American nonprofit organization Planetary Society, working on projects in the areas of astronomy, planetary science and space exploration, is going to spend this summer testing LightSail 2 – a new version of the solar sail, which can later be used in other scientific missions. A similar version of the sails you plan to use in the new NASA spacecraft Near-Earth Asteroid Scout (NEA Scout), compact coultate, the launch of which is scheduled for next year.
Startup LightSail 2 is planned for early June 13 from the Kennedy Space center using the new launch vehicle, the Falcon Heavy from SpaceX. The main goal of the project is the output of a solar sail in earth orbit at a height of about 725 kilometers, and verification of its effectiveness.
Recall that the principle of operation of solar sails is to use the pressure of sunlight or laser on the mirror surface for propulsion of the spacecraft. The advantage of this system is that there is no need to use any fuel – the main impetus in this case give light photons pushing the sail and, accordingly, the unit itself. According to Bruce Betts, chief scientific consultant to the Planetary Society, in the case of compact satellites, cube-Sats, it can give additional benefit, as here, on account of every additional gram of weight.
“We were waiting for the right launch window, when it will be possible to bring the apparatus to a higher orbit, where the solar light pressure will dominate over the atmospheric” — shared Betts website Space.com.
“In fact, we will try to implement controlled flight of a solar sail. During part of its orbital movement of the sail will be under direct sunlight, and the edge of this impact,” added Betts.
What is improved in comparison with the LightSail 1?
The launch of LightSail-1 was made on 20 may 2015. In orbit, the unit brought a top-secret space drone X-37B. In low earth orbit, the sail is held less than a month. Despite the success in achieving the main objectives of the mission the disclosure of the sails within this test he was faced with several problems.
After just two days since the launch of error in the software were forced to postpone the layout of the sail until June 7. Two days later the spacecraft transmitted an image where it was obvious that the sail was successfully opened up, which staged the main purpose of the mission. But then the problems started.
“Until such time as the engineers were able to get a picture with the camera located on the other side of the machine, LightSail radio transmitter began to broadcast a continuous and meaningless signal, whereby the camera ceased to respond to commands of the control center”, — explained the employee of the Planetary Society’s Jason Davis in his blog on 15 June 2015.
The spacecraft ceased to transmit messages on 10 June, shortly before he had, as planned, to enter the atmosphere.
“We learned a lot, thanks to the launch of LightSail 1. Gathering a lot of information about the spacecraft and examining the challenges encountered, we have made many improvements in the new version”.
Cubesat equipped by a solar sail, LightSail 1, took this picture on 8 June 2015
Some of the key changes made in the design of LightSail 2, allow the unit to more effectively use particles of sunlight. The most serious mechanical changes made to the design of LightSail 2, was the gyroscope that allows the camera to properly Orient themselves in space. It uses a new method of determining height and controlling software. In addition, the new device has a more advanced camera that allows you to transmit better quality images of the sail.
Other changes were designed to increase the reliability of the spacecraft. Now, instead of “need to wait and hope that the system in which case self-reboots,” says Betts, “the electronics of the spacecraft will be equipped with timers and automatic restart, which itself, in the worst scenario, be able to fully restart all system LightSail 2”. In addition, the unit will be equipped with reflectors, which will make it easier to track LightSail 2 from the Ground. And the device will be more likely to transmit radio messages to the Ground, to engineers the most current information about his condition.
The dream of interplanetary flights
This photograph shows a Japanese solar sail spacecraft Ikaros, moving to Venus. In the background of the image, about 80 000 kilometres from Ikaros, seen Venus
Not just Planetary Society is testing the technology of solar sails. One of the most notable recent examples is a Japanese spacecraft Ikaros (Interplanetary Kite-craft Accelerated by Radiation Of the Sun), where the solar sails were used as the main propulsion. His conclusion was produced by the passing spacecraft “akatsuki”, designed to study Venus. At the moment it is the only spacecraft solar sail, which was used for deep space exploration. In 2012, Ikaros was even recorded in the Guinness Book of records as the first interplanetary spacecraft on a solar sail.
In 2010, in low earth orbit the Earth was also removed from the spacecraft NanoSail-D2 space Agency NASA. This mission is largely focused on the task to deploy a solar sail in orbit and to see how it will lead yourself out there. In addition, the Agency planned to conduct another mission, called Sunjammer, but later it was canceled.
The spacecraft Ikaros, the Japanese space Agency JAXA after its launch on 14 June 2010. The photograph was obtained using a small camera ejected outside the apparatus
At the moment, the Planetary Society is in touch with the team that developed the spacecraft NEA Scout, which will also be used by a solar sail. Objective of the unit is the study of the asteroid 1991 VG, but the final details of the mission have not yet been approved. The launch is scheduled for 2019. It also plans to launch other compact satellites. Conclusion spacecraft into orbit will be carried out in the framework of the first mission of the Orion Exploration Mission-1 using the new launch vehicle Space Launch System.
“They plan to use a solar sail with the same design and technical characteristics of the sail, LightSail 2,” explained Betts.
The technology of solar sails are interested in the various space Agency because it eliminates the need to use any kind of fuel. Thanks to this, solar sails are considered as one of the possible methods for interplanetary space travel in the future.