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11/28/2022 – Ephemeris – The Artemis Program

November 28, 2022 Leave a comment

This is Ephemeris for Monday, November 28th. Today the Sun will be up for 9 hours and 8 minutes, setting at 5:04, and it will rise tomorrow at 7:57. The Moon, 2 days before first quarter, will set at 10:09 this evening.

Now that the Artemis I mission is ongoing, and the spacecraft is in a large orbit of the Moon, it’s time to look at the rest of the program. In 2024 the SLS or Space Launch System, which is the name for the whole rocket, will send a four-person crew in their Orion Capsule around the Moon and back. From what I’m seeing right now, it will be a simple mission. It doesn’t appear that they will actually orbit the Moon other than a free return trajectory back to the Earth. The mission a year or so after that will be one to attempt to land on one of the few flat sites near the south pole of the Moon. Speaking of the Moon, the planet Saturn will be about eight of the Moon’s diameter’s north or above the Moon tonight.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

Earthset from Artemis I's Orion spacecraft

Earthset from Artemis I’s Orion spacecraft, as it moves around to the far side of the Moon. Click on the image to enlarge it. Credit: NASA

10/06/2022 – Ephemeris – Artemis I rescheduled

October 6, 2022 Comments off

This is Ephemeris for Thursday, October 6th. Today the Sun will be up for 11 hours and 27 minutes, setting at 7:14, and it will rise tomorrow at 7:48. The Moon, 3 days before full, will set at 4:52 tomorrow morning.

Artemis 1 was going to launch on September 27th, But Hurricane Ian had other plans, so the rocket was trundled back to the Vertical Assembly Building. There, a battery or components of the auto destruct mechanism had to be swapped out before they attempted to launch again. All rockets launched from the US are required to be equipped with a destruct package to blow up the rocket if it veers off course, to not endanger lives on the ground. There are other tweaks, including charging or replacing batteries in all the CubeSats that are on board. The next possible launch period runs from November 12th to the 27th, with four blackout dates within that period. The weather should be better, being the tail end of hurricane season.

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

Addendum

Artemis I November launch calendar

Artemis I November launch calendar. Dates in green are possible launch dates. I’m not sure, but red dates are also forbidden because the Orion Capsule will experience more than 90 minutes in shadow at a time. It’s powered by solar panels. Light green dates allow a long mission of 1 1/2 orbits of the Moon in the distant retrograde orbit (DRO). The dark green dates can only have 1/2 a DRO. Source: NASA.

06/10/2022 – Ephemeris – The first Artemis mission: CAPSTONE

June 10, 2022 Comments off

This is Bob Moler with Ephemeris for Friday, June 10th. Today the Sun will be up for 15 hours and 30 minutes, setting at 9:27, and it will rise tomorrow at 5:56. The Moon, 3 days past first quarter, will set at 3:52 tomorrow morning.

Launching, perhaps, as soon a Monday is the CAPSTONE Mission, which is part of the Artemis program to send the next man and first woman to the Moon. The Capstone mission is to check out the special near rectilinear halo orbit the Lunar Gateway space station, and the Human Landing Craft will be in when the Orion spacecraft arrives before landing. CAPSTONE is, of course, an acronym that explains its purpose, to achieve and navigate itself into this near rectilinear halo orbit. CAPSTONE is basically a CubeSat made of 12 4 by 4 inch (12 100 mm by 100 mm) cubes. It will be launched by Rocket Lab from New Zealand on their Electron rocket with their Proton upper stage. It will take 3 months to reach the Moon.

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

Addendum

CAPSTONE spacecraft

Artist’s impression of the CAPSTONE spacecraft at perilune, the closest point in its orbit, over the north pole of the Moon.

CAPSTONE's near rectilinear halo orbit of the Moon

CAPSTONE’s near rectilinear halo orbit of the Moon, which precesses to keep face on to the Earth during the lunar orbit of the Earth.

12/30/2021 – Ephemeris – Looking forward to some space events in 2022

December 30, 2021 Comments off

This is Ephemeris for Thursday, December 30th. Today the Sun will be up for 8 hours and 51 minutes, setting at 5:11, and it will rise tomorrow at 8:20. The Moon, 2 days before new, will rise at 6 tomorrow morning.

If you thought 2021 was an active one in space, 2022 looks to be as exciting. The James Webb Space Telescope will continue to deploy itself as it journeys to reach it’s L2 halo orbit. It should become operational by mid-year. The launch of the uncrewed Artemis-1 mission to, and around the Moon, has been pushed back a month to no earlier than March 12th, because of having to swap out a control computer for one of its main engines. The launch of the Psyche probe to the mostly metallic asteroid of the same name will occur in August by a SpaceX Falcon Heavy rocket on a four-year journey to orbit this unique asteroid. And NASA’s DART spacecraft is scheduled to crash into the tiny Dimorphos asteroid to test a deflection method in late September.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). They may be different for your location.

Addendum

James Webb Space Telescope trajectory to L2

James Webb Space Telescope trajectory to L2 with some milestones of deployment. “ISIM” stands for Integrated Scientific Instruments Module. Credit: Space Telescope Science Institute (STScI).

Artemis-1 orbital plan

Artemis-1 orbital plan. Click on the image to enlarge it. Credit NASA.

Psyche spacecraft at the asteroid Psyche

Psyche spacecraft at the asteroid Psyche. Credit: NASA.

DART Mission

Schematic of the DART mission shows the impact on the moonlet of asteroid (65803) Didymos. Post-impact observations from Earth-based optical telescopes and planetary radar would, in turn, measure the change in the moonlet’s orbit about the parent body.
Credits: NASA/Johns Hopkins Applied Physics Lab

10/15/2021 – Ephemeris – NASA mission to Trojan Asteroids

October 15, 2021 Comments off

This is Bob Moler with Ephemeris for Friday, October 15th. Today the Sun will be up for 10 hours and 59 minutes, setting at 6:57, and it will rise tomorrow at 7:59. The Moon, 3 days past first quarter, will set at 3:25 tomorrow morning.

Tomorrow opens up a window to launch a satellite named Lucy to the Trojan asteroids of Jupiter. Lucy is named for a fossil of a human ancestor discovered in Africa. After launch, Lucy will make two gravitational assist passes of the Earth to get up enough velocity to reach Jupiter’s orbit and pass near Five asteroids in the leading L4 cloud of Trojans. Its orbit will take it back to the Earth, where another gravitational assist will send it to a double asteroid in the trailing Trojan group. On its way out it will pass close to a tiny main belt asteroid DonaldJohanson, named after the discoverer of the Lucy fossil. The mission will last 12 years. After that, Lucy will orbit between the Earth’s orbit and each of the Trojan swarms in turn.

Lucy is scheduled to launch on an Atlas V on Saturday, 16 October 2021 at 09:34 UT (5:34 a.m. EDT) from Cape Canaveral. If the launch can’t take place then, they have something like 22 more days in which they can get it launched.

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

Addendum

Animation showing Jupiter and zTYrojan asteroids during one Jovian year

Animated GIF showing Jupiter and Trojan Asteroids during one Jovian year, which repeats. Credit: Astronomical Institute of CAS/Petr Scheirich.

Lucy misssion in Jupiter's rotating frame

The Lucy spacecraft orbits as seen in the rotating frame of Jupiter’s orbit. Lucy’s orbits are actually ellipses. (I wish they would take the stars out, they should appear as circular trails centered on the Sun from Jupiter’s rotating frame.) Click on the image to enlarge it. Credit: Southwest Research Institute.

 

10/04/2021 – Ephemeris – Why we can’t talk to the Perseverance rover on Mars right now

October 4, 2021 Comments off

This is Ephemeris for Monday, October 4th. Today the Sun will be up for 11 hours and 32 minutes, setting at 7:17, and it will rise tomorrow at 7:46. The Moon, 2 days before new, will rise at 6:30 tomorrow morning.

NASA is no longer sending commands to its Perseverance rover or any of its assets roving or orbiting Mars now. The reason isn’t particularly sinister. It’s the approximately 26 month Mars solar conjunction. The Sun is a noisy radio source, and commands sent to or data received from these martian assets could be garbled. This affects everyone’s assets on or orbiting Mars, which includes the Europeans, India, China and the United Arab Emirates. For NASA, communication restrictions started two days ago and will last until the 14th. This will give the folks at JPL who are operating the Curiosity and Perseverance rovers some time off, and time to plan the next few months of activity.

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

Addendum

Mars in solar conjunction.

Mars in solar conjunction. Looking at the inner solar system.  Mars, near the bottom of the image, is 244.6 million miles (393.9 million kilometers) from Earth. Click on the image to enlarge it. Credit NASA’s Eyes app.

Mars beyond and to the upper left of the Sun yesterday

Mars beyond and to the upper left of the Sun yesterday. It’s tough to get intelligible radio signals through the solar corona. Credit: NASA/ESA SOHO* spacecraft. The annotation is mine.

* SOlar and Heliospheric Observatory, spacecraft in halo orbit around the Lagrangian L1 equilibrium point about  930,000 miles (1,500,000 kilometers) sunward of the Earth. This keeps the satellite roughly between the Sun and the Earth, instead of moving ahead of the Earth because it’s closer to the Sun.

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