The Moon is not just Earth’s closest celestial neighbor. It’s also a natural waypoint for any mission that will be going to Mars or beyond in the coming years. It’s little wonder then why space agencies like NASA, Roscosmos, the ESA and China are hoping to send crewed missions there in the near future and construct bases that could be used to resupply and refuel missions headed to deep space.
At the University of California, Santa Barbara, researchers with the UCSB Experimental Cosmology Group (ECG) are currently working on ways to achieve the dream of interstellar flight. Under the leadership of Professor Philip Lubin, the group has dedicated a considerable amount of effort towards the creation of an interstellar mission consisting of directed-energy light sail and a wafer-scale spacecraft (WSS) “wafercraft“.
If all goes well, this spacecraft will be able to reach relativistic speeds (a portion of the speed of light) and make it to the nearest star system (Proxima Centauri) within our lifetimes. Recently, the ECG achieved a major milestone by successfully testing a prototype version of their wafercraft (aka. the “StarChip“). This consisted of sending the prototype via balloon into the stratosphere to test its functionality and performance.
The milestones just keep coming for SpaceX. After the recent successful test flight of the Crew Dragon capsule, another of SpaceX’s ventures is about to meet its own milestone. The SpaceX Starhopper could have its first test flight as soon as this week.
The era of renewed space exploration has led to some rather ambitious proposals. While many have been on the books for decades, it has only been in recent years that some of these plans have become technologically feasible. A good example is asteroid mining, where robotic spacecraft would travel to Near-Earth Asteroids and the Main Asteroid Belt to harvest minerals and other resources.
At the moment, one of the main challenges is how these craft would be able to get around and refuel once they are in space. To address this, the New York-based company Honeybee Robotics has teemed up with the University of Central Florida (UFC) to develop a steam-powered robotic spacecraft. The company recently released a demonstration video that shows their prototype World is Not Enough (WINE) “steam hopper” in action.
In an announcement sure to make you quiver with delight, Elon Musk says that SpaceX could begin short-hop test flights of its Starship prototype as early as next Spring. The Starship, which looks like something from a 1950’s sci-fi novel cover (awesome!) is intended to carry people to the Moon and Mars. When the spacecraft design was originally announced in 2016, it was called the Mars Colonial Transporter, and it sent shockwaves through the community.
The search for life has led astronomers to the icy moons in our Solar System. Among those moons, Europa has attracted a lot of attention. Europa is Jupiter’s fourth-largest moon—and the sixth-largest in the Solar System—at 3,100 kilometres (1,900 mi) in diameter. Scientists think that its oceans could contain two or three times as much water as Earth’s oceans. The only problem is, that water is hidden under a sheet of planet-wide ice that could be between 2km and 30km (1.2 miles and 18.6 miles) thick.
A team of scientists is working hard on the problem. Andrew Dombard, associate professor of Earth and Environmental Sciences at the University of Illinois at Chicago, is part of a team that presented a possible solution. At the American Geophysical Union meeting in Washington, D.C., they presented their idea: a nuclear-powered tunneling robot that could tunnel its way through the ice and into the ocean.
The dream of traveling to another star system, and maybe even finding populated worlds there, is one that has preoccupied humanity for many generations. But it was not until the era of space exploration that scientists have been able to investigate various methods for making an interstellar journey. While many theoretical designs have been proposed over the years, a lot of attention lately has been focused on laser-propelled interstellar probes.
The first conceptual design study, known as Project Dragonfly was hosted by the Initiative for Interstellar Studies (i4iS) in 2013. The concept called for the use of lasers to accelerate a light sail and spacecraft to 5% the speed of light, thus reaching Alpha Centauri in about a century. In a recent paper, one of the teams that took part in the design competition assessed the feasibility of their proposal for a lightsail and magnetic sail.
The idea of exploring and colonizing Mars has never been more alive than it is today. Within the next two decades, there are multiple plans to send crewed missions to the Red Planet, and even some highly ambitious plans to begin building a permanent settlement there. Despite the enthusiasm, there are many significant challenges that need to be addressed before any such endeavors can be attempted.
These challenges – which include the effects of low-gravity on the human body, radiation, and the psychological toll of being away from Earth – become all the more pronounced when dealing with permanent bases. To address this, civil engineer Marco Peroni offers a proposal for a modular Martian base (and a spacecraft to deliver it) that would allow for the colonization of Mars while protecting its inhabitants with artificial radiation shielding.
Let’s be honest, launching things into space with rockets is a pretty inefficient way to do things. Not only are rockets expensive to build, they also need a ton of fuel in order to achieve escape velocity. And while the costs of individual launches are being reduced thanks to concepts like reusable rockets and space planes, a more permanent solution could be to build a Space Elevator.
And while such a project of mega-engineering is simply not feasible right now, there are many scientists and companies around the world that are dedicated to making a space elevator a reality within our lifetimes. For example, a team of Japanese engineers from Shizuoka University‘s Faculty of Engineering recently created a scale model of a space elevator that they will be launching into space tomorrow (on September 11th).
One of the more challenging aspects of space exploration and spacecraft design is planning for re-entry. Even in the case of thinly-atmosphered planets like Mars, entering a planet’s atmosphere is known to cause a great deal of heat and friction. For this reason, spacecraft have always been equipped with heat shields to absorb this energy and ensure that the spacecraft do not crash or burn up during re-entry.
Unfortunately, current spacecraft must rely on huge inflatable or mechanically deployed shields, which are often heavy and complicated to use. To address this, a PhD student from the University of Manchester has developed a prototype for a heat shield that would rely on centrifugal forces to stiffen flexible, lightweight materials. This prototype, which is the first of its kind, could reduce the cost of space travel and facilitate future missions to Mars.
To put it simply, planets with atmospheres allow spacecraft to utilize aerodynamic drag to slow down in preparation for landing. This process creates a tremendous amount of heat. In the case of Earth’s atmosphere, temperatures of 10,000 °C (18,000 °F) are generated and the air around the spacecraft can turn into plasma. For this reason, spacecraft require a front-end mounted heat shield that can tolerate extreme heat and is aerodynamic in shape.
When deploying to Mars, the circumstances are somewhat different, but the challenge remains the same. While the Martian atmosphere is less than 1% that of Earth’s – with an average surface pressure of 0.636 kPa compared to Earth’s 101.325 kPa – spacecraft still require heat shields to avoid burnup and carry heavy loads. Wu’s design potentially solves both of these issues.
The prototype’s design, which consists of a skirt-shaped shield designed to spin, seeks to create a heat shield that can accommodate the needs of current and future space missions. As Wu explained:
“Spacecraft for future missions must be larger and heavier than ever before, meaning that heat shields will become increasingly too large to manage… Spacecraft for future missions must be larger and heavier than ever before, meaning that heat shields will become increasingly too large to manage.”
Wu and his colleagues described their concept in a recent study that appeared in the journal Arca Astronautica (titled “Flexible heat shields deployed by centrifugal force“). The design consists of an advanced, flexible material that has a high temperature tolerance and allows for easy-folding and storage aboard a spacecraft. The material becomes rigid as the shield applies centrifugal force, which is accomplished by rotating upon entry.
So far, Wu and his team have conducted a drop test with the prototype from an altitude of 100 m (328 ft) using a balloon (the video of which is posted below). They also conducted a structural dynamic analysis that confirmed that the heat shield is capable of automatically engaging in a sufficient spin rate (6 revolutions per second) when deployed from altitudes of higher than 30 km (18.64 mi) – which coincides with the Earth’s stratosphere.
The team also conducted a thermal analysis that indicated that the heat shield could reduce front end temperatures by 100 K (100 °C; 212 °F) on a CubeSat-sized vehicle without the need for thermal insulation around the shield itself (unlike inflatable structures). The design is also self-regulating, meaning that it does not rely on additional machinery, reducing the weight of a spacecraft even further.
And unlike conventional designs, their prototype is scalable for use aboard smaller spacecraft like CubeSats. By being equipped with such a shield, CubeSats could be recovered after they re-enter the Earth’s atmosphere, effectively becoming reusable. This is all in keeping with current efforts to make space exploration and research cost-effective, in part through the development of reusable and retrievable parts. As Wu explained:
“More and more research is being conducted in space, but this is usually very expensive and the equipment has to share a ride with other vehicles. Since this prototype is lightweight and flexible enough for use on smaller satellites, research could be made easier and cheaper. The heat shield would also help save cost in recovery missions, as its high induced drag reduces the amount of fuel burned upon re-entry.”
When it comes time for heavier spacecraft to be deployed to Mars, which will likely involve crewed missions, it is entirely possible that the heat shields that ensure they make it safely to the surface are composed of lightweight, flexible materials that spin to become rigid. In the meantime, this design could enable lightweight and compact entry systems for smaller spacecraft, making CubeSat research that much more affordable.
Such is the nature of modern space exploration, which is all about cutting costs and making space more accessible. And be sure to check out this video from the team’s drop test as well, courtesy of Rui Wui and the MACE team: