AAE450 Spring 2009

Communications Equipment

Horizontal crashTrenten MullerFeb. 19, 2009

[Trenten Muller] [COM]

AAE450 Spring 2009

New communication system suitable for all phases

All Products by SpaceQuest Model Mass (kg) Size (mm) Power (W) Voltage Temp Price ($)

Antenna AC-100 0.1 Φ33 x 44.2 NA NA NA $10,000

Receiver RX-2000S 0.2 135 X 50 X 25 1.5 6-16 VDC -30 to 75 C $30,000

Transmitter TX-2400 0.2 68 X 35 X 15

37.00Peak

transmission 8-32 VDC -20 to 70 C $24,000

Controller CSC-75 0.57 150 X 100 X 25 0.50 9-16 VDC -20 to 60 C $40,000

Total per system 1.07 kg

39.00 WPeak

transmission $ 104,000.00

Possible Flight controller IFC-100 0.2 180 X 150 X 25 0.3 3.3 VDC -10 to 60 C $50,000

[Trenten Muller] [COM]

AAE450 Spring 2009

Horizontal Sliding Represents the Lander

sliding on Lunar surface without skipping, digging in, or creating a crater immediately upon impact.

Given the unpredictable nature and the long slide distance I would advise against landing with significant horizontal velocity.

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.50

1

2

3

4

5

6

7

horizontal velocity (km/sec)

dist

ance

(km

)

skid distance vs. horizontal velocity

10g15g20g

[Trenten Muller] [COM]

AAE450 Spring 2009

Computer Code clear all close all clc vhor = linspace(0,2500,10000); %horizontal velocity m/s % vver = linspace(0,50,1000); %vertical velocity m/s mass = 163.49; %mass of dry lander kg earthg = 9.80665; %gravitational constant of Earth m/s^2 moong = 1.622; %gravitational constant of moon m/s^2 coeff = 0.18; %coefficient of friction for regolith normf10 = mass * (moong+10*earthg); %normal force N coming in at 10g normf15 = mass * (moong+15*earthg); %normal force N coming in at 15g normf20 = mass * (moong+20*earthg); %normal force N coming in at 20g ff10 = normf10 * coeff; %frictional force N 10g ff15 = normf15 * coeff; %frictional force N 15g ff20 = normf20 * coeff; %frictional force N 20g horaccel10 = ff10 / mass; %horizontal acceleration m/s^2 10g horaccel15 = ff15 / mass; %horizontal acceleration m/s^2 15 horaccel20 = ff20 / mass; %horizontal acceleration m/s^2 20g

[Trenten Muller] [COM]

AAE450 Spring 2009

crashth10 = vhor ./ horaccel10; %time for horizontal impact s 10g crashth15 = vhor ./ horaccel15; %time for horizontal impact s 15g crashth20 = vhor ./ horaccel20; %time for horizontal impact s 20g dist10 = vhor.*crashth10-.5.*horaccel10.*crashth10.^2; %horizontal distance m 10g dist15 = vhor.*crashth15-.5.*horaccel15.*crashth15.^2; %horizontal distance m 15g dist20 = vhor.*crashth20-.5.*horaccel20.*crashth20.^2; %horizontal distance m 10g % crashtv = .01; %estimated time for vertical impact s % veraccel = -vver ./ crashtv; %vertical acceleration m/s^2 % vg = veraccel ./ -earthg; %vertical g load plot(vhor.*10^-3,dist10.*10^-3) hold on plot(vhor.*10^-3,dist15.*10^-3,'r') plot(vhor.*10^-3,dist20.*10^-3,'g') hold off

[Trenten Muller] [COM]

AAE450 Spring 2009

legend('10g','15g','20g') title('skid distance vs. horizontal velocity') ylabel('distance (km)') xlabel('horizontal velocity (km/sec)') grid on % figure(2) % plot(vver,vg) % title('g^,s vs. vertical velocity') % xlabel('vertical velocity (m/s)') % ylabel('earth g^,s') % grid on % hold on % plot(vver,15,'r')

[Trenten Muller] [COM]

AAE450 Spring 2009

References Creel et al., “Pressurized Lunar Rover,” Dept. of

Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University, May 1992. ~coefficient of friction for Lunar regolith

[Trenten Muller] [COM]