¶Upgrading downmass. Today, total annual (non-human) downmass—the amount of useful stuff that can be returned from orbit—is limited to what can be carried by a single spacecraft, Dragon, returning from the ISS 3-5 times per year. In its cargo configuration, Dragon supports 3,000 kg of downmass for a maximum of 9-12 tons returned from the ISS annually. (Dragon carries much less when in crew configuration due to crew and life-support equipment, and Soyuz is unable to carry any meaningful additional mass past crew.) This has been the case since the end of the Shuttle era—the Shuttle’s lifting body design allowed it to return large, heavy objects that were up to 14.4 tons (here are all the satellites that Shuttle retrieved, redeployed, etc.). To support on-orbit, free-flying manufacturing of ZBLAN, microgravity-grown organics, alloys, or other high-value products, downmass is a critically constrained resource (ex. here’s a list of the space factories that will need downmass). Starship’s massive payload capacity (50-100 tons of downmass) is a potentially huge improvement in the coming years, but the in-space mobility required to transport raw materials away from, and products back to, a Starship vehicle from a production facility is a difficult problem on its own—Starship will almost certainly not provide white glove delivery and (more importantly) retrieval services to an orbital altitude and inclination of your choice, making orbital tugs or custom transport required. To this end, Sierra Space (née Sierra Nevada Corp) is working on Dream Chaser for small, Shuttle-like cargo missions with 1,750 kg of downmass capacity. Joining Sierra are a number of energetic NewSpace startups focused on providing a lower cost of entry and the ability to service more flexible mission profiles. SpaceForge is addressing this market with a UK-landing, reusable-factory-in-a-satellite reentry vehicle (SpaceForge also has their own space fabrication newsletter). For more broad downmass needs, SpaceWorks is developing their RED series of reentry vehicles capable of returning up to 100 kg (and their small RED-Data2 vehicle can be used as a pathfinder for testing re-entry dynamics with a small payload of <6kg). They are planning a 30 km drop and landing test in October. ESA is also developing cubesat-scale reentry capabilities with their currently in-orbit Qarman reentry vehicle (cf. Issue 72). Qarman features an engineered cork heat shield (so it’s made of bark!) and was originally estimated to re-enter sometime in the second half of this month (but may have failed in orbit 😕). Other organizations working on re-entry include the recently funded Varda, and of course NASA, which is working on an inflatable heat shield. |
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¶More notes from SmallSat and Space Symposium. The Small Satellite and Space Symposium conferences both happen in August. Last week, we shared some notes from Siegfried Janson’s talk at SmallSat. Here are some more tidbits from both conferences: - At SmallSat, Florence Tan from NASA mentioned that NASA’s SMD has been shifting from very small CubeSats to 6U+ CubeSats, ESPA-class spacecraft, and constellations. Roger Walker from ESA mentioned a similar trend of moving from 3U to 6U and then 12U CubeSats for operational science missions, facilitated by accurate COTS pointing and propulsion.
- They also both talked about the growing focus on spacecraft autonomy instead of human-in-the-loop conops. For example, ESA’s upcoming RACE mission will experiment with autonomous proximity operations and docking between two 6U CubeSats. This was a theme across the conference: onboard AI, autonomous decision making, and anomaly detection.
- We heard a bit more about that private Rocket Lab Venus mission. It’ll nominally launch in May 2023 on an upgraded Photon bus to study the Venusian atmosphere, looking for signs of habitability and life. Rocket Lab is building it with private funding and university collaborations.
- At Space Symposium, Japanese ispace announced a design for a larger version of their lunar lander, to fly in 2024 on the company’s 3rd Moon mission. Their first two missions will each carry 30 kg payloads to the surface, while this new lander will carry 500 kg, as well as deploy up to 2,000 kg of payloads to lunar orbit along the way.
- Also at Space Symposium, Aerospace Corp proposed a new form factor alternative to CubeSats: DiskSats. These disks could be 1 m in diameter and 2.5 cm thick, allowing enough surface area for 200 watts of solar panels. On a CubeSat, this would require deployables. “The point of DiskSat is that it complements cubesats for missions that consist primarily of electronics that need higher power.” A stack of 20 plates is also easier to launch on a small launch vehicle than 20 CubeSats. It feels like this borrows a lot from Starlink’s form factor, and potentially, its deployment mechanism.
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¶News in brief. The first images emerge of Blue Origin’s “Project Jarvis” test tank ● Coming full circle (since Planet acquired Terra Bella, formerly Skybox Imaging, from Google in 2017), Planet has partnered with Google Cloud to create joint cloud-based solutions ● OneWeb launched 34 more satellites on a Soyuz-2.1b, bringing their constellation to 288 satellites ● Shareholders approved Rocket Lab’s SPAC and Virgin Orbit confirmed their intention to undergo a $3.2 billion SPAC merger of their own—Virgin’s investment offering presentation includes future plans to increase Launcher One’s performance and to add reusability ● Russia’s Luna-25 lunar lander has been delayed from October until May 2022 for further testing ● Two astronauts on China’s Tiangong space station took an extended spacewalk to install equipment outside the space station and work on its robotic arm ● The Zhurong mission on Mars has been officially extended beyond its initial 90 sol mission—so far it has driven 1 km and sent back 10 gigabytes of data via Tianwen—it is now roving towards a geological ‘groove’ 1.6 km away ● Curiosity, meanwhile, has now been on Mars for 9 (Earth) years—NASA just released a 360-degree, 215 MB panorama on the rover’s long climb up Mount Sharp and a video pointing out the highlights ● JAXA tested their rotating and pulsed detonation engines for the first time in space ● SpaceX announced that it has shipped over 100,000 Starlink terminals, has received 600,000+ pre-orders worldwide, and is now operating in 12 countries ● Maxar’s WorldView-3 captured an image of Starbase on August 9th that shows two Super Heavy boosters, with Booster 3 on the left and Booster 4 on the right, sitting on the launch mount. |
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¶Etc. - BryceTech just released their very thorough Smallsats by the Numbers Report, which they define as satellites under 600kg. 1,282 spacecraft launched in 2020, of which 94% were smallsats, representing 43% of the total upmass—of these, 937 were Starlink or OneWeb. A whopping 40% of all smallsats launched in the last 10 years launched in 2020. See also this interesting Tableau report on the uses, locations, and life-spans of satellites.
- Video from inside the new Russian Nauka ISS module.
- Veritasium received a 20 min tour with CEO Tim Ellis of Relativity Space’s factory in which they 3D print engine parts and entire rocket bodies. The first launch of their first vehicle, the Terran 1, has been pushed back to early 2022.
- When we use the unit ‘ton’ in Orbital Index, we always mean a metric ton (1,000 kg) since we consistently use metric units throughout the newsletter. However, ‘ton’ is an exceptionally slippery unit, and can mean everything from a unit of refrigeration equal to melting one ‘short ton’ (907 kg / 2,000 lbs) of ice daily (3.5 kW) to a unit of explosive energy roughly equivalent to 1,000 kg of trinitrotoluene. 💥
- NASA’s "Tour of Asteroid Bennu" was selected for the SIGGRAPH Film Festival. Meanwhile, data from the craft now puts Bennu at a 1-in-2,700 chance of hitting the Earth on Sept. 24, 2182. Presumably, we can improve our orbital projections and/or gravity tractors over the next 161 years.
- Microwaving lunar regolith. It's not tasty, but you might be able to build a Moon base out of it.
- A video of Solar Orbiter flying past Venus a couple of weeks back.
- One last tidbit from SmallSat: Ingenuity has 150x the computing power of the main processor on Perseverance. Also, for testing at JPL, they built a “wind wall” using 900 CPU fans. 💨
- If the Moon were only 1 pixel: a tediously accurate map of the solar system
- Two remotely-controlled Soviet rovers, Lunokhod-1 and Lunokhod-2, drove a combined 52 km across the lunar surface in the early 1970s. Data from the missions was only partially published, but now original data tapes have been found in a private collection. Help is needed to decode them.
- River Runner: watch the path of a raindrop from anywhere in the contiguous United States.
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