main.js

var telnet = require('telnet-client');
var connection = new telnet();

var params = {
  host: 'horizons.jpl.nasa.gov',
  port: 6775,
  shellPrompt: 'Horizons> ',
  timeout: 5000
};

 var commands = [

    ["399"," Select ... [E]phemeris, [F]tp, [M]ail, [R]edisplay, ?, <cr>: ", true],
    ["e", " Observe, Elements, Vectors  [o,e,v,?] :", false],
    ["v", " Coordinate center [ <id>,coord,geo  ] :", false],
    ["@sun", " Reference plane [eclip, frame, body ] :", false],
    ["eclip", " Starting CT  [>= 9999BC-Mar-20 00:00] :", false],
    ["2016-01-24 00:00:00", " Ending   CT  [<=   9999-Dec-31 12:00] :", false],
    ["2016-01-24 01:00:00", " Output interval [ex: 10m, 1h, 1d, ? ] :", false],
    ["1d", " Accept default output [ cr=(y), n, ?] :", false],
    ["y", " >>> Select... [A]gain, [N]ew-case, [F]tp, [K]ermit, [M]ail, [R]edisplay, ? :", true]

];

connection.on('ready', function(prompt) {
  console.log('Connected');

  (function recursiveCommands(i, result) {
    i = (i !== undefined) ? i : 0;
    result = result || [];
    console.log('Executing: ' , commands[i][0], ' awaiting ', commands[i][1]);
    connection.exec(commands[i][0], {shellPrompt: commands[i][1]}, function(err, response) {
      //console.log('Repsonse: ', err,response);
      if(commands[i][2]) {
        result.push(response);
      }
      if(i<commands.length-1) {
        recursiveCommands(++i,result);  
      } else {
        console.log(result[1]);
      }
    });
  })();

});
 
connection.on('timeout', function() {
  console.log('socket timeout!')
  connection.end();
});
 
connection.on('close', function() {
  console.log('connection closed');
});
 
connection.connect(params);