The following weekend warned an outside control space station carrying toxic chemicals that "cause cancer" in major cities.
The European Space Agency said it could remove garbage from China's Taianggong-1 in large metropolitan areas such as Rome, New York and Barcelona.
Chicago, Beijing, Istanbul and Toronto are other popular tourist destinations.
It is also a station - it has a laboratory on board - likely to look to the surface between March 30 and April 2.
This station contains hydrazine containing a high-toxic compound used in rocket fuel.
