Ambulance ships periodically contact your station asking for help. They have a number of ill peeps aboard and will pay you 1000 per patient treated and an additional 10000 for curing all the patients. To help them you will needed a minimum of one manned comsensor, one port and one manned sick bay.
Ambulance ships carry peeps with diseases of varying severity. One ship should be accepted with caution, this ship is called the Nostromo. Fans of the Alien film franchise will know why.
Most ambulance ships appear to be flown by Greys.