The DownlinkJul 30, 2021

We Love to Buggy

Space Snapshot

Apollo 15 rover

This week marked the 50th anniversary of NASA’s Apollo 15 mission to the Moon, which launched on July 26, 1971 and landed on July 30. This photo shows mission commander David Scott driving the Lunar Roving Vehicle, the first of three “Moon buggies” deployed on Apollo missions. These vehicles allowed Apollo astronauts to extend the range of their exploration and sample collection. It’s probably fair to say that driving them was a whole lot of fun, too. Image credit: NASA.

You love space, now take action

This weekly newsletter is your toolkit to learn more about space, share information with your friends and family, and take direct action to support exploration. Anyone can subscribe at to receive it as a weekly email.

Fact Worth Sharing

Moon illustration

The Apollo 15 crew brought more than 77 kilograms (170 pounds) of lunar rock and soil samples back to Earth, including the Genesis Rock. At around 4.1 billion years old, it is one of the oldest rocks ever studied by scientists.

Mission Briefings


Europa Clipper finally has a launch vehicle. NASA has selected SpaceX to provide launch services for the Europa Clipper, which is now slated to launch in October 2024 on a Falcon Heavy rocket. The Planetary Society previously urged Congress to drop a directive that required Europa Clipper to launch on the Space Launch System, and instead allow NASA to select the best rocket for the job. Europa Clipper will produce high-resolution images of Jupiter’s icy moon Europa and explore its geographical features. It’ll also investigate whether the world has the right conditions for life.


Hubble might have solved an age-old mystery about Ganymede. Astronomers revisiting archive Hubble data have found evidence of water vapor in the Jovian moon’s atmosphere. The discovery is just in time for the European Space Agency's upcoming JUICE mission, which launches in 2022 to study Ganymede and other Jovian moons.


Blue Origin says it’s willing to cover $2 billion of the cost for a second lunar lander contract, should NASA award one. In a letter to NASA Administrator Bill Nelson, Blue Origin founder Jeff Bezos said his company is willing to waive up to $2 billion in payments over the current and next two government fiscal years in exchange for a fixed-priced contract. In April, NASA selected SpaceX as the recipient of its Human Landing System (HLS) contract, a decision that competitors Blue Origin and Dynetics protested shortly after.


Russia's new Nauka science module is attached to the International Space Station after some last-minute drama. The module overcame communications and propulsion problems following launch on July 21 before successfully docking with the station on July 29. The trouble didn't end there: once attached, Nauka began firing its thrusters uncontrollably, knocking the entire station out of alignment by 45 degrees. As of Thursday afternoon NASA reported the situation was under control.

From The Planetary Society

Apollo artemis logo
Planetary Society logo bullet

Apollo made giant leaps, and Artemis aims to follow suit. In Greek mythology, Apollo and Artemis were the twin children of the god Zeus. Much like siblings, the Apollo and Artemis programs to send humans to the Moon have similarities as well as stark differences. Apollo historian and author Andrew Chaikin joins this week’s Planetary Radio to talk about the legacy of humanity’s first visits to the Moon, what we can expect from NASA’s plans to return, and much more. Pictured: NASA’s mission logos for Apollo (left) and Artemis (right). Image credit: NASA.

Planetary Society logo bullet

Do Enceladus’ plumes show possible signs of life? Recent studies of Cassini mission data show that Saturn’s icy moon ejects plumes containing higher levels of hydrogen, carbon dioxide and methane than previously thought, piquing curiosity about what’s happening inside the moon’s subsurface ocean. We’ve published a new article explaining the findings.

Planetary Society logo bullet

July 31 marks the two-year anniversary of LightSail 2’s mission success. Just a week after launching, the solar sailing spacecraft succeeded at raising the high point of its orbit around the Earth using only sunlight for propulsion. This successful demonstration of solar sailing paved the way for future missions like NASA’s Solar Cruiser and NEA Scout, and no doubt many more to come.

Planetary Society logo bullet

An asteroid strike is a preventable disaster, much like a pandemic. In an op-ed for Scientific American, Planetary Society chief advocate Casey Dreier makes the argument that to defend against both kinds of disaster, we have to make investments well in advance. For those of you living in the United States, you can help make sure planetary defense gets the investment it needs by signing this petition today.

What's Up

Venus illustration

Look for super-bright Venus low in the western sky shortly after sunset. Later, bright Jupiter and yellowish Saturn (higher and to the right) rise in the east, crossing the sky to set in the west before dawn. The Perseid meteor shower is underway right now and will continue throughout August, peaking around August 11 through 13. Learn more at

Wow of the Week

Nasa rover challenge

It may have been almost 49 years since the last time an astronaut drove on another world, but that doesn’t mean buggies have gone out of style. For the last 25 years, NASA has sponsored an annual competition for high school and college students from around the world to design, build, and race human-powered extraterrestrial buggies. Two-person teams negotiate a course that simulates the terrain found on rocky bodies in the solar system while performing mission tasks including sample retrievals and spectrographic analysis. The challenge was originally called “The Great Moonbuggy Race,” but in 2014 NASA opted for the less snazzy but more comprehensive “Human Exploration Rover Challenge” to reflect the fact that buggies are no longer just for the Moon. Pictured: A team from Bolivia tests their rover in this year’s competition. Image credit: Universidad Católica Boliviana La Paz.