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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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NASA NTRS2013

Internship at NASA Kennedy Space Center's Cryogenic Test laboratory

NASA's Kennedy Space Center (KSC) is known for hosting all of the United States manned rocket launches as well as many unmanned launches at low inclinations. Even though the Space Shuttle recently retired, they are continuing to support unmanned launches and modifying manned launch facilities. Before a rocket can be launched, it has to go through months of preparation, called processing. Pieces of a rocket and its payload may come in from anywhere in the nation or even the world. The facilities all around the center help integrate the rocket and prepare it for launch. As NASA prepares for the Space Launch System, a rocket designed to take astronauts beyond Low Earth Orbit throughout the solar system, technology development is crucial for enhancing launch capabilities at the KSC. The Cryogenics Test Laboratory at Kennedy Space Center greatly contributes to cryogenic research and technology development. The engineers and technicians that work there come up with new ways to efficiently store and transfer liquid cryogens. NASA has a great need for this research and technology development as it deals with cryogenic liquid hydrogen and liquid oxygen for rocket fuel, as well as long term space flight applications. Additionally, in this new era of space exploration, the Cryogenics Test Laboratory works with the commercial sector. One technology development project is the Liquid Hydrogen (LH2) Ground Operations Demonstration Unit (GODU). LH2 GODU intends to demonstrate increased efficiency in storing and transferring liquid hydrogen during processing, loading, launch and spaceflight of a spacecraft. During the Shuttle Program, only 55% of hydrogen purchased was used by the Space Shuttle Main Engines. GODU's goal is to demonstrate that this percentage can be increased to 75%. Figure 2 shows the GODU layout when I concluded my internship. The site will include a 33,000 gallon hydrogen tank (shown in cyan) with a heat exchanger inside the hydrogen tank attached to a refrigerator capable of removing 850 Watts at 20 Kelvin (shown in green). The refrigerator and most of its supporting equipment will be kept in a standard shipping container (shown in pink). Currently, GODU is in the fabrication process and some of the large components have already been purchased.

Holland, Katherine↗
NASA NTRS2014

Automated Standard Hazard Tool

The current system used to generate standard hazard reports is considered cumbersome and iterative. This study defines a structure for this system's process in a clear, algorithmic way so that standard hazard reports and basic hazard analysis may be completed using a centralized, web-based computer application. To accomplish this task, a test server is used to host a prototype of the tool during development. The prototype is configured to easily integrate into NASA's current server systems with minimal alteration. Additionally, the tool is easily updated and provides NASA with a system that may grow to accommodate future requirements and possibly, different applications. Results of this project's success are outlined in positive, subjective reviews complete by payload providers and NASA Safety and Mission Assurance personnel. Ideally, this prototype will increase interest in the concept of standard hazard automation and lead to the full-scale production of a user-ready application.

Stebler, Shane↗
NASA NTRS2024

NASA's Capture, Containment, and Return System: Bringing Mars Samples to Earth

The Mars Sample Return (MSR) campaign is one of the most ambitious and complex planetary science exploration missions ever pursued. With the participation of NASA, ESA, and many industry partners, MSR aims to bring Martian rock and atmosphere samples to Earth with the goal of answering key questions about Mars’ geological, climatological and, potentially, biological evolution. To accomplish this ambitious goal, the MSR campaign relies on three distinct flight elements and a ground element. The Earth Return Orbiter mission that would host the Capture, Containment, and Return System (CCRS) is the last flight element of the trio. The mission would capture the orbiting sample in low Mars orbit (launched into orbit by another mission), contain it, and return it to Earth, landing at the Utah Test and Training Range. Since its early architecture, several changes were adopted by CCRS to improve overall payload efficiency and reduce mass. This paper will discuss the CCRS design, how the current CCRS architecture contributes to an improved mission concept, and the next critical steps of the mission toward its launch.

Mars mission↗
NASA NTRS1986

A technique for incorporating the NASA spacelab payload dedicated experiment processor software into the simulation system for the payload crew training complex

The feasibility of some off-the-shelf microprocessors and state-of-art software is assessed (1) as a development system for the principle investigator (pi) in the design of the experiment model, (2) as an example of available technology application for future PI's experiments, (3) as a system capable of being interactive in the PCTC's simulation of the dedicated experiment processor (DEP), preferably by bringing the PI's DEP software directly into the simulation model, (4) as a system having bus compatibility with host VAX simulation computers, (5) as a system readily interfaced with mock-up panels and information displays, and (6) as a functional system for post mission data analysis.

Bremmer, D. A.↗
NASA NTRS1995

Time aspects of the European Complement to GPS: Continental and transatlantic experimental phases

The CNES project of a European Complement to GPS (CE-GPS) is conceived to fulfill the needs of Civil Aviation for a non-precise approach phase with GPS as sole navigation means. This generates two missions: a monitoring mission - alarm of failure - ,and a navigation mission - generating a GPS-like signal on board the geostationary satellites. The host satellites will be the Inmarsat constellation. The CE-GPS missions lead to some time requirements, mainly the accuracy of GPS time restitution and of monitoring clock synchronization. To demonstrate that the requirements of the CE-GPS could be achieved, including the time aspects, an experiment has been scheduled over the Last two years, using a part of the Inmarsat II F-2 payload and specially designed ground stations based on 10 channels GPS receivers. This paper presents a review of the results obtained during the continental phase of the CE-GPS experiment with two stations in France, along with some experimental results obtained during the transatlantic phase (three stations in France, French Guyana, and South Africa). It describes the synchronization of the monitoring clocks using the GPS Common-view or the C- to L-Band transponder of the Inmarsat satellite, with an estimated accuracy better than 10 ns (1 sigma).

Uhrich, Pierre J. M.↗
NASA NTRS2016

43rd Aerospace Mechanisms Symposium

The Aerospace Mechanisms Symposium (AMS) provides a unique forum for those active in the design, production and use of aerospace mechanisms. A major focus is the reporting of problems and solutions associated with the development and flight certification of new mechanisms. Sponsored and organized by the Mechanisms Education Association, responsibility for hosting the AMS is shared by the National Aeronautics and Space Administration and Lockheed Martin Space Systems Company (LMSSC). Now in its 43rd symposium, the AMS continues to be well attended, attracting participants from both the U.S. and abroad. The 43rd AMS was held in Santa Clara, California on May 4, 5 and 6, 2016. During these three days, 42 papers were presented. Topics included payload and positioning mechanisms, components such as hinges and motors, CubeSats, tribology, and mechanism testing. Hardware displays during the supplier exhibit gave attendees an opportunity to meet with developers of current and future mechanism components. The high quality of this symposium is a result of the work of many people, and their efforts are gratefully acknowledged. This extends to the voluntary members of the symposium organizing committee representing the eight NASA field centers, LMSSC, and the European Space Agency. Appreciation is also extended to the session chairs, the authors, and particularly the personnel at ARC responsible for the symposium arrangements and the publication of these proceedings. A sincere thank you also goes to the symposium executive committee who is responsible for the year-to-year management of the AMS, including paper processing and preparation of the program. The use of trade names of manufacturers in this publication does not constitute an official endorsement of such products or manufacturers, either expressed or implied, by the National Aeronautics and Space Administration.

Mechanism↗
NASA NTRS2000

Microbial Impact on Success of Human Exploration Missions

The purpose of this study is to identify microbiological risks associated with space exploration and identify potential countermeasures available. Identification of microbial risks associated with space habitation requires knowledge of the sources and expected types of microbial agents. Crew data along with environmental data from water, surfaces, air, and free condensate are utilized in risk examination. Data from terrestrial models are also used. Microbial risks to crew health include bacteria, fungi, protozoa, and viruses. Adverse effects of microbes include: infections, allergic reactions, toxin production, release of volatiles, food spoilage, plant disease, material degradation, and environmental contamination. Risk is difficult to assess because of unknown potential changes in microbes (e.g., mutation) and the human host (e.g., immune changes). Prevention of adverse microbial impacts is preferred over remediation. Preventative measures include engineering measures (e.g., air filtration), crew microbial screening, acceptability standards, and active verification by onboard monitoring. Microbiological agents are important risks to human health and performance during space flight and risks increase with mission duration. Acceptable risk level must be defined. Prevention must be given high priority. Careful screening of crewmembers and payloads is an important element of any risk mitigation plan. Improved quantitation of microbiological risks is a high priority.

Pierson, Duane L.↗
NASA NTRS2023

Mars Sample Return and The Capture, Containment, and Return System New Design and Path To 2027 Launch

The Mars Sample Return (MSR) campaign is one of the most ambitious and complex exoplanet scientific exploration missions currently underway. With the participation of NASA, ESA, and a large number of industry partners, MSR aims to bring back Martian rock and atmosphere samples with the goal of answering key questions about Mars’ geological, climatological, and (potentially) biological evolution. To accomplish this ambitious goal, the campaign relies on three distinct flight elements and a ground element. The Earth Return Orbiter (ERO) mission that would host the Capture, Containment, and Return System (CCRS) is the last element of the trio. The mission would capture the orbiting sample in low Mars orbit (launched into orbit by another mission), contain it and return it to Earth, landing it at the Utah Test and Training Range (UTTR). The CCRS continues its development. Since its early architecture, several changes were adopted by the project in order to improve overall payload efficiency and reduce mass. CCRS is currently on track to achieve the next milestone, Critical Design Review, expected in late 2024. This paper will discuss the CCRS design, how the current architecture contributes to an improved mission baseline, and the next critical steps of the mission towards its launch.

Mars mission↗
NASA NTRS2017

Capsulation Satellite or CapSat: A Low-Cost, Reliable, Rapid-Response Spacecraft Platform

The National Aeronautics and Space Administration (NASA) Goddard's Rideshare Office estimates that between 2013 and 2022, NASA launches of primary satellites will have left unused more than 20,371 kilograms of excess capacity. This equates to hundreds of millions of dollars in launch-vehicle costs going unutilized. To fill this void with a standard CubeSat or SmallSat spacecraft platform, which when required to be more reliable, still will cost in the neighborhood of $1M a kilogram, making it prohibitively expensive. A newly proposed solution, which NASA is pursuing, is called the Capsulation Satellite or CapSat. CapSat is a modularized, pressurized, thermally controlled spacecraft designed to host ruggedized commercially available instrumentation in a terrestrial like environment on orbit. Using a technique that is under review for a patent, CapSat actively manages internal air temperatures in a manner similar to a household thermostat. This gives CapSat high-thermal stability, which, in turn, provides component longevity. CapSat was specifically designed to take advantage of the United States Air Force (USAF) Rideshare Program and the Evolved Expendable Launch Vehicle Secondary Payload Adaptor, or ESPA ring. The ESPA ring comes in two sizes: standard and Grande. CapSat primarily will take advantage of the ESPA Grande to provide a 300-kilogram payload capability per attachment point, with up to four attachment points per ring. This approach combines a high-mass capability with a proven Rideshare mechanical interface and secondary payload management infrastructure. Opportunities for ESPA based co-manifests are continuing to expand. The CapSat program is currently funded to design and build a limited prototype and perform thermal-vacuum testing. CapSat is currently in the concept/study phase for both single missions and constellation of earth- and space-observing missions. One of these studies includes land imaging using state-of-the-art advanced infrared detector technology. This paper will report on the current status of the CapSat hardware design, testing, and results as well as any openly available advanced concept study results. The CapSat solution is intended to be a game-changing paradigm shift. CapSat will repurpose currently available, already-proven technology to reduce spaceflight hardware costs to less than $50,000 per kilogram.

Burt, Joe↗
NASA NTRS1991

An optical approach to proximity-operations communications for Space Station Freedom

An optical communications system is described that supports bi-directional interconnections between Space Station Freedom (SSF) and a host of attached and co-orbiting platforms. These proximity-operations (Prox-Ops) platforms are categorized by their maximum distance from SSF, with several remaining inside 1-km range and several extending out to 37-km and 2000-km ranges in the initial and growth phases, respectively. Two distinct Prox-Ops optical terminals are described. A 1-cm-aperture system is used on the short-range platforms to reduce payload mass, and a 10-cm-aperture system is used on the long-range platforms and on SSF to support the optical link budgets. The system supports up to four simultaneous user links, by assigning wavelengths to the various platforms and by using separate SSF terminals for each link.

Marshalek, Robert G.↗
NASA NTRSDate not supplied

Mercury Lander: A Planetary Mission Concept Study for the 2023–2032 Decadal Survey

Mercury holds unique clues to the distribution of elements at the birth of the solar system and how planets form and evolve in close proximity to their host stars. The Mercury Lander mission concept returns in situ measurements to: understand Mercury’s unique mineralogy and geochemistry; characterize the massive core’s structure; measure the planet’s active and ancient magnetic fields at the surface; investigate the processes that alter the surface and produce the exosphere; and provide groundtruth for remote datasets. The mission concept achieves one Mercury year (~88 Earth days) of surface operations with an 11-instrument, high-heritage payload delivered to a landing site within Mercury’s widely distributed low-reflectance material, and addresses science goals encompassing geochemistry, geophysics, the Mercury space environment, and geology. The spacecraft launches on an expendable SpaceX Falcon Heavy in 2035. The four-stage flight system uses a solar-electric propulsion cruise stage to reach Mercury in2045. The orbital stage brings the spacecraft into a thermally safe orbit, then performs orbital maneuvers to prepare for descent. During the orbital phase, a narrow-angle camera acquires images for selecting a low-hazard landing zone within our region of interest. The descent stage begins the braking burn ~120 s before landing. The lander continues to touchdown, using continuous LIDAR operations to support hazard detection and safely deliver the payload to the surface. Landing is at dusk to meet thermal requirements, permitting ~30 hours of sunlight for initial observations. The radioisotope-powered lander continues operations through the Mercury night. Direct-to-Earth communication is possible for the initial three weeks of landed operations, drops out for six weeks, and resumes for the final month. Thermal conditions exceed lander operating temperatures shortly after sunrise, ending operations. A total of ~11 GB of data are returned to Earth. The Phase A–D mission cost estimate (50% unencumbered reserves, excluding launch vehicle) is $1.2 B(FY25$), comparing favorably with past New Frontiers missions and to the cost cap in the New Frontiers4 call(~$1.1B FY25$). This cost estimate shows that a Mercury Lander mission is feasible and compelling as a New Frontiers-class mission in the coming decade.

C M Ernst↗
NASA NTRS2013

National Report on the NASA Sounding Rocket and Balloon Programs

The U. S. National Aeronautics and Space Administration (NASA) Sounding Rockets and Balloon Programs conduct a total of 30 to 40 missions per year in support of the NASA scientific community and other users. The NASA Sounding Rockets Program supports the science community by integrating their experiments into the sounding rocket payloads, and providing both the rocket vehicle and launch operations services. Activities since 2011 have included two flights from Andoya Rocket Range, more than eight flights from White Sands Missile Range, approximately sixteen flights from Wallops Flight Facility, two flights from Poker Flat Research Range, and four flights from Kwajalein Atoll. Other activities included the final developmental flight of the Terrier-Improved Malemute launch vehicle, a test flight of the Talos-Terrier-Oriole launch vehicle, and a host of smaller activities to improve program support capabilities. Several operational missions have utilized the new Terrier-Malemute vehicle. The NASA Sounding Rockets Program is currently engaged in the development of a new sustainer motor known as the Peregrine. The Peregrine development effort will involve one static firing and three flight tests with a target completion data of August 2014. The NASA Balloon Program supported numerous scientific and developmental missions since its last report. The program conducted flights from the U.S., Sweden, Australia, and Antarctica utilizing standard and experimental vehicles. Of particular note are the successful test flights of the Wallops Arc Second Pointer (WASP), the successful demonstration of a medium-size Super Pressure Balloon (SPB), and most recently, three simultaneous missions aloft over Antarctica. NASA continues its successful incremental design qualification program and will support a science mission aboard WASP in late 2013 and a science mission aboard the SPB in early 2015. NASA has also embarked on an intra-agency collaboration to launch a rocket from a balloon to conduct supersonic decelerator tests. An overview of NASA's Sounding Rockets and Balloon Operations, Technology Development and Science support activities will be presented.

Eberspeaker, Philip↗
NASA NTRS2008

Building on 50 Years of Systems Engineering Experience for a New Era of Space Exploration

Over the past 50 years, the National Aeronautics and Space Administration (NASA) has delivered space transportation solutions for America's complex missions, ranging from scientific payloads that expand knowledge, such as the Hubble Space Telescope, to astronauts and lunar rovers destined for voyages to the Moon. Currently, the venerable Space Shuttle, which has been in service since 1981, provides the United States (US) capability for both crew and heavy cargo to low-Earth orbit to construct the International Space Station, before the Shuttle is retired in 2010. In the next decade, NASA will replace this system with a duo of launch vehicles: the Ares I crew launch vehicle and the Ares V cargo launch vehicle. The goals for this new system include increased safety and reliability coupled with lower operations costs that promote sustainable space exploration for decades to come. The Ares I will loft the Orion crew exploration vehicle, while the heavy-lift Ares V will carry the Altair lunar lander, as well as the equipment and supplies needed to construct a lunar outpost for a new generation of human and robotic space pioneers. NASA's Marshall Space Flight Center manages the Shuttle's propulsion elements and is managing the design and development of the Ares rockets, along with a host of other engineering assignments in the field of scientific space exploration. Specifically, the Marshall Center's Engineering Directorate houses the skilled workforce and unique facilities needed to build capable systems upon the foundation laid by the Mercury, Gemini, Apollo, and Shuttle programs. This paper will provide details of the in-house systems engineering and vehicle integration work now being performed for the Ares I and planned for the Ares V. It will give an overview of the Ares I system-level testing activities, such as the ground vibration testing that will be conducted in the Marshall Center's Dynamic Test Stand to verify the integrated vehicle stack's structural integrity and to validate computer modeling and simulation, as well as the main propulsion test article analysis to be conducted in the Static Test Stand. Ultimately, fielding a robust space transportation solution that will carry international explorers and essential payloads will pave the way for a new era of scientific discovery now dawning beyond planet Earth.

Dumbacher, Daniel L.↗
NASA NTRS2009

Robotics Algorithms Provide Nutritional Guidelines

On July 5, 1997, a small robot emerged from its lander like an insect from an egg, crawling out onto the rocky surface of Mars. About the size of a child s wagon, NASA s Sojourner robot was the first successful rover mission to the Red Planet. For 83 sols (Martian days, typically about 40 minutes longer than Earth days), Sojourner - largely remote controlled by NASA operators on Earth - transmitted photos and data unlike any previously collected. Sojourner was perhaps the crowning achievement of the NASA Space Telerobotics Program, an Agency initiative designed to push the limits of robotics in space. Telerobotics - devices that merge the autonomy of robotics with the direct human control of teleoperators - was already a part of NASA s efforts; probes like the Viking landers that preceded Sojourner on Mars, for example, were telerobotic applications. The Space Telerobotics Program, a collaboration between Ames Research Center, Johnson Space Center, Jet Propulsion Laboratory (JPL), and multiple universities, focused on developing remote-controlled robotics for three main purposes: on-orbit assembly and servicing, science payload tending, and planetary surface robotics. The overarching goal was to create robots that could be guided to build structures in space, monitor scientific experiments, and, like Sojourner, scout distant planets in advance of human explorers. While telerobotics remains a significant aspect of NASA s efforts, as evidenced by the currently operating Spirit and Opportunity Mars rovers, the Hubble Space Telescope, and many others - the Space Telerobotics Program was dissolved and redistributed within the Agency the same year as Sojourner s success. The program produced a host of remarkable technologies and surprising inspirations, including one that is changing the way people eat

Source record↗
NASA NTRS2015

Impact of Co-Site Interference on L/C-Band Spectrum for UAS Control and Non-Payload Communications

In order to provide for the safe integration of unmanned aircraft systems into the National Airspace System, the control and non-payload communications (CNPC) link connecting the ground-based pilot with the unmanned aircraft must be highly reliable. A specific requirement is that it must operate using aviation safety radiofrequency spectrum. The 2012 World Radiocommunication Conference (WRC-12) provided a potentially suitable allocation for LOS CNPC spectrum in C-Band at 5030-5091 MHz band which, when combined with a previous allocation in L-Band (960-1164 MHz) may satisfy the LOS spectrum requirement and provide for high reliability through dual-band redundancy. However, the LBand spectrum hosts a number of aeronautical navigation systems which require high-power transmitters on-board the aircraft. These high-power transmitters co-located with sensitive CNPC receivers operating in the same frequency band have the potential to create co-site interference, reducing the performance of the CNPC receivers and ultimately reducing the usability of the L-Band for CNPC. This paper examines the potential for co-site interference, as highlighted in recent flight tests, and discusses the impact on the UAS CNPC spectrum availability and requirements for further testing and analysis.

radiofrequency spectrum↗
NASA NTRS1990

Miniaturized, 9-12 micron heterodyne spectrometer with space qualifiable design features

A demonstration-prototype CO2-laser heterodyne spectrometer operating at 9-12 microns and suitable for long-term space missions is described and illustrated with extensive diagrams, drawings, photographs, and graphs of test performance data. The spectrometer has total volume 0.63 cu m, mass 30 kg, and power requirement 60-70 W, compatible with miniature-class Space Shuttle experiment payload specifications. It comprises three modules: (1) an optical front end with reflecting optics, a 2-GHz BW HgCdTe photomixer, and a 0-2-GHz 40-dB RF preamplifier; (2) a local oscillator with an RF-excited waveguide CO2 laser, a 75-percent-efficiency RF amplifier, a stepper-driven grating mode selector, and an etalon stabilized for over 30,000 h of use; and (3) an RF-filter-bank spectral-line receiver with a 25-MHz RF channel, 1.6-GHz IF spectral coverage, onboard instrument control, a serial link to the host computer, and highly integrated design.

Glenar, D. A.↗
NASA NTRS2020

NASA Access 2 Space Workshop: Summary Report: Increased Science Return through Rideshare

This report summarizes the Access to Space (A2S) Workshop held on February 25-27, 2020 at the Johns Hopkins University Applied Physics Laboratory (APL) and hosted by NASA’s Science Mission Directorate (SMD). This workshop solicited community input on the creation and management of an ESPA-class1payload pipeline for NASA SMD launches. The workshop brought together roughly 180 participants including scientists, engineers, instrument developers, launch providers, and policy makers across NASA centers, government agencies, commercial industry, research institutes, and academia.

ESPA-Class Spacecraft↗
NASA NTRS2020

Terrestrial Planets Comparative Climatology (TPCC) mission concept

The authors and co-signers of the Terrestrial Planets Comparative Climatology (TPCC) mission concept white paper advocate that planetary science in the next decade would greatly benefit from comparatively studying the fundamental behavior of the atmospheres of Venus and Mars, contemporaneously and with the same instrumentation, to capture atmospheric response to the same solar forcing, and with a minimum of instrument-related variability. NASA’s vision is to understand the effects of the Sun on the solar system and the potential for life elsewhere (Obj,1.1 of [1]). This vision directly motivates the study of terrestrial climate histories and evolution, with the ultimate goal of understanding what factors allow the emergence and sustainability of life/biosphere. It is widely accepted that Venus, Mars, and Earth were formed at the same time and in the same neighborhood of the solar nebula [2,3], and had water—a necessary ingredient for life. In spite of strong overlap in the atmospheric composition of these planets, their current climatic states are vastly different. While Earth retains water, both Mars and Venus’ surfaces are now dry. The manner in which these terrestrial bodies evolved, and whether Mars or Venus currently hosts or previously hosted life, are fundamental mysteries in planetary science. As such, the TPCC mission concept has been developed.The TPCC guiding science goals are:(1) to understand Venus’ evolutionary history compared to Mars and Earth, and (2) to elucidate the driving forces and mechanisms of global circulation at Mars and Venus. These goals address the science question: Why have Mars’ and Venus’ climates evolved so differently from each other and from Earth’s? Furthermore, a greater depth of understanding our own solar system, enables us to understand the variability and likelihood of habitable conditions within extra-solar planetary systems.We suggest a mission architecture and payload that would determine the noble gas content and isotopic ratios, including the D/H ratio, at Venus with sufficient accuracy to identify the timeline of Venus’ climatic evolution for comparison with Mars. In addition, our concept would systematically “follow the energy” at Mars and Venus, in order to establish how solar forcing on the two atmospheric systems leads to the current balance of dynamical, chemical, and radiative processes responsible for each planet’s climatic state.This would include acquisition of the first global atmospheric wind profiles on either planet;global, continuous profiles of aerosols, gases, and water vapor at vertical resolutions higher than any previous mission;and regular UV and IR night glow observations tracking global circulation on both planets.To increase the fidelity of the planned planetary comparisons, the TPCC mission concept baseline (estimated to be New Frontiers Class)would send a single spacecraft to visit one planet and then the next, allowing measurements of each planet with the same instrumentation within similar parts of the solar cycle. The concept uses commercial solar-electric propulsion (SEP; e.g., [4])similar to the Psyche mission [5], plus a probesent deep into Venus’ atmosphere(e.g., LLISSE concept; [6]).Alternatively, “twin” spacecraft (with added probe to the Venus craft),developed at the same time,and launched close in time,would increase the overlap in operation periods and should also be studied. Either architecture is a timely alternative to independently developed and launched spacecraft payloads, which ultimately are more costly and difficult to inter-calibrate.

Leslie K. Tamppari↗