Boeing’s space fuel depot (PM article)

[holmec]

Back to topic....<br /><br />Would Parom have used any of the valves and stuff you described? <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[CalliArcale]

Since the idea with Parom is to have it stay in orbit for a very long time, it would have to use a different system from Soyuz. This could be as simple as choosing a more robust material for valves and seals and things, but I really don't know. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[holmec]

Thanks. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[cbased]

Thank you for such a detailed answer.<br />Yes, Soyuz uses hydrazine as a propellant for its <b>main</b> engine. The descent module RCS though uses hydrogen peroxide (H2O2) as a monopropellant (plus solid catalyst) and H2O2 <br />decomposes over time.<br /><br />There is (was?) a project (called Soyuz TMS) where (along with other upgrades) they plan to install thermo-electric coolers for H2O2 tanks. This increases Soyuz orbital life to 380 days (roughly 1 year)<br />

 

[CalliArcale]

Interesting. So there are two limiting factors! Ironically, each of them probably reduces the odds of the other being eliminated, since there's no point making the seals more robust if the RCS propellant is going to degrade by that time anyway, and vice versa. (Having been to a few change control board meetings in my time, I've seen that sort of circular reasoning quite a few times.) <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[publiusr]

As long as this is a way to augment Ares V--thats one thing. I wonder if it is just an EELV only plan in disguise...