see the wreckage of the titanic. this hour the supply of oxygen is rapidly running out. we ll show you what conditions are like inside the small, cramped sub that left with five people on board. china is now lashing out at the united states after president joe biden referred to chinese leader xi jinping as a dictator. this as cnn is getting an exclusive look at military drills preparing for a potential chinese invasion of taiwan. welcome to our viewers in the united states and all around the world. you re in the situation room. let s get right to the massive search for the missing submersible. the source of banging sounds in the area remains a mystery at this hour but they are giving rescue crews hope. when you are in the middle of a search and rescue you always have hope. that s why we re doing what we do. reporter: with what could be less than 24 hours of oxygen left onboard titan, hope at this point may rest on banging noises detected by sonar. the coast guard re
spacecraft and submarines is that many issues are almost identical. for example on life support you have to add oxygen, scrub out the co2, manage the total pressure, you want to keep the temperature within livable range. that sort of thing. then when you get to the pressures involved the two types of vehicles deviate dramatically. in the case of a spacecraft you re only having to hold in one atmospheric pressure compared to the vacuum of space. when you are going down, down to the mariana trench it is a thousand atmospheres of pressure. here at the titanic it is merely about 500 times the surface pressure of air. which is still obviously an enormous amount of pressure and that is why a spaceship hull is very thin, not much more than a coke can, but it takes numerous inches of steel or in this case carbon fiber to hold out the enormous pressure. plus the design is, you know, a spacecraft has often a more complex shape.
the presidency by retweeti inin something with no basis in fact and is just part of what ricks around in the web and internet spe spheres and it has the power to just sort of add oxygen in some of the dark corners. it is certainly drawing some criticism from democratic candidates who are seeking the nomination who even called it dangerous. and the president s advisers have been we ve asked number of times today for some sort of an explanation for the president s reason why he did this. what was he trying to say? is there any explanation, clarification? anything they could say about this. and they have not responded to us. kellyanne conway, konz to the president, appeared on television today. she, too, was asked about this and simply responded that the president wants this to be investigated. of course the president did not use his twitter time to talk about the attorney general who has called for an investigation.