling lines to our detector caused some problems when the shelter was rolled back from the launch rail. Extensive insulation has now been added to these lines and to the payload itself. The shelter was then rolled back again just before noon today, the same time as for tomorrow's launch, and we were able to verify that the cooling system is now working beautifully.
Our primary solar target will indeed be active region 9097, and this has been programmed into the operational command sequences for the CDS and EIT experiments aboard the SOHO spacecraft, as well as the YOHKOH and TRACE satellite missions, in order to provide collaborative observations. The target coordinates for the center of CDS coverage will be N06.2W26.0 heliographic, corresponding to +415,+24 arcsec heliocentric as seen from SOHO and +411,+24 arcsec as seen from Earth. SERTS will attempt to observe this active region with two pointings on either side of the CDS center position, with its slit at an angle of 104 degrees CW from solar north. Slit center will be aimed at N03.7W25.1 and then at N09.0W26.9 during these two pointings. The third available pointing opportunity will depend on the results of the first two. If these tries are not successful in hitting the CDS observing box, then the third pointing will be aimed at the CDS center. On the other hand, if successful CDS co-registration is achieved, then we will move the slit center to a position 60 arcsec above the west solar limb at a latitude of S14.0, allowing measurements of height structure and plasma flows in the loops above active region 9087, which has been very flare productive during its passage across the disk.
Mon. July 24 (T - 2)
Yesterday, the SERTS crew had yet another whole day off, our second in the two weeks since we have been out here. Two more visitors have now arrived; Nelson Reginald, Davila's graduate student from the University of Delaware, and Nic Young, associated with the Discovery Channel TV network. Mr. Young is the director of a program called 'Planet Storm', which may include some film footage of our launch and recovery. The Mission Readiness Review meeting was held this morning in a conference call with project management and technical support groups both from WSMR and from the Goddard-Wallops Flight Facility. This meeting went over results of all testing to date in considerable detail. Everything remains on schedule for the original launch time of July 26 at 18:00UT (12:00noon MDT or 2:00pm EDT).
Apparently some time between Saturday afternoon and this morning, there was a power outage at the rail causing our external instrument vacuum pumps to shut down and go into a safe holding mode. The EUV detector's vac-ion pumps automatically switched to backup batteries, so they kept running. Our external pumps have now been restarted, but we did lose some time and will have to stay late this evening in order to complete the planned set of detector cooling tests. And then, just to make things even a little more interesting around here, there was also a water main break over the weekend, affecting the bathrooms and drinking supplies all day today throughout the missile range.
Active region 9097 continues to be the most attractive primary solar target, with AR 9090 being considered as a secondary target. Using the latest EIT images, we predict that at launch time the peak EUV emission from these regions will be located at N06.3W26.2 and N11.8W61.0, respectively. The exact orientation of our slit and sequence of our three available pointing positions has still to be determined.
Photos from last Friday's flight simulation just came in. A general view shows Stewart, Miko, and Davila standing just behind the payload, while Swartz mans our GSE box on the right. A view of the SERTS front end shows the payload door, the Ritchey-Chretien EUV telescope in the lower right, the two circular units for the mounted UMBI biological samples, the square EUV monitor box from USC, and two black devices near center that are the MASS and LISS pointing control sun-guiders.
Sat. July 22 (T - 4)
Tests were made of the new detector cooling system at the launch rail. After fixing a few problems, we took the detector temperature down to -30C, significantly colder than the -15C reached on last year's flight. The associated monitoring and control systems allowed the detector CCD to be held constant at this temperature. A full set of dark images matching the flight exposure sequence of 2, 13, and 88 seconds were recorded from the cold detector, which will allow immediate correction of our solar EUV flight data. This test also verified that the EUV spectrograph detector and its readout system are functioning properly after yesterday's move to the rail.
Davila's mother Wilma, father Manuel, wife Pam, and three children Ross, Eliot, and Carrie arrived to check out our project. Eliot was with us for last year's SERTS flight, but this will be the first sounding rocket launch for the others, and they seem to be looking forward to it.
Fri. July 21 (T - 5)
Our two rocket motors have been installed on the rail and mated together. The first is a Terrier booster that will fire for a total of 6.2 seconds, at which time the payload will be at an altitude of 3.1 km (nearly 2 miles) travelling at a velocity of 1,340 miles per hour (nearly twice the speed of sound). It really gets moving in a hurry! After coasting for about 6 seconds, the second stage Black Brant sustainer kicks in for another 32.4 seconds, burning out at an altitude of 46.2 km (29 miles) and a maximum velocity of 4,930 miles per hour. About 15 seconds later, the payload despins, separates from the rocket motor, and starts seeking the sun. We expect to acquire our first solar target and begin scientific observations about 100 seconds after launch, with a total of 366 seconds available for collecting data before the payload starts to re-enter the Earth's atmosphere.
A lengthy meeting was held to negotiate the exact sequence of all events and times during our launch day. Because there will be another mission's launch at 9:00am MDT that day, there will be no access to the WSMR base after 7:00am, and everyone on the range (including visitors) will have to be at their launch locations by 8:15am. Official approval was received to have a live webcast of our flight; there had been some doubt due to budget constraints. Final payload assembly was completed, and another 'all fire' flight simulation through telemetry was carried out, our last chance to check opening and closing of the experiment door before the instrument is attached to the rocket motors. All systems look good, so the payload is being buttoned up for the truck ride to the launch site.
The payload is now on the launch rail, mated to the rocket motors. The pad was cleared and all systems powered up for the all important 'boom' test. There was no boom, so we passed the test. Further testing is in progress to make sure that all electrical connections are correct and that communications between the experiment command center, the blockhouse, and the payload are all working properly.
The sun is near the peak of its activity cycle, and there are a number of active regions already on the disk that would be excellent targets for SERTS observations. One possibility being considered is NOAA AR 9097 (at N05E53 on July 21 00:00UT), which will be at N05W24 reasonably near disk center at the time of our launch on July 26 18:00UT. This region has been rapidly growing over the past few days, and its spot has developed from Beta to Beta-Delta. We will continue to track this region, while looking for any other potential targets rotating onto the disk over the weekend.
Thur. July 20 (T - 6)
The 'horizontal' flight simulations went off without any major hitch, both with the payload in vacuum and with it at air. An initial improper setting of a test antenna was quickly corrected and did not affect the rest of the run. All flight support systems performed flawlessly, and the science payload went through its complete observing sequence exactly as planned. The EUV monitor from USC, which was not functioning during the previous full-up test, worked beautifully this time after its repair. All in-flight housekeeping channels recorded as expected. (Photo of Miko and Thomas monitoring the Horizontal test data.) Every available experiment command was exercised, both from the two internal timers and from the ground command station, all without problem. (Photo of Thomas operating the experiment control console.) The three redundant on-board vac-ion pumps continue to hold an excellent vacuum on the EUV imaging camera. (Photo of Swartz watching over the SERTS vacuum system.) Compressed dark images from the EUV camera were recorded, fully decompressed, and matched against prior lab dark images to verify that the main science detector and all steps in its telemetry process, hardware and software, are working properly. Now, Davila is carefully installing the two biological samples provided by UMBI, along with the extremely delicate thin-aluminum filters that protect the organisms from all radiation except EUV during our rocket flight. At the launch site, land lines between the rail and the blockhouse are being checked out to assure proper electrical connections to the payload when it is loaded onto the launch-rail tomorrow.
Wed. July 19 (T - 7)
One week to launch, and preparations continue to go well. The EUV Monitor from USC has been vibrated in three axes, electrically checked, and re-mounted onto our SERTS payload. It also passed a special end-to-end test through telemetry, which completes its qualification for flight, so Don McMullin was able to head back home. A meeting was held to combine the requests from all involved groups into one final schedule of flight event timings. These will be programmed into the two nearly redundant on-board timers that control the detailed sequence of events during flight. Tests of the new cooling system at the launch rail verify that the system works fine in a horizontal configuration on a dummy load. The payload is now being pumped down in preparation for the formal 'horizontal' flight simulation tests scheduled for tomorrow. Discussions have begun with our scientific collaborators on selecting the solar targets for observation. We hope to identify preliminary targets by this Friday, in order to exercise the SERTS pointing software, and to practice coordinating with other observing groups. A message just came in that the Russian's may wish to overfly the USA as a part of the Open Skys treaty, that WSMR might be a place they choose to do it, and that our launch date is a potential time for this to occur! Some very strange things can happen on these sounding rocket programs, but this is a new one to me.
Tue. July 18 (T - 8)
A meeting was held to cross-check all the scaling factors used in the SPARCS attitude control system, then these revised values were installed in the flight software and verified by using the SERTS slit-jaw camera images and in-flight pointing control system. Post-vibration alignments of the SERTS optical components were measured, and all are well within specs. Cooling lines are being installed at the launch rail, so that we can cool our detector with liquid Nitrogen vapor right up until the payload lifts off. Pixel by pixel comparisons of dark images taken during yesterday's flight simulations show that data recorded on the internal hard drives is identical to that which goes through a sequence of on-board compression, telemetry, and ground decompression. Furthermore these images closely match similar dark images taken in our GSFC lab before shipment to WSMR. Don McMullin arrived from USC this afternoon, returning the EUV monitor which has now been repaired; it will be separately vibrated and tested electrically, then re-mounted to the front of our SERTS payload. Our predicted trajectory just came in from Wallops Flight Center; timing of the detailed sequence of events during flight can now be adjusted to match the calculated altitude profile. Our plan is to observe three different targets on the sun, taking three exposures (2, 13, and 88 sec) on each target. The sequence will begin 100 sec after launch, the first pointing shift will occur at T + 217 sec, the second will be at T + 342 sec, and the last exposure will end at T + 466 sec, if all goes as planned. To accommodate any potential delays in starting the camera, the door will stay open until T + 485 sec, and then the instrument will close up and shut down in preparation for re-entry.
Mon. July 17 (T - 9)
Saturday evening we all relaxed at an elegant restaurant in old Mesilla (photo), while Sunday was a much needed day off that included a beautiful hike in the Organ Mountains overlooking WSMR (photo). Mr. Spencer's return home was much smoother than his trip out here. On Monday morning, a full set of flight simulations were run both in vacuum and at atmospheric pressure (photo), validating that all systems were still functioning properly after vibration. The instrument was then rolled into the Heliostat (photo) to check the operation and alignment of the H-alpha slit-jaw camera, and to practice using the joy-stick controller that allows fine pointing corrections during flight (photo). The slit jaw camera worked so well that we could easily monitor the development of the impressive 1N flare that occurred 20:16-20:29-20:58UT at S11E36 in NOAA region 9087 as we were doing our tests!
Sat. July 15 (T - 11)
Dennis Spencer arrived last night, after a harrowing tale of cancelled flights and missed connections, but safely delivering the set of biological samples that will be carried on SERTS-00. Dennis is a high school student at Baltimore Polytechnic, working with UMBI researchers Dr. Jocelyne DiRuggiero, Dr. Frank Robb, and Dr. Renu Nandakumar. Click here for a photo of Dr. Nandakumar preparing the samples for flight. A description of the extremophile microorganisms to be flown has been kindly provided by Dr. DiRuggiero, the Principal Investigator for that project. The SERTS T&E was completed this morning, including a bend test, spin balance, and measurements of mass, center of gravity, moments of inertia, and out-of-roundness. Here is a photo of Mr. Spencer checking out our instrument on the spin balance table. Then the instrument was trucked back to the Payload Integration Facility, where the operation of the main science camera was checked and the payload was pumped down for post T&E testing.
Fri. July 14 (T - 12)
The test flight of a Patriot missile blocked all access to the Range this morning, and delays in getting it off meant that we could not start work until nearly 11am, one of the problems of working on an active missile range. After we finally did get the payload assembly completed, it was trucked to the T&E Facility to undergo Test and Evaluation. The first tests consisted of flight-level vibrations, which were carried out in the thrust direction and in both lateral axes. This is a photo of the SERTS-00 payload on the vibration table. Because of the range delays, however, we will have to finish the remaining mechanical tests tomorrow. Heavy thunderstorms, some with violent hail, nearly every afternoon and evening, have added to the general excitement around here.
Thur. July 13 (T - 13)
A general meeting was held this morning to negotiate detailed plans for the next flight simulation test, while the full instrument was being pumped down. All of the payload support sub-systems, such as telemetry, attitude control, recovery parachute, and nose-cone, were mated to our science instrument, making it start to look like a real rocket experiment. A number of complete flight simulations were then run to verify that all these sub-systems were working properly, both with the instrument in vacuum (so that we could open our internal detector door) and at atmospheric pressure (so that we could open the outer payload door). These tests also checked all of the available command options, including manual start of the observing sequence, reset and restart of the sequence, manual control of the detector vac-ion pumps, and pointing offsets to up to three different solar targets during flight. All systems passed with flying colors. The full payload is now being assembled to flight specs in preparation for tomorrow's vibration tests.
Wed. July 12 (T - 14)
Joe Miko arrived last night to complete this year's SERTS crew from GSFC. Analyses of records from yesterday's flight simulations indicate that both of the two redundant onboard timers and the science observing sequence are working exactly as planned. We were able to read good test images from both the telemetry channel and from the internal hard-drive recorder. One problem uncovered in yesterday's testing was that the EUV monitor supplied by USC did not respond to any input stimulation; this small package is being returned to USC for further checkout and repair. Measurements were made of the optical coalignments between the spectrograph reference mirror, the attitude control sensor, and one of two new subsystems carrying biological samples. The latter result from a recent collaboration we have formed with the University of Maryland Biotechnology Institute to study the survivability of extremophiles exposed to space conditions, including ionizing EUV radiation from the Sun. Such microorganisms live in extreme environments and have evolved mechanisms for very efficient DNA repair. Understanding how they do this has significant implications for biotechnology, as well as for studies of the origins of life. Two different sets of microorganisms provided by UMBI will be exposed to solar EUV flux on this SERTS flight, while we carry out our sequence of EUV imaged spectroscopy observations.
Tue. July 11 (T - 15)
Davila's suitcase finally showed up at the motel, to everyone's relief. A spectacular thunderstorm last night caused some concern about possible power outages to our SERTS pumping station, but all was well when we got to work this morning. Actually, the vacuum level in the instrument is now better than it has been in the past. Our launch date of 2000 July 26 at 18:00 UT, with a window of 30 minutes, was officially confirmed at a formal Range Meeting of all the associated launch management and support teams. Several flight simulation tests were run today, verifying that the experiment can be started by ground command, as well as by backup signals from the internal timer, and that the instrument goes through its pre-programmed sequence of observations as planned. All telemetry, command, and guidance-control systems appeared to function properly. Next we need to study the charts in detail, and to process the compressed data from the EUV spectrometer detector to make sure there are no subtle problems.
Mon. July 10 (T - 16)
The SERTS instrument and partial crew (consisting of Principal Investigator: Dr. Joseph Davila, Co-Investigator: Dr. Roger Thomas, and Technicians: Marvin Swartz, Les Payne, and John Stewart) have now arrived safely at White Sands Missile Range (though Davila's suitcase missed the connection and is apparently still in Houston). Payload tests show that the EUV spectrometer detector and its critical vac-ion pumps are working well. Telemetry and guidance sub-systems are being prepared for mating to the payload. A preliminary flight timeline has been established, and will be tested in upcoming timer runs.
Mon. July 03 (T - 23)
The SERTS team is preparing to ship the experiment to White Sands, NM, for its 10th flight, now scheduled for 2000 July 26 at 18:00 UT. The experiment will leave for White Sands on July 8, with the team departing a day later. Information on how to participate in the observations can be found on the SERTS-00 Coordinated Observations page.
Last Revised: [an error occurred while processing this directive]
Responsible NASA Official: joseph.davila@gsfc.nasa.gov
NASA iT Security Banner & Privacy Statement
Feedback and comments: Emilie Drobnes (curator)