Possible Observations of the Upcoming Artemis 1 Mission to the Moon

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petemn2004
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Joined: Tue Aug 31, 2004 5:01 pm
Real Name: Mark Petersen
Location: Maple Grove, MN

Possible Observations of the Upcoming Artemis 1 Mission to the Moon

Post by petemn2004 »

The upcoming launch of Artemis 1 to the moon may provide opportunities to photograph and / or visually observe the Orion spacecraft and service module when it ventures to and from the moon.

Visual observations and photographs were done during the transits to and from the moon during the Apollo missions. These were reported by Sky and Telescope magazine in their March 1969 (Page 156), July 1969 (Page 62), November 1969 (Page 358), February 1970 (Page 127) and April 1971 (Page 251) issues. The reported brightness in some of the reports were from 10th to 14th magnitude.

Artemis 1’s first target launch opportunity is August 29th between 7:33 AM to 9:33 AM CDT. Given it takes about 4 days to get to the moon, and if launched on August 29th, the moon will be about 7 days old (near first quarter) when the spacecraft arrives in the vicinity of the moon. The moon will be in the constellation Libra and low in the southwest at 9 PM. The spacecraft will be going from west to east against the stars during the journey to the moon.

On the outbound trip to the moon the upper stage, which would have sent the spacecraft out of earth orbit and onto the moon, could also be a target of opportunity. The Orion spacecraft will arrive a few hours ahead of the upper stage when it reaches the moon and be east of the upper stage during the trip to the moon. During the Apollo missions several discharges of liquid oxygen and hydrogen were observed after being vented from the spent SIV-B third stage which created bright clouds visible for 10’s of minutes. Some of these were as bright as 1st magnitude, several degrees in width as viewed from earth, and were photographed with 35 mm cameras. These ventings occurred about 3 to 6 hours after launch. See attached photo of a fuel dump by the third stage of Apollo 8.

The upper stage will deploy 10 CubeSats after separation from Orion. The upper stage is 16 feet long and painted white.
The upper stage will follow Orion to the backside of the moon’s surface and without a burn will be flung out of the earth / moon system into heliocentric orbit. It may be that the upper stage could be tumbling later in its flight to the moon if the attitude control of the upper stage is no longer functioning.

The Orion spacecraft crew capsule is conical shaped and covered with silica tiles with a silver coated film applied over the tiles. The service module is painted white and has four solar panels for electrical power generation. The pointing of the solar panels towards the sun will tend to keep the conical capsule pointed towards the sun. The solar panels are moveable and will be pointed backwards towards the engine end of the service module during main engine firings. In addition, the solar panel can be canted to better point to the sun. There may some spacecraft attitudes where specular reflections are visible off the crew capsule.

There are nominally 4 outbound correction burns to the moon during which may brighten the appearance of the spacecraft.

The service module will perform a burn on the back side of the moon to put Orion initially into a large elongated lunar orbit. When the spacecraft reaches its highest point in the elongated orbit a burn by the service module will place the Orion into a distant retrograde orbit lunar orbit. This burn will take place well east of moon as viewed from earth and be much longer than the correction burns. The distant retrograde orbit lunar orbit has an average distance to the moon of about 38,000 miles.

The spacecraft will make one and one-half laps of the moon over the course of about two weeks.

To get out of the distant retrograde orbit a departure burn will take place well west of the moon to start the spacecraft on its journey back to the earth.

The observations of the Apollo spacecraft were made by both professionals in fields related to astronomy and by amateurs. The professionals were supplied with predicted positions supplied by telephone from Boeing tailored to a particular location, usually a professional or public observatory. Updates were made to amateurs by short wave radio. See attached plot of the predicted path of Apollo 8 to the moon. Today such predictions, if done for the Artemis 1 mission, would be available on the internet at such sites like Heavens-Above.com.

The Apollo 8 spacecraft’s apparent motion against the sky was quoted to be 3 or 4 degrees per hour early in its flight to the moon.

During the Apollo missions photographic recordings were made with film along with vidicon tubes for display on television screens. Today’s modern astronomical cameras available to the public should be quite suitable to photograph and create videos of the Orion spacecraft.

It might be possible to photograph the spacecraft while in its distant retrograde orbit when it is far from the moon. The was no known sightings or recordings of the Apollo spacecraft while in moon orbit because it only about 60 miles from the moon. I do not know how faint it will be, but it will be moving slowly against the stars.

After the August 29th launch opportunity there a scheduled launch attempts on September 2nd (starting at 11:48 AM CDT) and September 5th. (starting at 4:12 PM CDT). Each launch window is open for up to 2 hours.

if launched September 2ndh, the moon will be about 10 days old (waxing gibbous) when the spacecraft arrives in the vicinity of the moon. The moon will be in the eastern part of Sagittarius and almost due south low in the sky at 9 PM.

if launched September 5th, the moon will be nearly full when the spacecraft arrives in the vicinity of the moon. The moon will be in Aquarius and in the southeast part of the sky at 9 PM.

I believe it may be difficult to observe the spacecraft if launched on August 29 because it will be low in the southwest after sunset and if launched on September 5th the approaching full moon may challenge locating a dim spacecraft. The launch if it occurred on September 2nd may offer better chances to observe the spacecraft. Visual observations attempts of the spacecraft will likely be more successful when the spacecraft is within a days distance from the earth.

Mark Petersen
Attachments
Apollo 8 Predicted Path to the Moon
Apollo 8 Predicted Path to the Moon
Apollo 8 Predicted Path.jpg (138.03 KiB) Viewed 5372 times
Apollo 8 Third Stage Fuel Dump Cloud
Apollo 8 Third Stage Fuel Dump Cloud
Apollo 8 Third Stage Venting Cloud.jpg (55.4 KiB) Viewed 5372 times
petemn2004
Posts: 235
Joined: Tue Aug 31, 2004 5:01 pm
Real Name: Mark Petersen
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Re: Possible Observations of the Upcoming Artemis 1 Mission to the Moon

Post by petemn2004 »

Attached should be the flight profile of Artemis 1 with descriptions of actions during the mission.

The updated flight plan profile has 13 CubeSats being deployed from the upper stage, including a few after its closest approach to the moon. This implies the upper stage maintaining the ability to control its attitude until that time.

Missing on the profile is the description of the burn needed (counter point to #12) to get out of the distance retrograde orbit, where the purple path begins, to send it back near the far side of the moon that starts the journey back to the earth.

Mark
Attachments
Artemis 1 Flight Profile
Artemis 1 Flight Profile
artemis-1-update.jpg (102.26 KiB) Viewed 5342 times
petemn2004
Posts: 235
Joined: Tue Aug 31, 2004 5:01 pm
Real Name: Mark Petersen
Location: Maple Grove, MN

Re: Possible Observations of the Upcoming Artemis 1 Mission to the Moon

Post by petemn2004 »

I posted a slimmed down version of what I posted here on Cloudy Nights' Science! Astronomy & Space Exploration, and Other forum.

I got these responses:

============================================================
Posted Yesterday, 07:08 PM

Thanks for the information!

At some point (I'm surprised it hasn't happened already), the mission will be assigned a NAIF/DSN spacecraft ID and ephemerides will be made available via JPL's Horizons ephemeris system. For anyone not familiar, you can use that to get a table of predictions for where exactly to look as a function of time, from your specific observer location. That's generally the source behind "where to look" charts that you'll see in various publications when the time comes. Prior to launch, this system gives you predicted ephemerides assuming nominal launch trajectory. After launch, the system will automatically update as the actual trajectory is refined by radar and other navigation data.


I have a program that queries ephemerides for any cataloged body in the Horizons system and can drive a Celestron NextStar SE and CPC scopes or the iOptron AZMP to follow the object and can even track it optically. I used this to track JWST the day after it launched. Leading up to the ARTEMIS-1 launch, I'll put together a tutorial and a dedicated post here on CN about it. I might also add support for Meade scopes if I can get my hands on an LX200 before then.

Edited by rkinnett, Yesterday, 07:08 PM.

=====================================================

Posted Today, 05:35 AM

The Chinese Chang'e moon mission was observed by a few amateurs. Orion will be a lot bigger = brighter.

===============================================================

I have seen photos taken by amateurs of the James Webb Space Telescope heading out to its Lagrange Point 2 observation location.

JPL's Horizons ephemeris system. if it provides predictions for the position of Artemis 1. is what could be the ticket to enable observation of Artemis 1.

https://ssd.jpl.nasa.gov/horizons/app.html#/


Mark
petemn2004
Posts: 235
Joined: Tue Aug 31, 2004 5:01 pm
Real Name: Mark Petersen
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Re: Possible Observations of the Upcoming Artemis 1 Mission to the Moon

Post by petemn2004 »

A recent response from the thread I started on the Cloudy Nights' Science! Astronomy & Space Exploration, and Other forum:

==========================================================
"You might want to read the account of observations of various Apollo lunar missions using Earth-based telescopes here:

http://pages.astronomy.ua.edu/keel/space/apollo.html

=========================================================
The link takes you to a summary, "Telescopic Tracking of the Apollo Lunar Missions", that was written some time ago containing some of content of the Sky & Telescope articles I referenced and from multiple Apollo missions.

Mark
petemn2004
Posts: 235
Joined: Tue Aug 31, 2004 5:01 pm
Real Name: Mark Petersen
Location: Maple Grove, MN

Re: Possible Observations of the Upcoming Artemis 1 Mission to the Moon

Post by petemn2004 »

The following is a post from today on the Cloudy Nights' Science! Astronomy & Space Exploration, and Other forum:

==============================================
"Artemis-1 (Orion) is now in JPL’s Horizons ephemeris system (object ID -1023), so you can query precisely where to look from any point on Earth for any given time after launch (nominally 29 Aug 12:33 UTC). The system will automatically update once actual trajectory data is available post-launch and after each maneuver."
==============================================

You can now generate predictions on where Artemis 1 is projected to be given it launches at the opening of the launch window on Monday August 29.

https://ssd.jpl.nasa.gov/horizons/app.html#/


Mark
petemn2004
Posts: 235
Joined: Tue Aug 31, 2004 5:01 pm
Real Name: Mark Petersen
Location: Maple Grove, MN

Re: Possible Observations of the Upcoming Artemis 1 Mission to the Moon

Post by petemn2004 »

IF Artemis 1 launches at the beginning of the next launch window (this Saturday September 4th at 1:17 PM) there should be an excellent opportunity to search for the spacecraft on its way to the moon. It will be most opportune to search for it in the as close to the launch date if possible as it will be dimming on its way out to the moon.

Artemis 1 is now on the list of available objects to make position predictions on:
https://ssd.jpl.nasa.gov/horizons/app.html#/

Set the start time for the prediction period to the beginning of an hour (say 2:00:00 UT (Universal Time which is 9 PM CDT):

For the following position predictions, I put in a start time of 19:00:00 hours UT on September 3. I then edited the predictions down to Saturday September 3 from 9 PM CDT to Sunday 4 AM CDT

Date (CDT)
Right Ascension (HR:MIN)
Declination (DEG:MIN)

2022-Sep-03 9 PM
20 43
0 2

2022-Sep-03 10 PM
20 46
0 56

2022-Sep-03 11 PM
20 48
-1 46

2022-Sep-04 12 AM
20 49
-2 28

2022-Sep-04 1 AM
20 51
-3 4

2022-Sep-04 2 AM
20 52
-3 35

2022-Sep-04 3 AM
20 54
-4 3

2022-Sep-04 4 AM
20 56
-4 27


Note UT is 5 hours ahead of CDT.

The position in the sky is in the area of the boundary between Aquila and Aquarius near the celestial equator, which will be near the meridian at 11 PM.

It will move about 7 degrees in the sky to the southeast from 9 PM to 4 AM CDT.

Recommend getting a new prediction a few hours after it launches and then before you try to observe it in the subsequent days after it launches.


Mark
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