Belinda Arroyo is in charge of the team that negotiates tracking time with the Deep Space Network for 12 NASA missions.

May 10, 2002 - So many spacecraft - so little time - tracking time, that is. It's something of a luxury these days because of the dozens of space missions sprinkled around the solar system routinely competing for the undivided attention of the few antennas capable of communicating with their spacecraft.

Negotiating tracking time is what Belinda Arroyo's team does for a living. She is the team chief of the Mission Management Office Multi-Mission DSN Allocation and Planning Team, an organization that makes sure that the 12 NASA missions for which they are responsible have adequate time allotted with the Deep Space Network. Managed by NASA's Jet Propulsion Laboratory, the Deep Space Network has three sites disseminated in key areas of the world -- Spain, Australia and California. To communicate with spacecraft, each site has a 70-meter (230-foot) in diameter antenna and a variety of smaller ones.

Arroyo is so good at what she does that she is even attributed special powers by those JPL team members who depend on her skills to communicate with their spacecraft roaming the solar system.

"The Deep Space Network is usually over-subscribed by the many users, but with Belinda I don't worry about controlling our spacecraft and retrieving data," said Robert Ryan, Stardust mission flight director. "Belinda is our 'superwoman.' She makes a very complex negotiation process seem simple."

Longer missions and a drastic increase in the number of spacecraft needing the antennas's exclusive attention render scheduling which antenna to point to which spacecraft a daunting job. The Deep Space Network currently supports an average of 28 missions per month. Priority is given to spacecraft performing critical maneuvers such as orbit insertion or encounters with celestial bodies, but even during periods of low activities, demand for the antennas is always high because of limited ground resources.

A comprehensive study finished in February 2001 concluded that new antennas were needed to meet the growing demand on the network in the near future. However, NASA approved only one antenna. It is being built in the network's site near Madrid, Spain, leaving missions still scrambling for more access.

Arroyo's office is remarkably simple compared to the complicated schedules she supervises. Plants and flowers lay on top of a file cabinet, a few pictures adorn the walls. The whiteboard on the wall, however, tells a different story. Held by magnetic clips, loads of papers with schedules for each mission cover the writing underneath.

And while often stressful, she says her job is very stimulating.

"It's very exciting to be part of a flight project," Arroyo says. "I really like learning about each mission, interfacing with the different people in the missions and working with my team."

The fast pace does take its toll, though.

"It is constant activity. There are no peaks and valleys," she says smiling. "We are kind of always at a peak because we have a large number of missions. It can be stressful."

In addition to supporting 12 missions that are currently active, Arroyo's team is working on another 16 that are still in the development stages.

On average it takes about five minutes to lock on the signal from a spacecraft. To download information, however, can take up to many hours. The exact time depends on the data rate of transmission and the kind of information being received by the antennas. Images and other science data take the longest, while the so-called, "spacecraft health information" -- used by scientists and engineers to routinely monitor instruments functionality -- take the least time to download.

Scheduling problems occur because often the ideal view from Earth is shared by more than one spacecraft. And even a well-coordinated schedule is useless if an anomaly occurs, leaving Arroyo and her team of seven scrambling and negotiating, in real time, for additional time with other users.

"It doesn't happen often but, depending on the anomaly, it can be a real nightmare," she says. "But even without anomalies, sometimes it is difficult having to make trades and balance the workload."

Balancing loads, however, is something Arroyo does all week long. Besides working full time she is also completing a bachelor's degree in management and human resources at California State Polytechnic, Pomona. In her spare time, Arroyo does volunteer work with senior citizens, often in convalescent homes, and in community events. She also likes to read and when it's time to regenerate her seemingly inexhaustible energies, she enjoys camping and hiking.

At JPL, Arroyo began as a scheduling engineer in 1991 -- where she helped develop scheduling software for daily operations that increased productivity by approximately 50 percent.

Her talent and hard work didn't go unnoticed. In 1999, Arroyo was awarded NASA's Exceptional Service Medal. Last year, she moved to her current position as mission management office team chief, where beside marketing and negotiating services for flight projects, she develops and manages team processes.

Arroyo also trains new personnel.

"It's a lot of fun to train people and teach them your area of expertise and watch them grow," she says. "This area introduces you to a lot of different areas because you work not only with teams -- like the ground data system team or the sequencing team -- but you work across organizations like navigation and mission planning," she explains. "I think working in the mission management office is a good base for somebody coming in new to a flight project. It gives you a kind of a global view of a flight project and introduces you to options to help you decide where you might want to go next with your career."

Next year is looking up as the busiest time ever for the Deep Space Network. Red planet-bound NASA and European missions are scheduled to launch, and they will join the spacecraft already there, Mars Odyssey and the Mars Global Surveyor. These spacecraft, as well as all the other missions already in space, will need to communicate with Earth with the same scarce resources.