Tag: competition

Capitalism in space: In a series of tweets yesterday SpaceX founder Elon Musk revealed that the company is considering landing Starship’s first stage, Super Heavy, on its launchpad but rather than use landing legs it will be caught by the launch tower.

Instead, Musk says that SpaceX might be able to quite literally catch Super Heavy in mid-air, grabbing the booster before it can touch the ground by somehow slotting an elaborate “launch tower arm” underneath its steel grid fins. Although such a solution sounds about as complex and risky as it gets, it would technically preclude the need for any and all booster recovery infrastructure – even including the legs Super Heavy would otherwise need.

While true, catching Super Heavy by its grid fins would likely demand that control surfaces and the structures they attach to be substantially overbuilt – especially if Musk means that the crane arm mechanism would be able to catch anywhere along the deployed fins’ 7m (23 ft) length. Even more importantly, it seems extraordinarily unlikely that such a complex and unproven recovery method could be made to work reliably on the first one or several tries, implying that early boosters will still need some kind of rudimentary landing legs.

The idea is to save weight on the booster. It also would speed its reuse, as there would no longer be a need to transport it from a landing pad back to the launchpad.

Whether this will work will depend on the accuracy of SpaceX’s vertical landing software. That the company has repeatedly proven, from almost the first time it tried it, that it can bring its rockets down exactly where it intends suggests they will be able to be as accurate as necessary.

Nonetheless, expect more than a few launchpad crashes as they work out the kinks on another audacious engineering concept.

Capitalism in space: According to this nasaspaceflight update, the first 10-mile-plus flight of the ninth Starship prototype is now targeted for shortly after January 1st.

Starship SN9 has been undergoing integration ops on the launch mount over the Christmas holiday, setting the stage for what will be a streamlined pre-launch test series when compared to that undertaken by SN8.

The first test will involve filling the vehicle with nitrogen, usually in a two-step fashion. Initially, the vehicle will be filled with gaseous nitrogen – called the ambient test, ahead of being loaded with super-cold liquid nitrogen (LN2) for the cryo test. This test sequence is expected early in the coming week, with preparations for testing already ongoing on Monday morning.

Providing all goes to plan with the proofing test, SN9 will be prepared for what is currently expected to be one Static Fire test involving all three Raptors. This is an expedited test schedule compared to SN8, which underwent several Static Fire tests ahead of launch. Two of SN9’s Raptors were installed on the vehicle inside the High Bay. Once the vehicle had made it to the pad, a third engine – SN49 – was installed, completing the trio.

Only after these tests have been completed will a launch date become known, likely via a notice to local air and sea traffic. This, in turn, will be pending acceptable weather conditions and vehicle preparedness going into prop loading tasks. Based on the best-case scenario test flow, the launch could realistically occur within January’s first two weeks.

The goal on this flight likely be will be twofold. First, to reaffirm the engineering and software for controlling the stage during its return to Earth. Second, to complete a successful landing, to prove they have corrected the pressure issue that caused the landing failure during Starship prototype #8’s flight.

The article also gives an update on the many additional Starship prototypes being readied for flight, along with the first Super Heavy prototype. It is expected that Super Heavy will make its first short 500 foot hop sometime in ’21.