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Unmanned Spaceflight.com _ Lunar Exploration _ CAPSTONE

Posted by: Phil Stooke Jan 5 2024, 08:35 PM

Looks like we don't have a thread for CAPSTONE, the experimental spacecraft put into a near-rectilinear halo orbit to explore its dynamics for use in the future during the Artemis program.

It's not surprising that we wouldn't cover it given its purpose, but rather unexpectedly it turns out to have a little camera on it. Three images have been released so far:

https://advancedspace.com/capstone-primary-mission-success/

https://twitter.com/AdvancedSpace/status/1732139787211976909

They are low resolution images. I thought at first they might be star tracker images taken in Earthshine, but no, they were taken in sunlight. All are in the northern hemisphere where the very elongated orbit is closer to the surface. If imaging is possible at apolune it would show a global view centred on the south polar area.

Phil

Posted by: Phil Stooke Jan 5 2024, 10:09 PM

Here is a map of image coverage based on what has been released so far.

Phil

Posted by: John Whitehead Mar 11 2024, 03:02 AM

Here is an article from late 2022 when CAPSTONE entered lunar orbit.
https://spacenews.com/capstone-enters-lunar-orbit/

Not mentioned in that article, and worthy of a shout-out is Stellar Exploration, the small company that created the unique tiny hydrazine propulsion system.
https://www.stellar-exploration.com/

On the company website, the Datasheet link for their propulsion products leads to the following 2-page PDF.
https://static1.squarespace.com/static/5c54e307fd67934e24b27846/t/62e74d493ba1a46b5841fcb5/1659325786410/Datasheet+propulsion+2022+04+04.pdf

The Datasheet explains that they used low tank pressure for launch site safety, with a pump to feed the thrusters. That has got to be the smallest pump-fed rocket system ever used in space, and at the Moon, no less.

At the time when CAPSTONE reached the moon, I re-connected with Stellar Exploration founder Tomas Svitek to offer congratulations, and was delighted to hear that he was inspired by my talks at the Utah State Small Satellite Conference in the late 1990's, on the topic of different ways to use pumps to avoid high pressure tanks, for small satellites. Also in the late 1990's, cubesats were born at Stanford University, a few years after I had visited Professor Bob Twiggs classes as a guest lecturer for small propulsion.

It took decades because it was no small feat to make liquid propulsion small enough for cubesats.