¶How is Perseverance different from Curiosity? As Perseverance nears launch-readiness, we look at the differences 9 years make in the tech and mission of a Mars rover. Curiosity focused on gauging the past habitability of Gale Crater, finding an ancient, potentially habitable river and intermittent lake system. Like its closely-related predecessor, Perseverance will also gauge habitability of its landing region (Jezero Crater, a paleo-lakebed with preserved river delta and sediments). But, it will go further by directly hunting for ancient microbial biosignatures (with lasers!) and storing the most interesting samples in 20 sealed caches on the Martian surface for a future sample return mission (tentatively launching in 2026). Perseverance is phenomenally complex, its Sample Caching System alone contains 3,000+ parts and two robotic arms. Perseverance is based on Curiosity’s design, but has redesigned & more durable aluminum wheels, better skycrane and landing navigation systems, additional improved cameras, Mars’ first microphones, a larger drill (that can “cut intact rock cores, rather than pulverizing them”), an ISRU experiment that makes oxygen from CO2, more advanced autonomous navigation, and a very different set of instruments. Both rovers are powered by a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), allowing full time operation, with Perseverance carrying a unit left over from Curiosity. Oh, and Perseverance has a helicopter drone (cf. Issue 64)! Perseverance is scheduled to launch at 9:15 a.m. EDT July 20—any later than mid-August and it’ll need to wait two years for the next Mars launch window. If the flight goes as planned, it will land in Mars' Jezero Crater on Feb. 18, 2021.
¶How would the Mars Sample Return mission work? NASA recently settled on a solid-fuel design for their Mars Ascent Vehicle (MAV), the small (max 400 kg), two-stage rocket that will hopefully carry the samples, left on the surface of Jezero Crater by Perseverance, into orbit. Once there, it will perform the first autonomous rendezvous between two spacecraft beyond the Earth-Moon system, and transfer its samples into the care of ESA’s electrically-propelled Earth Return Orbiter (ERO). Solid fuel was selected because it needs to remain stable through the years of “cold soak” temperatures in space (-156° C) and on Mars—it’d launch in 2026, but not be fired up until 2029. Samples, carried by ERO, would later enter Earth’s atmosphere over Utah in a heat-shielded capsule in 2031. Here’s a video about the complex mission architecture from ESA.
| A concept image of the Mars Sample Return mission including NASA's Mars Ascent Vehicle, ESA's Earth Return Orbiter, the Mars sample canister, and the Earth entry capsule.|
¶See the edge of space in the balloon-born Spaceship Neptune. Last week, Space Perspectives revealed plans for a balloon-lofted suborbital space capsule. The capsule would take 8 passengers, a pilot, and research payloads on a 6-hour ride up to 30 km and then splash down for ship-based recovery (video). While only a third of the way to the Kármán line, it is high enough to observe the curvature of the earth with a black sky overhead. The capsule, which won't require special suits for passengers, would be equipped with a 360° viewing dome, seats that recline for landing, and a bar. Space Perspective's founders were part of the team behind Biosphere 2 and have revived this idea after their 2013 startup, World View, ended up launching uncrewed balloon-based platforms that station-keep for up to a month instead of humans. Seats on SS Neptune are expected to cost about $125,000, with initial launches from KSC. The balloon inflates to the size of a football stadium and uses hydrogen lifting gas due to its cost and environmental benefits over helium. One last important detail: the capsule does feature a toilet that may have the “best view of any loo in the world.” 🚽✨ A first uncrewed test flight is scheduled for early 2021.
- In 2015, Alan Eustace, then VP of Search at Google, jumped from a helium-filled balloon at a record altitude of 41,419 meters with the help of Paragon, a stratospheric balloon company founded by the same team that announced Spaceship Neptune. (Amusingly, Google search frequently reports the wrong record, referencing Felix Baumgartner’s 38,969 meter jump as the highest.)
- 📅 AAS is hosting SATCON1, a multiday virtual workshop on satellite constellations and mitigation efforts.
- Watch Mars’ north pole change over 6 Martian years in this animation from the Mars Reconnaissance Orbiter.
- Catch up on everything happening with UK-based launch vehicles (video).
- NASA is funding the “Characterizing Atmospheric Technosignatures” study to quantify ways of analyzing exoplanets for signs of technological life (this is the first SETI-specific NASA grant in 30+ years). Related: many exoplanets are likely to be ocean worlds, and there may be as many as six billion Earth-like planets in the Milky Way—one for every five Sun-like stars.
- Mars’ moons may have formed from an ancient Martian ring system, which was formed out of pulverized moons, which themselves were formed from rings, which… (pdf paper)
- Every Mars landing attempt visualized in an infographic from the Planetary Society.
- NASA is exploring using pulsars for navigation on the ISS and soon on Gateway (pdf).
- Satsearch has released another one of their CubeSat component reviews, this one is about Electrical Power Systems (EPSes). They also recently updated articles about CubeSat OBCs, sun sensors, GPSes, EPSes, and thrusters.
- Supposing you drained the Earth’s oceans and dumped them onto Curiosity, how would Mars change as the water accumulated?
- Astrobites has an excellent review of the impact of discrimination on the underrepresentation of African Americans in Astro/Physics. Very related: during the period between 1973 and 2012, 66 US physics doctorates went to black women, while 22,000 went to white men.