Starhopper

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Starhopper in Boca Chica, Texas (March 2019)

The Starhopper or Starship Hopper (German: Sternenhüpfer / Sternenschiffhüpfer) is an aircraft from the space company SpaceX . It is used to test the Raptor engine for the Starship and Super Heavy rocket project . The hopper completed two successful flights in summer 2019 and is to be used as an engine test bench in the future.

The designation Starship Hopper refers to the planned upper rocket stage - the Starship - and to the flight altitude: Compared to a rocket launch, the hopper only made small "hops".

background

Tintin models with the rocket that influenced Starship design

SpaceX has been working on the new super heavy lift rocket Starship and Super Heavy (then called ITS , later BFR ) since the mid-2010s . It should enable the construction of a lunar base and ultimately a colonization of Mars . After changing plans, an unusual design by the company's founder and head of development Elon Musk prevailed in 2018 . Highly polished stainless steel is to be used as the material for the outer shell of the rocket . The shape of the upper tier - the starship - was based for the time being on science fictions of the 1950s, in particular on the Tintin comic Steps on the Moon : The spaceship was to have three wing-like standing and landing legs and a rounded tip.

In order for all parts of the rocket to be finished at about the same time, the development proceeds from the most complicated part to the simplest. Testing of engine prototypes began as early as 2017. This is followed by the Starship and finally the lower rocket stage.

The Starhopper was primarily used for first flight attempts with a pilot series engine . It was built and tested at the SpaceX South Texas Launch Site on the Texas Gulf Coast and on the border between the United States and Mexico . At the same time, construction of a full-size Starship prototype began at the same time. Most of the work on both devices took place outdoors, a few meters from a public road, which attracted onlookers and photographers. This led to the establishment of a drone no-fly zone.

Structure and technology

Drawing of the mock-up with engine dummies

The Starhopper was built between November 2018 and March 2019. Its load-bearing structure consists of a triangular frame, surrounded by a steel cylinder with three welded-on legs. The hull of the hopper has roughly the planned diameter of the starship of 9 meters. Its outside and two of three legs are covered with thin, mirror-smooth stainless steel sheets.

Inside the aircraft there are tanks for at least 30 tons of liquid oxygen and liquefied methane . Hydraulic and / or pneumatic systems are available for operating valves and tilting the engine . Tilting the engine in any direction enables thrust vector control and thus control of pitch and yaw movements during flight. Rolling movements , on the other hand, are controlled with cold gas engines , which are identical to those of the SpaceX Falcon 9 rocket .

At the beginning - before the interior was finished - the appearance of the Starhopper corresponded to the Starship design at that time (see drawing); there were even three dummy engine nozzles used for a PR photo. The PR coup was a success and the media reported in January 2019 about a supposedly "finished prototype" of the Starship. Shortly afterwards, the upper half of the vehicle was blown away by the storm and damaged beyond repair; the surface of the lower half then crumpled when a bulkhead was installed . Since then, the bulkhead has been the "lid" of the construction. SpaceX decided not to build a new hopper top anymore. On top of the bulkhead, nitrogen pressure vessels ( COPVs ) for operating the cold gas engines and corresponding helium vessels for pressurizing the tanks were installed.

On March 9, the hopper was driven to the launch site on a low-loader , where a real Raptor engine was finally installed.

Testing

Regular refueling tests took place in the second half of March 2019, and the engine was ignited twice in early April. So that the hopper did not take off yet, it was tied to the legs. The engine was damaged during the two test runs and removed again. Other Raptor specimens were destroyed during test runs at the SpaceX test center in McGregor, Texas .

With the Raptor SN6 - the sixth engine built - the Starhopper completed its first flight on July 25, 2019 (local time), around 20 meters high and lasting 20 seconds. After the landing, several land fires started next to the launch site, which also affected a neighboring wildlife sanctuary . At least 40 hectares of land were burned  .

A second and final test flight took place on August 27, 2019 (local time) with the same engine. As planned, it reached a height of around 150 meters. About 50 seconds after take-off, the hopper landed within a circular marking about 200 meters east of the take-off site. At the same moment, one of the pressure vessels attached to the upper bulkhead came loose and flew from the landing site due to the recoil of the escaping gas.

Road and airspace closures were in effect during all tests. The residents of the exclusion zone had to identify themselves at the entrance, and visitors were not tolerated. The access to the nearby beach on the Gulf Coast was closed during the tests.

Historical classification

With the Starhopper flight on July 25, 2019, a rocket engine using full-flow staged combustion technology was used for the first time . Earlier attempts with this complex engine technology in both the Soviet Union and the USA were not ready for use. Together with the use of methane as fuel, it should enable high efficiency with little wear and tear and is therefore particularly suitable for reusable rockets.

In addition, with the Starhopper, a rocket technology was tested for the first time, which is intended for the manned flight to Mars .

See also

Web links

Individual evidence

  1. ↑ a b Michael Bayler: SpaceX's Starhopper completes 150 meter test hop. In: Nasaspaceflight.com. August 27, 2019, accessed August 27, 2019 .
  2. ^ Elon Musk: Why I'm Building the Starship out of Stainless Steel. In: Popular Mechanics . January 22, 2019, accessed on April 5, 2019 : "It took me quite a bit of effort to convince the team to go in this direction."
  3. ↑ Dave Mosher: Elon Musk says SpaceX is developing a 'bleeding' heavy-metal rocket ship. Making it work may be 100 times as hard as NASA's most difficult Mars mission, one expert says. In: Business Insider . February 16, 2019, accessed April 5, 2019 .
  4. ↑ Mike Wall: The New BFR: How SpaceX's Giant Rocket-Spaceship Combo for Mars Has Changed. In: space.com. September 21, 2019, retrieved on April 5, 2019 : "He also cited the new design's resemblance to the rocket used by the comic-book character Tintin in the 1954 adventure" Explorers on the Moon. " - "I love the Tintin rocket design, so I kind of wanted to bias it towards that," Musk said. "If in doubt, go with Tintin." "
  5. ↑ Dave Moshner: Elon Musk just gave the most revealing look yet at the rocket ship SpaceX is building to fly to the moon and Mars. In: Business Insider. September 22, 2018, accessed on April 5, 2019 : "Musk has said the spaceship is the" hardest part "of the system to build, so SpaceX is prototyping it first."
  6. ^ Alfredo Cuadros: No Drone Zone. In: KVEO.com. March 26, 2019, accessed April 15, 2019 .
  7. ^ Thomas Burghardt: SpaceX gearing up for Starship tests at Boca Chica. In: Nasaspaceflight.com. January 14, 2019, accessed April 8, 2019 .
  8. ↑ Eric Raph: SpaceX fits Starship prototype with tank bulkheads as hop test pad progresses. In: Teslarati. January 22, 2019, accessed May 1, 2019 .
  9. ^ Tariq Malke: SpaceX Aborts Starhopper Rocket Prototype Launch at Last Second. In: space.com. August 27, 2019, accessed August 28, 2019 .
  10. ↑ a b Eric Ralph: SpaceX's Starhopper gains thruster pods as hop test preparations ramp up. In: Teslarati. May 9, 2019, accessed on August 28, 2019 (see keyword "COPV").
  11. ↑ a b 150 meter Starhopper test . SpaceX video, August 27, 2019 (Youtube).
  12. ↑ Eric Ralph: SpaceX CEO Elon Musk arrives in Texas for milestone Starship engine test. In: Teslarati. February 3, 2019, accessed May 1, 2019 .
  13. ↑ Mike Wall: SpaceX Finishes Building 'Starship' Hopper Prototype (photo). In: space.com. January 19, 2019, accessed May 1, 2019 .
  14. ↑ Frank Wunderlich-Pfeiffer: The Starship is ready - as a prototype. Golem.de , January 11, 2019, accessed on January 13, 2019 .
  15. ↑ Tarek Maliq: SpaceX's 'Starhopper' Starship Prototype Just Aced Its 1st Hop, Elon Musk Says. In: space.com. April 4, 2019, accessed April 4, 2019 .
  16. ↑ Eric Raph: SpaceX's Starship prototype moved to launch pad on new rocket transporter. In: Teslarati. March 9, 2019, accessed April 5, 2019 .
  17. ↑ a b Chris Gebhardt: Starhopper conducts Raptor Static Fire test. In: Nasaspaceflight.com. April 3, 2019, accessed April 5, 2019 .
  18. ↑ SpaceX's Starship, Starhopper prototypes continue slow and steady progress. In: Teslarati. April 25, 2019, accessed May 1, 2019 .
  19. ↑ Eric Ralph: SpaceX ships Raptor to Texas for first Starhopper hover tests after fixing vibration bugs. In: Teslarati. July 11, 2019, accessed July 13, 2019 .
  20. ↑ Eric Ralph: SpaceX CEO Elon Musk says major Starship engine bug is fixed as Raptor testing continues. In: Teslarati. July 7, 2019, accessed on July 13, 2018 ( several have been destroyed so completely that they could barely be used to inform design optimization work ).
  21. ^ Thomas Burghardt: Starhopper successfully conducts debut Boca Chica Hop . In: Nasaspaceflight.com , July 25, 2019 (local time), accessed July 26, 2019.
  22. ↑ Twitter message with video by Elon Musk, July 26, 2019.
  23. ↑ Dave Mosher: SpaceX's launch of an experimental rocket ship set fire to about 100 acres of wildlife refuge in south Texas. In: Business Insider. July 27, 2019, accessed July 28, 2019 .
  24. ↑ Twitter message from Chris Bergin, Nasaspaceflight, with short video , August 28, 2019. COPV flight in the lower right corner of the picture.
  25. ^ Alejandro G. Belluscio: SpaceX advances drive for Mars rocket via Raptor power. In: Nasaspaceflight.com. March 7, 2014, accessed August 3, 2019 .