Category Archives: Space Exploration

Manned Circumnavigation of the Inner Solar System

Posted on April 27, 2026 by Kirk Sorensen

In 1969, a Bellcomm engineer named A. A. VanderVeen published a paper describing a family of trajectories so elegant they seem almost accidental. Fifty-five years later, the most attractive instance of that trajectory family departs Earth in August 2034. This … Continue reading →

Posted in Bigelow Aerospace, Commercial Space, Mars, Orbital Dynamics, Space Exploration, Space Tethers, Variable Gravity | 7 Comments

2006, a lunar architecture

Posted on April 13, 2026 by Kirk Sorensen

The astrodynamic case for Earth-Moon L2 rendezvous was made in 1972 and again in 2006. The math hasn’t changed. Neither has the conclusion. Back in January 2006, I opened a thread on the NASASpaceFlight forum with a bit of a … Continue reading →

Posted in ESAS, Lunar Exploration and Development, Space Development, Space Exploration | 3 Comments

An Updated Propellant Depot Taxonomy Part VI: Roving Depots

Posted on February 22, 2021 by Jonathan Goff

In the last post in this series, I discussed the idea of large-scale depots for human spaceflight applications, which operate in fixed, low-orbits. While the final post in this series will investigate human spaceflight depots that operate in fixed higher … Continue reading →

Posted in Commercial Space, ISRU, Launch Vehicles, Lunar Exploration and Development, Mars, NASA, NEOs, Orbital Dynamics, Propellant Depots, Space Development, Space Exploration, Space Transportation, ULA, Venus | 10 Comments

An Updated Propellant Depot Taxonomy Part V: Human Spaceflight Fixed Depots (Low-Orbit)

Posted on February 16, 2021 by Jonathan Goff

For this next depot taxonomy post, we’ll finally be talking about what people usually think about when they hear the term orbital propellant depot — larger, cryogenic refueling facilities, focused on enabling large-scale human spaceflight missions, performed by a diverse … Continue reading →

Posted in Blue Origin, Commercial Space, Launch Vehicles, Lunar Commerce, Lunar Exploration and Development, Mars, NEOs, Orbital Dynamics, Propellant Depots, RLV Markets, Space Development, Space Exploration, Space Transportation, SpaceX, ULA, Venus | Tagged , , , , , , , | 13 Comments

An Updated Propellant Depot Taxonomy Part IV: Smallsat Launcher Refueling Depots

Posted on November 14, 2020 by Jonathan Goff

After a brief hiatus, I’d like to continue this series with the type of depot I’ve spent the most time thinking about over the last several years, and the first type of depot that really fits the mold of what … Continue reading →

Posted in Launch Vehicles, Lunar Exploration and Development, Orbital Dynamics, Propellant Depots, Space Exploration, Space Transportation, SpaceX, ULA, Venus | Tagged , , , , , , | 6 Comments

An Updated Propellant Depot Taxonomy

Posted on September 15, 2020 by Jonathan Goff

After way too many years in the wilderness, the concept of orbital propellant depots and in-space refueling in general, are finally beginning to be taken seriously again in public circles. A couple of examples include: Elon’s announcement that he is … Continue reading →

Posted in Commercial Space, ISRU, Lunar Commerce, Lunar Exploration and Development, Mars, NASA, Orbital Dynamics, Propellant Depots, Space Development, Space Exploration, Space Transportation, Venus | Leave a comment

On Avoiding Some of the Mistakes of Apollo

Posted on July 21, 2019 by Jonathan Goff

Today is the 50th anniversary of the Apollo 11 moon landing. With a blog named Selenian Boondocks, I figured it probably made sense for me to say something. Earlier this year, thanks to some good advice from several friends, I … Continue reading →

Posted in Commercial Space, COTS, Lunar Commerce, Lunar Exploration and Development, Propellant Depots, Space Development, Space Exploration, Space Policy, Space Settlement | 21 Comments

Random Thoughts: First Pass Analysis of a White Dragon/Xeus Lunar Sortie Mission

Posted on February 28, 2017 by Jonathan Goff

After yesterday’s SpaceX announcement of having booked two customers for a Apollo-8 style mission around the Moon and back, using Falcon Heavy and Dragon V2, I got thinking about ways to take the next step in lunar tourism–surface missions. Now, … Continue reading →

Posted in Commercial Crew, Launch Vehicles, Lunar Exploration and Development, Propellant Depots, Random Thoughts, Space Exploration, Space Transportation, SpaceX, ULA, YHABFT | 51 Comments

SpaceX Mars Plans: Jon’s First Take

Posted on September 28, 2016 by Jonathan Goff

I’ve had a lot of friends ping me today about my thoughts on Elon’s Mars talk today. I was in a meeting when it happened, and literally was pinged by half a dozen people during the meeting… Now that I’ve … Continue reading →

Posted in Commercial Space, ISRU, Launch Vehicles, Lunar Commerce, Mars, NASA, Propellant Depots, Space Development, Space Exploration, Space Settlement, Space Transportation, SpaceX, ULA, Venus | 60 Comments

The Slings and Arrows of Outrageous Lunar Transportation Schemes: Part 0–An Elevator Pitch for the Moon

Posted on May 31, 2016 by Jonathan Goff

[Note: After getting a few posts into this series on the “how” of alternative lunar transportation concepts, I realized that some commenters were asking about why we should even be going to the Moon, or what we’d be doing there. … Continue reading →

Posted in ISRU, Lunar Commerce, Lunar Exploration and Development, Slings and Arrows of Outrageous Lunar Transportation Schemes, Space Development, Space Exploration, Space Settlement | 15 Comments