NASA's Applied Engineering Competition Round Two Problems Problem 1 The typical management profile for the Terra science data Solid State Recorder (SSR) consists of two 25-minute contacts scheduled per 100-minute orbit to transmit data to the ground via Tracking Data Relay Satellites (TDRS). Multiple playbacks can be performed on each contact. Each contact has 5 minutes of overhead during which data cannot be transmitted. The SSR has the capacity to store up to 169 Gigabits of science data. The average rate of data collection per orbit is a constant 25.606 Megabits per second (Mbps). The rate of data transmission is 131 Mbps. Because you are in charge of Terra's Mission Operations you are responsible for getting all of its data down to the ground. NASA Headquarters notifies you that due to increased TDRS usage by the Space Shuttle and International Space Station, Terra playback contact time has been reduced to 30 minutes per orbit. At least one contact must be less than 25 minutes long. Contacts may be cancelled without warning. This is because there are certain zones on the Earth where you cannot violate Radio Frequency restrictions, and there are other regions where Terra's High Gain Antenna is prone to spontaneous shutdown due to exposure to high energy particles in Earth's magnetic field. Given the Terra mission objective to maximize science data transmitted and minimize data lost due to SSR overflow, answer the following questions: Question 1: How many playback minutes should be scheduled per orbit? Question 2: How many contacts should be scheduled per orbit? Also, indicate how many minutes will be spent per contact and why? Question 3: Create an equation to solve for data transmitted as a function of the number of contacts? (Data Transmitted (n) = ?) Question 4: Create an equation to solve for data lost as a function of the number of contacts? (Data Lost (n) = ?) Question 5: If there are 3 contacts scheduled, how much data will be successfully transmitted? How much data will be lost? Problem 2 Terra has three high rate instruments: ASTER, MODIS, and MISR. The ASTER maximum rate of data collection is 90.410 Megabits per second (Mbps). ASTER is allowed to operate at its maximum data rate for 16 minutes per 2-orbit time span. MODIS collects data at rates of 10.686 Mbps over 50% of the orbit and 3.193 Mbps over 50% of the orbit. MISR collects data at rates of 6.487 Mbps over 60% of the orbit and 1 Kilobit per second (Kbps) over 40% of the orbit. The total storage capacity of Terra's onboard Solid State Recorder (SSR) can be partitioned into 3 separate buffers, so that each instrument has its own allocated buffer capacity. (Please note that CERES' and MOPITT's rates of data collection are small enough that, for purposes of solving this problem, they are not to be considered.) It is important for Terra Mission Operations engineers to allocate enough SSR capacity to each instrument's partition to store all of the data. Additionally, the percent full per orbit (or the ratio of data collected in the buffer to buffer capacity) that each of the 3 buffers gets should be as close to equal as possible to minimize the potential for overflow of any given buffer. Question: How much capacity (in Gigabits) should be allocated to each instrument buffer? Solutions to NASA's Applied Engineering Competition