"The spacecraft are able to stay in orbit for months by using a solar array to generate power."<p>http://news.yahoo.com/secretive-x-37b-military-space-plane-could-land-132030466.html<p>Why are the ground crew wearing protective gear if it just solar power? Seems like a radioactive power source with that type of protection.<p>Thoughts?
It is extremely likely it is the hypergolic fuel used for the on-orbit manoeuvring rockets. Hypergolic fuel is really nasty stuff.<p>It is likely the same rocket fuel (maybe the same rockets) as used by the space shuttle (OMS).<p><a href="http://en.wikipedia.org/wiki/Space_Shuttle_Orbital_Maneuvering_System" rel="nofollow">http://en.wikipedia.org/wiki/Space_Shuttle_Orbital_Maneuveri...</a><p>See also:<p>* <a href="http://en.wikipedia.org/wiki/Space_Shuttle_Discovery#Decommissioning_and_display" rel="nofollow">http://en.wikipedia.org/wiki/Space_Shuttle_Discovery#Decommi...</a><p>* <a href="http://en.wikipedia.org/wiki/Hypergolic_propellant#Disadvantages" rel="nofollow">http://en.wikipedia.org/wiki/Hypergolic_propellant#Disadvant...</a>
That's chemical protective gear designed to protect the ground crew against hydrazine or similarly hazardous vapors .<p>They were first developed in the 1960s for the Titan missiles, which use the chemically nasty (but room temperature) nitrogen tetroxide and Aerozine 50. See <a href="http://books.google.com/books?id=MdTZFu1fZ4AC&pg=PA186&lpg=PA186&dq=SCAPE+suits+%28Self-contained+atmospheric+protective+ensemble&source=bl&ots=qDQRlf_LXV&sig=7joCcfETaLVBPiNywk6yTG9p9uI&hl=sv&sa=X&ei=J7A6VLylGsXMyAOvpILwAg&ved=0CCoQ6AEwAQ#v=onepage&q=SCAPE%20suits%20%28Self-contained%20atmospheric%20protective%20ensemble&f=false" rel="nofollow">http://books.google.com/books?id=MdTZFu1fZ4AC&pg=PA186&lpg=P...</a> for some of the history.<p>Here you can see the suits in use at the end of the Space Shuttle STS-1 mission: <a href="http://www.youtube.com/watch?feature=player_detailpage&v=gYcqvMGla24#t=1323" rel="nofollow">http://www.youtube.com/watch?feature=player_detailpage&v=gYc...</a> along with explanation by both the news and NASA commentators.<p><a href="http://www.xcor.com/blog/category/thrusters/" rel="nofollow">http://www.xcor.com/blog/category/thrusters/</a> and <a href="http://www.esa.int/Our_Activities/Space_Engineering/Clean_Space/Considering_hydrazine-free_satellite_propulsion" rel="nofollow">http://www.esa.int/Our_Activities/Space_Engineering/Clean_Sp...</a> are pictures of people in similar suits, in order to fuel spacecraft. I picked those to give commentary about how hazardous hydrazine is, and that there's a push to use alternative fuels.
Months are not a particularly long duration for spacecraft, and solar arrays are not at all unusual as power sources for spacecraft in the inner solar system.<p>Some data on satellite lifetimes:<p>* <a href="http://www.ospo.noaa.gov/Operations/GOES/status.html" rel="nofollow">http://www.ospo.noaa.gov/Operations/GOES/status.html</a><p>* <a href="http://noaasis.noaa.gov/NOAASIS/ml/life_expectancy.html" rel="nofollow">http://noaasis.noaa.gov/NOAASIS/ml/life_expectancy.html</a><p>* <a href="http://noaasis.noaa.gov/NOAASIS/pubs/life%20expectancy.pdf" rel="nofollow">http://noaasis.noaa.gov/NOAASIS/pubs/life%20expectancy.pdf</a> (2009)<p>As for the protective equipment being used in that Yahoo photo, that's probably due to the use of hypergolic fuel:<p>* <a href="http://en.wikipedia.org/wiki/Hypergolic_propellant" rel="nofollow">http://en.wikipedia.org/wiki/Hypergolic_propellant</a><p>Notice nearly-identical protective equipment being used in the Wikipedia entry.<p>As for protective equipment for radioisotope thermoelectric generators, here's an example from Cassini:<p>* <a href="http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator" rel="nofollow">http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_gen...</a><p>This being the Internet, there's far more information on related topics available:<p>* <a href="http://en.wikipedia.org/wiki/Corona_(satellite)" rel="nofollow">http://en.wikipedia.org/wiki/Corona_(satellite)</a><p>* <a href="http://en.wikipedia.org/wiki/File:U.S._RecSat_Big_Picture.jpg" rel="nofollow">http://en.wikipedia.org/wiki/File:U.S._RecSat_Big_Picture.jp...</a><p>Hmmm. Wonder what other and far more familiar satellite that KH-11 Kennan looks like.<p>* <a href="http://en.wikipedia.org/wiki/File:HST-SM4.jpeg" rel="nofollow">http://en.wikipedia.org/wiki/File:HST-SM4.jpeg</a>
The protective equipment is probably for fuel or oxidizer leaks.<p>This page: <a href="http://www.airforce-technology.com/projects/boeing-x37/" rel="nofollow">http://www.airforce-technology.com/projects/boeing-x37/</a><p>says that the vehicle uses either hydrazine or nitrogen tetroxide.<p>Aside from the main engine, reaction thrusters could foul the surrounding fuselage with nasty chemicals.
the guy who took this picture gave a talk 30c3 he takes pictures of military instantiations Seeing The Secret State: Six Landscapes<p><a href="http://media.ccc.de/browse/congress/2013/30C3_-_5604_-_en_-_saal_1_-_201312282300_-_seeing_the_secret_state_six_landscapes_-_trevor_paglen.html" rel="nofollow">http://media.ccc.de/browse/congress/2013/30C3_-_5604_-_en_-_...</a>
I guess the fuel could be poisoning (that was case for some soviet military rockets). Other option is just caution not to introduce dust particles etc...
Exact same suits being worn here...<p><a href="http://en.wikipedia.org/wiki/Hydrazine#mediaviewer/File:Hypergolic_Fuel_for_MESSENGER.jpg" rel="nofollow">http://en.wikipedia.org/wiki/Hydrazine#mediaviewer/File:Hype...</a>
Apparently this thing can fly 500 miles high which is space, maybe it's related to that?<p><a href="http://www.space.com/25275-x37b-space-plane.html" rel="nofollow">http://www.space.com/25275-x37b-space-plane.html</a><p><a href="http://en.wikipedia.org/wiki/Outer_space#Boundary" rel="nofollow">http://en.wikipedia.org/wiki/Outer_space#Boundary</a>