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The Advanced Concepts Office at Marshall Space Flight Center completed a brief spacecraft design study for the 8- meter monolithic Advanced Technology Large Aperture Space Telescope (ATLAST-8m). This spacecraft concept provides all power, communication, telemetry, avionics, guidance and control, and thermal control for the observatory, and inserts...
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... The ATLAST will have a primary mirror diameter in the 8m to 16m range that will allow to perform some of the most challenging observations to answer some of most compelling astrophy-sical questions. The ATLAST-8m mission concept (Postman and et al., 2008; Hopkins and et al., 2010) takes real advantage to launch an 8-meter monolithic primary mirror telescope (Fig. 1) to the second Sun-Earth Lagrange(L2) point in the 2020 decade. For this space observatory specific technical problems must be studied, included optical design; structural design and a vibration analysis; thermal analysis ; launch vehicle performance and trajectory; spacecraft structure, propulsion, guidance, navigation, control and power systems; mass, power and cost budgets. ...
Some problems on a nonius guidance, robust attitude control and long-time image motion stabilization of a large space astronomical telescope are considered. Elaborated methods for dynamic research under external and parametric disturbances, partial discrete measurement of the state, digital control of the gyro moment cluster and a fine piezo-driver, are presented.
NASA’s "Enduring Quests Daring Visions" report calls for an 8- to 16-m Large UV-Optical-IR (LUVOIR) Surveyor mission to enable ultra-high-contrast spectroscopy and coronagraphy. AURA’s “From Cosmic Birth to Living Earth” report calls for a 12-m class High-Definition Space Telescope to pursue transformational scientific discoveries. The multi-center ATLAST Team is working to meet these needs. The MSFC Team is examining potential concepts that leverage the advantages of the SLS (Space Launch System). A key challenge is how to affordably get a large telescope into space. The JWST design was severely constrained by the mass and volume capacities of its launch vehicle. This problem is solved by using an SLS Block II-B rocket with its 10-m diameter x 30-m tall fairing and estimated 45 mt payload to SE-L2. Previously, two development study cycles produced a detailed concept called ATLAST-8. Using ATLAST-8 as a point of departure, this paper reports on a new ATLAST-12 concept. ATLAST-12 is a 12-m class segmented aperture LUVOIR with an 8-m class center segment. Thus, ATLAST-8 is now a de-scope option.
The space solar telescope (SST) is designed to obtain its diffraction limit quality with aperture over one meter. It observes the sun with a small view field of 2.8' × 1.5' to obtain its high spatial resolution imaging of 0.1″ -0.15″. SST observes the sun directly can receive huge heat flow more than 1 000W that will lead to unacceptable thermal distortion of the optical components. The sunlight enters into the telescope, which is an intense source of both heat and stray light. Based on the special thermal effect and stray light in the solar telescope, a compatibility analysis of the thermal effect of vanes in SST was performed. In the compatibility analysis, the geometric parameter of vane structure became a key point which would affect the geometry composing function (GCF) in stray light analysis and affect the radiation shape factor in thermal analysis synchronously. This paper presented the relationship between the thermal control design and scatting elimination plan on the vane structures in SST. The objective and method of the compatibility analysis were determined. With the thermal analysis software, the temperature fields were calculated for different geometric parameters of vane structure including depth, separation, and angle. A design of the vane structure was put forward in thermal control terms and the suggestion was put out synchronously, which restrains the vanes with less depth, more separation to the primary mirror and angled at 90°. The aims of the optimal design of the vane structure of SST were studed reached. The thoughts and methods of the optimal analysis are also useful for similar optical telescopes designed for solar observation.
Future large telescope arrays require careful balancing of satisfaction across the stakeholders' community. Development programs usually cannot afford to explicitly address all stakeholder tradeoffs during the conceptual design stage, but rather confine the analysis to performance, cost, and schedule discussions, treating policy and budget as constraints defining the envelope of the investigation. Thus, it is of interest to develop an integrated stakeholder analysis approach to explicitly address the impact of all stakeholder interactions on the design of large telescope arrays to address future science and exploration needs. This paper offers a quantitative approach for modeling some of the stakeholder influences relevant to large telescope array designs - the linkages between a given mission and the wider NASA community. The main goal of the analysis is to explore the tradespace of large telescope designs and understand the effects of different design decisions in the stakeholders' network. Proposed architectures that offer benefits to existing constellations of systems, institutions, and mission plans are expected to yield political and engineering benefits for NASA stakeholders' wider objectives. If such synergistic architectures are privileged in subsequent analysis, regions of the tradespace that better meet the needs of the wider NASA community can be selected for further development. © 2015 Society of Photo-Optical Instrumentation Engineers (SPIE).
Based on the thermal control system of Space solar telescope, the temperature of primary mirror in deep-space solar observatory was simulated under new orbit and larger view. Based on the theory of thermal-structural-optical integrated analysis, thermal deformation of the primary mirror under supported condition was calculated. And the deformed surface point of the primary mirror is fitted using parabolic polynomial and Zernike formula. The Root Mean Square(RMS) of deformed surface was greater than λ/40(λ=533 nm). It indicates the former thermal control system cannot meet its 0.1″ diffraction limit quality. Owing to the former thermal control system meets the demands of optical design difficultly, the supporting system of mirror is suggested to be adjusted in order to decrease thermal deformation. The integrated analysis of primary mirror is useful for optimizing the thermal control system and supporting system of Deep-space solar observatory.
The Advanced Technology Large Aperture Space Telescope (ATLAST)
preliminary design concept consists of an 8 meter diameter monolithic
primary mirror enclosed in an insulated, optical tube with stray light
baffles and a sunshade. ATLAST will be placed in orbit about the
Sun-Earth L2 point and will experience constant exposure to the sun. The
insulation on the optical tube and sunshade serve to cold bias the
telescope which helps to minimize thermal gradients. The objective is to
maintain the primary mirror at 280K with an active thermal control
system. The geometric model of the primary mirror, optical tube, sun
baffles, and sunshade was developed using Thermal Desktop. A detailed
model of the primary mirror was required in order to characterize the
static performance and thermal stability of the mirror during maneuvers.
This is important because long exposure observations, such as
extra-solar terrestrial planet finding and characterization, require a
very stable observatory wave front. Steady state thermal analyses served
to predict mirror temperatures for several different sun angles.
Transient analyses were performed in order to predict thermal time
constant of the primary mirror for a 20 degree slew and a 30 degree roll
maneuver. This paper describes the thermal model and provides details of
the geometry, thermo-optical properties, and the solar environment that
influences the thermal performance. All assumptions that were used in
the analysis are also documented. Estimates of mirror heater power
requirements are reported. The thermal model is used to predict
gradients across and through the primary mirror using an idealized
boundary temperature on the back and sides of the mirror of 280 K.
ATLAST-8m is an 8-meter monolithic UV/optical/NIR space observatory which could be placed in orbit at Sun-Earth L2 by a heavily lift launch vehicle. Two development study cycles have resulted in a detailed concept including a dual foci optical design; several primary mirror launch support and secondary mirror support structural designs; spacecraft propulsion, power and pointing control design; and thermal design. ATLAST-8m is designed to yield never before achieved performance to obtain fundamental astronomical breakthroughs.
Some problems on a nonius (vernier) guidance, robust attitude control and long-time image motion stabilization of a large space astronomical telescope are considered. Elaborated methods for dynamic research under external and parametric disturbances, partial discrete measurement of the state, digital control of the gyro moment cluster and a fine piezo-driver, are presented.
