SLIM leaves Earth orbit and is on its way to the Moon
The Japanese lunar lander SLIM fired its engines on September 30, 2023 to begin its journey to the Moon. The map to the right indicates the planned route after this trans-lunar injection burn, first flying past the Moon to put it on a trajectory that will bring it back to the Moon at the proper speed and direction for its landing several months hence.
The main goal of this mission is engineering, to test the ability of an autonomous unmanned spacecraft to land precisely within a small target zone about 300 feet across. If proven, this ability will make it possible to send unmanned landers to many places that are presently impossible due to their rough topography.
The route that SLIM is taking to the Moon is also unusual, and is probably also an engineering test of its own. Flybys of planets to change a spacecraft’s path is not a new technique, but in the past it has been used to slingshot the probe to another object, not send it back to that planet.
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The Japanese lunar lander SLIM fired its engines on September 30, 2023 to begin its journey to the Moon. The map to the right indicates the planned route after this trans-lunar injection burn, first flying past the Moon to put it on a trajectory that will bring it back to the Moon at the proper speed and direction for its landing several months hence.
The main goal of this mission is engineering, to test the ability of an autonomous unmanned spacecraft to land precisely within a small target zone about 300 feet across. If proven, this ability will make it possible to send unmanned landers to many places that are presently impossible due to their rough topography.
The route that SLIM is taking to the Moon is also unusual, and is probably also an engineering test of its own. Flybys of planets to change a spacecraft’s path is not a new technique, but in the past it has been used to slingshot the probe to another object, not send it back to that planet.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
Robert wrote: “The route that SLIM is taking to the Moon is also unusual, and is probably also an engineering test of its own. Flybys of planets to change a spacecraft’s path is not a new technique, but in the past it has been used to slingshot the probe to another object, not send it back to that planet.”
Scott Manley explains the use of these strange or unexpected routes to the Moon.
https://www.youtube.com/watch?v=WVrWcbyOmxY (14 minutes)
It seems that with computing power at the level we have these days, we don’t necessarily have to solve the three body problem (or, in this case, a four body problem: Earth, Moon, Sun, and spacecraft*) to find new and unusual — but useful — orbits. Manley does not have an example of using the Moon in the way Robert described: slingshot the probe with the Moon to send it back to the Moon. This may be a first.
Notice that these strange orbits take weeks and months to reach the Moon, rather than the three days that Apollo missions took. The advantage is that less propellant is required; the disadvantage is that more time is required.
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* The two-body problem is easily solved. It is a simple inverse-square law solution that results in elliptical orbits. The Lagrange Points are a specific solution to the three-body problem, and as Manley shows, it is not a simple solution, but has some locations and concepts that are fairly easily understood.
I wonder if ISS could be sent out of Earth’s orbit gradually…a Starship giving a constant but gentle push.
If you want a “gentle but constant push” you don’t need chemical rockets such as those used on the starship. You need some high-ISP, low thrust system like an ion drive. The ISS can provide plenty of energy to power it.
On the other hand, ISS was designed for low earth orbit. Period. Adapting it for someplace else would cost so much you might as well build a new station. The radiation environment is different. The thermal environment is different. The ISS’s resupply needs are also a problem. The first long term habitat for humans in deep space will have to be purpose built, since moving the ISS carries too much additional risk. Its hard enough to do new things in newly built hardware By the time human occupied deep space stations are proven, the ISS will likely be at least a decade older and still in its present location. Or it will be taken apart and used on other LEO stations.