1In today's astronomy lecture,
2I'm going to talk about the need for a system to manage the movement of satellites
3and other objects in orbit around the Earth.
4In other words, a Space Traffic Management system.
5We already have effective Air Traffic Control systems
6that are used internationally to ensure that planes navigate our skies safely.
7Well, Space Traffic Management is a similar concept,
8but focusing on the control of satellites.
9The aim of such a system would be to prevent the danger of collisions in space
10between the objects in orbit around the Earth.
11In order to do this, we'd need to have a set of legal measures,
12and we'd also have to develop the technical systems to enable us to prevent such accidents.
13But unfortunately, at present we don't actually have a Space Traffic Management system that works.
14So why not?
15What are the problems in developing such a system?
16Well, for one thing, satellites are relatively cheap these days,
17compared with how they were in the past,
18meaning that more people can afford to put them into space.
19So there's a lot more of them out there,
20and people aren't just launching single satellites
21but whole constellations, consisting of thousands of them designed to work together.
22So space is getting more crowded every day.
23But in spite of this, one thing you may be surprised to learn
24is that you can launch a satellite into space
25and, once it's out there, it doesn't have to send back any information to Earth to allow its identification.
26So while we have international systems for ensuring we know where the planes in our skies are,
27and to prevent them from colliding with one another,
28when it comes to the safety of satellites,
29at present we don't have anything like enough proper ways of tracking them.
30And it isn't just entire satellites that we need to consider.
31A greater threat is the huge amount of space debris in orbit around the Earth -
32broken bits of satellite and junk from space stations and so on.
33And some of these are so small that they can be very hard to identify,
34but they can still be very dangerous.
35In addition, some operators may be unwilling to share information about the satellites they've launched.
36For example, a satellite may be designed for military purposes,
37or it may have been launched for commercial reasons,
38and the operators don't want competitors to have information about it.
39And even if the operators are willing to provide it,
40the information isn't easy to collect.
41Details are needed about the object itself,
42as well as about its location at a particular time -
43and remember that a satellite isn't very big,
44and it's likely to be moving at thousands of kilometres an hour.
45We don't have any sensors that can constantly follow something moving so fast,
46so all that the scientists can do is to put forward a prediction concerning where the satellite is heading next.
47So those are some of the problems that we're facing.
48Let's consider now some of the solutions that have been suggested.
49One key issue is the way in which information is dealt with.
50We need more information,
51but it also needs to be accessible at a global level,
52so we need to establish shared standards that we can all agree on
53for the way in which this information is presented.
54We already do this in other areas of science,
55so although this is a challenge, it's not an impossible task.
56Then, as all this information's collected,
57it needs to be put together so it can be used,
58and that will involve creating a single database on which it can be entered.
59As we continue to push forward new developments,
60congestion of the space environment is only going to increase.
61To cope with this, we need to develop a system like the one I've described
62to coordinate the work of the numerous spacecraft operators,
63but it's also essential that this system is one that establishes trust in the people that use it,
64both nationally and at a global level.
65One interesting development...