“A microsecond lag in GPS could miss a moon landing by hundreds of meters”
The competition and space disagreements between the United States and China are one of the main geopolitical problems in 21st century science. We might think that this effort to be first only harms them, but in reality it can be a problem for anyone who enters the space race. There are many issues that serve as examples, although the most recent is the one that concerns lunar time. It has long been clear that there must be a lunar standard time, but The United States has decided to establish a and China another. The consequence is a weak satellite navigation system, which can affect anyone who wants to land on the Moon. At the moment, it seems that NASA is the most advanced in this regard, but it is possible that it will have to do so under Chinese standards, so the conflict, if they do not agree, is served. Two hours for one place. USA has agreed determine the lunar time under something called Coordinated Lunar Time (LTC). That would be the time under which the LunaNet satellites would work, a satellite system projected by NASA in 2019in order to control the first navigation system of our satellite. For its part, China has decided to establish the time according to the Lunar Time Ephemeris (LTE-440). This is the system with which both Queqiao-1 and Queqiao-2, the only two lunar relay satellites that are currently active, maneuver. They are designed for communications and would be the first step towards a lunar GPS system. Why is it necessary? Gravity is very different on Earth and the Moon. We know that gravity, in addition to generating attraction on bodies, also curves space-time. As a consequence, time passes more slowly the greater the gravity. And what does that mean? Well, basically, time passes faster on the Moon. Specifically, 56 microseconds faster. That means we can’t use the same time on Earth as we do on the Moon. Our natural satellite needs its own schedule. Be careful with the GPS. GPS systems work by signaling temporal signals measured by satellites. It measures how long it takes for the satellite signal to get from one point to another and, thus, the distance can be calculated. Therefore, it is very important that satellites and clocks work with the same time system. When traveling to the Moon, you should take into account how the satellites used by GPS measure time. But we have already seen that China and the United States do not agree on that. For now, LunaNet is nothing more than a project. The Chinese lunar GPS system too, but at least there are already satellites. Those from the United States have not been launched. Therefore, if NASA lands on the Moon without taking into account the Chinese time system, there could be problems. Just a microsecond of difference in lunar time can affect hundreds of meters away. That can be very dangerous in the face of a moon landing. China has already tried it. The Asian country is the only one that has landed a ship on the far side of the moon. Terrestrial radio systems do not reach this area of our satellite. Therefore, this unmanned moon landing had complete dependence on Queqiao-1. It was proven to work, as the moon landing was a success. But of course, the ship was synchronized with the satellite time system. It is necessary to reach agreements. Sometimes these types of political disagreements make scientists quite lazy. They may want to reach agreements to work in a safer way. At the moment, NIST, which is the United States Standards Institute, is having conversations with the Purple Mountain Observatory (Zijinshan). This institution is one of the main managers of Chinese satellites, so its decisions are very important in the decision to use one time system or another. For everyone to achieve their goals, this time it would be necessary to work as a team. The grudges and competitions could end up delaying the space race for both sides. Image | Magnificent In Xataka | Mars was the great space battleground between China and the US. Now it’s the Moon and there’s too much at stake
