The process actually starts before a spacecraft is launched. We have several groups that are involved, depending on where you are relative to the actual tracking time. So in 2001 we would be working on the '03-'04 contention periods, trying to trade those upcoming with our preliminary schedules. In some cases it continues right down to an hour or half an hour before a track, we can make changes. And in fact, we put out a schedule called a seven-day schedule, and that frequently has hundreds of changes made to it during the course of the seven-day period.

Usually it is not at that level. Usually it's the manager who's responsible for the operations. Then, when it's a big enough mission that has a large number of requirements, they'll have a member of the staff whose job is just to make sure that their requirements can be met and to participate in the negotiation. Smaller projects do it by just the fractional time of a person. Usually the smaller projects have less difficult requirements to meet.

We are actually oversubscribed in that we have more tracking hours required than we are able to provide. What we do in this case is to work very closely with the flight projects and get them to work together to try to meet the bulk of their requirements. In addition, we are currently building a new antenna in Madrid to help with the load.

Yes.

Well, depending on the velocity of the wind, we have to stow the 70-meter antenna, and all the antennas. Typically, if the wind is sustained to about 45 miles an hour with gusts up to about 50, the 70-meter gets stowed. That means points straight up. Its minimum wind resistance. Sometimes when you look at the data after the fact, you find out that something like a gust of wind caused a temporary interruption of the signal, but the system just kept on tracking and didn't have to reinitialize. So sometimes we have those interruptions in the data, gaps in the data that are caused by miscellaneous factors, including wind.

Sometimes we have that. It's planned far in advance, but typically, we don't. There is a capability to override any warning or interlock, so that if the data is determined to be of extremely high value, we'll actually risk an asset to get it down. That's a very complicated process for making that decision, but we have used it in the past.

In real time? One. But it really depends on how you want to count. On the DSN side there's a single operator who is responsible for operating all the equipment associated with the tracking of a particular spacecraft. Now, behind that guy, there's people that generate the support data, to configure the station properly, to generate what we call predicts, to be able to point the antenna and to compute the frequency. And there are also maintainers that make sure the equipment is working properly. And then on the project side, there's multiple people to generate the commands and to verify the commands, to make sure they get properly placed. So for any one command, there's probably 30 or 40 people associated with making it happen.

For each antenna, we try to schedule about eight hours a week of maintenance time. During that period, they check the oil and all the grease. They actually can look into the bearings with a tool called a baroscope to check that everything is okay. These bearings all sit on a structure made of grout, and the grout tends to get uneven after a while. We actually do what's called shimming, where we take small pieces of aluminum and push them between the bearing and the grout, to keep the bearings at the proper tolerance. Remember, you're talking about gear boxes that are bigger than a human being. You're talking about I don't know how many tons of oil flowing in those systems. It's big.

In the huge 70-meter antenna, the moveable structure sits on a bearing with a film of oil on it that is about six thousandths of an inch thick. If dust or dirt or even paint flecks get into that oil, it will actually stop the antenna, and we have to send someone out to check the oil and sometimes raise a roller, so that it can continue to go on.

It's amazing, when you look at the space business, and even just the DSN and ground operations part, there is an amazing number of disciplines involved in accomplishing a mission. It really depends upon what aspect of this business you'd like to get into. Certainly a double-E major (electrical engineering) would be useful, but telecommunications with a really good theoretical background in it is another important major. There's a tremendous amount of software involved, so competence in software is another alternative. Some of our DSN staff has Physics degrees.