It’s fair to say that there’s really no phase of spaceflight that could be considered easy. But the case could be made that the most difficult part of a spacecraft’s journey is right at the very beginning, within the first few minutes of flight. At this point the vehicle’s booster rocket will be fighting with all its might against its own immense propellant-laden mass, a battle that it’s been engineered to win by the smallest of margins. Assuming the balance was struck properly and the vehicle makes its way off of the launch pad, it will still need to contend with the thick sea-level atmosphere as it accelerates, a building dynamic pressure that culminates with a point known as “Max q” — the moment where the air density imposes the maximum structural load on the rocket before quickly dropping off as the vehicle continues to ascend and the atmosphere thins.
While the vast majority of rocket launches have to contend with the realities of flying through the lower atmosphere, there are some exceptions. By launching a rocket from an aircraft, it can avoid having to power itself up from sea level. This allows the rocket to be smaller and lighter, as it doesn’t require as much propellant nor do its engines need to be as powerful.
The downside of this approach however is that even a relatively small rocket needs a very large aircraft to carry it. For example, Virgin Orbit’s LauncherOne rocket must be carried to launch altitude by a Boeing 747-400 airliner in order to place a 500 kg (1,100 lb) payload into orbit.
But what if there was another way? What if you could get all the benefits of starting your rocket from a higher altitude, without the cost and logistical issues involved in carrying it with a massive airplane? It might sound impossible, but the answer is actually quite simple…all you have to do it throw it hard enough.
In an era where anyone with deep enough pockets can hitch a ride to the edge of space and back, you’d be forgiven for thinking that Axiom’s Ax-1 mission to the International Space Station was little more than a pleasure cruise for the four crew members. Granted it’s a higher and faster flight than the suborbital hops that the likes of William Shatner and Jeff Bezos have been embarking on, but surely it must still be little more than a publicity stunt organized by folks with more money than they know what to do with?
Thankfully, there’s a bit more to it than that. While the mission was privately funded, the Ax-1 crew weren’t just orbital sightseers. For one thing, there was plenty of real-world experience packed into the SpaceX Dragon: the mission was commanded by Michael López-Alegría, a veteran NASA astronaut, and crew members Larry Connor and Eytan Stibbe are both accomplished pilots, with the latter clocking in thousands of hours on various fighter jets during his time with the Israeli Air Force.
But more importantly, they had work to do. Each member of the crew was assigned a list of experiments they were to conduct, ranging from medical observations to the testing of new hardware. Of course there was some downtime — after all, if you spent $50 million on a ticket to space, you’d expect to have at least a little fun — but this wasn’t just a photo op: Axiom was looking for results. There was no hiding from the boss either, as López-Alegría is not just the Mission Commander, he’s also Axiom’s Vice President of Business Development.
Which makes sense when you consider the company’s ultimate goal is to use the ISS as a springboard to accelerate the development of their own commercial space station. The data collected during Ax-1 is going to be critical to Axiom’s path forward, and with their first module already under construction and expected to launch by 2025, there’s no time to waste.
So what did the crew members of the this privately funded mission to the International Space Station accomplish? Let’s take a look at a few of the more interesting entries from the docket.
We’ve all heard it said, and it bears repeating: getting to space is hard. But it actually gets even harder the smaller your booster is. That’s because the structure, engines, avionics, and useful payload of a rocket only make up a tiny portion of its liftoff mass, while the rest is dedicated to the propellant it must expend to reach orbital velocity. That’s why a Falcon 9 tipping the scales at 549,054 kilograms (1,207,920 pounds) can only loft a payload of 22,800 kg (50,265 lb) — roughly 4% of its takeoff weight.
As you might imagine, there’s a lower limit where there simply isn’t enough mass in the equation for the hardware necessary to build a fully functional rocket. But where is that limit? That’s precisely what aerospace newcomer Astra is trying to find out. Their Rocket 3 is among the smallest orbital boosters to ever fly, closer in size and mass to the German V2 of World War II than the towering vehicles being built by SpaceX or Blue Origin. Even the Rocket Lab Electron, itself an exceptionally svelte rocket, is considerably larger.
The reason they’re trying to build such a small rocket is of course very simple: smaller means cheaper. Assuming you’ve got a payload light and compact enough to fit on their launcher, Astra says they can put it into orbit for roughly $2.5 million USD; less than half the cost of a dedicated flight aboard Rocket Lab’s Electron, and competitive with SpaceX’s “rideshare” program. Such a low ticket price would have been unfathomable a decade ago, and promises to shake up an already highly competitive commercial launch market. But naturally, Astra has to get the thing flying reliably before we can celebrate this new spaceflight milestone.
Their latest mission ended in a total loss of the vehicle and payload when the upper stage tumbled out of control roughly three minutes after an otherwise perfect liftoff from Cape Canaveral Space Force Station in Florida. Such issues aren’t uncommon for a new orbital booster, and few rockets in history have entered regular service without a lost payload or two on the books. But this failure, broadcast live over the Internet, was something quite unusual: because of the unconventional design of Astra’s diminutive rocket, the upper stage appeared to get stuck inside the booster after the payload fairing failed to open fully.
It’s often said that getting into orbit is less about going up, and more about going sideways very fast. So in that sense, the recent launch conducted by aerospace startup Astra could be seen as the vehicle simply getting the order of operations wrong. Instead of going up and then burning towards the horizon, it made an exceptionally unusual sideways flight before finally moving skyward.
As you might expect, the booster didn’t make it to orbit. But not for lack of trying. In fact, that the 11.6 meter (38 feet) vehicle was able to navigate through its unprecedented lateral maneuver and largely correct its flight-path is a testament to the engineering prowess of the team at the Alameda, California based company. It’s worth noting that it was the ground controller’s decision to cut the rocket’s engines once it had flown high and far enough away to not endanger anyone on the ground that ultimately ended the flight; the booster itself was still fighting to reach space until the very last moment.
There’s a certain irony to the fact that this flight, the third Astra has attempted since their founding in 2016, was the first to be live streamed to YouTube. Had the company not pulled back their usual veil of secrecy, we likely wouldn’t have such glorious high-resolution footage of what will forever be remembered as one of the most bizarre rocket mishaps in history. The surreal image of the rocket smoothly sliding out of frame as if it was trying to avoid the camera’s gaze has already become a meme online, arguably reaching a larger and more diverse audience than would have resulted from a successful launch. As they say, there’s no such thing as bad press.
Naturally, the viral clip has spurred some questions. You don’t have to be a space expert to know that the pointy end of the rocket is usually supposed to go up, but considering how smooth the maneuver looks, some have even wondered if it wasn’t somehow intentional. With so much attention on this unusual event, it seems like the perfect time to take a close look at how Astra’s latest rocket launch went, quite literally, sideways.
When Mary Wallace “Wally” Funk reached the boundary of space aboard the first crewed flight of Blue Origin’s New Shepard capsule earlier today, it marked the end of a journey she started 60 years ago. In 1961 she became the youngest member of what would later become known as the “Mercury 13”, a group of accomplished female aviators that volunteered to be put through the same physical and mental qualification tests that NASA’s Mercury astronauts went through. But the promising experiment was cut short by the space agency’s rigid requirements for potential astronauts, and what John Glenn referred to in his testimony to the Committee on Science and Astronautics as the “social order” of America at the time.
To hear founder Richard Branson tell it, the first operational flight of Virgin Galactic’s SpaceShipTwo has been 18 months out since at least 2008. But a series of delays, technical glitches, and several tragic accidents have continually pushed the date back to the point that many have wondered if it will ever happen at all. The company’s glacial pace has only been made more obvious when compared with their rivals in the commercial spaceflight field such as SpaceX and Blue Origin, which have made incredible leaps in bounds in the last decade.
But now, at long last, it seems like Branson’s suborbital spaceplane might finally start generating some income for the fledgling company. Their recent successful test flight, while technically the company’s third to reach space, represents an important milestone on the road to commercial service. Not only did it prove that changes made to Virgin Space Ship (VSS) Unity in response to issues identified during last year’s aborted flight were successful, but it was the first full duration mission to fly from Spaceport America, the company’s new operational base in New Mexico.
The data collected from this flight, which took pilots Frederick “CJ” Sturckow and Dave Mackay to an altitude of 89.23 kilometers (55.45 miles), will be thoroughly reviewed by the Federal Aviation Administration as part of the process to get the vehicle licensed for commercial service. The next flight will have four Virgin Galactic employees join the pilots, to test the craft’s performance when loaded with passengers. Finally, Branson himself will ride to the edge of space on Unity’s final test flight as a public demonstration of his faith in the vehicle.
If all goes according to plan, the whole process should be wrapped up before the end of the year. At that point, between the government contracts Virgin Galactic has secured for testing equipment and training astronauts in a weightless environment, and the backlog of more than 600 paying passengers, the company should be bringing in millions of dollars in revenue with each flight.
They weren’t scheduled to return to Earth until April 28th at the earliest, so why did NASA astronauts Michael Hopkins, Victor Glover, and Shannon Walker, along with Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi, suit up and climb aboard the Crew Dragon Resilience on April 5th? Because a previously untested maneuver meant that after they closed the hatch between their spacecraft and the International Space Station, there was a chance they weren’t going to be coming back.
On paper, moving a capsule between docking ports seems simple enough. All Resilience had to do was undock from the International Docking Adapter 2 (IDA-2) located on the front of the Harmony module, itself attached to the Pressurized Mating Adapter 2 (PMA-2) that was once the orbital parking spot for the Space Shuttle, and move over to the PMA-3/IDA-3 on top of Harmony. It was a short trip through open space, and when the crew exited their craft and reentered the Station at the end of it, they’d only be a few meters from where they started out approximately 45 minutes prior.
The maneuver was designed to be performed autonomously, so technically the crew didn’t need to be on Resilience when it switched docking ports. But allowing the astronauts to stay aboard the station while their only ride home undocked and flew away without them was a risk NASA wasn’t willing to take.
What if the vehicle had some issue that prevented it from returning to the ISS? A relocation of this type had never been attempted by an American spacecraft before, much less a commercial one like the Crew Dragon. So while the chances of such a mishap were slim, the crew still treated this short flight as if it could be their last day in space. Should the need arise, all of the necessary checks and preparations had been made so that the vehicle could safely bring its occupants back to Earth.
Thankfully, that wasn’t necessary. The autonomous relocation of Crew Dragon Resilience went off without a hitch, and SpaceX got to add yet another “first” to their ever growing list of accomplishments in space. But this first relocation of an American spacecraft at the ISS certainly won’t be the last, as the comings and goings of commercial spacecraft will only get more complex in the future.