When the space shuttle Atlantis finished with its last mission in 2011, it really was the end of an era. Few could deny that the program has become too complex and expensive to continue, but even humanity’s ability to do useful work in low Earth orbit has dealt a severe blow with the withdrawal of the shuttle fleet. Worse, there was no data on when or if another spacecraft would be developed that could really compete with the capabilities of the winged orbits first conceived in the late 1960s.
While its main function was to transport large payloads such as satellites into orbit, the shuttle’s ability to retrieve objects from space and return them was undoubtedly just as important. Throughout her career, sensitive experiments conducted on the International Space Station or aboard the Orbiter itself have been carefully returned to Earth thanks to the vessel̵
For 30 years, the space shuttle and its various facilities at the Kennedy Space Center have provided a reliable way to deliver fragile or time-sensitive scientific experiments into the hands of researchers just hours after leaving orbit. It was a valuable service that simply did not exist before the shuttle and that scientists were deprived of their retirement.
So far. With the successful launch of the first Cargo Dragon 2 off the coast of Florida, NASA is one step closer to regaining a critical capability it hasn’t had in a decade. Although not yet as convenient as simply moving the shuttle to an orbiter after a mission, the fact that SpaceX can direct its capsule into the waters near the space coast significantly reduces the time it takes to return the researchers’ experiments. who designed them.
On the dragon’s wings
Although it took nearly ten years to resume launches with a crew from American soil after the retreat of the space shuttle, there was almost no downtime for cargo flights. SpaceX launched its first Dragon capsule into orbit in 2010 and just over a year after the last flight of Atlantis, they were ready to launch regular supply missions to the International Space Station. Not only can a privately designed vessel carry a combined 6,000 kilograms (£ 13,000) of pressurized and non-pressurized cargo to an orbital outpost, but it can also return approximately 3,000 kilograms (£ 6,600) back to Earth.
By comparison, the shuttle can land safely with about 14,400 kg (31,700 pounds) packed in its cavernous cargo compartment. But realistically, this capacity was designed to download satellites and was completely too large to simply return racks with scientific experiments. The price was also a consideration: the Dragon’s mission cost NASA only a fraction of what the shuttle’s flight did. In combination with the much higher clock speed of the Dragon, it is clear which vehicle is more suitable for regular “milk runs” to the ISS and vice versa.
But there was a downside. Despite SpaceX’s declared intention to one-point propulsion with the Dragon one day, the small spacecraft found itself in the ocean under parachutes just like the Apollo and Gemini capsules before it. This meant that returning to Earth with the Dragon was a much rougher journey than the shuttle offered. While not a problem for many payloads, it can be a devastating experience for sensitive experiments such as those designed to study the growth of crystals in microgravity.
An additional complicating fact is the fact that the capsule landed in the Pacific Ocean, a few hundred kilometers from shore. This has facilitated operations to rebuild California-based SpaceX, but because NASA lacked adequate payload handling facilities on the West Coast, it will have to transport cargo to the Johnson Space Center in Houston or back to the Kennedy Space Center. The prospect of experiments that potentially have to withstand flight before they can be made available to scientists makes it difficult or impossible to perform certain research.
The human element
Although hardly perfect, landing cargo and experiments on the West Coast and returning them to Florida was still better than having to transport them back from Kazakhstan if they were flying with the Union. But that wouldn’t happen when it came time for SpaceX to start carrying astronauts as part of a commercial crew program. NASA wanted the main deployment point for the new Dragon crew to be as close as possible to the Kennedy Space Center to use existing shuttle-era resources and facilities, with a take-off in the Gulf of Mexico reserved for unforeseen circumstances.
This requires a significant expansion of SpaceX’s recovery capabilities. Two ships, GO Searcher and GO Navigator, were equipped by the company and equipped with medical equipment, a helicopter pad and a stern lifting device for lifting the Crew Dragon floating capsule on deck. In addition, the two vessels are practically identical and can be deployed simultaneously.
With operational assets and trained personnel relocated to the East Coast for Crew Dragon, restoring the spacecraft’s cargo variant in California no longer made fiscal sense. In addition, given how similar the two vehicles are, the experience gained in pulling the Cargo Dragon out of the ocean would serve to improve crew recovery operations. Because NASA requirements state that astronauts must emerge from the capsule within 60 minutes of spraying, the teams need all the practice they can get.
In addition to faster delivery times, Cargo Dragon has a number of other advantages over its predecessor. The upgraded capsule has increased payload capacity, twice as many air-conditioned cabinets for storing sensitive materials and a fully autonomous docking system that reduces the load on astronauts aboard the orbital outpost. It can also be more easily repaired for reuse, which not only reduces costs but allows a higher launch cadence than would otherwise be possible.
Pursuit of the dream
With a helicopter waiting to pick up time-sensitive payloads from the recovery ship to the space station’s processing facility, SpaceX can now conduct experiments on scientists between four and nine hours after spraying. This is a huge improvement over what was possible before, and perhaps the best that can really be expected for an offshore operation. But it’s still not as fast as the space shuttle.
After all, the need to pull a spacecraft out of the ocean and transport crew members or scientific payloads back to land by helicopter will always take more time than just landing the vehicle in a specific facility. As SpaceX no longer pursues targeted propulsion landings with its Dragon spacecraft, this means that another company will need to step up to meet the challenge of a really fast payback.
As this happens, this is exactly what the Sierra Nevada Corporation hopes to do with its Dream Chaser spacecraft. Currently scheduled to fly in 2022 as part of NASA-2’s commercial supply program, the vehicle can return up to 1,750 kg of cargo to a slightly horizontal landing. Being a quarter of the size of the space shuttle’s orbit, the Dream Chaser has the advantage of being able to use any runway long enough to accommodate a large passenger plane.
This ability to land essentially anywhere on the planet has clear benefits for international scientific cooperation. But more importantly, when the company completes work on their version of the man-made spacecraft, it could be a potentially life-saving capability in the event of an urgent medical need for a crew member to be transported back to Earth as quickly as possible.
Cosmic forces lead the way
The fact that many commercial spacecraft are now competing to bring cargo and crew to and from the International Space Station is an incredible achievement. This is something that many people in the industry believed would never happen and things are just beginning. Over the next decade, several more cars and boosters will appear, vying to be the fastest, most reliable and, of course, the cheapest. The democratization of space has officially begun.
But as is often the case historically, the military appears to be well ahead of the curve. The Boeing X-37B spacecraft, now operated by the newly formed space force, is an ideal platform for orbital research and development, which in many ways exceeds the capabilities of its commercial peers.
Of course, there are still many things we don’t know about the secret vessel, but its ability to conduct free-flight experiments and return scientific payloads from space to a soft runway has been publicly demonstrated several times. As a fully autonomous, the X-37B can also stay in orbit far longer than any crew vehicle. This provides a unique opportunity to conduct long-term experiments in complete isolation; something that is simply not possible on the bustling International Space Station.
As you might expect for a shady military operation, most of the research conducted aboard the X-37B is classified. Some believe the vehicle is designed to evaluate new intelligence equipment and techniques, while others believe it is a test platform for anti-satellite weapons. But there are signs that the Space Force is ready to share its miniature spacecraft with non-military researchers, with the last launch in May bringing a record number of NASA experiments.
After all, none of these vehicles can carry more scientific payload than the space shuttle, and to date only government-operated vessels are able to approach the kind of rapid turnaround needed for truly time-sensitive experiments. But for the first time in history, there are a number of competitive options for researchers who want to retrieve their payload in space and return to one place; and this is definitely a step in the right direction.