Solar sails could reach Mars in just 26 days

A recent study submitted to Acta Astronautica and presently accessible on the arXiv preprint server explores the potential for utilizing aerographite solar sails for touring to Mars and interstellar space, which might dramatically cut back each the time and gasoline required for such missions.

This research comes whereas ongoing analysis into the usage of solar sails is being carried out by a plethora of organizations together with the profitable LightSail2 mission by The Planetary Society, and holds the potential to develop quicker and extra environment friendly propulsion programs for long-term space missions.

“Photo voltaic sail propulsion has the potential for speedy supply of small payloads (sub-kilogram) all through the solar system,” Dr. René Heller, who’s an astrophysicist on the Max Planck Institute for solar system Analysis and a co-author on the research, tells Universe Right this moment. “In comparison with standard chemical propulsion, which may deliver lots of of tons of payload to low-Earth orbit and ship a big fraction of that to the moon, Mars, and past, this sounds ridiculously small. However the important thing worth of solar sail know-how is pace.”

Not like standard rockets, which depend on gasoline within the type of a combustion of chemical compounds to exert an exterior pressure out the again of the spacecraft, solar sails do not require gasoline. As an alternative, they use daylight for his or her propulsion mechanism, as the large sails catch solar photons very like wind sails catching the wind when touring throughout water. The longer the solar sails are deployed, the extra solar photons are captured, which progressively will increase the pace of the spacecraft.

For the research, the researchers carried out simulations on how briskly a solar sail manufactured from aerographite with a mass as much as 1 kilogram (2.2 kilos), together with 720 grams of aerographite with a cross-sectional space of 104 sq. meters, might attain Mars and the interstellar medium, additionally referred to as the heliopause, utilizing two trajectories from Earth often called direct outward switch and inward switch strategies, respectively.

The direct outward switch technique for each the journey to Mars and the heliopause concerned the solar sail each deploying and departing immediately from a polar orbit across the Earth. The researchers decided that Mars being in opposition (immediately reverse Earth from the sun) on the time of solar sail deployment and departure from Earth would yield the perfect outcomes for each velocity and travel time.

This similar polar orbit deployment and departure was additionally used for the heliopause trajectory, as properly. For the inward switch technique, the solar sail can be delivered to roughly 0.6 astronomical models (AU) from the sun through conventional chemical rockets, the place the solar sail would deploy and start its journey to both Mars or the heliopause. However how does an aerographite solar sail make this journey extra possible?

“With its low density of 0.18 kilograms per cubic meter, aerographite undercuts all standard solar sail supplies,” Julius Karlapp, who’s a Analysis Assistant on the Dresden College of Expertise and lead creator of the research, tells Universe Right this moment. “In comparison with Mylar (a metallized polyester foil), for instance, the density is 4 orders of magnitude smaller. Assuming that the thrust developed by a solar sail is immediately depending on the mass of the sail, the ensuing thrust pressure is far larger. Along with the acceleration benefit, the mechanical properties of aerographite are wonderful.”

By these simulations, the researchers discovered the direct outward switch technique and inward switch technique resulted within the solar sail reaching Mars in 26 days and 126 days, respectively, with the primary 103 days being the journey time from Earth to the deployment level at 0.6 AU.

For the journey to the heliopause, each strategies resulted in 5.3 years and 4.2 years, respectively, with the primary 103 days of the inward switch technique additionally being dedicated to the journey time from the Earth to the deployment level at 0.6 AU, as properly. The rationale the heliopause is reached in a quicker time with the inward switch technique is because of the solar sail reaching most pace at 300 days, versus reaching most pace with the outward switch technique at roughly two years.

Present journey occasions to Mars vary between 7 and 9 months, which solely occurs throughout specified launch home windows each two years whereas counting on the positions of each planets to be aligned at each launch and arrival of any spacecraft going to, or coming from, Mars. Estimating present journey occasions to the heliopause could be executed utilizing NASA’s Voyager 1 and Voyager 2 probes, which reached the heliopause at roughly 35 years and 41 years, respectively.

The researchers observe that one main query of utilizing solar sails is deceleration, or slowing down, upon arriving on the vacation spot, particularly Mars, and whereas they point out aerocapture as one answer, they admit this nonetheless requires additional research.

“Aerocapture maneuvers for hyperbolic trajectories (like flying from Earth to Mars) use the environment to progressively cut back velocity resulting from drag,” Dr. Martin Tajmar, who’s a physicist and Professor of Area System on the Dresden College of Expertise and a co-author on the research, tells Universe Right this moment.

“Due to this fact, much less gasoline is required to enter the Martian orbit. We use this braking maneuver to get rid of the necessity for extra braking thrusters, which in flip reduces the mass of the spacecraft. We’re presently researching what various methods would possibly work for us. But the braking technique is just one of many alternative challenges we’re presently going through.”

Whereas solar sail know-how has been proposed by NASA way back to the Nineteen Seventies, a current instance of solar sail know-how is the NASA Photo voltaic Cruiser, which is presently scheduled to launch in February 2025.