AENG 3150 (Astrodynamics) Spring 2021

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• Final Exam Details

  • Comprehensive (everything from class is fair game)

  • Open books / notes / etc (but no collaboration)

  • About the length of 1.5 midterms

  • The link is now live and available here.

  • It is due by Wednesday at noon. You must also upload your handwritten work to your shared drive.

• Grading Update

  • Unless you received an email me this week (5/10-5/17), I have received all of your assignments

  • Midterm 2 was returned electronically

    • You can find the numerical solutions here.

  • Regrades are being worked on

  • Paper assignments will go back in the secret copy room (MDD 2075)

  • HW08/Case Study unlikely to be completed before Wednesday

• Latest News/Information

  • Section A: In-person on Tuesdays, online on Thursdays (see below)

    • Section B: Online on Tuesdays (link below), in-person onThursdays

    • The Zoom Meeting for our brave new world

    • Zoom meeting link

    • Meeting ID: 923 9389 5933

    • Password: astro

• Course Resources

  • • Syllabus (Spring 2021)

    • Course internal website (Spring 2021) *

• Useful (and semi-useful) things

  • • Things* you need to know about orbital mechanics on one (double-sided) page [revised March 2020].

    • A 15-minute primer on using Matlab.

    • The Solar System

      • Quick overview of the solar system. *

      • A scale model of the solar system, built in the desert (7 Minutes)

    • AGI's Spacebook (real-time viewer of all cataloged spacecraft in orbit)

• Presentations

  • • Course introduction (Spring 2021) *

  • Prussing Chapter 1 (Two-body problem):

    • • Classic orbits: ellipse and hyperbola *

  • Prussing Chapter 2 (Time):

    • Calculating time as a function of position (13 Minutes) *

    • Examples

      • • Time from position (PDF) *

        • Position from time using Newton's method (PDF) *

      • Video walkthrough (16 Minutes) *

    • Prussing, Chapter 5 (Lambert Problem)

      • Lambert Example 1: Earth orbit *

      • Lambert Example 2: Solar orbit *

    • Prussing Chapter 6 (Rocket Propulsion):

      • Introduction to rocket propulsion (45:28) *

      • The Rocket Equation (11:44) *

      • Rocket equation summary *

      • Handouts *

    • Prussing Chapter 7 (Orbit Maneuvers):

      • Handouts *

      • Lengthy Orbit Transfer Example (updated after class)

    • Mission Flowdown *

    • Interplanetary Mission Analysis *

      • Overview of the Swingby (14:53 and handout - the video cuts off abruptly, but the lesson was over) *

      • Jupiter Swingby Example (13:35 and handout) *

      • Venus Swingby Example (29:13; handout and calculations) *

    • Earth Orbits *

  • Recorded Classes. All class sessions will be recorded and posted to the Panopto folder (here *). Below is a list of topics covered in each class session.

    • Thu 01/28. Introduction and overview of the solar system.

    • [Handouts/charts: Syllabus, Course Introduction, Solar System Overview.]

    • Tue 02/02. Kepler, Newton and conic sections. The elliptical orbit.

    • Thu 02/04. SpaceX, Spaceship, more ellipses, and the hyperbola. (No exaggeration!)

    • Tue 02/09. Time from position. Prof. Swartwout struggles to present on Zoom.

    • Thu 02/11. Position from time (numerically).

    • Tue 02/16. Overview of Mars Exploration.

    • Thu 02/18. Lambert's Problem

      • Part 1 : Introduction and how/why are we doing this/

      • Part 2: The low-level details of finding the correct option for semimajor axis among the four candidates

    • Tue 02/23. Lengthy digression about JPL's Perserverance mission design. Searching for life in the solar system. A well-intentioned but messy attempt to compute battery sizing for the Ingenuity helicopter.

    • Thu 02/25. Part 3 of Lambert's problem: a worked example (Earth orbit).

    • Tue 03/02. Orbit transfers (fast transfer and out-of-plane).

    • Thu 03/04. Discussion of SSRL, SpaceX's Spaceship SN-10 landing and explosive disassembly. Mission flowdown.

    • Tue 03/09. Mission Flowdown and a massive orbit-transfer example [Lengthy Orbit Transfer Example (updated after class)]

    • Thu 03/11. No class. Enjoy your Spring Break!

    • Tue 03/16. Rocket propulsion [Handouts* for the entire Rocketry unit.]

    • Thu 03/17. Rocket propulsion, from propulsion options through the initial sizing equations.

• Midterm Preparation

  • • First Exam:

      • Take-home midterm covering the topics of HW01 - HW03 (Prussing Chapters 1, 2 and 5, plus the related material I added).

        • At 11:00am on 03/23, the exam will be loaded into your Google Drive folder.

        • You have 24 hours to complete the exam and return it to the same folder. [I will not grade any submissions until the 24-hour period is complete, so you are free to upload new solutions during that window of time.]

        • Your solution must be hand-written (either in the exam printout, or you can use your own paper) and loaded into a single document named aeng3150sp2021mid01_lastname_firstinitial.pdf

        • The exam is open-book, open-notes (including all files on this website) but you are not allowed to work with anyone else. All work must be demonstrably your own.

        • There will be multiple versions of the exam: the same problems, but different numbers; the same general multiple choice / true-false, but with the wording changed.

      • Spring 2019 exam * and solutions *.

      • [Apologies in advance for the scrawled solutions; I had not expected to publish this. Also, the answer to 6h was incorrect and has been noted.]

      • Spring 2020 exam * and solutions *.

  • Second Exam

    • Bonus equation sheet for Exam 2: Rocket Equations

      • Practice Exams

        • Spring 2014: Exam 2 * and Solutions *

      • Spring 2018: Exam 2 * and Solutions *

  • Homework Assignments. All assignments are due on the due date. You can submit them in class or by 5pm local time at the instructor's office (MDD 2081). Assignments received after the deadline will be graded (eventually) at a 20% discount in points.

    • Update/clarification: All assignments must be submitted in paper (physical) form; we tried downloading/printing from your electronic copies and it was a time-consuming, toner-consuming disaster.

      • Students who have registered as online-only are, of course, an exception to that rule.

      • If you cannot make it to the building on the date the assignment is due (for any reason), you may upload an electronic copy/photo of your assignment. The only thing this does for you is you are not counted late (assuming you turned it in on time). You must still turn in the physical copy, ideally by (or before) the next time your subsection has in-person class.

      • If you want to submit electronically, please share a Google Drive folder with me. (Instructions are here.) You are welcome to use the shared drives I am creating to push out the exams.

    • Regrade policy.

      • Regrades will cover the following cases:

        • We graded it incorrectly (i.e., you were correct but we marked it wrong)

        • You followed the equation/process correctly, but because you got part (a) wrong, later parts were marked as wrong, too.

      • In both cases, please submit the original assignment with the disputed parts clearly identified (circle/star/highlight) and attach a sheet of paper with a list of the disputed elements and why you should get the credit. If the dispute is that you used the correct formula with incorrect inputs, please indicate which input(s) were incorrect.

• And now, the assignments themselves ...

  • • HW00: I have altered the deal; pray I don't alter it further (Due 02/16)

    • HW01: Stop your grinnin' and drop your linen (Due 02/09) Solutions

    • HW02: You can learn all the math in the 'Verse, but you take a boat in the air that you don't love, she'll shake you off just as sure as the turning of the worlds (Due 02/16) Solutions

    • HW03: You know, sometimes I amaze even myself (Due 03/09) Solutions

    • HW04: Never give up, never surrender! (Due 04/05) Solutions

    • HW05: I don't believe in the no-win scenario. (Due 04/09)

    • HW06: Space is disease and danger wrapped in darkness and silence. (Due 04/20)

    • HW07: Nothing goes over my head. My reflexes are too fast; I would catch it. (Due 04/27)

    • HW08: You're backed into a hyperdimensional corner. (Due 05/10, online/email okay)

  • Case Study: Case Study of Spacecraft Contractor. Due 05/10

    • Topic [1 pt]: Find a space mission or contractor that interests you. Please review the other parts of the assignment before settling on a topic. If you cannot find sufficient information, you will need to change topics.

      • A contractor is an organization that builds all or part of a space mission, such as: the spacecraft, the reaction wheels on the spacecraft, the launch vehicle, the on-board thrusters, the mission control center.

      • Examples:

        • Missions: Galileo, OneWeb [the constellation], Curiosity, Ingenuity, MEV-1

        • Contractors: OneWeb [the company in bankruptcy], SpaceX, Blue Canyon, Virgin Orbit, Ball Aerospace, Aerojet, MOOG. [I can provide guidance if you're unsure.]

        • "NASA" or "Boeing" are too big for this project; if you want to study something big like that, pick one of their missions. (For example, you could look at NASA's ISS Mission Operations center.)

    • Schedule [10 pts]: Provide a brief overview of the mission or contractor

      • Contractor: When did the company start? What did they make when they started, and has the product line changed since then? How large is the company, today?

      • Mission: What was the purpose of this mission? Has it changed from its inception? What were the main contractors on the mission? What are the key points in the mission timeline (from the start of the contract until today)?

    • Cost [5 pts]: Provide rough estimates of the financials (annual sales of the company, total cost of the mission)

    • Performance [10 pts]: Identify similar/competing missions/contractors.

      • Contractor: What other companies do the the things that this company does, and how do they distinguish themselves from the competition (i.e., stay in business)?

      • Mission: Is this mission part of a series of missions (e.g., the search for life on Mars)? In what unique ways does this mission contribute? (In other words, why spend money on this new mission when the other missions were already paid for?)

    • Risk [5 pts]: Has the mission or contractor had challenges it had to overcome?

    • Careers [10 pts]: Identify one person (if able) or type of job that is performed at this company. How would one go from where you are now to holding that job? (Education, skills training, personal abilities.)

    • Quality [4 pts]: The report should be on the order of 3 pages (750 words), submitted in PDF format to your class folder.

    • Je Ne Sais Quoi [5 pts]: For going above and beyond the assignment, including reflecting on what you've learned.

• What Have We Learned?

  • • Mars 2020 Perseverance is scheduled to land ~2:45pm Central time on Thursday, 18 February. Information and livestreaming options are here: https://mars.nasa.gov/mars2020/timeline/landing/watch-online/.

    • [A Parks alum - Fernando Abilleira - is Deputy Mission Manager. I asked him to push up the landing time to happen during class; he declined, citing something about the laws of physics being unfair to space travel ...]

Planetary Constants

Universal gravitational constant (G): 6.67408 × 10^-11 m³/( kg s²)