To stand on a coastal shore and watch how eagles, ravens, seagulls, and crows take flight in high winds. it’s an inspiring sight, to be sure. Additionally, it illustrates an important concept in aerial mechanics, like how the proper angling of wings can allow birds to exploit differences in wind speed to hover in mid-air. Similarly, birds can use these same differences in wind speed to gain bursts of velocity to soar and dive. These same lessons can be applied to space, where spacecraft could perform special maneuvers to pick up bursts of speed from “space weather” (solar wind).
This was the subject of a recent study led by researchers from McGill University in Montreal, Quebec. By circling between regions of the heliosphere with different wind speeds, they state, a spacecraft would be capable of “dynamic soaring” the same way avian species are. Such a spacecraft would not require propellant (which makes up the biggest mass fraction of conventional missions) and would need only a minimal power supply. Their proposal is one of many concepts for low-mass, low-cost missions that could become interplanetary (or interstellar) explorers.
A team led by NASA’s Marshall Space Flight Center (MSFC) was recently selected to develop a solar sail spacecraft that would launch sometime in 2025. Known as the Solar Cruiser, this mission of opportunity measures 1653 m2 (~17790 ft2) in area and is about the same thickness as a human hair. Sponsored by the Science Mission Directorate’s (SMD) Heliophysics Division, this technology demonstrator will integrate several new solar sail technologies developed by various organizations to mature solar sail technology for future missions.
In a recent video released by NASA, we see engineers and industry partners at the MSFC in Huntsville, Alabama, unfurling a segment of the prototype solar sail. The video, taken on October 13th, shows how the teams used two 30.5 m (100-foot) lightweight composite booms to unfurl a 400 m2 (4,300 ft2) quadrant of the solar sail prototype for the first time. Once realized, the Solar Cruiser demonstrator will validate technologies that enable future missions to study the Sun, its interaction with Earth, and its extended atmosphere (aka. heliosphere).
Solar sailing seems like a simple concept – instead of being pushed along by the wind, as in a typical sailing ship, a spacecraft can use highly reflective said to be pushed along simply by sunlight. But as with almost all engineering challenges, that technique is much easier said than done. Sunlight can head up one side of a sail more than another, causing the ship to rotate unexpectedly. Other unforeseen situations could arise that can also have catastrophic consequences for any mission using this propulsion technology. Luckily, there is a way to account for those situations, though it involves a lot of math. Control theory is common in system design, and now researchers at Beihang University have devised a control scheme that they think could help minimize the risk to solar sails.
Have you ever seen wispy arcs and rings in astronomical images taken by the Hubble Space Telescope and other observatories? These unusual features are caused by a quirk of nature called gravitational lensing, which occurs when light from a distant object is distorted by a closer massive object along the same line of sight. This distortion effectively creates a giant lens which magnifies the background light source, allowing astronomers to observe objects embedded within those lens-created arcs and rings that are otherwise be too far and too dim to see.
A group of researchers are working on plans to build a spacecraft that could apply this quirk by using our Sun as a gravitational lens. Their goal is to see distant exoplanets orbiting other stars, and to image an Earth-like exoplanet, seeing it in exquisite detail, at a resolution even better than the well-known Apollo 8 Earthrise photo.
Solar sailing technology has been a dream of many for decades. The simple elegance of sailing on the light waves of the sun does have a dreamy aspect to it that has captured the imagination of engineers as well as writers. However, the practicalities of the amount of energy received compared to that needed to move useful payloads have brought those dreams back to reality. Now, a team led by Amber Dubill of John Hopkins University Applied Physics Laboratory and supported by the NASA Innovative Advanced Concepts (NIAC) program is developing new solar sail architecture that might have already found its killer app – heliophysics.
Solar sails have been receiving a lot of attention lately. In part that is due to a series of high profile missions that have successfully proven the concept. It’s also in part due to the high profile Breakthrough Starshot project, which is designing a solar sail powered mission to reach Alpha Centauri. But this versatile third propulsion system isn’t only useful for far flung adventures – it has advantages closer to home as well. A new paper by engineers at UCLA defines what those advantages are, and how we might be able to best utilize them.
We used to think we were the center of everything. That wasn’t that long ago, and even though we’ve made tremendous advancements in our understanding of our situation here in space, we still have huge blind spots.
For one, we’re only now waking up to the reality of interstellar objects passing through our Solar System.
LightSail 2, the brainchild of The Planetary Society, has gifted us two new gorgeous images of Earth. The small spacecraft is currently in orbit at about 720 km, and the LightSail 2 mission team is putting it through its paces in preparation for solar sail deployment sometime on or after Sunday, July 21st.
On June 25th, 2019, The Planetary Society‘s cubesat spacecraft known as LightSail 2 lifted off from the NASA Kennedy Space Center in Florida aboard a Falcon Heavy rocket. This was the second solar sail launched the Society, the first (LightSail 1) having been sent into space in 2015. Like its predecessor, the purpose of this spacecraft is to demonstrate the technology that would allow for solar sails operating within Low Earth Orbit (LEO).
Since reaching orbit, the LightSail 2 has been indicated that it is in good working order, as indicated by the Mission Control Dashboard recently introduced by The Planetary Society. In addition to establishing two-way communications with mission controllers and passing a battery of checkouts, the spacecraft also took its first pictures of Earth (and some selfies for good measure).