SD card initialization failed i use the example sketch of SD card presented in Arduino IDE.
It runs well, but when i reboot my Adruino Mega by the reset button, the SD card initialization fails.
To fix it, i need to remove the SD card, insert it in his socket and reboot the board again. Then, SD card initialization is OK.
How can i update my code to try initialize the SD card until initialization is OK?
Also, can you explain me where come this bug ? 

See the example SD card setup on the Arduino Mega:

Serial.print("Initializing SD card...");

  if (!SD.begin(53)) {
    Serial.println("initialization failed!");
    while (1);
  }
  Serial.println("initialization done.");
I just add an external 9V power supply to my Arduino Mega. The SD device is power by arduino 5V pinout.