LS2022 23 Call5

Pagina 1

First name Last name Personal ID number Score Launch systems (8 credits) September 6th, 2023 First part - Closed book Each question is worth 1 point. The student must obtain at least 6 points (without rounding) otherwise the second part of the exam will not be corrected. WRITE THE ANSWERS IN THIS SHEET Preamble Bonus eligibility Did you clear the flipped class assignment (If yes, write team name)? Did you get a point for PEER evaluation? Mark the proper box …………………………….. Project participation Do you want to use the project evaluation and skip the second part of the exam? (If yes, write team name and score) Mark the proper box ……………………………………………………. Launch Systems Page 1 NO YES NO YES NO YES Scenario – Orbital mission 1. Consider a launch mission from the Earth. The launch site latitude isλ. (Three valid answers. The selection of a wrong answer invalidates the question.) For an equatorial mission launched from λ >0a change of plane is always needed. For a constant launch latitude, a higher launch azimuth reduces the possible payload. The contribution to launch velocity from Eastward launch is proportional to tan λ Launch to polar orbit from λ =0needs less propellant than a launch from λ > 0 Delta V losses are mostly given by aerodynamic drag Polar orbits are always possible with a direct route (no change of plane) 2. Coffee-time discussion with one of your colleagues Do you agree? Mark them as true (T) or false (F) (correct answer +2, wrong answer -1, no answer 0) If second stage ignition occurs at 70 km I am going to neglect drag losses in my Delta V analysis I have to initiate my computation of a ground-vbased orbital launcher and I need a first guess for total Delta V losses. What about 40% of the ideal DeltaV? Burning time reduction (with consequent thrust increment)…