Jennifer Neighbours of NRAO/Tucson relates:
NRAO arranges its travel through a travel agency in Santiago:

Aeromar Centro
Miraflores 178 Piso 11
Santiago
Tel:  +56 2 6330008
Fax:  +56 2 6326810

Jennifer's contact is Angelica Marambio and she can reach her by e-mail:

mmarambio@aeromar.cl

She requests the ticketing and provides a credit card number and
expiration date.  She needs the name and passport number of the
traveler.  She then faxes the itinerary and the ticket can be
picked up at the counter when checking in at domestic airline
desk/Santiago Airport.  Substantial savings may be realized through
tickets purchased in Chile for internal flights.