Php AWS S3 download multiple files at a time through server cron job

Question

I am trying to download multiple files at a time by using the following script. But it is only downloading only the very first file.

require 'vendor/autoload.php';

use Aws\S3\Exception\S3Exception;
use Aws\S3\S3Client;

// Initial configurations.
$region     = '*****';
$bucket     = '*****';
$keyname    = '**************';
$secret     = '**************';

$s3 = Aws\S3\S3Client::factory([
  'credentials' => [
    'key'     => $keyname,
    'secret'  => $secret
  ],
    'version' => 'latest',
    'region' => $region
]);

$object_lists = [ 'Initial_Data.csv', 'Processed_Data.csv' ];

foreach( $object_lists as $object_list ) {
    $object = $s3->getObject([
    'Bucket'  => $bucket,
    'Key'     => $object_list,
  ]);

  header('Content-Description: File Transfer');
    header('Content-Type: binary/octet-stream');
    header('Content-Disposition: attachment; filename='.$object_list);
    header('Expires: 0');
    header('Cache-Control: must-revalidate');
    header('Pragma: public');

    //send file to browser for download. 
    echo $object["Body"];
}

How do I download both the files at once? Also can someone tell me is this a right way to download the files through server cron?