To image nearby Earth-like exoplanets (located 10 parsecs from us) with a spatial resolution of less than 1 microarcsecond, which would allow us to distinguish surface environments such as oceans, land, plants, and volcanoes, we would need an optical space telescope with an aperture exceeding 100 km. Given the unprecedented scale and technical difficulties of such a telescope, it is necessary to think beyond the constraints of existing telescopes. Accordingly, we have initiated a study to assess the feasibility of a novel telescope concept. This concept employs a combination of “magnetic formation flight of ultra-small satellites” and a “diffractive optical system”. The advantages of the diffractive optical system include its lightweight focusing optical system, low installation accuracy requirements, low manufacturing cost, and high storability when loaded in a rocket. However, there is no precedent for a telescope with multiple apertures using Diffractive Optical Elements (DOEs). Therefore, for a ground-based demonstration, we have fabricated two types of DOEs: binary amplitude and 4-level phase. The 4-level phase type exhibits significantly higher diffraction efficiency compared to the binary amplitude type, enabling high throughput of the optics. Each DOE is a 30 mm square and part of 100 mm diameter optics with a focal length of 1000 mm. We describe the experimental results of their point spread functions, wavefront errors, and transmittances.
GEOspace X-ray imager (GEO-X) is a small satellite mission aiming at visualization of the Earth’s magnetosphere by X-rays and revealing dynamic couplings between solar wind and the magnetosphere. In-situ spacecraft have revealed various phenomena in the magnetosphere. X-ray astronomy satellite observations recently discovered soft X-ray emissions originating from the magnetosphere. We are developing GEO-X by integrating innovative technologies of a wide field of view (FOV) X-ray instrument and a small satellite for deep space exploration. The satellite combines a Cubesat and a hybrid kick motor, which can produce a large delta v to increase the altitude of the orbit to about 30 to 60 RE from a relatively low-altitude (e.g., geo transfer orbit) piggyback launch. GEO-X carries a wide FOV (5 × 5 deg) and a good spatial resolution (10 arcmin) X-ray (0.3 to 2 keV) imaging spectrometer using a micro-machined X-ray telescope and a CMOS detector system combined with an optical blocking filter. We aim to launch the satellite around the solar maximum of solar cycle 25.
We have been developing an ultra-lightweight Wolter type-I X-ray telescope fabricated with micro electro mechanical systems (MEMS) technologies for GEO-X (GEOspace X-ray Imager) mission.
GEO-X will aim global imaging of the Earth's magnetosphere using X-rays.
The telescope is our original micropore optics which is light in weight (~5 g), compact with a short focal length (~250 mm), and has a wide field-of-view (~5 deg x 5 deg).
In this talk we show developed assembly processes to meet the requirements of the GEO-X mission and the telescope's X-ray imaging performance as an engineering model with this method.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.