Elon Musk Proves the Apollo 11 Mission was a Fraud
(www.youtube.com)
You're viewing a single comment thread. View all comments, or full comment thread.
Comments (178)
sorted by:
Then get used to having a whole lot of tanking flights. Would you enter a Greyhound bus in the Indianapolis 500? It is really great for commercial transport and probably has good engines. The velocity requirement to go to the Moon is far greater than to reach low Earth Orbit, and the difficulty in meeting the requirement gets greater very quickly as the requirement gets larger. Increased specific impulse (exhaust velocity) and more staging are the only ways you can bring it down to one flight.
Why don't you do the numbers, if you think Musk has a better idea? Find the delta-v required. Find the specific impulse of his rocket engines. Find the mass ratio of his rocket. Solve the Tsiolkovsky equation. You will find you can't, by a large margin. Or, get ready for 6, 8, or 20 tanking flights to make it all happen, whatever the number works out to be. In the end, he will burn up a LOT of propellant getting propellant into space, and propellant use is the measure of efficiency when it comes to rockets. I admit, propellant is cheap. But can you afford all the time for the tanking? And take the risk that a tanking flight might go awry?
Look, I'm not saying Musk can't get to the Moon in that approach. I am just saying that just because his system is not optimally designed for the mission and needs to take an unknown number of tanking flights, is not any kind of proof that the Apollo mission was impossible. Apollo was designed from the beginning to be optimal for the mission without any thought of reusability, so it could be done in one flight. And it did, thanks to the genius of Von Braun and his team.
You simply aren't thinking big enough. Going to the moon and staying for a day or two - been there done that. Six times according to the historical record and its been what almost 60 years ago ? In order to build a moon base and eventually colonize Mars, you need BIG ships with massive heavy lift capability. And it has to be reusable or we're not gonna make it.
I don't mind reusable if (1) the total system is optimized for the mission, and (2) the mission complexity is not increased by the reusability. There can be a mix. Upper stages are smaller and may cost less to produce than to supply by tanker methods. You will notice that on Falcon 9, Musk does not re-use the second stage. Too troublesome to re-enter from orbital altitudes and speeds, and needful of carrying extra landing equipment and propellant...which competes for payload capability.
You aren't thinking of safety at all. Since we haven't done this for 60 years and all the mission activities must be re-learned from scratch, the wisest course of action is to make sure we CAN replicate the missions that we did. Then it is reasonable to expand the mission complexity. We nearly lost a crew on Apollo 13 because of a system failure mode that was unexpected. The proposed Artemis approach bypasses repeating what we knew how to do with an approach that is totally new, with the new (and not-yet built or tested) so-called Gateway station, involving more complex docking than in Apollo, and a Space X lander, totally unlike the lander of the past. To me, the Gateway is just one flashing neon sign saying "failure opportunity." Without it, we can't get to the lunar surface. The astronauts can get there, the lander can get there, but you can't transfer from the crewed ship to the lander. Then you need a new Gateway. Things aren't "reusable" when they fail. We could get to the Moon without Gateway, prove those elements of the architecture, then move to incorporate Gateway for use with missions to the South Pole.
I agree that one needs to go to the Moon in order to prove out the systems that will go to Mars. The Moon is only a day or so from Earth and emergencies have some prospect of being overcome or recovered from. Facing an emergency midway to Mars is a bad scene, because you are months away from anywhere with no tow truck or ambulance available. I'm afraid you are the one who is not thinking big enough. A trip to Mars is far more "alone" than any walking trip across Antarctica.
Have you ever heard of Boeing's Reusable Aerodynamic Space Vehicle (RASV)? It was a horizontal takeoff / horizontal landing single-stage-to-orbit spaceplane, totally reusable and operational like an airplane. It was proposed to the Air Force in the 1970s. We proposed an updated version again in 1997 (I was on the proposal team), but missed out on the study contract award due to competition rules. You really don't need to argue reusability with me, since I've been aware of it for---I don't know---maybe longer than you've been alive? Boeing even had designs for reusable "flyback" versions of the Saturn S1-C stage. It's an old ambition.
As for Mars, Musk is totally banking on finding Martian-derived propellants available when he gets there. If some fault occurred and they are not available quite as expected, he may be stranded. This is why my preferred approach is to develop a good nuclear thermal rocket engine and take all the propellant you need for a both-way trip.