05/25/2023 – Ephemeris – NASA awards contracts for a second lunar lander

This is Ephemeris for Thursday, May 25th. Today the Sun will be up for 15 hours and 9 minutes, setting at 9:14, and it will rise tomorrow at 6:04. The Moon, 2 days before first quarter, will set at 2:26 tomorrow morning.

A week ago, NASA announced that the contract for the second Artemis moon lander would go to a group of companies headed by Blue Origin for 3.4 billion dollars. Unlike Apollo, the rocket that sens crews to the Moon will not contain a moon landing craft. It will be sent out separately before the crew. SpaceX’s Lunar Starship will be used on the first two landings, for Artemis III and IV, while the Blue Origin lander will be used for Artemis V, sometime around 2029 or later. Little detail has been released about the lander, except for an artist’s rendering. It appears to be shorter than the Boeing lander first proposed, which would require an astronaut to climb up and down a very long ladder. SpaceX’s Starship would be taller still, but will have an elevator on the side.

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

NASA picks Bezos’ Blue Origin to build second lunar lander. The crew compartment is on the bottom, allowing for a shorter ladder to the surface. The liquid oxygen (LOX) and hydrogen (LH) tanks are on top. The LH tank is on top with sun shields, with the LOX tank below. I’m guessing here, since very little information has been released. Credit: NASA.

The craft is officially known as the Human Landing System (HLS).

11/29/2022 – Ephemeris – Observing the Moon tonight

This is Ephemeris for Tuesday, November 29th. Today the Sun will be up for 9 hours and 6 minutes, setting at 5:04, and it will rise tomorrow at 7:58. The Moon, 1 day before first quarter, will set at 11:28 this evening.

The illuminated part of tonight’s Moon will be a fat crescent shape, 12 hours, give or take from first quarter. Besides the lunar seas visible there are some large craters on its terminator, or sunrise line On the upper right are two distinctive craters near each other. The larger is Aristoteles named after the Greek philosopher Aristotle which is 53 miles wide. The smaller is Eudoxus, named after an older Greek philosopher, 41 miles in diameter. Both of these should be visible in small telescopes or even binoculars. They stand out because there are only a few small craters around them in pretty much flat terrain. Meanwhile Artemis 1’s Orion capsule is continuing to make a large lazy loop around the Moon before heading back to the Earth in 12 days.

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

Annotated Moon animation as it might appear tonight at 8 pm, November 29, 2022. Created using Stellarium and GIMP.

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

11/28/2022 – Ephemeris – The Artemis Program

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, as it moves around to the far side of the Moon. Click on the image to enlarge it. Credit: NASA

11/10/2022 – Ephemeris – Artemis I launch scheduled for next week

This is Ephemeris for Thursday, November 10th. Today the Sun will be up for 9 hours and 46 minutes, setting at 5:19, and it will rise tomorrow at 7:34. The Moon, 2 days past full, will rise at 6:32 this evening.

As I’m writing and recording this last Sunday, the Artemis I launch to send the Orion spacecraft, without crew, around the Moon is scheduled for Monday the 14th. However, there is a developing tropical storm (Now named Hurricane Nicole) that is expected to strengthen and hit Florida about now actually, or maybe tomorrow or Saturday. (It’s today!) NASA has two weeks to launch this lunar month, the 14th through the 27th, with three embedded dates in there that they cannot launch because Orion’s solar panels will be in Earth’s shadow too long during the journey. It will really mess up the schedule if NASA has to roll the spacecraft back to the Vertical Assembly Building again, as they did for Hurricane Ian. (They did not roll it back.) Here’s hoping all goes well.

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.

(Comments in parentheses were added last night as is the addendum, and were not part of the broadcast)

Addendum

According to the National Hurricane Center, the eye of Hurricane Nicole will pass south of Cape Canaveral by a fair distance and shouldn’t receive hurricane force winds, but should receive 2-4 inches of rain. It will delay the launch until at least the 16th.

Block 1 Space Launch System with Orion Capsule. Credit NASA.

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.

10/13/2022 – Ephemeris – CAPSTONE satellite stabilized again

This is Ephemeris for Thursday, October 13th. Today the Sun will be up for 11 hours and 5 minutes, setting at 7:01, and it will rise tomorrow at 7:57. The Moon, half way from full to last quarter, will rise at 8:59 this evening.

The CubeSat named CAPSTONE, was launched June 28th to prove out the near rectilinear halo orbit of the Moon that the Lunar Gateway Space Station and Orion Capsule will be located in on missions to the south pole of the Moon. CubeSats are built on a 10 by 10 centimeter or 4 by 4 inch cube. They are relatively inexpensive. CAPSTONE is a 12 unit CubeSat arranged 4 by 3 cubes with a solar panel/antenna attached to one side. Back on September 8th it made a course correction which caused it to tumble. It took almost a month, until last Friday to regain control of the satellite and stop the tumbling. Apparently a stuck propellant valve was the problem. CAPSTONE should enter this halo orbit of the Moon on November 13th.

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

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

CAPSTONE low-energy trajectory to the Moon. TCM are trajectory Correction Maneuvers (Thruster firings). Click on the image to enlarge it. Credit: Advanced Space, builder of the CAPSTONE CubeSat.

NASA CAPSTONE pathfinder for gateway orbit to prove out the near rectilinear halo orbit for the Lunar Gateway.

10/06/2022 – Ephemeris – Artemis I rescheduled

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. 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.

09/26/2022 – Ephemeris – The DART spacecraft will attempt to deflect an asteroid tonight, Artemis I launch postponed

This is Ephemeris for Monday, September 26th. Today the Sun will be up for 11 hours and 57 minutes, setting at 7:32, and it will rise tomorrow at 7:35. The Moon, 1 day past new, will set at 8:07 this evening.

Tonight at 7:14 pm EDT (23:14 UTC), NASA’s DART spacecraft will collide with the tiny asteroid Dimorphos, which is orbiting the somewhat larger asteroid Didymos. They are potentially hazardous asteroids. The idea is to see what effect the collision has on the orbit of Dimorphos as it orbits Didymos at four tenths of a mile an hour. Trailing DART is an Italian CubeSat LiciaCube (pronounced LEE-cha-cube), which was launched from DART more 15 days ago to witness the collision. DART is an acronym for Double Asteroid Redirection Test, part of the Planetary Defense Program. Earth based radio and optical telescopes will assess if and how much the collision alters the orbit of Dimorphos. LICIAcube will return images of the collision, crater and the other side of Dimorphos. NASA will air it live on their channels.

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

Unlike the Artemis I launch, this event cannot be postponed. It will either hit Dimorphos at 7:14 pm or miss forever.

Graphic on NASA’s DART mission to crash a small spacecraft into a mini-asteroid to change its trajectory as a test for any potentially dangerous asteroids in the future. Click on the image to enlarge it. Credit: AFP / AFP (Agence France-Presse)

A Note from EarthSky.org:

If you want to watch the event live, coverage begins at 6 p.m. EDT (22 UTC) on September 26, 2022, on NASA’s website. You can also watch it via Facebook, Twitter and YouTube.

Artemis I news

The Artemis I launch, scheduled for Tuesday, September 27, has been postponed due to the threat from tropical storm Ian.

09/06/2022 – Ephemeris – Ongoing NASA Missions

This is Ephemeris for Tuesday, September 6th. Today the Sun will be up for 12 hours and 59 minutes, setting at 8:10, and it will rise tomorrow at 7:12. The Moon, 3 days past first quarter, will set at 3:11 tomorrow morning.

The Artemis I launch has been postponed until later this month. The next try will come no sooner than the 25th, or next month. Another launch that is delayed is the Psyche mission to the asteroid Psyche that was supposed to be launched last month on a Falcon Heavy rocket. The problem this time isn’t the rocket, but the satellite. There is a delay with delivery and testing of the software for the satellite. The launch this year would have used a Mars flyby for a gravitational assist to shorten the flight time. A launch next year would not have that advantage and would increase the flight time. On the 26th of this month the DART satellite will impact the tiny asteroid Dimorphos, that’s orbiting a larger asteroid Didymos, to test that method of planetary defense.

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 availability dates for September and October 2022. As I understand it, launches on red dates would cause the Orion capsule to be in the Earth’s shadow for longer than 90 minutes. Gray dates would have the Orion Capsule land at night. Credit NASA. A cut & paste from Artemis I Mission Availability 2022-2023 (EST/EDT) pdf.

An artist’s rendition of the Psyche spacecraft at the metal-rich asteroid Psyche. Credit: NASA.

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.

08/30/2022 – Ephemeris – The Space Launch System (SLS) will evolve over time

This is Ephemeris for Tuesday, August 30th. Today the Sun will be up for 13 hours and 20 minutes, setting at 8:22, and it will rise tomorrow at 7:04. The Moon, 3 days past new, will set at 10:02 this evening.

The Space Launch System or SLS rocket that’s used for Artemis I is not the final configuration of the rocket to be flown. For Artemis I and II, which will take astronauts around the Moon and back, the SLS is in its Block 1 configuration with an Interim Cryogenic Propulsion Stage, or ICPS as the upper stage. After the Moon landing by Artemis III, the upper stage will be replaced by the Exploration Upper Stage with nearly four times the thrust of the other. That’s Block 1B. After Artemis VIII, or the eighth launch of the SLS, NASA will have run out of solid booster segments left over from the Shuttle program and will have them replaced with more powerful boosters, making it Block 2. With Block 1 the ICPS needs the core stage to get into a highly elliptical orbit, to send the Orion capsule to the Moon. The ICPS cannot do it by itself.

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

Diagram comparing SLS variants. The chart also shows the cargo variant, one of which was supposed to launch the Europa Clipper mission to Jupiter’s icy moon Europa. That launch has since been reassigned to a SpaceX Falcon Heavy rocket, due to SLS delays. The Falcon Heavy is not as powerful as the SLS, so the Europa Clipper spacecraft will take longer to reach Jupiter’s vicinity (6 vs. 3 years), but will save $2 billion in launch costs. Click on the image to enlarge it. Credit: NASA.

08/29/2022 – Ephemeris – On the day of the first Artemis I launch opportunity, a look at possible landing sites for Artemis III

As usual, the Ephemeris radio programs are recorded prior to them being aired. Monday’s programs have the longest lead times, being written and recorded eight days earlier, Sunday of the previous week. This blog post was created on the 28th. So I have no idea if Artemis I launches today or not. All three times this program will be sent out on-air will be before the scheduled launch.

This is Bob Moler with Ephemeris for Monday, August 29th. Today the Sun will be up for 13 hours and 23 minutes, setting at 8:24, and it will rise tomorrow at 7:02. The Moon, 2 days past new, will set at 9:43 this evening.

Earlier this month, NASA announced the selection of 13 possible landing areas near the South Pole of the Moon. The South Pole of the Moon was selected as the Artemis target since ice was found at the bottom of some of the craters there. Back in the Apollo days, landing sites were selected by being smooth, and the first were in the broad lava plains called lunar seas. The Moon’s South Pole is the opposite. It’s in the rugged lunar highlands. The landing areas turn out to be crater rims and ridges or small plateaus that catch the Sun, just above the lunar horizon. NASA is developing autonomous landing systems that can cope with landing on such difficult terrain, with deep shadows illuminated by a very low Sun. These are not ideal landing conditions.

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

On August 19, 2022, NASA released the candidate lunar landing sites for Artemis III near the Moon’s South Pole. Click on the image to enlarge it. Credit: NASA, Lunar Reconnaissance Orbiter.