LRO Role in NASA Moon to Mars Mission
The Lunar Reconnaissance Orbiter has been circling the moon since 2009, taking pictures of the landscape and sending them home. Now NASA wants to head back. Why? They want to send people to the moon and beyond. What does a 10-year-old satellite in orbit around the moon have to do with NASA's planned Moon to Mars mission?
Phase 1: The Lunar Reconnaissance Orbiter
The Lunar Reconnaissance Orbiter, or LRO, has been orbiting our satellite for nearly a decade, collecting detailed information about its surface. At its launch, the orbiter contained seven different tools to help it complete its missions. The ultrawide-angle high-resolution camera takes some of the most detailed pictures of the moon's surface that we've seen since Neil Armstrong stood on it. Its laser altimeter allows it to create a 3D topographical map of the surface. It's also looking for cold traps and areas that might still contain water that has been frozen for billions of years.
While the LRO has sent us back some fantastic data and helped us make so many discoveries over the years, what does it have to do with getting us, as a species, from here to Mars?
Phase 2: The Orion Spacecraft
Before we can head back to the moon, we need a spacecraft capable of carrying us there — and that's where Orion comes in. The Orion spacecraft will carry up to four astronauts, as well as cargo and supplies, from Earth to the moon and beyond. The spacecraft completed its first successful test flight in 2014 when, uncrewed, it attained a stable orbit, made two passes around our planet and splashed down safely in the Pacific Ocean.
Orion is scheduled to make its next test flight in 2020. After launching from the Kennedy Space Center in Florida, it will make a lunar flyby and head thousands of miles past the moon's orbit as its trial by fire. This test flight will also be uncrewed, but if it is successful, it might pave the way for NASA's Moon to Mars mission.
Phase 3: Restore-L and Satellite Rescue
NASA isn't just looking toward interstellar space right now. It's also focusing on things much closer to home. There are nearly 5,000 satellites orbiting our planet right now, and many of them are nearing the end of their operational life due to dwindling fuel supplies. Instead of decommissioning these satellites — directing them to burn up in Earth's atmosphere before they entirely run out of fuel — NASA is working on a way to repair and refuel them in flight.
Why? By practicing refueling missions on satellites orbiting the Earth, NASA will have ample practice before they’re required to refuel or repair satellites around the moon or Mars. Robotics are key to this aspect of the mission.
Restore-L is a robot that will be able to navigate to each satellite remotely, intercept it in orbit and refuel it. It will also have robotic arms capable of simple repairs, controlled by a team here on Earth.
Restore-L's first target will likely be Landsat-7, a government-owned mapping satellite that's been in orbit since 1999. It's been experiencing problems since a few years after its launch, and engineers are hoping Restore-L could give the aging satellite a new lease on life. Its first refueling attempt is scheduled for sometime in 2020.
Since Restore-L will be continually moving through the cosmos and will depend on advanced communication technology to allow it to complete its mission, it will need to be equipped with high-tech heat sinks to keep its internal computer components at the optimum temperature. On Earth, computers are cooled by the atmosphere, or with liquid-cooled heat-sinks filled with distilled water. In space, there is nothing to dissipate the heat, so liquid cooling systems are the only option.
On devices like Restore-L and future vacuum-based computing, a liquid cooling system filled with ammonia could provide the heat-dissipating action these computers need without freezing in extremely low temperatures. In addition to saving earth-based satellites from early decommissioning, Restore-L will also be part of the Asteroid Redirect Mission, which will be based on the Gateway Station.
Phase 4: Gateway to the Stars
Gateway will likely be one of the most significant human construction projects to date. When the Gateway Station is finished, it will orbit the moon and provide a permanent human presence in a lunar orbit. Establishing a lunar station will also provide us with a literal gateway to the stars.
Right now, launching a crewed space mission from Earth requires millions of pounds of fuel. Spacecraft aren't light, and it takes a tremendous amount of thrust to allow them to break free from the planet's gravitational pull. To reach a low Earth orbit — such as where the International Space Station sits — a spacecraft needs to travel more than 250 kilometres straight up at a velocity of 9.4 kilometres per second. Once it reaches that speed it can slow down, but it still has to travel a couple thousand more kilometres at 3.2 kilometres per second to escape our planet's gravity.
Launching from the moon is much easier because it has less gravity. To reach a low lunar orbit, a spacecraft only has to travel 100 kilometres above the surface of the moon at 1.73 kilometres per second, then a hundred more kilometres at 0.91 kilometres per second to escape the moon's gravity.
Once we have an established lunar base, launching deep space missions from the moon could save NASA and companies like SpaceX billions of dollars in fuel costs alone.
The Gateway project is still in its planning phase, but NASA scientists hope to have something ready to launch by 2024.
Phase 5: Moon to Mars and Beyond
We are well on our way to becoming a multi-planet species. NASA's Moon to Mars mission is only the first step. The Gateway station will provide a stepping stone along the way, and eventually, it may be possible to establish a permanent colony on Mars or even further out in the solar system. On the moon, the 10-year-old LRO will act as our eye-in-the-sky as we build the Gateway station and plan missions to the lunar surface.
It's a fantastic time to be alive, as we can watch science fiction become fact, and we can't wait to see how far the Moon to Mars mission takes us.