# The Orbital Index

Issue No. 92 | Nov 25, 2020

🚀 🌍 🛰
 ¶The end of the Arecibo Observatory. It looks like the world is losing Puerto Rico’s iconic and prolific 305-meter radio and radar observatory due to underfunded maintenance and a second cable break on Nov 7th. Critically, the second cable broke at ~60% of it’s rated minimum breaking strength (pdf), meaning that current structural models are wrong and assumptions about the underlying condition and strength of the remaining cables are strongly suspect. The cables were last inspected less than a year ago after a series of earthquakes occurred near the array, with no indications of issues at the time. Adding new cables to the 820 metric ton platform 150 m off the ground would require workers to be present on the platform, which could fall due to cascading cable failure at any time. This represents an unacceptable safety risk, and so the NSF has decided to decommission and demolish the radio installation. While no longer the largest radio telescope in the world (China’s FAST is 500 m wide), the Arecibo Observatory is by far the most powerful radar observatory, providing the highest sensitivity and transmitting power of any deep space radar. Among other things, this is important for precisely determining the orbits of potentially-dangerous near earth objects. Arecibo’s scientific contributions are too numerous to list, but a few include the radar determination of the rotational periods of Venus and Mercury, the first solid evidence of neutron stars, the first binary pulsar, the first millisecond pulsar, the first direct radar image of an asteroid, and the discovery of the first exoplanets. In 2006, the NSF cut Arecibo’s budget drastically, then again in 2017, from $12 million to$2 million (or 2.5% of a single F-35A fighter jet). As Scott Manley says in his analysis 📺, unfortunately the time to fix Arecibo was 10 years ago. 😭
 ¶The week in Rocketry 🚀A Long March 5 successfully launched Chang’e 5 on Monday 📺 to kick off the 3-4 week lunar sample return mission which will yield the first lunar samples (~2 kg of them) since the last Apollo and Luna missions of the 70s. (Also China: a few days earlier, a Long March 3B vehicle delivered a telecom satellite to orbit, the 34th Chinese launch this year.)SpaceX launched its first rocket from the US West coast in well over a year. The Falcon 9 delivered NASA & ESA’s Sentinel-6 sea level monitoring satellite into a high-inclination orbit after taking off from Vandenberg AFB. The flight also featured a visually impressive ‘return to launch site’ (RTLS) 📺 landing for the booster.After two scrubs, SpaceX also successfully launched, landed, and deployed Starlink-14’s stack of 60 more LEO internet satellites on a booster flying for a record seventh time 📺. The Starlink beta continues to return many positive reviews, and, during a recent Reddit AMA, team members mentioned plans to expand the current invite-only beta to the public early next year.Starship SN8 completed its last 3-engine static fire before a 15 km flight, currently scheduled for sometime next week. Musk suggests a ⅓ chance of success for the flight.The Avum upper stage of a Vega vehicle failed to reach orbit, causing the loss of Spain’s first optical imaging satellite and a French satellite intended to study lightning—the failure was due to misconnected cables, causing the engine nozzle to turn in the opposite direction as commanded.After delivering 30 small satellites (and a gnome) to orbit, Rocket Lab used shielding and two parachutes to bring its first booster back from 8.5 times the speed of sound to a 10 m/s soft splashdown and recovered it from the ocean. Recovery hardware on the appropriately named ‘Return to Sender’ mission (their 16th) used around 15 kg of the 200kg of Electron’s payload capacity. Mid-air recovery with a helicopter is the eventual goal in Rocket Lab’s booster reuse program. This type of maneuver has been used before, perhaps most prominently during the US military’s CORONA program, to catch returning spy satellite film canisters.
 The first-stage of the ‘Return to Sender’ Electron booster floating in the Pacific.
 ¶News in brief. A 5-10 meter-wide meteor missed the Earth by only 400 km (2020 VT4), the altitude of the ISS—had it hit, it’d have been a once-a-decade-level light show, but probably not damaging; OneWeb emerged from bankruptcy and has a new CEO; Ukraine became the 9th nation to join the Artemis Accords; Raytheon is acquiring Blue Canyon Technologies; and, Virgin Galactic has delayed the upcoming SpaceShipTwo test flight due to surging COVID-19 cases.
 ¶Etc.Another (this is the 5th) Earth-size rogue planet has been detected wandering alone in the Milky Way. It is suspected that billions of such planets exist.A NASA challenge to design a system architecture to excavate and process icy lunar regolith, with \$500,000 in prizes, and a NASA call for proposals for how to “visually bring the public along for the ride in new ways, starting as early as a trip around the Moon with astronauts on the Artemis II mission, targeted for 2023.” In Russia's secretive space town, the woman who fell from the sky.NASA’s ousted human exploration director Doug Loverro called Boeing to make sure they wouldn’t hold up the Artemis contracting process by challenging it in court due to their lack of an award. Instead, Boeing tried to revise their bid, raising red flags that led to Loverro’s eventual resignation.Emily Atkin covers President-elect Biden’s appointment of John Kerry as ‘climate czar’ in HEATED. Kerry signed the Paris Agreement and will likely do so again. Critics see Kerry as an uninspired, business-as-usual choice, while proponents see the creation and filling of the position with a past Secretary of State as an indication of coalescing focus on a response to the climate emergency by the incoming administration. Prospects for life on Venus fade — but aren’t dead yet. NASA's Workmanship Standards compiled into a single PDF. Timeline of the far future. In case you haven't yet felt small and impermanent today.
 Every cometary nuclei imaged by spacecraft and radar, to scale. Linked from Jatan’s “why explore asteroids, comets, and other small worlds.”