Your all wrong, what Justintime really means by;
“Cannot pass the Mustard test”, is a reference to a little known British spacecraft design with the acronym M.U.S.T.A.R.D a space craft design proposed by BAC. (British Aircraft Corparation)
“BAC proposed the MUSTARD winged vehicle design (Multi-Unit Space Transport and Recovery Device) could place 5,000 lb. (2,268 kg) payloads into orbit. Two of the units would act as boosters to launch the third into orbit. They would be stacked for launch and would feed any excess fuel to the unit which was to become the spacecraft. At 150,000 to 200,000 ft. (45,720 to 60,960 m.) the boost units would separate and land in aircraft fashion. After placing its payload into orbit the spacecraft unit would return similarly”.
http://www.unrealaircraft.com/wings/bac_mustard.php
Problem was, after a government review the design was deemed to, "Not to cut the Mustard", and consequently, funding was cut for the MUSTARD!
A European version was also proposed, called “Moutarde”, this further confused the UK government, and was similarly cancelled.