AVIATR - Aerial Vehicle for In-situ and Airborne Titan Reconnaissance A Titan Airplane Mission Concept

We describe a mission concept for a stand-alone Titan airplane mission: Aerial Vehicle for In-situ and Airborne Titan Reconnaissance (AVIATR). With independent delivery and direct-to-Earth communications, AVIATR could contribute to Titan science either alone or as part of a sustained Titan Exploration Program. As a focused mission, AVIATR as we have envisioned it would concentrate on the science that an airplane can do best: exploration of Titan's global diversity. We focus on surface geology/hydrology and lower-atmospheric structure and dynamics. With a carefully chosen set of seven instruments-2 near-IR cameras, 1 near-IR spectrometer, a RADAR altimeter, an atmospheric structure suite, a haze sensor, and a raindrop detector-AVIATR could accomplish a significant subset of the scientific objectives of the aerial element of flagship studies. The AVIATR spacecraft stack is composed of a Space Vehicle (SV) for cruise, an Entry Vehicle (EV) for entry and descent, and the Air Vehicle (AV) to fly in Titan's atmosphere. Using an Earth-Jupiter gravity assist trajectory delivers the spacecraft to Titan in 7.5 years, after which the AVIATR AV would operate for a 1-Earth-year nominal mission. We propose a novel 'gravity battery' climb-then-glide strategy to store energy for optimal use during telecommunications sessions. We would optimize our science by using the flexibility of the airplane platform, generating context data and stereo pairs by flying and banking the AV instead of using gimbaled cameras. AVIATR would climb up to 14 km altitude and descend down to 3.5 km altitude once per Earth day, allowing for repeated atmospheric structure and wind measurements all over the globe. An initial Team-X run at JPL priced the AVIATR mission at FY10 $715M based on the rules stipulated in the recent Discovery announcement of opportunity. Hence we find that a standalone Titan airplane mission can achieve important science building on Cassini's discoveries and can likely do so within a New Frontiers budget

Comparison of orbital and Supercam in situ investigation of the floor Units of Jezero crater

International audienceOn February 18, 2021, NASA’s Mars 2020 Perseverance rover landed successfully on the floor of Jezero crater. Two geological and compositional units had previously been identified from orbital data analysis within the floor of Jezero crater [1,2]: a dark pyroxene-bearing floor unit and an olivine-bearing unit exposed in erosional windows [3]. During the 420 first sols of the mission, the rover has completed an in situ exploration campaign of these two units.The SuperCam instrument contains a suite of techniques including passive spectroscopy in the 0.40-0.85 (VIS) and 1.3-2.6 microns (IR) wavelength ranges, Raman spectroscopy, Laser Induced Breakdown Spectroscopy (LIBS) and a camera providing high resolution context images [4,5]. Since the landing, SuperCam has acquired more than 3 thousands of observations.From orbit the two geological units in the floor of Jezero have distinctive morphology and spectral signature. The crater floor unit called Cf-fr (Crater floor fractured rough) has a pyroxene signature [2] with no clear evidence of alteration.  The unit is laying on the top of the olivine rich unit. The interpretations varied from lacustrine deposits to volcanic deposits. The underlying unit seems to be part of the regional olivine-rich deposits with parts altered into carbonates and clays [1,6]. Interestingly, this regional olivine rich unit has a unique spectral signature on Mars, an effect of either grain size or composition [7]. Many hypotheses have been suggested: Isidis impact related ejectas layer [8], pyroclastic deposits [i.e. 6] or clastics deposits [9].   In situ, we discovered that the Cf-fr, composed of different sub-units is not layered, composed of grainy rocks, dominated by plagioclase and Fe-rich pyroxenes [10] with a restricted but pervasive multistage [10]. From in situ data, Maaz is interpreted lava flows [11, 12] emplaced before the last lacustrine activity associated with the main western delta fan. Below the cf-fr, Seitah occurs as layered Mg-olivine rich rocks generally flat but slightly plunging below Maaz on the edges. The rocks are dominated by mm grains of pristine Olivine and some pyroxenes [10, 13, 14] .  The various spectroscopic methods detected alteration phases such as Mg- phyllosilicate and Mg Carbonates. [15, 16]. The rock texture and petrology of Seitah were interpreted as an olivine cumulate with limited alteration.Lessons learned from this in situ campaign will be presented such as how accurate are the orbital spectral analyses, the morphological analysis and how to transfer the results of Jezero to the other places on Mars investigate by orbital data only