1. Energy in Space By Astrid Raisanen
Time: 1min; Introduce self and thank Raytheon and mentors; explain that I will be talking about a power/energy analysis.
NASA Space Grant Symposium
Saturday, April 19, 2008

2. Stages of A Lunar Mission (Example)
Time: 30s: just explain that this is the sequence of events during a lunar mission. They will be highlighted momentarily.

3. Method: Data Input and Analysis
Divert Valves
ACS Valves
Computer
IMU
Low Gain Comm
High Gain Antenna
Star Tracker
Payload
Radar Altimeter
Heaters
Cameras W
100 80 20 12 60 2 10 35 5 4
0.5 1 60
TLI Ignition (STAR 37 motor)
600
TLI Burnout
120
TLI stage separation
De-spin
360
Stabilization
300
Stellar attitude reference update 20
Slew to comm attitude
Launch Vehicle Power?
Battery Used?
Solar Panels Used?
Battery Charging?
Battery Drainage
Battery Charging
yes=1
no=o
no=0
[W-hr] 1
0.00
0.0
0.1
0.99
0.74
0.19
=IF(AM58-AK59+AL59>Constants!$B$8,Constants!$B$8,AM58-AK59+AL59)

4. Goal of Power/Energy Analysis
To size the battery for a lunar mission by:
Calculating the power and energy required by the space vehicle at any time
Calculating the power/energy that will likely be provided by the solar arrays at any time during flight
Assuming that the rest of the power will be drawn from the battery
Time: 30s: clearly highlight goal of analysis. Mention that the 2 power sources of concern are the solar arrays and the battery.

5. Given Solar Array Configuration
Triple Junction Germanium Cells
A=.3m2/panel; 4 panels
Assumption:
Solar cells are approximately 27% efficient
Time: 45s: Go over dimensions and assumptions. Talk about anything “unique” that the structure might offer.

6. The Course To The Lunar Surface
Targeting TCM
Mid Course TCM
POS I TLI TCM

8. BDL
Earth-Moon Cruise

9. Lithium Ion Battery Energy Requirement: 225Wh Original Estimate: 270Wh
36 cells in parallel/series combination
29V total
9.3 Ah
Time: 45s: Discuss characteristics of Li ion battery. Conclude.

10. Astrid Raisanen Sophomore, University of Arizona Aerospace Engineering
A special thanks to: NASA Space Grant and the University of Arizona, Raytheon Missile Systems, James Head, Kristin Schmidt, and Tom Gardner
Astrid Raisanen
Sophomore, University of Arizona
Aerospace Engineering