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#224 - Hopes, Holes and Clippers



Harriet Joins Matt to chat about Hope's arrival at Mars, Blackholes in globular clusters, a liberated Europa Clipper, Nuclear Propulsion ...and much more.


Philosophy is written in this grand book, the universe, which stands continually open to our gaze. But the book cannot be understood unless one first learns to comprehend the language and read the letters in which it is composed.

Born OTD Feb 15th 1564 – Galileo Galilei, Italian astronomer, physicist, and mathematician (d. 1642)


also Born this day

1935 – Roger B. Chaffee, American lieutenant, engineer, and astronaut (d. 1967)

1964 – Leland D. Melvin, American engineer and astronaut



This week

NASA’s next robotic explorer and Ingenuity, the experimental helicopter it is carrying, will hurtle toward the Martian surface on Thursday ...Join us on the Discord for a 7min terror party. Starting as Nasa Live coverage and landing commentary from NASA’s Jet Propulsion Laboratory in Southern California will begin at 2:15 p.m EST 7.15pm UK. on the NASA TV Public Channel and the agency’s website, as well as the NASA App, YouTube, Twitter, Facebook, LinkedIn, Twitch, Daily Motion, and THETA.TV. , and landing on the Red Planet, with touchdown scheduled for approximately 3:55 p.m. EST Thursday, Feb. 18, 20:55 (GMT) and Coordinated Universal Time (UTC)


NASA’s first-ever Spanish-language show for a planetary landing. On Thursday, Feb. 18, at 2:30 p.m., NASA will air “Juntos perseveramos,” a show that will give viewers an overview of the mission to Mars and highlight the role Hispanic NASA professionals have had in its success.




Tianwen 1 did arrive succesfully at Mars, with some amazing video footage as it got into orbit. But the day before saw ….


Hope

successfully reaches Mars and get into orbit.

During the Mars orbital insertion, the toughest time.They needed to turn on the thrusters for a 27 minutes burn, and they had never done that before. This is a completely new design for a spacecraft. You can't test thrusters here on Earth that will work in a vacuum. They have only tested portions of it. 7 years of international effort for theses 27 minutes!!!


UAESA/MBRSC/LASP/EMM-EXI The image shows three shield volcanoes in a line, as well as Olympus Mons, the largest volcano in the Solar System

It’s a mind-blowing achievement. The project was only announced 6 years ago, and the space agency has only been going for 7 years!!! Yet they have a successful interplanetary Probe. The US were, of course, major partners in this, advising all the way, but the average age of the scientist on the UAE side is 27!!! And women make up 80% of their number. Of course, this is all for the push for a post Oil world, a Knowledge Economy,


UAE was just a desert made up of nomadic people. Made up of 7 emirates that joined a federation in late 1971 and early 1972. The states were formerly British protectorates called Trucial states the population was about 200,000 at the time and has grown to about 10 million, they transformed the state into a financial powerhouse with the worlds tallest building

So as UAE comes up to its 50th Birthday it now has another world-class achievement under its belt a Mars probe doing real science. Next Plan to build a Mars City ...a science city in the desert of Dubai



“Her Excellency” Sarah Al Amiri, is still only 34, yet is the Minister of State for Advanced Sciences!!! And Chair of the space agency, and the Project Manager for Hope!!

  • Born in Iran

  • Computer Science degree 2008 and masters 2014 from at the American University of Sharjah in UAE, Masters while working as Head of Space Science

  • began her career at the Emirates Institution for Advanced Science and Technology, where she worked on the Korean built DubaiSat-1 and DubaiSat-2, UAE first Satellites

  • She joined the UAE Ministry of Climate Change and the Environment

  • Then a senior role at the Dubai World Trade Centre

  • Still in her 20’s when made head of the Emirates Science Council

  • Ted Talk at the age of 30 about Hope. The first UAE citizen to do so.

  • In the BBC top 100 women.

  • Interplanetary Podcasts top 100 people... full stop

  • One of the youngest Ministers in the world

The Hope Orbiter, objectives

Two main objectives.

  • One is to gather data on changes in the atmosphere through an entire Martian year, which equals two earth years, find out more about Mars, its climate and weather, and how it changes. it's the very first holistic weather satellite of Mars. Characterizing the weather system of Mars throughout the entire day and in every region of Mars. overall dust storm systems, clouds, water vapor. How far hydrogen and oxygen extend out into space from Mars, What role does the weather system on Mars play in the atmospheric loss. There will be consistent coverage. During every single time slot of the day, they want to know what happens across an entire day, Seasons on Mars

  • The transition from an oil-based economy to a knowledge-based one. They staffed the space programme with young graduates - the average age of the team is 27. People aged between 15 and 29 make up over 30% of the Middle East's population, and the push is to give them big projects. UAE are end-users of tech, they want to become developers and designers. Going back to the Arab routes of leaders in Space Science.


The Hope probe has three main instruments:

  1. The Emirates Mars Infrared Spectrometer (EMIRS) Measures temperature profiles, measures clouds, and measures dust.,

  2. The Emirates Exploration Imager (EXI) EXI provides visible images and looks at Mars in red, green and blue, and two ultraviolet frequencies to give an understanding of ozone and water vapour in the lower atmosphere

  3. The Emirates Mars Ultraviolet Spectrometer (EMUS) looks at the upper atmosphere and the extension of hydrogen and oxygen using the ultraviolet spectrometer The whole mission links upper and lower.

It is worth noting that Sarah says that most scientists in the UAE are women and it’s only when they go to international meetings does she suddenly realises she’s the only woman in the room. Which she puts down to the equality inherent at the start of the UAE, legislation to promote women in leadership, limited people pool means you only get by on accomplishments


[2010.05532] Does NGC 6397 contain an intermediate-mass black hole or a more diffuse inner subcluster?

Eduardo Vitral, Gary A. Mamon

Paper on the arxiv revised on 8th feb 2021 but from the end of 2020.


Eduardo and Gary form of the Institut d'Astrophysique de Paris have been looking at the globular Cluster Cladwell 86 or NGC 6397, a great target for astrophotography, perhaps not the most spectacular of Globular clusters, but still, incredibly interesting.

The crazy things about this Globular cluster

  • Contains about 400,000 stars!

  • located about 7,800 light-years from Earth, one of the two nearest globular clusters to Earth (the other one being Messier 4)

  • Can be seen with the naked eye

  • One of about 20 Globular Clusters that have undergone Core Collapse, the core has contracted to a very dense stellar agglomeration. Over time, dynamic processes cause individual stars to migrate from the centre of the cluster to the outside. This results in a net loss of kinetic energy from the core region, leading the remaining stars grouped in the core region to occupy a more compact volume

  • The shocking age of this cluster is about 13.4 billion years old.


Using Hubble’s large data set of images of the Cluster, measuring the Proper motion of these stars at the core. Using the Gaia Space Telescope to add more accuracy to this and last but not least the Muse Spectrograph, multi-unit spectroscopic explorer (MUSE) is an integral field spectrograph installed at the Very Large Telescope (VLT) of the European Southern Observatory (ESO), to measure line of sight velocities.


What Gary and Eduardo were trying to do was detect an intermediate black hole at the centre of the cluster. Which is pretty much what everyone expected. There is strong evidence for a central dark component of 0.8 to 2% of the total mass of the cluster, so an IMBH of 1000 to 2000 x mass of the sun.

However, they have found robust evidence that in this core, roughly 2% of the diameter of the cluster is a swarm of compact stars (white dwarfs and neutron stars) and stellar-mass black holes. The mass didn’t appear to be point-like, but more diffuse. The bulk of the unseen concentration is made of stellar-mass black holes

"Our analysis would not have been possible without having both the Hubble data to constrain the inner regions of the cluster and the Gaia data to constrain the orbital shapes of the outer stars, which in turn indirectly constrain the velocities of foreground and background stars in the inner regions," Mamon


Their mergers in the cores of core-collapsed globular clusters could be an important source of the gravitational wave events detected by LIGO

The future of GC and IMBH science is very exciting, thanks to Gaia now supplementing HST PMs at large projected radii. The discovery of a diffuse central mass, composed in large part of stellar-mass black holes, enrichens the physics of the inner regions of GCs, and renders the search of IMBHs in Milky Way GCs even more delicate. Continued pointings of GCs with HST and soon James Webb Space Telescope will lead to longer baselines and more accurate PMs. The third data release of the Gaia mission will double the PM precision, thus enabling more accurate mass-orbit modelling, not only of nearby GCs such as NGC 6397 but also of more distant ones, in conjunction with HST data.



Europa Clipper gets a launch date! October 2024!!!


  • On 25 January 2021, NASA's Planetary Missions Program Office formally directed the mission team to "immediately cease efforts to maintain SLS compatibility" and move forward with a commercial launch vehicle.

Cool features named after Celtic mythology!

  • Pwyll crater - Pwyll, in Celtic mythology king of Dyfed, a beautiful land containing a magic cauldron of plenty

  • Pwyll, featured in this image, is thought to be one of the youngest features on Europa's surface. The diameter of the central dark spot is approximately 25 miles (about 40 kilometres), and bright white rays extend for hundreds of miles in all directions from the impact site. The rays cross over many different terrain types, indicating that they are younger than anything they cross. Their bright white colour may indicate that they are composed of fresh, fine water-ice particles, as opposed to the blue and brown tints of older materials elsewhere in the image.

  • In Celtic mythology, Argadnel one of the Islands of the Earthly Paradise that were visited by Bran the Blessed

  • Symmetric ridges in the dark bands of Argadnel Regio suggest that the surface crust was separated and filled with darker material. While some craters are visible, the absence of more craters indicates this area is geologically young. The youngest ridges in the area have central fractures, aligned knobs and irregular dark patches. These and other features might indicate cryovolcanism or processes related to the eruption of ice and gases.


Some Other Facts

  • The SLS option would have entailed a direct trajectory to Jupiter taking less than three years..

  • The alternative to the direct trajectory was identified as using a commercial rocket such as a Falcon Heavy, with a longer 6-year cruise time involving gravity assist manoeuvres at Venus, Earth and/or Mars.

  • Another option is to launch on a Falcon Heavy nut with a Star 48B solid rocket (812 m/s) or a Castor 30B solid rocket (3030 m/s) as a kick stage. This would require only one gravity assist, with Earth, and would shorten the cruise phase significantly

Mission

  • Orbits Jupiter to do series of Europa Flybys

  • designated a Large Strategic Science Mission (like hubble),It is also supported by the new Ocean Worlds Exploration Program

  • Follow up-to Gallileo

  • Due to the adverse effects of radiation from Jupiter's magnetosphere in Europa orbit, it was decided that it would be safer to inject a spacecraft into an elliptical orbit around Jupiter and make 44 close flybys of the moon

  • The mission will complement ESA's Jupiter Icy Moons Explorer launching in 2022, which will fly-by Europa twice and Callisto multiple times before moving into orbit around Ganymede.

  • Three objectivess

  1. Ice shell and ocean: Confirm the existence, and characterize the nature, of water within or beneath the ice, and processes of surface-ice-ocean exchange

  2. Composition: Distribution and chemistry of key compounds and the links to ocean composition

  3. Geology: Characteristics and formation of surface features, including sites of recent or current activity.

  • May have a bunch of deployable Nanosats, orbiters, impactors etc

  • A lander is probably abandoned as being too expensive


NASA Reports on Nuclear Propulsion

We reported a while back that the UK government were partnering with Rolls-Royce to look at nuclear propulsion in space. So just like the Europa clipper mission to get anywhere you need massive rockets like SLS. However, it's still very very slow getting to places like Mars and that's bad news for humans. So we need to look at other things other than chemical propulsion and a new report from NASA basically says that they really need to start looking at nuclear thermal and nuclear electric propulsion for human missions to Mars

  • nuclear thermal propulsion (NTP) system designed to produce a specific impulse of at least 900 s and (2)

  • a nuclear electric propulsion (NEP) system with at least 1 megawatt of electric (MWe) power >2000s

We cover the conjunction class and opposition class. missions in previous episodes Podcast 193. Conjunction-class have the lower delta V but the longest mission up to 900 days.



In the paper it shows that to do the mission you need 1000-4000 tons of propellant for chemical propulsion to do the mission. SLS carries about 100 ...isn’t this just dead in the water then for Mars?


NTP look more viable than NEP,

Problems for NTP

  • scale up the operating power of each NEP subsystem and to develop an integrated NEP system suitable for the baseline mission

  • scaling power and thermal management systems to power levels orders of magnitude higher than have been achieved to date

  • no integrated system testing has ever been performed on MWe-class NEP systems

  • operational reliability over a period of years

  • parallel development of a compatible large-scale chemical propulsion system to provide the primary thrust when departing Earth orbit and when entering and departing

Problems for NEP

  • System that can heat its propellant to approximately 2700 K at the reactor exit for the duration of each burn

  • long-term storage of liquid hydrogen in space with minimal loss

  • lack of adequate ground-based test facilities

  • rapidly bring an NTP system to full operating temperature (preferably in 1 min or less).

  • Ground tests have been done, but this was over 50 years ago, and nothing in space of course

Also what type of Nuclear fuel needs to be reviewed.


NEP and NTP systems show great potential to facilitate the human exploration of Mars.

Using either system to execute the baseline mission by 2039, however, will require an aggressive research and development program. Such a program would need to begin with NASA making a significant set of architecture and investments decisions in the coming year. In particular, NASA should develop consistent figures of merit and technical expertise to allow for an objective comparison of the ability of NEP and NTP systems to meet requirements for a 2039 launch of the baseline mission.



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