N.A.P.T.I.M.E. (NASA And Patriots on Titan Investigating Molecular Elements)

Transcription

1 Team Name: High School: Group Members: Project Manager: Chief Engineer: N.A.P.T.I.M.E. (NASA And Patriots on Titan Investigating Molecular Elements) Bob Jones High School Patrick Robert Thor Bradley, J'len Dowdy, Chris Elegante, Ben Ford, John Monroe Trey Gould V, Isaac Harries-Williams, Zach Harris, Michael Heileman, Ben Nelson Michael Heileman Chris Elegante Logo:

2 Science Question: What is the lateral structural layout of Titan's atmosphere, and how do various conditions affect the system? These conditions include, but are not limited to: Content and Composition Tholin Presence Temperatures Pressure Surface Landscape Our Answer: We plan to investigate this by developing a payload that will eject from the UAH InSPIRESS team's orbiter as it circles Saturn and pierce Titan's atmosphere. Once the payload has slowed down within Titan's atmosphere, the payload will deploy several instruments to collect data. These instruments include a FTIR Spectrometer to measure gas composition as well as to analyze atmospheric) tholin presence, a thermometer to measure temperature, a camera for still images of the surface, and a pressure gauge to measure pressure. In addition to these instruments to collect external data, we will have a transmitter to relay all this data to the orbiter or the lander, as well as a CPU and flash drive to handle the direction of data as well as manage any data overflow. Because the payload will be constantly descending due to Titan's gravity, we will be able to capture data at many different altitudes, providing a wide range of data values to create a robust picture of Titan's atmospheric conditions. Science Traceability Matrix: Table 1.1 Science Instruments

3 Engineering Requirements from Orbiter: The only action the payload will require from the orbiter is to be ejected from the orbiter to enter Titan a full orbit after the lander would be ejected, using the same launch specifications. The payload will require an exit chute directed at Titan, so the payload may eject itself. Also, the payload will require power form the orbiter in order to keep the battery fully charged. Alternative Concepts and the Decision Analysis used to Determine the Final Concept: When our team initially brainstormed for ideas about what to study on Titan, we decided to focus on the most unique aspect of Titan: its atmosphere. Being that it is the only natural satellite with any substantial atmosphere at all it certainly fits the bill. Initially, our team was of the opinion that studying the recently discovered molecules known as tholins in the atmosphere of Titan would be the primary purpose, and ideal concept for our payload. After further in-depth research, however, we found that it was already explored by the Cassini-Huygens probe with additional terrestrial lab studies. The data gathered from both the Cassini-Huygens probe and the terrestrial lab studies had had already explored most of practical study options. As such, we preceded to pursue a much broader subject matter, focusing on the overall atmospheric composition, pressure, and temperature, requiring the implementation of numerous additional data-gathering instruments, as well as revamping our initial payload design and our overall science question. Once we had decided upon analyzing the atmosphere as a whole, we considered actually taking a sample of the atmosphere from the outside of our probe, and bringing this sample into

4 our probe and analyzing the sample with a spectrometer within our probe. However, we soon discarded this idea, as actually capturing some of the 90 Kelvin atmosphere and transporting it within the probe would be dangerous and require superfluous instruments. We instead decided upon installing a spectrometer that would peer out into the outside atmosphere, and analyze it there from afar. We also decided upon installing other instruments, including a pressure gauge and a thermometer, to measure the pertinent aspects of Titan's atmosphere as the payload descends. Payload Concept of Operations: In order to answer the previously stated science question, we have proposed a analysis system payload that will deploy from the orbiter while the orbiter is in orbit around Saturn (exactly one orbit after the launch of the lander). The payload will be launched using the same trajectory and calculated launch speed as the lander. Then, the payload will be captured by Titan's gravity field and descend into the atmosphere, upon which it will deploy a parachute to further slow its descent. The payload will be protected by a robust heat shield to protect the craft's delicate inner workings from the intense heat of atmospheric entry. After the bulk of the payloads deceleration occurs, the craft will begin collecting data as it slowly descends, at a terminal velocity rate of about six meters per second, due to increased drag and lesser gravity on Titan as compared to Earth. The payload will begin collecting data on atmospheric composition via a FTIR spectrometer in the aft of the vessel. In addition to this main focus of the program, we will also have a pressure gauge on the nose of the payload craft to measure pressure, as well as an accelerometer to measure our acceleration and eventually our terminal velocity so we can calibrate the data from our pressure gauge. Another important instrument we will utilize is a small, lightweight camera that will take a picture at equal intervals from the time the payload reaches terminal velocity until touchdown. Additionally, the payload will have a temperature probe at the aft of the craft to measure the variation in temperature. While these instruments will perform the scanning analysis and data collecting, the power for all these sensors will come from an on-board nickel-cadmium battery stored below the spectrometer. However, in order to facilitate the collection of data from all these varied instruments, the payload will contain an Kingston MicroSD flash memory storage card that will catalog this data. This flash drive will send all the data consecutively to the miniature telemetry transmitter in UHF to the orbiter. The Heat Shield will be compromised of a specialized Phenolic Impregnated Carbon Ablator (PICA) material. The compound is extensively heatresistant, absorbing astoundingly high amounts of heat. Used as a burn shield, the substance should protect our payload from the devastating temperatures associated with entering the atmosphere. The massive reduction in velocity caused by the payload's ensuing collisions with Titan's thickening atmosphere will result in an intense energy transfer, and therefore an extremely large amount of heat will be generated

5 Design Iterations and Overview of Final Design: As we have further developed our payload's concept of operation, the design of our payload has evolved as well. At first just a atmosphere collection device, the payload is now tasked with surviving entry into Titan's atmosphere, collecting a wide range of data about Titan's atmosphere as it descends, and transporting this data to the orbiter or lander craft, all while surviving the harsh conditions of Titan. Therefore the payload has to be robust. All the important and delicate instruments aboard the payload will be stored in one section of the craft, along with the flash drive and radio UHF transmitter, that will be kept at a livable temperature through insulation, the heat of entry, and the running of our numerous instruments. The craft will be shaped much like the Apollo capsules of the 1960s, with a 60 degree arc, so that our payload will survive entry into Titan's atmosphere at over five kilometers per second, which is a much more robust design than our original conceptual design, which was basically a rectangular prism. Once the payload has slowed down in atmosphere to a certain point, the payload will deploy all the instruments, and begin the collection and transmission of the data to the orbiter or lander until it smashes into Titan's ground at around five meters a second. Instrumentation aboard Final Payload: Our total mass budgeted for this enterprise is 5 kg. Our total volume budgeted is 44 cm by 24 cm by 28 cm. We also have access to the at delivery system so our only transmission needs to between the payload and the orbiter through our Miniature Telemetry Transmitter. Our battery can generate approximately 6.6 amp-hours worth of power. Table 1.2 Instrumentation Requirements Name of Instrument Power Required Mass of Instrument FTIR TruDefender Spectrometer Less than.444* watts Less than 1.3* kilograms Thermometer Camera.0459 watts.02 kilograms Pressure Gauge Nickel-Cadmium Battery Power Generated = 6.6 Amp Hours Kingston Micro SD (2 GB) Infinitesimally small power consumption.3402 kilograms.0014 kilograms Miniature Telemetry Transmitter 1.0 watts.0128 kilograms Heat Shield none Other Insulation none All remaining available

6 TOTAL 6.6 Amp Hours 5 kilograms *This number is calculated with a fully functional lit LCD touch-pad screen, as well as full rugged casing. Design of Module:

7 Diagram 1.1 Solid Edge CAD Design All of the components are rendered at maximum dimensions, to make sure every instrument will fit: The grey capsule is the payload's heat shield and substructure The green rectangular prism is the spectrometer The black cylinder is the camera The orange cube is the CPU The light gray rectangular prism is the transmitter