Contents

Explore parameter space for straight-line interstellar mission

------------------------------------------------------------------------- See also: StraightLineConstantThrust, SimulateStraightLineTrajectory, He3MassFromPower (Fusion Toolbox) -------------------------------------------------------------------------

%--------------------------------------------------------------------------
% Copyright 2018 Princeton Satellite Systems, Inc.
%--------------------------------------------------------------------------
% Since Version 2018.1
%--------------------------------------------------------------------------

Explore a range of uE and thrust

g      	= StraightLineDataStructure;
g.mP    = 1000; % kg
g.mE    = [];
eta   	= 0.6;
sigma  	= 100e3; % W/kg
years  	= 300;
g.f     = 0.03;
year    = 365.25*86400;
g.tF    = years*year;
uE      = linspace(2000,24000); % km/s
n       = length(uE);
thrust  = [5 10 20 30];
dists   = zeros(length(thrust),n);
tS      = zeros(length(thrust),n);
leg     = cell(1,length(thrust));
for j = 1:length(thrust)
  for k = 1:length(uE)
    % compute distance traveled for each parameter combo
    g.uE        = uE(k);
    g.thrust    = thrust(j);
    g           = StraightLineConstantThrust( g );
    dists(j,k)  = g.dF;
    tS(j,k)     = g.tS;
  end
  leg{1,j} = sprintf('%4.1f N',thrust(j));
end

lY = 9.46728e+12; % light year

dD = 4.27*lY;

aS = abs(dists-dD);

jMin = 1;
kMin = 1;
dMin = aS(1,1);
for j = 1:length(thrust)
  for k = 1:length(uE)
    if( aS(j,k) < dMin )
      jMin = j;
      kMin = k;
      dMin = aS(j,k);
    end
  end
end

Plot2D(uE,dists/lY,'u_e (km/s)','Distance (ly)','Alpha Centauri');
legend(leg);

What is the maximum distance achieved?

[~,kk]      = max(dists(end,:));
g.uE        = uE(kk);
g.thrust    = thrust(end);
d           = StraightLineConstantThrust( g );
SimulateStraightLineTrajectory( d );
power = 0.5*g.thrust*g.uE*1000/eta;


s = {}; k = 1;
s{k,1} = 'Payload';           s{k,2} = sprintf('%12.0f',g.mP);              s{k,3} = 'kg';    k = k + 1;
s{k,1} = 'Travel time';       s{k,2} = sprintf('%12.2f',g.tF/year);         s{k,3} = 'years'; k = k + 1;
s{k,1} = 'Specific Power';    s{k,2} = sprintf('%12.2f',sigma*1e-3);        s{k,3} = 'kW/kg'; k = k + 1;
s{k,1} = 'Exhaust velocity';  s{k,2} = sprintf('%12.1f',g.uE);              s{k,3} = 'km/s';  k = k + 1;
s{k,1} = 'Thrust Efficiency'; s{k,2} = sprintf('%12.2f',eta);               s{k,3} = '';      k = k + 1;
s{k,1} = 'Fuel Fraction';     s{k,2} = sprintf('%12.2f',g.f);               s{k,3} = '';      k = k + 1;
s{k,1} = 'Switch time';       s{k,2} = sprintf('%12.2f',d.tS/year);         s{k,3} = 'years'; k = k + 1;
s{k,1} = 'Thrust';            s{k,2} = sprintf('%12.2f',g.thrust);          s{k,3} = 'N';     k = k + 1;
s{k,1} = 'Total Mass';        s{k,2} = sprintf('%12.2f',d.m0);         s{k,3} = 'kg';    k = k + 1;
s{k,1} = 'Mass Dry';          s{k,2} = sprintf('%12.2f',d.mD);              s{k,3} = 'kg';    k = k + 1;
s{k,1} = 'Mass Engine';       s{k,2} = sprintf('%12.2f',d.mE);              s{k,3} = 'kg';    k = k + 1;
s{k,1} = 'Mass Fuel';         s{k,2} = sprintf('%12.2f',d.mF);              s{k,3} = 'kg';    k = k + 1;
if exist('He3MassFromPower','file')
  masses   = He3MassFromPower(power*years*86400*365.25);
  mHe3     = masses(1);
  s{k,1} = 'Mass He3';        s{k,2} = sprintf('%12.2f',mHe3);              s{k,3} = 'kg';  k = k + 1;
end
s{k,1} = 'Flow Rate';         s{k,2} = sprintf('%12.2f',d.mF/g.tF*1e3);     s{k,3} = 'g/s';   k = k + 1;
s{k,1} = 'Power';             s{k,2} = sprintf('%12.2f',power/1e6);       s{k,3} = 'MW';    k = k + 1;
s{k,1} = 'Final Distance';    s{k,2} = sprintf('%12.2f',dists(end,kk)/lY);	s{k,3} = 'ly';    k = k + 1;



DisplayLatexTable( s )

%--------------------------------------

          Payload         1000    kg 
      Travel time       300.00 years 
   Specific Power       100.00 kW/kg 
 Exhaust velocity      24000.0  km/s 
Thrust Efficiency         0.60       
    Fuel Fraction         0.03       
      Switch time       172.20 years 
           Thrust        30.00     N 
       Total Mass     26347.02    kg 
         Mass Dry     14512.92    kg 
      Mass Engine     13157.89    kg 
        Mass Fuel     11834.10    kg 
        Flow Rate         0.00   g/s 
            Power       600.00    MW 
   Final Distance         3.55    ly 

Published with MATLAB® R2019a