|
   |
 |
                 
|
S P A C E T E A M O N L I N EUPDATE # 66 - January 15, 1999 PART 1: A virtual panoply of projects A VIRTUAL PANOPLY OF PROJECTS
Some deadlines and plans to firm up: Female Frontiers is already off and running. We had our first chat last week with Nancy Roman. It was obvious that we've not really gotten folks in gear for these. So, here's word on the next one: Did you know that until 1945 the Webster dictionary definition of the word "computer" began with "a person who..." Jean Bartik is one of the women who was a computer and transitioned to the new definition, "a machine that..." with the Eniac computer in 1945. Truly a pioneer in a field that is extremely apropos to our world today. Chat with her on Wednesday (tomorrow!). You can register from the Female Frontiers Schedule page: http://quest.arc.nasa.gov/space/frontiers/schedule.html The deadline for participation in this go-around of Projects from Space is less than two weeks away. Again, this is your invitation to join the men and women of NASA in collaboration with other classrooms to explore topics dealing with space survival. Register by January 28 to participate in the first launch! See the link at: http://quest.arc.nasa.gov/space/events The CASE project mail list is actively supporting scientists with helpful information, and they are about to announce their first chat. Just a reminder, this is the project that will take a student-eye look at the preparation of a specific experiment (Cell Adhesion Space Experiment) to fly on STS-93 in April. Remember, this information will only be sent via the list, so if you want to be aware of the activities, register for the CASE project at: http://quest.arc.nasa.gov/space/events/case During the month of February the Quest Project will celebrate Black History Month. Most of the Sharing NASA projects will feature a chat with African American scientists and engineers who contribute their work to the missions and goals of NASA. For a schedule of these events, see: http://quest.arc.nasa.gov/ltc/special/mlk99/ And, of course, don't forget our continuing live events listed below. Do join us! Linda UPCOMING LIVE EVENTS QuestChats require pre-registration. Unless otherwise noted, registration is at: http://quest.arc.nasa.gov/space/chats Wednesday, January 20, 1999, 11 a.m. PST (2 p.m. EST) Female Frontier's Chat with Jean Bartik, First programmers started out as computers. Please read her profile at: http://quest.arc.nasa.gov/space/frontiers/roman.html Register through the FF schedule page at: http://quest.arc.nasa.gov/space/frontiers/schedule.html ->Wednesday, January 20: 10 a.m. PST (1 p.m. EST) Tour of the International Space Station Training and Mockup Facility You are invited to join our tour guide at Johnson Space Center (JSC) in Houston, Texas. You will be able to ask your questions during the tour and have them answered during the event. If you are not able to join us this month, we hope you can make next month's tour. For more info: http://quest.arc.nasa.gov/ltc/sto/tours/index.html ->Thursday, January 28, 1999, 10 a.m. PST (1 p.m. EST): Mark Weller, (see journal below) facility systems electrical engineer THE FINAL CHALLENGE PUZZLE QUESTION Subject: The Challenge Project and STS-95 http://quest.arc.nasa.gov/space/events/puzzle This week's question: Deadline 1/30/99 Just days before the launch of the Challenge mission aboard the Scott Carpenter Space Analog Station, Station Commander Dennis Chamberland joined us in a chat. Name at least three ways in which Dennis responded to the question: How is living in the ocean like living in space? Final Puzzle solution: Deadline 1/30/99 As you write a description with a maximum of 50 words, consider answering the following questions as accurately and specifically as you can: * Who is the primary person pictured? * When? (with a touch of research you can pinpoint the day!) * What are the circumstances * Who else is pictured? * Where are they? Detail is available online. [Editor's note: One of Greg's many responsibilities is film analysis: he reviews over 100 high speed films to verify everything about a Shuttle launch and landing and to make sure it worked correctly. If not, he must determine what happened and why so that changes can be made prior to the next launch. Greg shares with online the much publicized STS-95 drag chute issue. http://quest.arc.nasa.gov/space/team/journals/katnik/01-11-99.html ] FINDING OUT WHAT WENT WRONG WITH THE DRAG CHUTE AND LOOKING FORWARD
TO A NEW YEAR OF CHALLENGES Interviewer: Brandt Secosh January 11, l999 First, I would like to take a moment to thank all of you for being a part of the Space Team Online for 1998! 1998 was a very successful year for the space program and was highlighted by many significant events. STS-95 will be remembered as the "John Glenn" flight, but in the bigger scheme of things it shows that you don't have to be a 22-year-old athlete to fly into space. The STS-95 flight has brought a whole new reality on the ability of people of all ages to live and function in orbit. STS-95 rejuvenated the public interest in the space program. The number of visitors that came to see the launch of STS-95 far exceeded any other launch in the history of the space program, to include the Apollo 11 launch! It captured the imagination and spirit of the world! Madeleine Albright, the United States Secretary of State, visited the Kennedy Space Center Firing Room during the STS-95 launch. She commented, "I spend all of my days mediating between countries disputing something. It was nice to come and participate in something where everybody is working together." STS-95 was a near flawless launch and I will elaborate on that later in this journal. 1998 also began a new era with the launch of STS-88. We now have hardware components of the Space Station in space that have been successfully mated together. This was completed ahead of schedule with a record number of three incredible space walks. Being so far ahead of schedule, we were even able to do some maintenance work on the solar arrays of the Russian module that hadn't fully deployed and an antenna that hadn't deployed. This showed our ability to deal with unforeseen situations in a totally effective manner. That leads us into 1999, which will continue to focus on delivery and construction of the International Space Station (ISS) components. The Space Shuttle Processing Facility (SSPF) is currently housing many of these components that will be delivered into space later this year. The ISS program has brought many nations together to obtain the common goal of building the space station and working together in space. It is amazing to me that nations such as Russia were once cold war enemies and now we all work together with this common goal. Many of the people in our directorate have taken Russian language classes and several have visited Russia to interface with their engineer counterparts. This is also taking place with the 15 other nations involved with this incre dible project. Although 1998 was a spectacular year, we still had situations that kept us very busy and continue to do so. As many of you may recall, during the STS-95 launch a door to the drag chute came off during the launch. Although no significant damage was noted on post flight inspection of orbiter, we are still investigating how this occurred. These photographs were taken by the launch pad cameras during launch and have been a valuable resource in the investigation of this event. Click on either image to see a larger version. In the first photograph, you will notice the red square that shows the drag chute door in its normal position. There are twenty-two cameras set up in the surveillance mode during each launch. During the STS-95 launch I was watching these particular cameras and at approximately T-4 seconds prior to liftoff I saw something white and rigid falling to the ground past the main engines. In real time this all happened very fast. The person sitting next to me commented "Was that a white tile that went by?" I responded with "No, it was bigger than that - it was probably a flexible insulation blanket mounted to a carrier panel which would account for the rigidity of the object." I told everybody to keep watching the engines and watch the ascent to make sure nothing else happened. We continued to monitor the ascent and detected no further anomalies. Although I wasn't sure, I thought the object had struck one of the main engines. My concern at the time was that if the object had struck one of the 1,080 cooling tubes on the main engine nozzle it would cause a puncture. The tubes on the main engines have hydrogen running through them at 4,000 pounds per square inch (PSI) and this is done for two reasons. First, they preheat the hydrogen and second, they keep the main engine nozzles cool. If the object had punctured one of these tubes a potential jet of hydrogen could have been directed towards the vertical stabilizer of the orbiter. This could have ignited and become a blowtorch causing structural damage and thermal protection problems to the vertical stabilizer. Additionally, this situation could have caused improper operation of the affected main engine. After announcing that the orbiter had safely reached orbit, we immediately reviewed the tape in slow-motion. We clearly saw where the object came from and that it was the drag chute door. In photograph two you can actually see the drag chute and the pyrotechnics that are use to blow the door off to deploy the chute. We now knew what was going on, but the big question was why! The rest of the day was spent collecting video and documenting the sequence of events in preparation to brief management of the situation. The number one consideration at this point was "What does this mean on orbit and reentry?" There are no cameras available to view this area of the orbiter once it is airborne so, we did not know if the drag chute was damaged or even if it was still ther e. The possibilities were that the nylon drag chute was gone, melted by the exhaust plume, or not reliable because of partial damage. Additionally, the pyrotechnics were an issue. The pyrotechnics may have fired already, may be defective or may be an explosion waiting to happen given the right conditions. None of this was known and that led us into exploring all the possibilities for the remainder of the mission. The reentry plan had to based on all the "unknowns" and contingency plans had to be developed for each potential situation. We determined that there were three possible scenarios that could give the crew problems in flight. The first one was that the drag chute could deploy during reentry high in the atmosphere. The lack of air pressure in this mode of flight would cause the chute to just trail behind and not fully deploy. In this scenario, the chute would be jettisoned (released) by the pilot and not cause significant problems. The second scenario was if the chute deployed in the lower atmosphere where the air is more dense and the air pressure is greater. In this scenario the chute would probably melt from air friction heating and again cause no significant problems. Our main concern was scenario three - the final approach and landing phase. Unlike scenario one and two, this scenario could cause very significant problems. The orbiter does not have the ability to add power during reentry and so the flight profile for this kind of glider is just one shot. If the chute deployed during this phase, the drag could cause the airspeed to decrease and place the orbiter in an unsafe landing profile. The possible results could be that the orbiter may not make the runway and that the airspeed would get so slow that a stall condition could occur. Additionally, the deployment of the chute would also cause the nose of the orbiter to pitch up and cause controllability problems. The solution to this scenario was to have the pilot ready to jettison the chute if this happened. The commander would be ready to recover from the initial nose up attitude. Once the chute was jettisoned the nose of the orbiter would pitch back down and the commander would regain the correct flight profile for landing. We also had an astronaut trailing the orbiter in a Gulfstream aircraft with high power binoculars monitoring the condition of the chute. When the orbiter landed, we found virtually no damage to the chute. Nevertheless, we disconnected the pyrotechnics from the drag chute bay area and noted that the drag chute nylon holding straps were still in place with minor discoloration from the heat. Now that the orbiter was safely home we went to the next phase of our investigation - why? In gathering evidence and trying to piece this all together we had gone to the pad to find the drag chute door. We had found twenty-two pieces of the door that had shattered due to the velocity of the impact on the launch pad. The door was reconstructed for evaluation. Amazingly, no damage was noted to the main engines of the orbiter. There was only one white mark on the main engine nozzle that indicated any impact. Keep in mind that if this had hit one of the cooling tubes on the engine nozzle it could have been an entirely different situation. Our ongoing investigation has shown that all the characteristics of the metals used for the drag chute door met all the correct criteria, the door was installed properly for launch. The shear pins to the door were fractured; however, they fractured under load and in a nominal manner. Therefore they worked properly. Since we could find no problems with the door itself or the orbiter structure, we are now looking at environmental factors, such as acoustic shock waves and vibration for the cause. As you can imagine, being an Investigative Systems Engineer has provided me with many challenges in problem solving and provides a great example of the kind of work engineers do. When we solve this mystery I will be sure to update you right here on the Space Team Online web site. Until then, best wishes for the New Year and thanks for your support of the space program. I know this will be another great year! [Editor's note: Join us to chat with Marc, January 28. Marc is responsible for the electrical power system at Pad-B. His office is in a small building next to the Gate of launch Pad-B, giving him a front-row view of the vehicle sitting on the Launch Pad out of his office window. From that perspective, he shares the after-the-launch activities first hand. The online version includes pictures: http://quest.arc.nasa.gov/space/team/journals/weller/01-13-99.html ] Reentry by the Post Launch Safing Team http://quest.arc.nasa.gov/space/team/weller.html Interviewer: Brandt Secosh January 13, l999 After the space shuttle leaves the pad for orbit it leaves behind a significant amount of damage to the launch pad structures and platform. Much of this damage is expected, but Mark Weller points out that many times unexpected results occur. In most cases when the term "reentry" is used, it means the shuttle and its crew have completed their mission in space and are ready to come home. In the case of the "Safing Team", it means that they are the first ones to go inside the perimeter of the launch pad to assess the damage caused by the heat and blast of the launch. As you can imagine, the intense heat and incredible thrust from the space shuttle are mind-boggling! Mark Weller is a member of the Safing Team and performs duties as the electrical representative of the team. Other team representatives include safety, pneumatics, hyper fuels, environmental health, and water representatives assembled in four separate groups. When this team receives a "go-ahead" to reenter the launch pad perimeter each member dons protective clothing and a hard hat and begins recording data that will later be compiled into a formal report known as a Launch Damage Assessment Report. The report is used to assign repair tasks to get the launch pad ready for the next orbiter rollout from the Vehicle Assembly Building (VAB). The usual sequence of events for the Safing Team during post launch reentry is for the Environmental Health and Safety representatives to lead the initial inspection groups for assessment of the pad in order to identify situations that may be hazardous and to begin their damage assessments. Once this is complete, the areas that are hazardous are marked off and the Launch Control Cent er (LCC) is informed that the inspection is complete. Mark points out that much of the damage is very obvious at first and even expected. There are surprises; however, such as when one of the electrical substations that services the pad was blown up by a sequence of events during launch. The substation had been hardened (protected) by a steel enclosure which is accessed through two very large and heavy doors. The main engines of the orbiter are mounted on gimbals and will change their thrust vector to counteract environmental conditions such as wind. Mark believes this to be the situation when the main engines vectored their thrust in the direction of the substation and blew the locked doors open. Once the doors were blown open, water from the pad was blown inside, and caused shorts throughout the system and then went up into a ball of fire. In the case of this substation, its function was to provide power to the compressed air facility which is used for many functions such as opening and closing valves. Another incident was when Mark re-entered the pad and a water valve would not remotely close resulting in a cascade of water covering the pad. The team had to get to a manual valve in their fire-retardant coveralls, which immediately became soaked, in order to stop the water deluge. Most of the damage occurs at the 95 to 115 foot levels of the Fixed Service Structure (FSS). This is because that is the first two levels above the deck of the Mobile Launch Platform (MLP) where much of the blast is deflected toward the FSS once the Shuttle has lifted off. Another situation is the flame trench arrangement where the main engines have a deflector which directs the blast upward, but the SRB's heat and blast are directed straight out one end of the flame trench. This blast from the SRB often damages the perimeter fence. Wooden poles have been placed in front of the concrete perimeter light poles to provide protection. During this part of the launch sequence a lot of debris is scattered around and must be accounted for afterwards. The Safing Team does not touch or move anything during the assessment process. They record the position of all of the large debris and damaged items they find. After all of the debris is recorded, a clean-up crew is then called in to gather the debris and remove it. The debris is then identified and efforts are made to determine where it came from. Mark notes that each time a launch occurs, the engineers find ways to prevent repeat occurrences of damage to the launch pad. This may include using barriers to deflect the blast and heat, using improved paints that withstand the heat better, or placing objects on the pad in a manner that reduces exposure to the blast and heat from the launch. In the case of the damaged substation, an entire new concrete building was constructed to protect the unit and no problems have occurred to this substation since. In any event, when a launch occurs here at Kennedy Space Center, there is plenty of work to be done afterwards! Please follow these links to learn more about launch pads 39 A & B. http://www.ksc.nasa.gov/facilities/lc39a.html Mark Weller will be conducting a Space Team Online Chat on January 28th. Be sure to register to chat with Mark. STATUS OF COLUMBIA PROCESSING
Below, we provide reports on the processing of Shuttle Columbia taken from the detailed daily reports found at the NASA Shuttle Status web site at http://www-pao.ksc.nasa.gov/kscpao/status/status.htm At times these reports will contain jargon and unfamiliar terms; our intent is not to confuse you but to provide a glimpse at all the steps involved. Probably due to the holiday, there are no new reports online. STS-93 SCHEDULED OPERATIONAL MILESTONES (dates are target only): Payload bay doors closed prior to OPF rollout (Jan. 13) Orbiter weight and center of gravity tests (Jan. 28) Orbiter transferred to VAB for external tank mate (Feb. 1)
|
||
|
|
|
