Assertion: gas balloon | /r/CapableOf | float in stable conditions
Facets:
value: for scientific research
type: PURPOSE
value: for even months
type: TEMPORAL
value: at a time
type: TEMPORAL
value: for days
type: TEMPORAL
Source sentences:
text: For scientific research, special gas balloons can float in stable conditions for days or even months at a time, carrying instrument payloads through the upper reaches of the stratosphere .