¶Starhopper took its last and largest hop. The flight was an initial demonstration of the viability of Raptor, the world's first flight-proven full-flow staged combustion engine. However, while the flight was successful—it showed a roughly 150 m vertical takeoff, hover (with clearly visible thrust vectoring), 100 m sideways translation, and soft landing—there were a few issues including a potentially problematic change in engine exhaust during landing and a COPV that broke free of the vehicle and spun furiously off into the Texas sunset 🌅. Next up is the maiden flight for Starship Mk1, which will use 3 Raptors (engine #10 has just been completed) and target a 20 km flight as early as October, followed shortly by an orbital launch. (This seems like a traditionally Muskian aggressive—fanciful?—timeline.) SpaceX continues to have an independent team work on the competing Starship Mk2 in Florida, and that vehicle could also fly this year. An official update on Starship progress (undoubtedly including annual design changes) is now scheduled for September 28th.
¶ The year’s third attempted launch of an Iranian rocket failed last week—it is believed to be the previously-successful Safir liquid-fueled orbital rocket (derived from a North Korean missile). The bigger news, though, is that the US president tweeted a strikingly high-resolution image of the aftermath. While legal, it’s unclear if Trump sharing this was a good idea, as it allowed Cees Bassa (and others—basically anyone with a knowledge of trigonometry and Python) to determine, based on the angle of shadows and tracking data from amateur satellite observers, both which classified spy satellite took the photo and insights into its capabilities. According to Bassa’s analysis, the satellite was USA-224, a US Keyhole 11 satellite launched in 2011 (here is a rare image of it in orbit), and the resolution is around 10 cm/pixel (e.g. an iPad would take up roughly 4 pixels). Spaceflight Now has a discussion and side-by-side photos with Planet Lab’s 3 m/pixel resolution photo, Maxar’s WorldView-2 ~46 cm/pixel photo, and the released ~10 cm/pixel photo. This is the first released photo from a current-generation US spy satellite. As the photo was taken at a 46° angle, the satellite is probably capable of a 5-7 cm/pixel resolution when looking straight down. Given the camera’s 2.4 m mirror and orbit, this is very close to the fundamental diffraction limit for visible light. (It’s thought that Keyhole satellites use 2.4 m mirrors because Hubble used the same production facilities and the NRO gifted two satellites with 2.4 m mirrors to NASA in 2011—one of these will be used for WFIRST, which just passed design review.) Scott Manley has a detailed video and suggests that perhaps declassifying this photo was allowed because the US just launched NROL-71, assumed to be a next-generation spy satellite.
¶News in brief. Mars is currently exactly on the other side of the Sun (in conjunction), preventing NASA from communicating with its Martian craft for 10 days; Hayabusa2 has stored the collected Ryugu samples in its return capsule which will depart later this year, hopefully arriving safely back at Earth in 2020; the uncrewed Soyuz MS-14 finally docked with the ISS after automated navigation systems failed to lock onto the first port it tried and astronauts re-parked an older Soyuz to make a different port available; initial assembly has completed on both ESA’s Rosalind Franklin Mars rover (the parachutes are still in question, though) and (finally!) the James Webb Space Telescope; and, last week we mentioned the Europa Clipper and Congress’s mandate that it launch on SLS—now NASA’s inspector general is pushing back, saying NASA could save as much as $1 billion by using a commercial vehicle.
- Awesome Space, our open directory of free space-related resources, has reached 500 stars on GitHub. Thanks for all of your contributions! ❤️
- As Ars Technica explored in-detail in 2014, after the Columbia disaster (caused by foam breaking off during launch and damaging wing insulation tiles), NASA put together the prosaically-named "STS-107 In-Flight Options Assessment" (pdf) detailing what they could have done, had they known about the damage while in orbit. The report concludes that Space Shuttle Atlantis could have theoretically been prepared, launched, and rendezvous-ed within the 30 days that Columbia’s CO2 scrubbers could have maintained their air supply. As detailed in the article, this would have been a truly herculean effort, but one befitting NASA. Unfortunately, they didn’t know the level of wing damage because they didn’t check. Starting with STS-114, there were no shuttle launches without a rescue shuttle on standby.
- According to NOAA, July 2019 was the hottest month on record. “Nine of the 10 hottest Julys have occurred since 2005—with the last five years ranking as the five hottest.” 🌎🌡
- AGI’s SpaceBook visualizes current and defunct satellites and their orbits.
- “The nature of the radiation environment in space will not deter our efforts to travel to Mars, but it may be the single biggest obstacle humankind must resolve to travel beyond the Earth’s orbit.”
- Future space telescopes may use free-flying starshades to block the light from individual stars in order to image the planets orbiting them. A telescope like WFIRST, NASA's future infrared telescope with a 2.4 m primary mirror (that repurposed NRO spy satellite), would require a 26 m shade flying 20,000 - 40,000 km away with a precision of under 1 meter. This sounds crazy, but is technically possible according to JPL by using a control system that fires thrusters based on feedback from light that bends around the edge of the shade. A shade could be added to WFIRST sometime in the late 2020s. Starshades are currently estimated to be at TRL level 5. (Related: HabEx, a proposed planet-hunter, includes a huge origami-style starshade as well.)