Yesterday (Tuesday, Aug. 26th), SpaceX conducted the second untethered test of its Starship Hopper – and nailed it! For this test, the prototype test vehicle took off from the Boca Chica test facility, ascended to an altitude of 150 m (~500 ft) and then landed again safely. This comes just a month after the first successful hop test and brings the company one step closer to tests using their full-scale prototype.Continue reading “SpaceX Starship Hopper Prototype Makes its Highest Hop Test So Far!”
In May of 2019, NASA’s Commercial Lunar Payload Services (CLPS) selected Astrobotic to fulfill a contract to deliver 14 payloads to the Moon by 2021. The Pittsburg-based aerospace company plans to do this using their Peregrine Lander, a robotic lunar spacecraft that is capable of delivering payloads to the Moon for the competitive price of $1.2 million per kilogram (~$544,300 per lbs).
To get the Peregrine lander and NASA’s payloads to the Moon, Astrobiotic recently announced that it would be relying on United Launch Alliance (ULA) to provide launch services. ULA will do this using their next-generation heavy-lift launch system known as the Vulcan Centaur rocket, which will also be the inaugural launch of this new vehicle.Continue reading “Astrobotic is Going to Use a Vulcan Rocket For its Lunar Lander in 2021”
In 2006, Peter Beck founded the US and New Zealand-based aerospace company Rocket Lab with the vision of reducing the costs of individual launches. Whereas companies like SpaceX and Blue Origin have sought to do this through the development of reusable rockets, Beck’s vision was to create a launch service that would use small rockets to send light payloads into orbit with regular frequency.
However, in a recent statement, Mr. Beck revealed that his company plans to begin recovering and reusing the first stage of its Electron launch vehicle. This change in direction will allow Rocket Lab to further increase the frequency of its launches by eliminating the need to build first stage rockets from scratch for every individual mission.Continue reading “Rocket Lab is Going to try to Re-use its First Stage Booster, Catching it in Mid-air With a Helicopter”
Yesterday, on Wednesday, July 24th, the prototype test vehicle for the Starship (the Starhopper) commenced its first untethered “hop test” at the company’s test facility in Boca Chica, Texas. This test is an important milestone for SpaceX, intended to validate the Raptor engine in free flight and bring the company one step closer to creating the super-heavy launch system that will allow for trips to the Moon and Mars.
Unfortunately, the ground team was forced to abort the test due to a fire that began shortly after engine ignition. This comes shortly after a static fire test that took place last Tuesday, July 16th where the newly-installed Raptor engine erupted in a sudden and unexpected fireball. Though no damage appears to have been caused (again, thankfully!), this latest flare-up represents another technical glitch and another delay for the Starship.Continue reading “First Free Flight of SpaceX’s Starhopper Aborted After Engine Fire”
The year of 2019 has not been very kind to SpaceX so far. Back in April, the company lost one of its new Crew Dragon capsules when an explosion occurred during a static firing test of their In-Flight Abort test vehicle. Earlier this week, the company revealed that they had determined the cause of the explosion, saying that it was due to a nitrogen tetroxide leak that occurred just prior to the final test.
And now, just a few days later, another accident has occurred, this time involving the Starhopper test vehicle. Once again, a fire occurred shortly after the vehicle conducted an engine test; fortunately, it resulted in no injuries. However, the Starhopper appears to have come through the fire completely unscathed, though it might cause a slight delay with the vehicle’s scheduled hop tests.Continue reading “Starship Prototype Catches Fire After a Recent Test, But Appears Undamaged”
Since 2015, Virgin Orbit has been developing a launch system that will send satellites into space using a rocket launched from a modified 747. This is part of Sir Richard Branson’s plan to crack the burgeoning market of cost-effective satellite deployment. This market is especially lucrative considering how many satellites are expected to be launched into orbit in the coming years.
This week, the Virgin Orbit team achieved a major milestone by flying the LauncherOne rocket into the air and releasing it over the Mojave desert for the first time. This drop-test not only validated the design of the modified 747 (named Cosmic Girl) that serves as its flying launchpad, it also demonstrated the effectiveness of the launch system – which can rely on regular airstrips instead of launch pads to send satellites into space.Continue reading “Virgin Orbit Tests its Satellite-Delivery Rocket for the First Time”
Virgin Galactic has reached another milestone in their fight test program. The VSS Unity spacecraft carried a third crew member on board, in its fifth rocket-powered test flight. It was the second time that the spacecraft reached space.Continue reading “Virgin Galactic Sends Three People to the Edge of Space. Flights with Paying Customers Around the Corner Now”
Space technology company Lunar Outpost has unveiled their new Lunar Prospector rover that will explore the surface of the Moon to search for and map resources. The Lunar Prospector is designed to drill for and analyze sub-surface samples. The first of the smallish robots was recently demonstrated on simulated Lunar regolith at the Colorado School of Mines.
Continue reading “Lunar Outpost Shows off their New Rover that will Crawl the Moon, Searching for Resources”
The commercial space sector is about to get a little more crowded. SpaceX and Blue Origin have created headlines with their ongoing development of reusable launch vehicles. Now Virgin Orbit‘s “Launcher One” is carving out its own niche in the commercial space market, as an efficient, flexible launcher of small satellites.
When Elon Musk of SpaceX tweets something interesting, it generates a wave of excitement. So when he tweeted recently that SpaceX might be working on a way to retrieve upper stages of their rockets, it set off a chain of intrigued responses.
SpaceX will try to bring rocket upper stage back from orbital velocity using a giant party balloon
— Elon Musk (@elonmusk) April 15, 2018
SpaceX has been retrieving and reusing their lower stages for some time now, and it’s lowered the cost of launching payloads into space. But this is the first hint that they may try to do the same with upper stages.
Twitter responders wanted to know exactly what SpaceX has in mind, and what a “giant party balloon” might be. Musk hasn’t elaborated yet, but one of his Twitter followers had something interesting to add.
Quinn Kupec, a student at the University of Maryland’s James Clark School of Engineering tweeted to Musk:
If you're proposing what I think you are, an ultra low ballistic entry coefficient decelerator, then you and @SpaceX should come see what we have at the @UofMaryland . We've been working on this for awhile and just finished some testing pic.twitter.com/nJBvyUnzaK
— Quinn Kupec (@QuinnKupec) April 16, 2018
Universe Today contacted Mr. Kupec to see if he could help us understand what Musk may have been getting at. But first, a little background.
An “ultra low ballistic entry coefficient decelerator” is a bit of a mouthful. The ballistic coefficient measures how well a vehicle can overcome air resistance in flight. A high ballistic coefficient means a re-entry vehicle would not lose velocity quickly, and would reach Earth at high speeds. An ultra low ballistic entry coefficient decelerator would lose speed quickly, meaning that a vehicle would be travelling at low, subsonic speeds before reaching the ground.
To recover an upper stage booster, low speeds are desirable, since they generate less heat. But according to Kupec, there’s another problem that must be overcome.
“What happens when these things slow down to landing velocities? If your center of gravity is offset significantly behind your center of drag, as would be the case with a returning upper stage, it can get unstable. If the center of gravity of the re-entry vehicle is too high, it can become inverted, which is obviously not desirable.”
So the trick is to lower the speed of the re-entry vehicle to the point where the heat generated by reentry isn’t damaging the booster, and to do it without causing the vehicle to invert or otherwise become unstable. This isn’t a problem for the main stage boosters that SpaceX now routinely recovers; they have their own retro-rockets to guide their descent and landing. But for the upper stage boosters, which reach orbital velocities, it’s an obstacle that has to be overcome.
“My research is specifically focused on how high you can push the center of gravity and still maintain the proper flight configuration,” said Kupec.
But what about the “giant party balloon” that Musk tweeted about?
Musk could be referring, in colorful terms, to what’s called a ballute. The word is a combination of the words balloon and parachute. They were invented in the 1950’s by Goodyear Aerospace. They can arrest the descent of entry vehicles and provide stability during the descent.
“…the balloon would have to be 120 ft. in diameter, and made of a high-temperature fabric…” – Professor Dave Akin, University of Maryland
Universe Today contacted Professor Dave Akin of the University of Maryland for some insight into Musk’s tweet. Professor Akin has been working on reentry systems for over 2 decades.
In an e-mail exchange, Professor Akin told us, “There have been concepts proposed for deploying a large balloon on a cable that is towed behind you on entry. The balloon lowers your ballistic coefficient, which means you decelerate higher in the atmosphere and the heat load is less.” So the key is to scrub your speed before you get closer to Earth, where the atmosphere is thicker and generates more heat.
But according to Professor Akin, this won’t necessarily be easy to do. “To get the two orders of magnitude reduction in ballistic coefficient that Elon has been talking about the balloon would have to be 120 ft. in diameter, and made of a high-temperature fabric, so it’s not going to be all that easy.”
But Musk’s track record shows he doesn’t shy away from things that aren’t easy.
Retrieving upper rocket stages isn’t all about lowering launch costs, it’s also about space junk. The European Space Agency estimates that there are over 29,000 pieces of space junk orbiting Earth, and some of that junk is spent upper stage boosters. There have been some collisions and accidents already, with some satellites being pushed into different orbits. In 2009, the Iridium 33 communications satellite and the defunct Russian Cosmos 2251 communications satellite collided with each other, destroying both. If SpaceX can develop a way to retrieve its upper stage boosters, that means less space junk, and fewer potential collisions.
There’s a clear precedent for using balloons to manage reentry. With people like Professor Akin and Quinn Kupec working on it, SpaceX won’t have to reinvent the wheel. But they’ll still have a lot of work to do.
Musk tweeted one other thing shortly after his “giant party balloon” tweet:
And then land on a bouncy house
— Elon Musk (@elonmusk) April 16, 2018
No word yet on what that might mean.
Elon Musk’s “giant party balloon” tweet: https://twitter.com/elonmusk/status/985655249745592320
Quinn Kupec’s tweet: https://twitter.com/QuinnKupec/status/985736260827471872