Wednesday was an exciting day for space exploration enthusiasts, as NASA announced the two finalist missions selected as part of its New Frontiers Program – a new robotic mission to be launched in the mid-2020s. The two winners are a sample return mission from a comet and a drone-like rotorcraft to further explore Saturn’s moon Titan. Other mission proposals which didn’t make the cut included a sample return mission from the Moon’s south pole, a new Venus lander, a Saturn atmospheric probe and a new Enceladus mission. However, two of those missions, for Enceladus and Venus, were selected for further technology development.
Even though Venus is Earth’s closest planetary neighbour, it is still one of the most mysterious. Numerous landers and orbiters have visited this extremely hostile world, but there are still many unanswered questions to be resolved. Now, NASA is proposing a new mission using a small CubeSat, called CubeSat UV Experiment (CUVE), to further study Venus’ atmosphere and hopefully solve at least one of the more perplexing mysteries.
The mission concept has now received funding from the agency’s Planetary Science Deep Space SmallSat Studies (PSDS3).
Something in the atmosphere of Venus is absorbing ultraviolet light and scientists still don’t know what it is. When seen in visible light, Venus looks rather bland and featureless, with the thick, perpetual cloud layers obscuring the view of the surface. But when viewed in ultraviolet light, unusual dark bands become clearly visible in the atmosphere. This indicates that something in the clouds is absorbing ultraviolet light. But what is it?
“The exact nature of the cloud top absorber has not been established,” said CUVE Principal Investigator Valeria Cottini, a researcher at the University of Maryland. “This is one of the unanswered questions and it’s an important one.”
The absorber is thought to be found only in the dark streaks according to one theory, where convection drags the absorber from deeper down in the thick clouds, transporting the substance to the cloud tops. Then, winds disperse the material in the direction of the wind, creating the long dark streaks. That still doesn’t explain what the absorbing material itself is however.
“Since the maximum absorption of solar energy by Venus occurs in the ultraviolet, determining the nature, concentration, and distribution of the unknown absorber is fundamental,” Cottini said. “This is a highly-focused mission – perfect for a CubeSat application.”
The CUVE team would use miniaturized instruments and related technologies to try to figure what is causing this phenomenon. CUVE would carry a Goddard-developed spectrometer to analyze light over a broad spectral band – 190-570 nanometers – covering both ultraviolet and visible wavelengths.
“A lot of these concepts are driven by important Goddard research-and-development investments,” said Tilak Hewagama, a CUVE team member who has worked with Goddard scientists to demonstrate a CubeSat-compatible spectrometer. “That’s what got us started.”
Another theory even says that the dark streaks could be composed of microbes. It may seem unlikely, although microbes have been found at similar heights in Earth’s atmosphere, in a region beginning around 50 kilometres (31 miles) in altitude and extending several miles outward, where temperatures range from 30 ºC to 70 ºC (86 ºF to 158 ºF) and the pressure is similar to that on Earth’s surface.
“CUVE is a targeted mission, with a dedicated science payload and a compact bus to maximize flight opportunities such as a ride-share with another mission to Venus or to a different target,” Cottini said. “CUVE would complement past, current, and future Venus missions and provide great science return at lower cost.”
It was also reported earlier this year that NASA is studying the possibility of a new joint mission with Russia to return to Venus, called Venera-D. This mission would consist of both an orbiter, and a lander which could last longer than previous probes in the intense heat and high pressure on the surface.
This article was first published on AmericaSpace.
Europa is one of the most fascinating places in the Solar System, and is considered to be at or near the top of the list of worlds to search for possible evidence of life. Beneath its outer ice crust lies a deep and dark salty ocean, thought to be quite to Earth’s own oceans. Could that ocean be inhabited, even if just by microbes? Scientists want to know, and now a new proposal calls for a joint orbiter/lander mission between NASA and ESA (European Space Agency), to try to answer that question.
Last week, Planetaria reported on why NASA should return to Venus, and new technology being developed to help make that happen, especially as in longer-lived landers or rovers. With its extremely hostile conditions, Venus has been much less of a priority in more recent years, at least in terms of surface missions, despite it being Earth’s closest planetary neighbour. But now there may be more impetus towards a new mission – not one that NASA would do alone, but rather a joint mission with Russia, known as Venera-D.
The Solar System has been a busy place in recent years, with missions to a diverse range of worlds, from Mars, Jupiter and Saturn to distant Pluto and even comets and asteroids. Most of these have been NASA spacecraft, which continues to lay the path to exploring such distant places. There are, however, some places which have been visited in the past, decades ago, but now are seemingly no longer a priority, such as Uranus and Neptune. But there is another planet which is actually Earth’s closest neighbour, yet was only last visited in the 1970s and 1980s, by American and Soviet spacecraft – Venus.