Requirements, Alternatives, & ConOps

Requirements

Science Requirements Two sources Primary science instruments Mission supporting instruments

Science Traceability Matrix Science Objective Measurement Objective Measurement Requirements Instrument When Where Who What How Next Table

Instrument Requirements Table Mass (kg) Power (W) Data Rate (Mbps) Dimensions (cm) Lifetime Frequency Duration Mass Spec 0.230 1.5 22.4 0.45 x 0.50 x 0.80 30 days 12 hours 5 minutes Thermocouple 0.020 N/A 0.100 Wire of length X Continuous (Hint: Look in the book)

Support Equipment Requirements Component Mass (kg) Power (W) Data Rate Dimensions Other Technical Specifications (Hint: Look in the book)

Environmental Requirements Destination needs to be specific A planet/moon name is NOT specific enough! Things to consider Temperature Pressure Gravity Radiation Chemistry Wind Other stuff???

Functional Requirements

Alternative Designs Team divided into 2 or 3 groups Each develops at least one payload concept Usually, PM and CE each take a group Each concept needs to be viable Should satisfy science objective(s) Should satisfy at least the 6 basic functions Deploy, take measurements, collect data, send data, provide power, and house instruments/equipment Should list instruments & support equipment required Think about what the concept will “do” to accomplish objective(s) (ConOps) Brainstorming encouraged! (Think outside the box!) Come back together & discuss Be honest & critical, but not personal Rinse, repeat

Alternatives PM’s Group CE’s Group Not to Scale

Concept of Operations A description of how the system will be operated during the mission phases in order to meet stakeholder expectations Mission Phase: period of time, during which, the circumstances of your payload remain fairly constant (i.e., not much changes for your payload during a “phase” of the mission)

ConOps Checklist Word document on Downloads page Asks you many questions about how your payload will operate/function Divided into main “phases” for typical payloads Initial Conditions Deployment Measurements Sending Data “other” Go through the questions, as best as you know right now.

Example ConOps Lunar Probes Concept 1: Penetrator A penetrator is released from the orbiter It falls toward the surface, accelerating with gravity It impacts the surface and buries itself It takes measurements of heat flow from the inside of the moon, outward, along the length of the penetrator Concept 2: Surface Probe A spherical probe is released from the orbiter It impacts the surface, but does not bury itself Instead, it bounces/skips and comes to rest after a longer distance It then measures surface temperatures

Example ConOps: Lunar Probes Penetrating the Surface Remaining on the Surface Not to Scale

ConOps: Wrap Up USE THE CONOPS CHECK LIST!!! Divide your mission into “phases” based on when things “change” for your payload Explain what happens before, during, and at the end of each phase PICTURES PICTURES PICTURES Practice explaining this to someone not in the class – do they understand it? Did we mention PICTURES???

Back to Alternatives Come back together as a team Openly and fairly discuss the design alternatives List the positives and negatives for each alternative. Design Alternative Positives Negatives Lunar Penetrator Very good contact with soil Temperature from surface to certain depth High impact (g-forces) Higher mass Lunar Bowling Ball Lower impact Lower mass (potentially more probes) Loose contact with surface Subject to surface anomalies

Alternatives: Wrap Up More than one way to skin a cat! “Explore the design space” Two different groups for each team Brainstorm No bad ideas New ideas Outside the box MUST satisfy science objective(s)! Think about “what happens” (ConOps) of the alternatives Come back together Be honest, critical Accept criticism It’s not personal – it’s about getting the best design

Checklists InSPIRESS Downloads Page Requirements Checklist MS Word Format Not required – just for your benefit Requirements Checklist Project Functional Environmental Science Housing Checklist Environment Deployment Instruments Support Equipment ConOps Checklist Initial Conditions Measurements Sending Data Other