FWIU, barring FTL; superluminal communication breakthroughs and controls, Deep Space Networking needs a new TCP, as well:

From https://github.com/torvalds/linux/blob/master/net/ipv4/tcp_t... :

  void tcp_retransmit_timer(struct sock *sk) {
  
 /* Increase the timeout each time we retransmit.  Note that
  * we do not increase the rtt estimate.  rto is initialized
  * from rtt, but increases here.  Jacobson (SIGCOMM 88) suggests
  * that doubling rto each time is the least we can get away with.
  * In KA9Q, Karn uses this for the first few times, and then
  * goes to quadratic.  netBSD doubles, but only goes up to *64,
  * and clamps at 1 to 64 sec afterwards.  Note that 120 sec is
  * defined in the protocol as the maximum possible RTT.  I guess
  * we'll have to use something other than TCP to talk to the
  * University of Mars.
  *
  * PAWS allows us longer timeouts and large windows, so once
  * implemented ftp to mars will work nicely. We will have to fix
  * the 120 second clamps though!
  */

/? "tp-planet" "tcp-planet" https://www.google.com/search?q=%22tp-planet%22+%22tcp-plane... https://scholar.google.com/scholar?q=%22tp-planet%22+%22tcp-...