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.

09/16/2021 – Ephemeris – How safe is the Space Launch System (SLS) compared to the Space Shuttle?

This is Ephemeris for Thursday, September 16th. Today the Sun will be up for 12 hours and 27 minutes, setting at 7:51, and it will rise tomorrow at 7:24. The Moon, 3 days past first quarter, will set at 3:10 tomorrow morning.

Tonight, the planet Saturn will appear above the bright gibbous Moon. It might be a bit hard to spot.

The big NASA moon rocket, the Space Launch System or SLS, borrowed a lot of features from the Space Shuttle. Is it any safer? The answer is yes. The Space Shuttle had no abort system for a catastrophic failure, as we saw with the Challenger accident in 1986. However, even though the SLS uses the same type solid rocket boosters that failed Challenger, the Crew in the Orion capsule is on top of the rocket with an escape system to rocket them away from an exploding core stage. With the Orion capsule, the escape tower will be jettisoned at some point before reaching orbit, possibly making escape impossible in the latter stage of powered flight. Both SpaceX’s Dragon and Boeing’s Starliner have escape rockets built in for the entire flight.

Addendum

Shuttle-SLS comparisons. Note that this image is 10 years old. The center core stage will, like the external tank on the shuttle, remain unpainted. So far, the cargo version of the is still in the design stage. The Multipurpose Crew Vehicle is now called the Orion Spacecraft. Credit: How Stuff Works.

03/25/2021 – Ephemeris – NASA successfully tests the core stage of the Artemis Moon Rocket

This is Ephemeris for Thursday, March 25th. Today the Sun will be up for 12 hours and 25 minutes, setting at 8:02, and it will rise tomorrow at 7:34. The Moon, 3 days before full, will set at 6:57 tomorrow morning.

Last week’s 8-minute static fire test of the four Shuttle main engines of the core stage of the NASA’s Space Launch System or SLS rocket was an apparent success at the Stennis Space Center in southern Mississippi. This came after a failed test two months ago. The core stage will be refurbished and floated through the Gulf, around the tip of Florida to Cape Canaveral where the solid boosters are waiting to be mated to it in the Vertical Assembly Building. It will be used for the Artemis 1 mission to be launched late this year. That mission will take an uncrewed  Orion Crew Capsule and European Service Module to the Moon for several orbits close and more distant from it before returning to the Earth. The entire mission could take nearly a month.

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

Addendum

Views of the SLS Core Stage green run test. Credit NASA via scitechdaily.com.

02/22/2021 – Ephemeris – What’s happening with NASA’s Artemis Moon Program

This is Ephemeris for Monday, February 22nd. Today the Sun will be up for 10 hours and 49 minutes, setting at 6:21, and it will rise tomorrow at 7:30. The Moon, 3 days past first quarter, will set at 5:28 tomorrow morning.

It appears that the Artemis Moon Program is still on schedule despite a new administration and a setback when a few weeks ago an all up 8 minute firing of the 4 main engines of the Space Launch System Core Stage aborted after little over a minute. (NASA is scheduled to repeat this Green Run test this week) The first launch of the complete rocket is slated for later this year with an uncrewed lunar orbit mission. Recently NASA announced that Elon Musk’s SpaceX was awarded the contract to launch the first two lunar gateway modules on a single Falcon Heavy rocket. The two modules, Power and Propulsion Element (PPE) and Habitation and Logistics Outpost (HALO) will be placed in low earth orbit. From there the PPE would use its ion engines to propel the two modules out to a near rectilinear halo orbit of the Moon over many months.

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

Addendum

SLS first green run of all 4 RS-25 engines mounted on the core stage for the Artemis-1 mission on a test stand at Stennis Space Center in Mississippi. Credit: NASA.

An artist’s depiction of the Lunar Gateway PPE and HALO modules in lunar orbit. The PPE module is the part with the solar panels. Credit: NASA.

 

10/02/2020 – Ephemeris – The rocket that will take NASA crews to the Moon

This is Ephemeris for Friday, October 2nd. Today the Sun will be up for 11 hours and 37 minutes, setting at 7:20, and it will rise tomorrow at 7:43. The Moon, 1 day past full, will rise at 8:05 this evening.

While we’re looking at the nearly full Moon tonight lets look at the rocket that will take crews to the Moon or as NASA says first woman and next man to the Moon in the Artemis program. It’s called the Space Launch System or SLS, which has been in development for a very long time. The core stage looks the color of the Space Shuttle main tank, because it uses the same insulation. At its bottom are four shuttle main engines. These will not be reused. Strapped to the sides will be two shuttle derived solid rocket boosters or SRBs, with 5 segments, rather than 4, and are upgraded for extra thrust. These will also be discarded, rather than reused. The second stage now is an interim stage to be replaced after a few flights with a more powerful stage. To top it off will be the service module and Orion capsule with an escape tower.

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

Addendum

The Block 1b version of the Space Launch System (SLS) which uses elongated Space Shuttle boosters and a core stage with 4 Space Shuttle main engines for the first stage. At lift-off the core stage and the boosters will ignite. The boosters will burn for two minutes and 6 seconds 7,2000,000 pounds  (32,000 kN) of thrust. The core stage contributes 1,670,000 pounds  (7,440 kN) of thrust and will burn for 8 minutes, nearly achieving orbit. The Interim Cryogenic Propulsion Stage and later the Exploration Upper Stage will place the payload first into orbit, and then to send it to the Moon, or interplanetary destination. Credit NASA.

Note that the rocket configuration does not contain a lunar lander craft like the Saturn V of Apollo. The lander, a commercially developed craft will be sent up before the astronauts by a commercial company like SpaceX or Blue Origin and be waiting in lunar orbit or at the Lunar Gateway satellite.

12/05/2019 – Ephemeris – Artemis the new Moon program

Ephemeris for Thursday, December 5th. Today the Sun will be up for 8 hours and 58 minutes, setting at 5:02, and it will rise tomorrow at 8:05. The Moon, 1 day past first quarter, will set at 2:01 tomorrow morning. | NASA has a new program to return to the Moon, perhaps to stay. The program is called Artemis, named after the Greek god Apollo’s twin sister. NASA is building a massive rocket called the Space Launch System, or SLS, and the Orion

, which I’m sure will guarantee European astronauts a ride. This is not going to be an Apollo type one rocket up and back. There will be a space station called the Lunar Gateway of International partners that will orbit the Moon. There the crew of the Orion Spacecraft will transfer to a Lunar Lander for the trip to and from the surface of the Moon. It’s a heavy push to accomplish by 2024.

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

Addendum

The Block 1b vrsion of the Space Launch System (SLS) which uses elongated Space Shuttle boosters and a core stage with 4 Space Shuttle main engines for the first stage. Credit NASA.

Cone-shaped Orion Multi-Purpose Crew Vehicle with a European Service Module. Credit NASA.

Lunar Gateway supplied by the same partners that built the International Space Station. It will orbit the Moon, Credit NASA.

Lunar Lander. This vehicle has not been designed yet. This is Blue Origin’s Ascent Module on top of a yet to be designed propulsion module. Credit Blue Origin.