X-37B plane can stay in space for years, power source?

[MysticFear]

"The spacecraft are able to stay in orbit for months by using a solar array to generate power."

http://news.yahoo.com/secretive-x-37b-military-space-plane-could-land-132030466.html

Why are the ground crew wearing protective gear if it just solar power? Seems like a radioactive power source with that type of protection.

Thoughts?

[gvb]

It is extremely likely it is the hypergolic fuel used for the on-orbit manoeuvring rockets. Hypergolic fuel is really nasty stuff.

It is likely the same rocket fuel (maybe the same rockets) as used by the space shuttle (OMS).

http://en.wikipedia.org/wiki/Space_Shuttle_Orbital_Maneuveri...

See also:

* http://en.wikipedia.org/wiki/Space_Shuttle_Discovery#Decommi...

* http://en.wikipedia.org/wiki/Hypergolic_propellant#Disadvant...

[dalke]

That's chemical protective gear designed to protect the ground crew against hydrazine or similarly hazardous vapors .

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 http://books.google.com/books?id=MdTZFu1fZ4AC&pg=PA186&lpg=P... for some of the history.

Here you can see the suits in use at the end of the Space Shuttle STS-1 mission: http://www.youtube.com/watch?feature=player_detailpage&v=gYc... along with explanation by both the news and NASA commentators.

http://www.xcor.com/blog/category/thrusters/ and http://www.esa.int/Our_Activities/Space_Engineering/Clean_Sp... 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.

[Hoff]

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.

Some data on satellite lifetimes:

* http://www.ospo.noaa.gov/Operations/GOES/status.html

* http://noaasis.noaa.gov/NOAASIS/ml/life_expectancy.html

* http://noaasis.noaa.gov/NOAASIS/pubs/life%20expectancy.pdf (2009)

As for the protective equipment being used in that Yahoo photo, that's probably due to the use of hypergolic fuel:

* http://en.wikipedia.org/wiki/Hypergolic_propellant

Notice nearly-identical protective equipment being used in the Wikipedia entry.

As for protective equipment for radioisotope thermoelectric generators, here's an example from Cassini:

* http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_gen...

This being the Internet, there's far more information on related topics available:

* http://en.wikipedia.org/wiki/Corona_(satellite)

* http://en.wikipedia.org/wiki/File:U.S._RecSat_Big_Picture.jp...

Hmmm. Wonder what other and far more familiar satellite that KH-11 Kennan looks like.

* http://en.wikipedia.org/wiki/File:HST-SM4.jpeg

[jeroen]

Clickable url

http://news.yahoo.com/secretive-x-37b-military-space-plane-c...

[JabavuAdams]

The protective equipment is probably for fuel or oxidizer leaks.

This page: http://www.airforce-technology.com/projects/boeing-x37/

says that the vehicle uses either hydrazine or nitrogen tetroxide.

Aside from the main engine, reaction thrusters could foul the surrounding fuselage with nasty chemicals.

[MysticFear]

It states at the end: "The X-37 is powered by a single Rocketdyne AR2-3 rocket engine, manufactured by Pratt & Whitney. Each engine can produce a maximum of 29.341kN thrust and uses solar power and lithium-ion batteries instead of the traditional fuel cell system."

But earlier states: "Fuelled with military fuel JP-8 and hydrogen peroxide, the Rocketdyne engine of the X-37 is designed to run for nine months. The engine installed in the aircraft currently uses hypergolic nitrogen tetroxide or hydrazine."

Odd, no?

[throwketchup]

What exactly do you consider odd? As others have replied, hydrazine has a long history for RCS systems in spacecraft, and kerosene + oxidizer mixtures have long been used for propulsion engines. The only technology here that isn't entirely orthodox is the lithium battery, but that's just an evolutionary upgrade from NiCads. Apparently the range safety guys finally decided that it was ok for an unmanned craft to fly with lithium.

[MysticFear]

Says it is powered by a single engine, but states it powered by hydrazine. Later on contradicts, and says it is powered by lithium ion batteries. Which is it?

[bradleyland]

Both. A more accurate statement would be that it is propelled to stable orbit by a single rocket. The plane's systems are powered by lithium ion batteries, which are recharged by a solar array.

You appear to want something secretive to be uncovered here, but I'm afraid that the use of this protective gear is not the smoking gun you think it is.

Also, it wouldn't be all that strange for there to be a nuclear device on board. Nuclear power is regularly used in satellites. The reactors are not the same as the ones used in terrestrial nuclear power plants though. A satellite typically uses a radioisotope thermoelectric generator.

[MysticFear]

"You appear to want something secretive to be uncovered here"

Not exactly, just wanted to know more. I know satellites and spacecraft in the past have used nuclear/radioactive energy:

http://en.wikipedia.org/wiki/Cassini%E2%80%93Huygens

[JabavuAdams]

This is also why you should stay away from F-16 and other aerospace wrecks. The F-16 has a tank of hydrazine onboard. Very nasty stuff.

[stevengg]

the guy who took this picture gave a talk 30c3 he takes pictures of military instantiations Seeing The Secret State: Six Landscapes

http://media.ccc.de/browse/congress/2013/30C3_-_5604_-_en_-_...

[MysticFear]

Thanks, that was really informative. The green X-Files uniform patch for the X-37 program is very ominous.

[qwerta]

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...

[exabrial]

Exact same suits being worn here...

http://en.wikipedia.org/wiki/Hydrazine#mediaviewer/File:Hype...

[anovikov]

It is simply an MMH or UDMH propellant onboard, which is carcinogenic.

[benologist]

Apparently this thing can fly 500 miles high which is space, maybe it's related to that?

http://www.space.com/25275-x37b-space-plane.html

http://en.wikipedia.org/wiki/Outer_space#Boundary