ASEN 5050 SPACEFLIGHT DYNAMICS Mid-Term Review, A-Train

1
ASEN 5050SPACEFLIGHT DYNAMICSMid-Term Review,
A-Train

• Prof. Jeffrey S. Parker
• University of Colorado Boulder

2
Announcements

• Homework 7 is due!
• HW 8 will be released Wednesday.
• Mid-Term handed back Wednesday (the grading is
  almost done)
• Reading Chapter 12

3
Schedule from here out

• 10/27 Three-Body Orbits
• 10/29 General Perturbations (Alan)
• 10/31 General Perturbations part 2
• 11/3 Mid-Term Review, A-Train
• 11/5 Interplanetary 1
• 11/7 Interplanetary 2
• 11/10 Entry, Descent, and Landing
• 11/12 Low-Energy Mission Design
• 11/14 STK Lab 3
• 11/17 Low-Thrust Mission Design (Jon Herman)
• 11/19 Finite Burn Design
• 11/21 STK Lab 4
• Fall Break
• 12/1 Constellation Design, GPS

4
Schedule from here out

• Our last lecture will be Friday 12/12.
• Final review and final QA.
• Showcase your final projects at least any that
  are finished!
• Final Exam
• Handed out on 12/12
• Due Dec 18 at 100 pm either into D2Ls DropBox
  or under my door.
• I heartily encourage you to complete your final
  project website by Dec 12th so you can focus on
  your finals. However, if you need more time you
  can have until Dec 18th. As such the official
  due date is Dec 18th.
• The final due date for everything in the class is
  Dec 18th - no exceptions unless you have a very
  real reason (medical or otherwise - see CU's
  policies here http//www.colorado.edu/engineerin
  g/academics/policies/grading). Of course we will
  accommodate real reasons.
• If you are a CAETE student, please let me know if
  you expect an issue with this timeframe. We
  normally give CAETE students an additional week
  to complete everything, but the grades are due
  shortly after the 18th for everyone. So please
  see if you can meet these due dates.

5
Final Project

• Get started on it!
• Worth 20 of your grade, equivalent to 6-7
  homework assignments.
• Find an interesting problem and investigate it
  anything related to spaceflight mechanics (maybe
  even loosely, but check with me).
• Requirements Introduction, Background,
  Description of investigation, Methods, Results
  and Conclusions, References.
• You will be graded on quality of work, scope of
  the investigation, and quality of the
  presentation. The project will be built as a
  webpage, so take advantage of web design as much
  as you can and/or are interested and/or will help
  the presentation.

6
Final Project

• Instructions for delivery of the final project
• Build your webpage with every required file
  inside of a directory.
• Name the directory ltLastName_FirstNamegt
• there are a lot of duplicate last names in this
  class!
• You can link to external sites as needed.
• Name your main web page index.html
• i.e., the one that you want everyone to look at
  first
• Make every link in the website a relative link,
  relative to the directory structure within your
  named directory.
• We will move this directory around, and the links
  have to work!
• Test your webpage! Change the location of the
  page on your computer and make sure it still
  works!
• Zip everything up into a single file and upload
  that to the D2L dropbox.

7
Space News

• Its looking like Space Ship 2s feathering
  system was deployed while accelerating through
  Mach 1, causing the disintegration.
• Rosettas Philae lander prepping for its big
  descent in 9 days!

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ASEN 5050SPACEFLIGHT DYNAMICSMid-Term Exam

• Prof. Jeffrey S. Parker
• University of Colorado Boulder

9
Mid-Term Exam

• Problem 1
• Common errors
• Since this isnt a circular orbit, the DT is not
  half of the orbital period. Though the Delta-nu
  is indeed 180 deg.

10
Mid-Term Exam

• Hard way generate the two-body orbit and map the
  latitude

?
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Mid-Term Exam

• Problem 1 solution
• Easy way (and precise)
• Argument of latitude u ? ?
• At ascending node u 0 deg
• At descending node u 180 deg
• ? 310 deg
• At ascending node ? -310 deg 50 deg
• At descending node ? -130 deg 230 deg
• Compute time past periapse for both
• Delta-t 1.138 hours

Quadrant Checks! Ascending ? Descending
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Mid-Term Exam

• Problem 2

13
Mid-Term Exam

• Problem 2

Periapsis Range 5473.0 km
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Mid-Term Exam

• Problem 2

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Mid-Term Exam

• Problem 2

Quadrant Checks!
Use eccentricity and semi-major axis, and find
the eccentric anomaly needed to make radius
6378.1363 km. Convert to TimePastPeriapse.
And also compute TimePastPeriapse of initial
state. We find   Time past periapse of initial
state -2049.99566 sec Time past periapse of
impact -676.70889 sec Duration of time
to impact 1373.28677 sec 0.38147
hours
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Mid-Term Exam

• Problem 2

The missile will strike the surface traveling
8811.91852 m/s in velocity
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Mid-Term Exam

• Problem 3

18
Mid-Term Exam

• Problem 3

19
Mid-Term Exam
C/W Equations Algorithm 48
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Mid-Term Exam

• Problem 3

21
Mid-Term Exam

• Problem 3
• omega 0.00114400182253 rad/s
• Satellite A will be located at a position of
  0.0, 0.0, 80.8050388 in meters, after 7
  minutes, relative to Shuttle
• Satellite B will be located at a position
  of79.17972504, 142.440310957, 0.0 in
  meters, after 7 minutes, relative to Shuttle
• Satellite A will have a velocity relative to the
  shuttle of0.0, 0.0, 0.177354562 in
  m/s, after 7 minutes
•  
• Satellite B will have a velocity relative to the
  shuttle of0.369764446, 0.2188365,
  0.0 in m/s, after 7 minutes

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Mid-Term Exam

• Problem 3

23
Mid-Term Exam

• Problem 3

24
Mid-Term Exam

• Problem 3
• Satellite A's state relative to Satellite B at
  t7 minutes, in meters and m/s, before executing
  any maneuver (A-B)
• x0 -79.179725045 m
• y0 -142.440310958 m
• z0 80.8050388697 m
• vx0 -0.369764446945 m/s
• vy0 -0.218836500483 m/s
• vz0 0.17735456256 m/s

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Mid-Term Exam

• Problem 3
• What velocity is NEEDED? Equation 6-66

t 13 min 780 sec
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Mid-Term Exam

• Problem 3
• What velocity is NEEDED? Equation 6-66
• The velocity that Satellite A needs to obtain
  (m/s)
• vx 0.00953422198546 m/s
• vy 0.247527429082 m/s
• vz -0.0745206696574 m/s

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Mid-Term Exam

• Problem 3
• What CHANGE in velocity is needed?
• The Delta-V impulse that A has to perform, in m/s
  relative to B
• Delta-Vx 0.37929866893 m/s
• Delta-Vy 0.466363929565 m/s
• Delta-Vz -0.251875232218 m/s
• Delta-V magnitude 0.651769842549 m/s

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Mid-Term Exam

• Problem 3

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Mid-Term Exam

• Problem 3
• Use Algorithm 48 again to propagate state of A
  relative to B. You should see the position go to
  zero!!!
• The rendezvous Delta-V impulse that A has to
  perform, in m/s relative to B
• Delta-Vx -0.17983714361 m/s
• Delta-Vy -0.066363929565 m/s
• Delta-Vz 0.11873790189 m/s
• Delta-V magnitude 0.225486715161 m/s

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Mid-Term Exam

• Problem 3

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Mid-Term Exam

• Problem 3
• Answer yes!
• If satellite A does not do anything, it will
  collide with the shuttle in about 45 minutes.
  Half an orbit later.
• If satellite A DOES perform one maneuver, and
  then no more, it will collide with Satellite B.

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Mid-Term Exam

• Problem 4
• Inclination 9014 104 deg
• Altitude 1666.18 km

Big error sidereal time!
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Mid-Term Exam

• Problem 5

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Mid-Term Exam

• Problem 5

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Mid-Term Exam

• Problem 5

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Mid-Term Exam

• Problem 5
• mu muEarth muMoon 403503.2405 km3/s2
• rp 362600 km
• ra 405400 km
• a 384,000 km
• e 0.0557292
• Period of lunar orbit 2353711.295 sec
  39228.5216 min 653.80869 hours 27.242029 days

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Mid-Term Exam

• Problem 5

38
Mid-Term Exam

• Problem 5
• use equation (for example)
• r 380,000 km rEarth 386,378.1363 km
• E 1.68215420 rad 96.380336 deg
• Time past periapse 609395.909 sec 10156.5985
  min 169.27664 hours 7.053193 days
• Total Duration within 386378 km 1218791.818 sec
  20313.1970 min 338.55328 hours 14.106387
  days

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Mid-Term Exam

• Problem 5

Percentage of time the Earth and Moon are within
386378 km 51.782
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ASEN 5050SPACEFLIGHT DYNAMICSA-Train

• Prof. Jeffrey S. Parker
• University of Colorado Boulder