1. University of Colorado Boulder ASEN 6008 Interplanetary Mission Design Spring 2015 Kate Davis Launch Considerations 1

2. University of Colorado Boulder  One of the most required aspects of an interplanetary mission design. ◦ Until we invent teleportation or master the control of an Einstein-Rosen bridge  From a mission design perspective, the primary three concerns we have for choosing a launch site: ◦ Availability / cost ◦ Performance (closer to the equator = more performance) ◦ Range of orbital inclinations / departure asymptotes that may be reached 2

3. University of Colorado Boulder 3

4. University of Colorado Boulder 4

5. University of Colorado Boulder 5 Courtesy of NASA: Sergeyevsky, A. B., Snyder, G. C., and Cunniff, R. A., Interplanetary Mission Design Handbook, Vol. 1, Part 2, Earth to Mars Ballistic Mission Opportunities, 1990-2005, JPL Publication 82-43, 1983.

6. University of Colorado Boulder  As you recall: ◦ The right ascension and declination of the launch may be computed from the outgoing v-infinity vector, departing Earth 6

7. University of Colorado Boulder  The Departing Hyperbolae 7

8. University of Colorado Boulder  The Departing Hyperbolae  There are an infinite number of options. Though not all are created equal. 8

9. University of Colorado Boulder  The Departing Hyperbolae  One constraint: ◦ Launch vehicles may target departure hyperbolae with inclinations less than or equal to the launch site latitude without suffering performance penalties. ◦ The minimum inclination of the departure hyperbolae is equal to the declination of the launch asymptote 9

10. University of Colorado Boulder  The Departing Hyperbolae  Question: what coordinate frame are these vectors in? 10

11. University of Colorado Boulder  V is some value between -23.4 and +23.4 degrees, depending on the situation. ◦ Transformation from an ecliptic frame to an equatorial frame of reference. ◦ Earth’s obliquity  DLA equatorial describes the minimum inclination of a parking orbit used. ◦ If the parking orbit has a smaller inclination, then there will be launch penalties. 11

12. University of Colorado Boulder  In addition to desired inclination, there is another HUGE factor to consider when launching.  Allowable Launch Azimuths  Launching over inhabited regions is generally frowned upon ◦ Most people wouldn’t want an SRB landing in their front yard. 12

13. University of Colorado Boulder 13

14. University of Colorado Boulder 14

15. University of Colorado Boulder 15

16. University of Colorado Boulder 16

17. University of Colorado Boulder 17 Question 1 Which azimuth yields the highest performance for a launch vehicle? Question 2 What is the resulting orbital inclination? Question 3 What is the range of DLA values that don’t suffer a penalty? (Equatorial)

18. University of Colorado Boulder Assume: Launch from Florida into 28.5 deg inclined LEO parking orbit. Observe: θ at right  If you wanted to target an equatorial DLA of 0 degrees, where would you perform the Earth-departure maneuver?  If you wanted to target an equatorial DLA of 28.5 deg, where would you perform the Earth-departure maneuver? 18

19. University of Colorado Boulder  How do you target RLA?  Launch at the right time!  Pay attention to your launch vehicle provider. 19 Can the upper stage re-light? Does the system require staging orbits? How many?