A sampling of recent articles, videos, and images dealing with space transport (find previous roundups here):
** Dec.9: First high altitude flight test of a SpaceX Starship prototype successfully demonstrated two key requirements for returning from orbit: (1) controlled stable flight while in a horizontal orientation during unpowered descent and (2) the flip to vertical maneuver after restarting the engines. The vehicle was powered by three Raptors, which fired for nearly five minutes before reaching the 12 km altitude. (Two of the engines shut down sequentially during the later phase of the ascent.) This provided a big gain in the amount of data on in-flight performance of the LOX/Methane engines compared to the short hops with earlier prototypes.
Unfortunately, during the SN8 vehicle’s relatively short vertical descent to the bullseye of the landing pad, a drop in pressure from the propellant tank in the tip of the nosecone reduced the thrust of the Raptor engine and the vehicle landed too hard and exploded. This operational problem can be prevented in a straight-forward manner in future flights. After 60+ successful Falcon 9 booster recoveries, the company knows how to land a rocket vertically. However, SpaceX has had no experience with flying a rocket in a horizontal attitude and controlling it with side fins. It also had never swung a vehicle from horizontal to vertical. So this was a very successful test. While it might have flown again if it landed safely, SN8 was never intended to provide more than suborbital test data.
This multi-exposure image nicely captures the liftoff and return of Starship SN8’s epic test flight:
Omg. Only image I had in my mind for SN8 & it worked perfectly!
Big thx to @Erdayastronaut, @SpacePadreIsle @considercosmos & @thejackbeyer for helping me make the trip to TX/a huge success🚀⚙️/⬇️/🖼: https://t.co/VvOyEejkx0
2021 starship calendar: https://t.co/DTkCXERMvo pic.twitter.com/wMa9v0yYpq— Trevor Mahlmann (@TrevorMahlmann) December 11, 2020
A view of SN8 from the landing pad:
Starship landing flip maneuver pic.twitter.com/QuD9HwZ9CX
— SpaceX (@SpaceX) December 10, 2020
An analysis by Scott Manley: SpaceX’s Biggest Starship Flight Is A Spectacular Success Even After Crash Landing
Articles and commentary about the test:
- From hops to hopes – Starship SN8 set to advance test program into the next phase – NASASpaceFlight.com
- On the Spectacular Flight of Starship SN8 and the Future of Starship Development – Main Engine Cut Off
- So, it turns out SpaceX is pretty good at rocketing | Ars Technica
- Fiery crash of SpaceX’s Starship rocket ignites dreams of future spaceflight – National Geographic
- Space advocacy organizations congratulate SpaceX – Space Development Network
- Starship contradictions – The Space Review
- Starship flies! – Behind the Black
- Starship: Old-fashioned American know-how – Behind the Black
Find more on SpaceX activities below
** Dec.16: Astra reaches space for first time but falls just short of orbit: The launch from the Alaskan spaceport sent the upper stage of the two-staged Rocket 3.2 to 390 kilometers in altitude and “just a half a kilometer per second short” of orbital velocity according to Astra CEO Chris Kemp. According to Eric Berger,
The company had not quite gotten the mixture of kerosene to oxidizer correct—something that is difficult to test on the ground—and wound up with an excess of liquid oxygen. Had the upper stage burnt kerosene for a few more seconds, the upper stage would have reached orbit. As it was, the booster peaked at an apogee of 390km above the Earth’s surface.
Kemp claimed this flight nevertheless exceeded the team’s expectations for the rocket, which did not have a payload on board.
A quick video recap of our 8.5-minute flight to space today! pic.twitter.com/gvElF4fbAZ
— Astra (@Astra) December 16, 2020
Kemp has said that it would take three launches before they achieved orbit. Last March, Rocket 3.0 was destroyed in a fire on the pad and, in September, Rocket 3.1 flew for 30 seconds before a guidance problem led to a shutdown of the engines and the loss of the vehicle. Rocket 3.3 is expected to fly early in 2021 and it will carry a payload for a customer.
The company’s goal is to offer very low cost access to orbit for small satellites. To achieve this they have sought a simple but robust rocket design that can be built at low cost. According to Astra,
Rapid test and iteration are the cornerstones of our development process. We’ve performed thousands of rocket engine tests at our headquarters in Alameda, a few hundred feet away from where those engines are designed and built. We can afford to experiment quickly and repeatedly because our rockets are far less expensive. The rockets are primarily constructed from lightweight aluminum, instead of costly composite and 3D printed materials.
Small crews for launch are also a part of the plan: Astra set up a rocket launch with five people and came within seconds of orbit | Ars Technica
Astra was founded to provide rapid, low-cost access to space for small satellites. The quick turnaround between its first and second flights suggests it may make good on this promise. It’s impressive, too, that the company needs just five people to set up its launch site. At Kodiak, Astra has a concrete pad and a tent. A week before launching the rocket, its launcher, propellant, and other equipment arrived in four shipping containers from California. A team of five set the launch system up, and employees back at Astra’s headquarters in Alameda, California, controlled the launch through cloud computing.
The company needs to prove in 2021 that it can build and operate rockets that not only get to orbit but do so reliably and frequently.
More at:
- Astra Rocket 3.2 reaches space after launch from Alaska – CNBC
- Astra succeeds in reaching space with Rocket 3.2 – NASASpaceFlight.com
- Astra narrowly misses reaching orbit on second launch – SpaceNews
- Rocket 3.2 Ready To Launch! | Astra
- Astra (@Astra) / Twitter
** Dec.15: Rocket Lab Electron rocket puts Synspective StriX-α synthetic aperture radar (SAR) satellite into a 500km circular orbit. This was the 17th Electron launch. There was no attempt to recover the first stage.
- Rocket Lab Successfully Launches 17th Electron Mission, Deploys SAR Satellite for Synspective | Rocket Lab
- Rocket Lab closes out year with launch of Synspective’s first radar satellite – Spaceflight Now
- The Owl’s Night Begins: Japan’s StriX-α satellite launches with Rocket Lab – NASASpaceFlight.com
** Dec. 12: Virgin Galactic SpaceShipTwo test flight aborted after avionics failure prevents engine ignition: Virgin Galactic Update on Test Flight Program – Virgin Galactic
Virgin Galactic Holdings, Inc. (NYSE: SPCE), a vertically integrated aerospace and space travel company, announced an update following its recent test flight on December 12, 2020. During the test flight, the rocket motor did not fire due to the ignition sequence not completing. Following this event, the pilots conducted a safe landing and return to Spaceport America, New Mexico as planned.
Virgin Galactic is now conducting post-flight analysis and can so far report that the onboard computer which monitors the propulsion system lost connection, triggering a fail-safe scenario that intentionally halted ignition of the rocket motor. This system, like others on the spaceship, is designed such that it defaults to a safe state whenever power or communication with sensors is lost. The pilots in the spaceship, as well as the engineers and pilots in mission control, are well prepared for any off-nominal results, as they plan and rehearse many potential scenarios during pre-flight simulation practice sessions, including a scenario where the rocket motor does not ignite after release from the mothership.
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