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09/14/2021 – Ephemeris – Lack of spacesuits just one of Artemis problems of getting humans back to the Moon

September 14, 2021 Comments off

This is Ephemeris for Tuesday, September 14th. Today the Sun will be up for 12 hours and 33 minutes, setting at 7:54, and it will rise tomorrow at 7:21. The Moon, 1 day past first quarter, will set at 12:53 tomorrow morning.

The bright gibbous Moon is a feast for binoculars or a telescope. However, the speed-up plan to land crews on the Moon in 2024 proposed by the former President is not appearing to pan out. One major item is space suits, which must be more rugged and impervious to the Lunar regolith, or soil, whose grains are tiny, angular and sharp, and get into everything, and can destroy spacesuit joints. NASA has been working on them for 14 years, and by itself could cost a billion dollars. They might be ready by 2025. Besides delays to the SLS rocket, the contract with SpaceX to furnish a lunar lander is now tied up in litigation by one of the contract losers. NASA’s trying to land humans on the Moon on one half of one percent of the Federal budget, plus do everything else it does.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hr). They may be different for your location.

Addendum

Prototype lunar spacesuit

Prototype lunar spacesuit. xEMU stands for Exploration Extravehicular Activity Mobility Unit. Of course. This uncredited image is from slashgear.com in 2019, so I wouldn’t believe the date. These xEMU suits may eventually cost a billion dollars to develop and produce. Click on the image to enlarge it.

03/29/2021 – Ephemeris – NASA will fly spacecraft Psyche to asteroid 16 Psyche

March 29, 2021 1 comment

This is Ephemeris for Monday, March 29th. Today the Sun will be up for 12 hours and 38 minutes, setting at 8:07, and it will rise tomorrow at 7:26. The Moon, 1 day past full, will rise at 9:28 this evening.

In the summer of 2022, about 15 months from now, NASA will launch a spacecraft called Psyche on a SpaceX Falcon Heavy rocket to 16 Psyche, an asteroid. 16 Psyche is a very special asteroid. It is mostly made of iron and nickel like iron meteorites and the cores of planets like the Earth. The spacecraft will be launched to get a gravity assist from Mars and will be using an ion engine to make its way to 16 Psyche and orbit it at various altitudes to see if it really is the remnant core of a protoplanet that was destroyed by collisions with other large asteroids. It would be of great interest for the future of asteroid mining companies for the precious metals it might contain. It’s big and has an average diameter of 140 miles (225 kilometers).

<p value="<amp-fit-text layout="fixed-height" min-font-size="6" max-font-size="72" height="80">The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

An artist's concept of the Psyche spacecraft orbiting the asteroid 16 Psyche
An artist’s concept of the Psyche spacecraft orbiting the asteroid 16 Psyche. The spacecraft will be sent past Mars for a gravity assist, and also use ion thrusters to speed it on its three and a half journey to the asteroid. Credit: NASA/JPL-Caltech/Arizona State Univ./Space Systems Loral/Peter Rubin

02/25/2021 – Ephemeris – Moon Dust, bad stuff

February 25, 2021 Comments off

This is Ephemeris for Thursday, February 25th. Today the Sun will be up for 10 hours and 58 minutes, setting at 6:25, and it will rise tomorrow at 7:24. The Moon, 2 days before full, will set at 7:30 tomorrow morning.

One of the big problems that will have to be solved before the Artemis program sets up a permanent base on the Moon is what to do about lunar soil or Moon dust. That stuff gets into everything. The Apollo astronauts said it smelled like gunpowder. Unlike beach sand the particles aren’t rounded, but angular, being produced by rocks being hit by meteoroids large and micro over the eons by space weathering. With no atmosphere small particles can even weld themselves together. Though no studies have been done, any brought into the habitat would do damage to the lungs, like that to miners on Earth. Moon dust has compromised the seals on the containers of soil the Apollo crews brought back from the Moon.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Lunar soil

Lunar soil sample. Credit Larry Taylor U of TN Knoxville from https://ntrs.nasa.gov/api/citations/20090026015/downloads/20090026015.pdf

02/18/2021 – Ephemeris – The Perseverance Rover will land on Mars this afternoon

February 18, 2021 Comments off

This is Ephemeris for Thursday, February 18th. Today the Sun will be up for 10 hours and 37 minutes, setting at 6:15, and it will rise tomorrow at 7:36. The Moon, 1 day before first quarter, will set at 1:30 tomorrow morning.

Later this afternoon the Perseverance Rover will land in Jezero crater on Mars. NASA will have a live Internet feed from the Jet Propulsion Laboratory starting at 2:15 pm EST (19:15 UTC). Atmospheric entry will be at 3:48 pm EST (20:48 UTC), landing at 3:55 pm EST (20:55 UTC). This is Earth received time. The events actually happened 11 minutes 22 seconds earlier on Mars. Though cameras on the spacecraft will be recording the landing activity it will not be sent to Earth in real time due to the weak signal during entry. The spacecraft will be sending tones only for specific events during what is called EDL, Entry, Descent and Landing or “Seven Minutes of Terror”. If all goes well the first images will be taken and sent of its surroundings. And in the next weeks we’ll get an actual replay sent back of the landing with color and sound. It will be so cool!

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Links

NASA on YouTube: https://www.youtube.com/results?search_query=nasa

NASA TV: https://www.nasa.gov/multimedia/nasatv/#public

Entry, Descent and Landing

Graphic of the Entry, Descent and Landing of the Perseverance Rover. Click on the image to enlarge. Credit: NASA/JPL.

Perseverance drilling for sample

Perseverance drilling for a sample in Jezero crater. Artist drawing – NASA/JPL

02/16/2021 – Ephemeris – Perseverance lands on Mars in two days

February 16, 2021 Comments off

This is Ephemeris for Fat Tuesday, Tuesday, February 16th. Today the Sun will be up for 10 hours and 32 minutes, setting at 6:13, and it will rise tomorrow at 7:39. The Moon, 3 days before first quarter, will set at 11:24 this evening.

In two days, Thursday afternoon, the Perseverance Rover will land on the planet Mars in a crater call Jezero. It’s mission to actually look for evidence of past life, fill specimen tubes to be cached for later pickup and returned to earth by a future mission, presumably by the end of the decade. It is also bringing a helicopter drone named Ingenuity to check out the feasibility of using future aircraft in Mars rarefied atmosphere. The vehicle, including the back shell and descent stage sports 23 cameras. Even Ingenuity has 2 cameras. That shouldn’t be a big deal today. Heck, my smartphone has 5 cameras, each with lots more megapixels than the digital camera I bought 15 years ago. Only two days to go to landing.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Entry, Descent and Landing

Graphic of the Entry, Descent and Landing (EDL) of the Perseverance Rover. Click on the image to enlarge. Credit: NASA/JPL.

Link to the Mars 2020 Perseverance Landing Press Kit

01/21/2021 -Ephemeris – The Perseverance rover is less than a month from landing on Mars

January 21, 2021 Comments off

This is Ephemeris for Thursday, January 21st. Today the Sun will be up for 9 hours and 24 minutes, setting at 5:36, and it will rise tomorrow at 8:11. The Moon, 1 day past first quarter, will set at 2:40 tomorrow morning.

The Mars Perseverance Rover is approaching the Red Planet. In a bit less than a month, on February 18th it will plunge into the martian atmosphere to land near an ancient river delta in the 28 mile (45 kilometer) wide crater Jezero. The dramatic entry-descent-and-landing or EDL is what the Jet Propulsion Laboratory, that built and manages the rover, calls Seven Minutes of Terror due to the complexity of the landing process and the fact that they will be bystanders at that point. By the time they receive confirmation that the encapsulated rover has hit the top of the martian atmosphere it would have already landed, or crashed on the martian surface. It will take over 11 minutes for signals to reach us from Mars that day.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Ancient delta flowing into

Delta of ancient river that flowed into a lake in the Jezero crater. This is a false color imaging highlighting mineral types. Credit NASA.

Mars Endurance Rover's planned landing ellipse

Mars Perseverance Rover’s planned landing ellipse partially overlapping the dried up river delta. Credit: NASA/JPL.

Mars 2020 Rover "Endurance"

Mars 2020 Rover “Perseverance” destined for the martian crater Jezero.

01/19/2021 – Ephemeris – The Moon is a pretty straight up orb

January 19, 2021 Comments off

This is Ephemeris for Tuesday, January 19th. Today the Sun will be up for 9 hours and 20 minutes, setting at 5:33, and it will rise tomorrow at 8:13. The Moon, 1 day before first quarter, will set at 12:36 tomorrow morning.

The Earth has an axial tilt to its orbit of the Sun of 23 ½ degrees. So the Earth has seasons, the cycle of which last one orbit of the Sun, or one year. Our Moon on the other hand has a 5 ½ degree axial tilt to its orbit of the Earth, but more importantly for future moon colonists, has only a degree and a half tilt compared to the Earth’s own orbit of the Sun. So there are spots at the north and south poles that never get the Sun’s heat or light. The Moon’s south polar region is more rugged with more and smaller craters than the north, so has collected, over the eons, what seems to be a great amount of water ice that is cold enough to be stable in the vacuum of space. That makes it an ideal place to build a sustainable lunar base.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Map of water at the Moon's poles

The Moon’s south pole area on the left and north pole on the right. The cyan color shows shadowed areas where ice is located. Credit NASA

10/26/2020 – Ephemeris – Why does everyone want to go to the Moon’s south pole?

October 26, 2020 Comments off

This is Bob Moler with Ephemeris for Monday, October 26th. Today the Sun will be up for 10 hours and 26 minutes, setting at 6:39, and it will rise tomorrow at 8:14. The Moon, 3 days past first quarter, will set at 4:01 tomorrow morning.

Why are the United States and other countries interested in the south pole of the Moon? Two reasons: Water and power. The Moon’s axial tilt to the Earth’s orbit is only a degree and a half. And I’ve seen a mountain peak at the south pole of the Moon sticking out in sunlight in a telescope on a crescent moon, with black all around it. While most of the Moon gets two weeks of daylight and another two of night, that peak is probably always in sunlight. And on the Moon there’s no atmosphere to diminish the strength of the Sun when its low in the sky. And there’s the floors of craters that have never seen the Sun where water ice and other volatile compounds from comets have collected over the eons.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

South pole ice

The south pole of the Moon where the presence of water ice is detected by the absorption of neutrons by the hydrogen atoms in the ice. Credit NASA/GSFC/SVS/Roscosmos.

 

10/23/2020 – Ephemeris – What is a Near Rectilinear Halo Orbit?

October 23, 2020 Comments off

This is Ephemeris for Friday, October 23rd. Today the Sun will be up for 10 hours and 34 minutes, setting at 6:44, and it will rise tomorrow at 8:10. The Moon, at first quarter today, will set at 12:46 tomorrow morning.

When the astronauts of the Artemis program head for a landing on the Moon is as little as four years from now they will meet their lunar landing craft or Lunar Gateway space station with landing craft docked to it before they descend to the Moon. The orbit of the gateway and/or lander is an odd one. It’s called a near rectilinear halo orbit. And uses the motion and gravitational interaction of the Moon and Earth to create an orbit of the Moon which is nearly face-on to the Earth. The vehicles will never pass behind the Moon. The orbit will pass 1,900 miles (3,000 km) above the Moon’s north pole and out to 43,000 miles (70,000 km) above the south pole. It’s called a halo orbit, because as seen from the Earth it appears to trace a halo around the Moon.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

NASA CAPSTONE pathfinder for gateway orbit

NASA CAPSTONE* pathfinder for gateway orbit is to be launched next year by Rocket Lab to prove out the near rectilinear orbit for the Lunar Gateway. The orbit will always be more or less face on to the Earth, so it and the lunar lander will be always be in contact with the Earth. Credit Advanced Space via Spaceflight Now.

* Yes, CAPSTONE is an acronym: Cislunarˆ Autonomous Positioning System Technology Operations and Navigation Experiment. Aren’t you glad you asked?

ˆ Cislunar: The volume of space between the Earth and Moon’s orbit.

Lunar Gateway NASA

An artist’s rendition of the Lunar Gateway with the Orion spacecraft docked to it. Credit NASA.

For more information

https://spaceflightnow.com/2019/09/26/nasa-to-fly-cubesat-pathfinder-for-gateway-in-unique-lunar-orbit/

https://www.space.com/nasa-capstone-cubesat-moon-gateway.html

 

07/30/2020 – Ephemeris – This morning is the first opportunity to launch the Perseverance Rover to Mars

July 30, 2020 Comments off

This is Ephemeris for Thursday, July 30th. Today the Sun will be up for 14 hours and 42 minutes, setting at 9:10, and it will rise tomorrow at 6:28. The Moon, 3 days past first quarter, will set at 3:11 tomorrow morning.

This morning is the scheduled launch of the Mars 2020 Rover named Perseverance. The launch will have or had launched at 7:50 am. Or the whole thing was scrubbed for today. I can’t tell, I recorded this last Sunday night. To hit a spot on Mars less than six miles in diameter after a six and a half month coasting flight is quite a fete. Mars is not only moving in orbit of the Sun, but also rotating. The aeroshell the rover is packed in must hit the Mars atmosphere in the right place, and the right time despite the light time from Mars of 11 minutes, 22 seconds. It will take 6 minutes, 50 seconds for the rover to land after it hits the top of Mars’ atmosphere. So it will have landed one way or another before we get the signal that it hit the atmosphere.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Atlas V with Mars 2020 Rover aboard on launch pad

Atlas V with Mars 2020 Rover aboard on launch pad. Click on the image to enlarge. Credit: United Launch Alliance (ULA).