Methane dropped from CEV

[JonClarke]

Such as?<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[vt_hokie]

So, you're saying that a hydrazine tank is forever considered contaminated, even if it is purged? <br /><br />And are the space shuttle's RCS thrusters reused? I never really thought about what would be involved in turning those around for the next flight, in terms of testing and possible refurbishment.

 

[vt_hokie]

Wow, I'm sorry to hear that.

 

[JonClarke]

How was the issue handled in the Apollo era?<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[propforce]

<font color="yellow">I know many engineers and technicians that have liver damage from being exposed to hypergolic fuel vapors. </font><br /><br />Yeah I am one of them, not from the shuttle program though... <div class="Discussion_UserSignature"> </div>

 

[JonClarke]

Sorry to hear that. I hope you are managing OK <br /><br />Which is the more dangerous component? The hydrazine or the nitrogen tetroxide? Is there a significant difference between the toxicities of of plaine hydrazine, UDMH and MMH?<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[mikejz]

I'm trying to remember, outside of H2O2 are there any other realtivily safe hypergolic alternatives out there?

 

[mikejz]

My mistake, sorry. <br /><br />I should of described it as a fuel/oxy that does not require an ignition system and would be suitable for a RCS.

 

[drwayne]

"H202 can be used with a cataliyst to produce hydrogen rich steam that can be used fro propulsion."<br /><br />Yes, hydrogen peroxide can in fact be used as a monopropellant - as you describe.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[rubicondsrv]

Well it would not be any safer but a florine/lox mixture would be hypergolic with most fuels. and it might have a higner isp than the propelland combination of hydrazine/n2o4. you would also have only one toxic propelant element florine although the exaust products might be toxic. <div class="Discussion_UserSignature"> </div>

 

[rubicondsrv]

it also reacts violently with many metals.<br />leaking h2o2 likely caused the kursk sinking. <div class="Discussion_UserSignature"> </div>

 

[drwayne]

Has anyone talked seriously in recent years of using FLOX? I ask out of curiosity, I hadn't hear much on that front...<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[rubicondsrv]

I dont know. I am just a high school student. <div class="Discussion_UserSignature"> </div>

 

[rubicondsrv]

for those that have not seen this before here is a video that gives you an idea of how reactive it can be.<br /><br />http://media.armadilloaerospace.com/misc/MaterialTest.mpg <div class="Discussion_UserSignature"> </div>

 

[rubicondsrv]

duplicate post deleted <div class="Discussion_UserSignature"> </div>

 

[rubicondsrv]

it was 90% peroxide <div class="Discussion_UserSignature"> </div>

 

[tap_sa]

<font color="yellow">"H2O2 is not hypergolic"</font><br /><br />It is with hydrazine, according to Sutton's book. But is that combination practical is another question. Getting rocket-grade H2O2 is difficult (most of it is manufactured in lesser purity) and you'd still have the toxic hydrazine left. <br /><br />Does potassium permanganate dissolve into RP-1? That would make it hypergolic with H2O2.

 

[mikejz]

Obtaining H2O2 in high concentrations is not that hard for small amounts via distilling. Of course, not exactly the safest way (I could simply be done by remote control). <br /><br />While toxic, I believe, by the fact that it has been used in 'stunt' rocket powered cars, etc. That ground handling is easier than hydrazine. In fact, I'm willing to bet that simply flushing the system with water would be sufficient to allow for safe handling. <br /><br />If used with a catalyst, the ISP may be very bad, but for a CM RCS, given its limited use, could be sufficient. <br /><br />On another note, how about resistojets or arcjets for finer adjustments?

 

[rubicondsrv]

that could be a problem because h202 decomposes over time. <br /><br /><br />it also produces oxygen gas as it decomposes which would need to be vented to maintain a constant pressure in the tanks. <div class="Discussion_UserSignature"> </div>

 

[JonClarke]

As I recall an X-15 pilot, Mckay I think, died from liver disease some years after veing exposed to hypergolics after an X-15 crash.<br /><br />I will check the safety data sheets for nitogen tetroxide and hydrazine compared to other nasties - peroxide, cyanide, sulfuric acid hydrochloric acid and fluorine.<br /><br />Jon<br /> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[rubicondsrv]

I just looked at the MSDS for N2o4 hydrazine,flourine and h2o2.<br />of these Flourine seems to be the most toxic followed by n2o4 then hydrazine then peroxide. <div class="Discussion_UserSignature"> </div>

 

[mikejz]

Isn't hydrazine basically hypergolic with any oxidizer, and so (with ISP penalty) N2O could also be used?

 

[spacefire]

bye bye Mars. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[mikejz]

iron oxide + powered Aluminum = Fun <img src="/images/icons/smile.gif" />

 

[rubicondsrv]

thermite <div class="Discussion_UserSignature"> </div>