hydrazine

Its a hydrazine monopropellent, or so they say, so an Isp of 250 or so would be impressive.

You can smell hydrazine long before it's dangerous - it smells a bit fishy, somewhat like ammonia.

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

Don’t forget bezoars from unripe persimmons, or hydrazine poisoning from improperly cooked morels, or hydrogen cyanide poisoning from fruit pits.

This seems pretty far off considering the exotic materials needed for rocket fuel, like hydrazine.

Says it is powered by a single engine, but states it powered by hydrazine.

Satellites just can keep going on, but a hydrazine fueled or battery powered plane would have a mission length counted in hours.

They validated components, like the hydrazine engines, radar, and bridle release mechanism, but not the combination of all.

Colloid thrusters (or other ionic propulsion), or even a chemical hybergolic propellant (hydrazine + oxygen for example) would work perfectly for propulsion.

As a result Russia has an excessive amount of Hydrazine in storage.

I picked those to give commentary about how hazardous hydrazine is, and that there's a push to use alternative fuels.

They've got a problem with the propellent system, but they think it's a clog from some nitrogen bubbles, not that it's out of hydrazine.

Edit: "burning storable propellant combination of nitrogen tetroxide as oxidizer and unsymmetrical dimethyl hydrazine as fuel.

The engine installed in the aircraft currently uses hypergolic nitrogen tetroxide or hydrazine." Odd, no?

Not Hydrazine, these are not hypergolic fuels just "regular" liquid oxygen and hydrogen.

Hydrazine was the first choice, but it sometimes exploded when used for regenerative cooling, and in 1949, when the program was conceived, there wasn't enough of it around, anyway.