China Tested its First Solar Sail Demonstrator

The Shenyang Institute of Automation (SIA) announced on Thursday that China's first solar sail, SIASAIL-I, has successfully verified a number of key technologies in orbit, a big breakthrough in China's solar sail development.

The solar sail developed by the institute of the Chinese Academy of Sciences based in Northeast China's Liaoning province is a spacecraft powered by the reflected light pressure of the sun on the spacecraft's membrane. Because it does not consume additional chemical fuel, a solar sail is considered to be the one and only spacecraft that may reach outside the solar system. It can be applied to a wide range of fields, including asteroid exploration, geomagnetic storm monitoring, solar polar exploration and space debris removal.

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How to Build a Reusable Solar Sail for Mars

Mass breakdown model of solar-photon sail shuttle: The case for Mars

Authors:

Vulpetti et al

Abstract:

The main aim of this paper is to set up a many-parameter model of mass breakdown to be applied to a reusable Earth–Mars–Earth solar-photon sail shuttle, and analyze the system behavior in two sub-problems: (1) the zero-payload shuttle, and (2) given the sailcraft sail loading and the gross payload mass, find the sail area of the shuttle. The solution to the subproblem-1 is of technological and programmatic importance. The general analysis of subproblem-2 is presented as a function of the sail side length, system mass, sail loading and thickness. In addition to the behaviors of the main system masses, useful information for future work on the sailcraft trajectory optimization is obtained via (a) a detailed mass model for the descent/ascent Martian Excursion Module, and (b) the fifty–fifty solution to the sailcraft sail loading breakdown equation. Of considerable importance is the evaluation of the minimum altitude for the rendezvous between the ascent rocket vehicle and the solar-photon sail propulsion module, a task performed via the Mars Climate Database 2014–2015. The analysis shows that such altitude is 300 km; below it, the atmospheric drag prevails over the solar-radiation thrust. By this value, an example of excursion module of 1500 kg in total mass is built, and the sailcraft sail loading and the return payload are calculated. Finally, the concept of launch opportunity-wide for a shuttle driven by solar-photon sail is introduced. The previous fifty–fifty solution may be a good initial guess for the trajectory optimization of this type of shuttle.

NASA's Sunjammer Mission Canceled

Citing a lack of confidence in its contractor’s ability to deliver, NASA has abandoned plans to fly a solar-sail mission in 2015 after investing four years and more than $21 million on the project.

The Sunjammer mission, including the spacecraft and a deployable 1,200-square-meter solar sail, was being developed by L’Garde Inc. of Tustin, California, under a contract awarded in September 2011. The contract is slated to expire this coming December, and NASA has no plans to continue the work, according to an internal memo circulated at NASA headquarters here the week of Oct. 7.

“NASA is working with L’Garde to de-scope the existing contract to close out the documentation and deliver completed work to the Agency by the end of 2014,” the memo reads.

NASA spokesman David Steitz said problems with the program surfaced a year ago. “During the annual review last October NASA identified key integration issues that increased the schedule risk,” he said via email Oct. 7.

Nathan Barnes, president of L’Garde, said in an Oct. 17 phone interview that the company’s final delivery to NASA will be a design for a spacecraft module and solar sail that in theory could propel a small spacecraft by harnessing the energy of photon strikes. L’Garde will turn over its design in a Critical Design Audit scheduled for Nov. 7, he said.

After that, L’Garde will lay off about 16 employees, all of them in Tustin, cutting the company’s head count roughly in half. L’Garde employed some 35 people when the Sunjammer project was in full swing.

The mission had been manifested as a secondary payload aboard a Space Exploration Technologies Corp. Falcon 9 rocket scheduled to launch the National Oceanic Atmospheric Administration’s Deep Space Climate Observatory in 2015.

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Using Solar Sails to Hover Over Spinning Asteroids

Asteroid body-fixed hovering using nonideal solar sails

Authors:

Zeng et al

Abstract:

Asteroid body-fixed hovering problem using nonideal solar sail models in a compact form with controllable sail area is investigated in this paper. The nonlinear dynamic equations for the hovering problem are constructed for a spherically symmetric asteroid. The feasible region for the body-fixed hovering is solved from the above equations by using a shooting method. The effect of the sail models, including the ideal, optical, parametric and solar photon thrust, on the feasible region is studied through numerical simulations. The influence of the asteroid spinning rate and the sail area-to-mass ratio on the feasible region is discussed in a parametric way. The required sail orientations and their corresponding variable lightness numbers are given for different hovering radii to identify the feasibility of the body-fixed hovering. An attractive mission scenario is introduced to enhance the advantage of the solar sail hovering mission.

Forces Which Effect Very Flexible Solar Sails

Dynamics of highly-flexible solar sail subjected to various forces

Authors:

Liu et al

Abstract:

Solar sail is a novel spacecraft and has the potential applications in the near future. The large amplitude vibration should be considered because it is characterized by its huge and lightweight structure. In this paper, the supporting beam of solar sail is regarded as the most important structure and used to model the sailcraft as it accounts for most of the mechanical energies when it is in deformed configuration, also as the Euler beam can model the bending motion dominant sailcraft when it experiences attitude motions. The structural dynamics of solar sail supporting beam with geometric nonlinearity undergoing the forces generated by solar radiation pressure, sliding masses and control vanes are presented. The axial and transverse vibration equations with the properties of strong coupling, nonlinearity and time-varying coefficient matrices are obtained by using Lagrange equation method after calculating the related energies and works. The vibration equations are transformed into nonlinear algebraic equations utilizing implicit unconditionally stable Newmark-β algorithm for each time step. The nonlinear algebraic equations are solved by Newton-iterative algorithm. We compute and analyze the linear and nonlinear vibration responses affected by the mass and velocity of the sliding mass, the angular velocity of the force generated by control vane in detail. The computational results indicate that the mass and velocity of sliding mass affect the vibration responses (including the vibration frequency), but the angular velocity of the force generated by control vane hardly affects the vibration responses. Moreover, the linear and nonlinear vibrations are distinct obviously by comparing the linear and nonlinear responses. It is demonstrated that the geometric nonlinearity of the highly-flexible structure should be considered for performing vibration analysis exactly, and the vibration responses excited by the prescribed motion of the attitude control actuators should be analyzed carefully.

How Much Interplanetary Dust Impacted on Japan's Ikaros Solar Sail Demonstrator?

Microparticle impact calibration of the Arrayed Large-Area Dust Detectors in INterplanetary space (ALADDIN) onboard the solar power sail demonstrator IKAROS

Authors:

Hirai et al

Abstract:

The Arrayed Large-Area Dust Detectors in INterplanetary space (ALADDIN) is an array of polyvinylidene fluoride (PVDF) based dust detectors aboard the solar power sail demonstrator named IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun). The total sensor area of ALADDIN (0.54 m2) is the world's largest among the past PVDF-based dust detectors. IKAROS was launched in May 2010 and then ALADDIN measured cosmic dust impacts for 16 months while orbiting around between 0.7 and 1.1 AU. The main scientific objective of ALADDIN is to reveal number density of ≥10-μm-sized≥10-μm-sized dust in the zodiacal cloud with much higher time-space resolution than that achieved by any past in-situ measurements. The distribution of ≥10-μm-sized≥10-μm-sized dust can be also observed mainly with the light scattering by optical instruments. This paper gives the scientific objectives, the instrumental description, and the results of microparticle impact calibration of ALADDIN conducted in ground laboratories. For the calibration tests we used Van de Graaf accelerators (VdG), two-stage light gas guns (LGG), and a nano-second pulsed Nd:YAG laser (nsPL). Through these experiments, we obtained depolarization charge signal caused by hypervelocity impacts or laser irradiation using the flight spare of 20-μm-thick20-μm-thick PVDF sensor and the electronics box of ALADDIN. In the VdG experiment we accelerated iron, carbon, and silver microparticles at 1–30 km/s, while in the LGG experiment we performed to shoot 100's-μm-sized100's-μm-sized particles of soda-lime glass and stainless steel at 3–7 km/s as single projectile. For interpolation to ≥10-μm≥10-μm size, we irradiated infrared laser at the energy of 15–20 mJ directly onto the PVDF sensor. From the signal analysis, we developed a calibration law for estimation of masses of impacted dust particles. The dynamic range of ALADDIN corresponds from 9×10−14 kg to 2×10−10 kg (View the MathML source4−56μm in diameter at density of 2.0 g/cm3) at the expected impact velocity of 10 km/s at 1 AU on the IKAROS inbound orbit. It was found that ALADDIN has ability to measure spatial densities of interplanetary dust particles larger than View the MathML source10μm in size by setting the sensor threshold to an output voltage of 1 V.

European Space Agency to Test Gossamer Deorbiter Sail

In Europe, the European Space Agency (ESA) has committed to freeing up orbits within 25 years under the European Code of Conduct for Space Debris Mitigation – an ambitious target considering dormant satellites in low-Earth orbits of as little as 750km altitude can stick around for a hundred years or more, ticking time bombs that threaten new sats with obliteration as they hurtle through space.

The agency now says that it’s close to a real test of the method it’s hoping will get space junk out of the sky in the quarter century target – a Gossamer Deorbiter Sail. The first of its kind in the world, the gossamer sail system is an aerodynamic drag technique that’s designed to take down telecoms satellites when they reach the end of their life. The sail is ultra-lightweight and extremely compact, taking up a space of just 15x15x25cm on the satellite and weighing only 2kg. It can deploy in minutes, expanding to 5m2, creating enough drag to pull a craft of up to 700kg out of orbit to burn up in the high atmosphere.

The ESA said on Friday that the sail, which was developed by the University of Surrey’s Space Centre, has now been subjected to rigorous testing, including thermal, vibration and vacuum tests. The team is hoping to see it get its first tryout in orbit using a demonstration satellite by the end of 2014, providing it can get a piggy-back launch opportunity.

“We are delighted to have completed the design, manufacture and testing of ESA’s Gossamer Deorbit Sail, the first of its kind internationally,” said Professor Vaios Lappas from the university.

“The project has been able to show that the design of a low-cost and robust end-of-life deorbiting system not only is possible, but it can also lead to tangible products with a strong commercial interest.”

Although the gossamer sail is the first of its kind, it’s not the only sail-type system currently being tested. For example, NASA finished its first-ever deployment of a solar sail in low-Earth orbit, the NanoSail-D, at the end of 2011. The US space agency’s system measures around 9.3m2 when open and deployed in just five seconds in the test. The demonstration satellite “sailed” through space for 240 days – using solar radiation pressure to get around with the help of a control system – before burning up during re-entry in September that year. NASA is using the data from the mission to better understand the drag influences of the Earth’s upper atmosphere.

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NASA MSFC Solicitation: Cubsesat Solar Sail Systems

Synopsis - Oct 25, 2013

General Information

Solicitation Number: NNM14ZPS001L

Posted Date: Oct 25, 2013

FedBizOpps Posted Date: Oct 25, 2013

Recovery and Reinvestment Act Action: No

Original Response Date: Nov 01, 2013

Current Response Date: Nov 04, 2013

Classification Code: A -- Research and Development

NAICS Code: 927110

Contracting Office Address

NASA/George C. Marshall Space Flight Center, Procurement Office, Marshall Space Flight Center, AL 35812

Description

This notice is issued by NASA/MSFC to post a Request for Information (RFI) via the internet, and solicit responses from interested parties. Pursuant to FAR 52.215-3, this document is for information and planning purposes and to allow industry the opportunity to verify reasonableness and feasibility of the requirement, as well as promote competition. It does not constitute a Request for Proposal. This RFI is open but not limited to educational, industrial and not-for-profit organizations. Prospective offerors are invited to submit their responses no later than November 4, 2013.

NASA/MSFC is interested in solar sail systems for interplanetary robotic exploration that may be deployed from a cubesat. This RFI solicits information about solar sail systems that may be delivered for flight as soon as 2016.

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Japanese Are Planning an Ikaros Follow-on

Japanese researchers are working on a solar-sail spacecraft with 10 times the surface area of the Ikaros testbed launched toward Venus last year, after achieving all of their technical objectives with the testbed.

This spacecraft will launch on a five-year mission instead of the six-month span allotted to Ikaros. Lofted as a piggyback payload with the Venus Climate Orbiter Akasuki on May 21, 2010, Ikaros passed Venus on Dec. 8.

Researchers hoped to demonstrate automatic sail deployment, power generation with thin-film solar cells on the sail surface, verification that the pressure of photons from the Sun caused the sail to accelerate, and guidance and navigation with the sail. The sail met its intended acceleration of 100 meters per second and veered off the ballistic trajectory it would have followed without the Sun’s pressure, says Yuichi Tsuda, an assistant professor in the Japan Aerospace Exploration Agency (JAXA) Space Exploration Center, in an English-language report on the experiment’s outcome.

The deployment and power generation were demonstrated early on. To control the 14 x 14-meter (46 x 46-ft.) spin-stabilized sail, the Ikaros team used a non-toxic “gas-liquid equilibrium thruster” for attitude control, and an attitude-detection system that combined a Sun sensor and Doppler measurements from the low-gain antenna.

To tilt the spin axis of the spacecraft, the team powered a liquid-crystal variable-reflectivity element mounted as a thin polyimide film around the edges of the sail off and on to throw the spinning sail off balance and tilt it as it spun. As it happened, the spacecraft required almost no fuel to keep its sail facing the Sun, even though it turned a full 180 deg. over the six months, according to Tsuda.

*sighs* This is actually a pretty important piece of tech going forward.

Japan Plans Solar Sail Called Ikaros

Japan is planning to launch an interplanetary solar sail mission called Ikaros next May.

[...]

Ikaros stands for the Interplanetary Kite-craft Accelerated by Radiation Of the Sun. The name also harkens to the Greek mythological figure Icarus, who fashioned feathers and attempted to escape exile but flew too close to the sun.

The mission will launch next May on an H-2A rocket with the Akatsuki mission to Venus, according to the Japan Aerospace Exploration Agency.

The sqaure Ikaros sail, with a diagonal diameter of 66 feet, is covered with thin film solar cells to generate electricity. The spacecraft will spin up to about 20 rpm for stability during its mission.

Interesting...mmm. the cells on the sail make me wonder if this is truly a solar sail rather than a light weight solar panel, but...they say so, even in the acronym.

Planetary Society Trying Solar Sail Again

The Planetary Society announced today that an anonymous donor has put upone million dollars to help us get a solar sail in flight. That money will kick-start our ambitious new LightSail program, a series of three increasingly large solar sails that mark individual steps in the path toward viable solar sail flight.

LightSail-1 will start with the same basic goal that Cosmos-1 had: to demonstrate that sunlight alone can propel a spacecraft in Earth orbit. But its design is quite different: it will be built of a stack of three cubesats, each only ten centimeters on a side, or one liter in volume. One cubesat will house the electronics, and the other two the ultrathin Mylar sails, four of them, together comprising 32 square meters of sail area. It'll launch to an orbit more than 800 kilometers above Earth, out of reach of the atmosphere.

*sighs*

I wish I had million dollar donors.

I actually love solar sails more than rockets, but there's more of a market for rockets than solar sails.